CA 02994098 2018.-01-29
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DESCRIPTION
POWER SUPPLY SYSTEM AND DUMMY LOAD DEVICE
Technical Field
[0001]
The present invention relates to a power supply
system suitable for consumption of surplus power.
Background Art
[0002]
Conventionally, a technique has been known in which
relay devices that reproduce or amplify communication
signals are mounted on a large number of subsea devices,
respectively, and these subsea devices are connected in a
chain shape by subsea cables and laid on the seafloor
spreading between two points on shore in this state, in
subsea cable communication systems. Power lines are mounted
to such subsea cables, and power supply circuits provided
in the respective subsea devices are connected in series to
the power lines. Further, it is configured such that a DC
having a constant value (DC constant current) is
transmitted from an onshore power supply device arranged at
both ends on shore to this power line, and each of the
subsea devices uses the amount of a voltage drop of the DC
constant current as power.
[0003]
In the above-described subsea cable communication
1
system, however, it is configured such that it is possible
to distribute a constant amount of power to all the subsea
devices connected to the subsea cables by allocating the
amount of power that needs to be consumed to each of the
subsea devices.
Thus, when power is not supplied to an observation
device despite a state where the subsea device can supply
power, it is necessary to consume the entire power that
needs to be consumed by the observation device with a dummy
load device. That is, the dummy load device is configured
to consume surplus power, which is no longer consumed by
the observation device in a non-power supply state (not in
a power supply state), out of the power allocated to the
subsea device.
[0004]
The inventions described in Patent Documents 1 (JP
5176152 B2) and 2 (JP 11-150492 A) have been known as
examples of the power supply system having such a
configuration.
Patent Document 1 which is JP 5176152 B2 aims to
prevent received power on an input side from changing with
respect to an output load change. A first circuit receives
a DC constant current at a primary input port, detects a
voltage of a secondary port as an output, and controls a
first switching circuit on a primary side such that this
first voltage detection value becomes a constant value,
thereby outputting a DC constant voltage to the secondary
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port. A second circuit receives the DC constant voltage
output from the secondary port of the first circuit,
converts the received DC constant voltage into a constant
current by a constant current circuit, and supplies the
converted constant current to an external load connected to
a tertiary port as a final output. Thus, disclosed is a
balanced DC constant current input/DC constant current
distribution output device having a configuration in which
the third circuit receives the voltage generated on the
primary side of the first circuit as a primary side input
voltage, detects this primary side voltage, and controls a
second switching circuit on a primary side such that this
second voltage detection value becomes a constant value,
thereby supplying power to a constant resistance load
connected to a secondary side.
[0005]
Patent Document 2 which is JP 11-150492 A aims to
prevent supply of constant current from being affected even
if there is a large change in power consumption. A subsea
cable system of a constant current power supply system
includes: a switching circuit which is connected in series
to a constant current line and converts a constant current
into a rectangular wave current; a transformer which
converts the rectangular wave current to another
rectangular wave current; and a rectifier circuit which
rectifies an output of the transformer, in which the high-
voltage constant current is insulated by the switching
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circuit, the transformer, and the rectifier circuit to be
electrically isolated from a load side. Thus, disclosed is
a power supply circuit for
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,
the subsea cable system having a configuration in which a
Zener diode is connected to an output of the rectifier
circuit, and with regard to a voltage of a low-voltage side
isolated by the transformer and rectified by the rectifier
circuit, a current change of a load is absorbed by the
Zener diode.
Prior Art Documents
Patent Documents
[0006]
Patent Document 1: JP 5176152 B2
Patent Document 2: JP 11-150492 A
Summary of the Invention
Problems to be Solved by the Invention
[0007]
In this manner, in Patent Document 1, the third
circuit is configured so as to supply the power to the
constant resistance load connected to the secondary side of
the second switching circuit by receiving the voltage
generated on the primary side of the first circuit as the
primary side input voltage and controlling the second
switching circuit on the primary side such that the second
voltage detection value which is the primary side voltage
detection value becomes the constant value, whereby the
surplus power which is no longer consumed in an observation
device (not in a power supply state) is consumed by the
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constant resistance load.
In Patent Document 1, however, a space for mounting
the third circuit is required due to complexity as the
number of parts constituting the third circuit increases.
In addition, the surplus power that is no longer
consumed in the observation device in the non-power supply
state out of power allocated to the single subsea device is
consumed by the dummy load system in the conventional
subsea device as described above. At this time, feedback
control is performed between a DC power conversion device
configured to supply power to the observation device and
the dummy load device such that power balance between the
DC power conversion device and the dummy load device is
held at an optimally stable point.
However, circuit configurations of both the DC power
conversion device and the dummy load device become complex
when performing the feedback control between the devices.
[0008]
Further, the dummy load device can be implemented
using the Zener diode, but needs to be connected at
multiple stages when being used at high power and high
voltage, such multi-stage connection is problematic in
terms of stability and reliability due to a characteristic
variation of each element.
Specifically, the Zener diode is a semiconductor
element obtained by PN-junction of a semiconductor.
Practically, characteristics of commercially available
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Zener diodes vary by about 5% to 10% due to manufacturing
errors or the like. Incidentally, a highly accurate type
with little characteristic variation also exists, but is
extremely expensive.
When connected at the multiple stages to consume the
high power and high voltage as in this case, the
characteristic variations of the elements accumulate so
that it is difficult to obtain characteristics as expected.
Incidentally, the use of the highly accurate Zener diodes
connected in the multiple stages requires high cost.
In general, when a current starts to flow, a constant
voltage property of the Zener diode begins to fluctuate and
collapse. An example in which a current of 8 A is caused
to flow to the Zener diode is described, for example, in
the paragraph [0035] of Patent Document 2, but there is a
disadvantage that the voltage stability is inferior.
Thus, there has been a request for provision of a
dummy load device with a simple configuration that can
consume the surplus power that is no longer consumed in the
observation device (in the non-power supply state).
The present invention has been made in view of the
above-described problem, and an object thereof is to
provide a power supply system capable of consuming surplus
power that is no longer consumed with a simple
configuration.
Means for Solving the Problem
6
[0009]
In order to solve the above-described problem, the
invention described in the description is a power supply
system including: a parent device which has a power supply
means and a control means; and a child device which is
connected to the parent device via a cable, and is
characterized in that the child device includes: a DC power
conversion unit which converts first DC power supplied to a
primary side into second DC power and outputs the second DC
power to a secondary side; and a power distribution unit
which distributes the second DC power to a dummy load
device and at least one of devices, wherein
the dummy load device includes a plurality of dummy
load units connected in series, and
each of the dummy load units includes:
an inter-terminal voltage monitoring unit which
monitors a voltage applied between both terminals of the
dummy load unit to generate a first control voltage and
adjusts a level of the first control voltage such that the
voltage applied between both the terminals is constant;
a control voltage amplification unit which amplifies
the first control voltage generated by the inter-terminal
voltage monitoring unit to generate a second control
voltage; and
a power consumption unit which causes a power
semiconductor to consume power by causing a required
current to flow to the power semiconductor according to the
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second control voltage generated by the control voltage
amplification unit, wherein the dummy load device includes
a plurality of dummy load units connected in series, and
each of the dummy load units includes: an inter-terminal
voltage monitoring unit which monitors a voltage applied
between both terminals of the dummy load unit to generate a
first control voltage and adjusts a level of the first
control voltage such that the voltage applied between both
the terminals is constant; a control voltage amplification
unit which amplifies the first control voltage generated by
the inter-terminal voltage monitoring unit to generate a
second control voltage; and a power consumption unit which
causes a power semiconductor to consume power by causing a
required current to flow to the power semiconductor
according to the second control voltage generated by the
control voltage amplification unit, and the dummy load
device is connected to the primary side or the secondary
side of the DC power conversion unit and consumes surplus
power out of the first DC power or the second DC power in
accordance with an increase or a decrease of the number of
the devices connected to the power distribution unit.
According to the present invention, there is provided a
dummy load device comprising a plurality of dummy load
units connected in series, wherein
each of the dummy load units includes:
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an inter-terminal voltage monitoring unit which
monitors a voltage applied between both terminals of the
dummy load unit to generate a first control voltage and
adjusts a level of the first control voltage such that the
voltage applied between both the terminals is constant;
a control voltage amplification unit which amplifies
the first control voltage generated by the inter-terminal
voltage monitoring unit to generate a second control
voltage; and
a power consumption unit which causes a power
semiconductor to consume power by causing a required
current to flow to the power semiconductor according to the
second control voltage generated by the control voltage
amplification unit.
Effects of the Invention
[0010]
According to the present invention, it is possible to
provide a power supply system capable of consuming surplus
power that is no longer consumed with a simple
configuration.
Brief Description of the Drawings
[0011]
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Fig. 1 is a block diagram for describing a schematic
configuration of a power supply system according to a first
embodiment of the present invention.
Fig. 2 is a block diagram for describing a
configuration of a subsea device provided in the power
supply system according to the first embodiment of the
present invention.
Fig. 3 is a block diagram for describing a more
detailed connection relationship between a main DC/DC
converter and an output DC/DC converter which are
illustrated in Fig. 2 and used in the power supply system
according to the first embodiment of the present invention.
Fig. 4 is a block diagram illustrating a dummy load
unit as one unit of a dummy load device used in the power
supply system according to the first embodiment of the
present invention.
Fig. 5 is a graph regarding a voltage, time, and a
current that represents an operation when an input voltage
is input to the dummy load unit which is one unit of the
dummy load device used in the power supply system according
to the first embodiment of the present invention while
changing the input voltage.
Fig. 6 is a graph regarding a voltage, time, and a
current that represents an operation when a load change is
applied to the dummy load unit as one unit of the dummy
load device used in the power supply system according to
the first embodiment of the present invention.
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Figs. 7(a) to 7(f) are sequence diagrams (Part 1) for
describing a start-up operation of each device provided in
the power supply system according to the first embodiment
of the present invention.
Figs. 8(a) to 8(g) are sequence diagrams (part 2) for
describing the start-up operation of each device provided
in the power supply system according to the first
embodiment of the present invention.
Fig. 9 is a block diagram illustrating a dummy load
unit as one unit of a dummy load device used in a power
supply system according to a second embodiment of the
present invention.
Fig. 10 is a block diagram illustrating a dummy load
unit as one unit of a dummy load device used in a power
supply system according to a third embodiment of the
present invention.
Fig. 11 is a block diagram for describing a
configuration of a subsea device provided in a power supply
system according to a fourth embodiment of the present
Invention.
Fig. 12 is a block diagram for describing a more
detailed connection relationship between a main DC/DC
converter and an output DC/DC converter which are
illustrated in Fig. 11 and used in the power supply system
according to the fourth embodiment of the present invention.
Best Mode for Carrying Out the Invention
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A
[0012]
Hereinafter, the present invention will be described
in detail with reference to embodiments illustrated in the
drawings.
The present invention has the following configuration
in order to provide a power supply system capable of
consuming surplus power that is no longer consumed with a
simple configuration.
That is, the power supply system of the present
invention is a power supply system including: a parent
device which has a power supply means and a control means;
and a child device which is connected to the parent device
via a cable, and is characterized in that the child device
includes: a DC power conversion unit which converts first
DC power supplied to a primary side into second DC power
and outputs the second DC power to a secondary side; a
power distribution unit which distributes the second DC
power to a dummy load device and at least one of devices;
and the dummy load device which is connected to the primary
side or the secondary side of the DC power conversion unit
and consumes surplus power out of the first DC power or the
second DC power in accordance with an increase or a
decrease of the number of the devices connected to the
power distribution unit.
With the above configuration, it is possible to
provide a power supply system capable of consuming surplus
power that is no longer consumed with a simple
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configuration.
Hereinafter, the above-described features of the
present invention will be described in detail with
reference to the drawings.
[0013]
Embodiments of the present invention will be
described with reference to the drawings.
<First Embodiment>
<Configuration of Power Supply System>
Fig. 1 is a block diagram for describing a schematic
configuration of a power supply system 1 according to a
first embodiment of the present invention.
As illustrated in Fig. 1, the power supply system 1
includes an onshore control device 2, an onshore power
supply device 10, subsea cables 16-1 to 16-4, and subsea
devices 20-1 to 20-3.
In the power supply system 1, the subsea cable 16-1,
obtained by bundling a control cable 4 extending from the
onshore control device 2 arranged on shore and a power line
12 extending from the onshore power supply device 10, is
connected to one end of the subsea device 20-1. Further,
the subsea devices 20-1 to 20-3 are connected to the subsea
cables 16-1 to 16-4, respectively, in series such that each
of the subsea devices 20-1 to 20-3 is interposed between
the subsea cables, and finally, the subsea device 20-3 is
connected to a sea ground 22-4 via the power line 12-4
accommodated in the subsea cable 16-4.
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[0014]
Incidentally, the onshore power supply device 10 is
electrically grounded to a ground 11 on a shore side and
the power line 12-4 accommodated in the subsea cable 16-4
is grounded to the sea ground 22-4 in the subsea device 20-
3 arranged on seafloor at the farthest end from the shore
side in the power supply system 1, thereby forming a closed
circuit for power supply as illustrated in Fig. 1.
In addition, the subsea devices 20-1 to 20-3 provided
in the power supply system 1 are connected to functional
sea grounds 22-1 to 22-3 via resistors, respectively,
thereby serving a role of stabilizing a potential of a
power supply line to an observation device (not
illustrated) connected to the subsea devices 20-1 to 20-3,
respectively.
[0015]
The onshore control device 2 forms the control means
and outputs control data to each of the subsea devices via
the control cable 4.
In addition, the onshore control device 2 includes a
transmission unit 2a that transmits control data configured
to perform various types of control, such as switching of a
power supply line pass relay 62, to a transmission unit 40
provided in the subsea device 20.
The onshore power supply device 10 forms the power
supply means, and is, for example, a DC power supply device
which generates a DC constant current having a negative
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polarity.
In the present embodiment, the parent device is
configured by including the onshore power supply device 10
(power supply means) and the onshore control device 2
(control means).
The subsea cable 16 includes the control cable 4
formed of optical fibers that transmit light of a plurality
of different wavelengths and transfer the control data and
the power line 12 which transfers power.
The subsea device 20 forms the child device, and is
usually connected to the observation device such as a
seismograph installed on the seafloor, and thus, called a
junction box. The subsea device 20 distributes and
supplies power, supplied from the onshore power supply
device 10 or the other subsea devices 20 via the subsea
cable 16, to the observation device, and transmits
observation data observed by the observation device to the
onshore control device 2 via the subsea cable 16.
Although the power supply system 1, for example,
including the three subsea devices 20 on the seafloor has
been described in the present embodiment, the number of the
subsea devices 20 is not limited in the present invention.
[0016]
<Configuration of Subsea device>
Fig. 2 is a block diagram for describing a
configuration of the subsea device 20 provided in the power
supply system 1 according to the first embodiment of the
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=
present invention.
The subsea device 20-1 illustrated in Fig. 1 is
connected between the subsea cable 16-1 and the subsea
cable 16-2, and the other subsea devices 20-2 and 20-3 are
also connected so as to be interposed between two different
subsea cables. Thus, the description will be given using
the respective names and reference signs of the subsea
device 20, the subsea cable 16, and the functional sea
ground 22 for the sake of simplicity of description. Thus,
it is assumed that the subsea cable 16 on the left side of
the page is laid toward the shore side in Fig. 2.
The subsea device 20 illustrated in Fig. 2 includes
the transmission unit 40, a drive power supply unit 50, a
receiving unit 60, a control unit 70, and an output unit 80.
Main DC/DC converters 64 and 66 whose primary sides
are connected in series are provided between the receiving
unit 60 and the control unit 70.
The subsea device 20 includes underwater detachable
connectors 30a and 30b for connection of the subsea cables
16 in a casing 20a. Inside the casing 20a, a power
distribution line connected from the underwater detachable
connector 30a to the receiving unit 60 is referred to as a
power supply line 32a, a power line that supplies DC power
to a primary winding provided in a transformer of the main
DC/DC converter 64 is referred to as a power supply line
32b, a power line connected between the primary winding of
the main DC/DC converter 64 and a primary winding of the
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main DC/DC converter 66 is referred to as a power supply
line 32c, and a power line that supplies DC power to the
primary winding of the main DC/DC converter 66 is referred
to as a power supply line 32d, a power distribution line
connected from the receiving unit 60 to the drive power
supply unit 50 is referred to as a power supply line 32e,
and a power distribution line connected from the drive
power supply unit 50 to the underwater detachable connector
30b is referred to as a power supply line 32f.
[0017]
The transmission unit 40 receives the control data
from the onshore control device 2 via the control cable 4
of the subsea cable 16.
The drive power supply unit 50 includes a DC/DC
converter 52 and switches a contact point state of the
power supply line pass relay 62 based on the control data
received by the transmission unit 40. The drive power
supply unit 50 is provided with a low-voltage circuit, for
example, a Zener diode ZD1 connected in series between the
power supply lines 32e and 32f, generates drive power by
operating the DC/DC converter 52, and switches a contact
point of the power supply line pass relay 62 from a closed
state to an open state by supplying power to a solenoid
coil, provided in the power supply line pass relay 62 to be
described later based on the control data received by the
transmission unit 40, by using a Zener voltage generated
between an anode and a cathode of the Zener diode ZD1.
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[0018]
The receiving unit 60 includes the power supply line
pass relay 62 which is connected between the power supply
lines 32a and 32e and passes between the power supply lines
32a and 32e.
The receiving unit 60 includes the primary winding of
the transformer of the main DC/DC converter 64 and the
primary winding of a transformer of the main DC/DC
converter 66.
The main DC/DC converter 64 includes a switch SW65
connected between the power supply lines 32b and 32c, the
primary winding of the transformer connected between the
power supply lines 32b and 32c, a switching element (not
illustrated), a secondary winding opposing the primary
winding, and a rectifying and smoothing circuit (not
illustrated) connected to the subsequent stage of the
secondary winding.
Further, the main DC/DC converter 66 includes a
switch SW67 connected between the power supply lines 32c
and 32d, a primary winding of a transformer connected
between the power supply lines 32c and 32d, a switching
element (not illustrated), and a secondary winding opposing
the primary winding.
In addition, the switches SW65 and SW67 are so-called
break relays, and are configured such that the contact
point is turned into the open state when a current is cause
to flow to the solenoid coil. It is possible to increase
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or decrease the power supply to the secondary sides of the
main DC/DC converters 66 and 67 by switching the switches
SW65 and 67 based on the control data received by the
transmission unit 40.
[0019]
The main DC/DC converters 66 and 67 form a DC power
conversion unit, and serve a role of converting first DC
power supplied to the primary side into second DC power and
outputting the second DC power to the secondary side. The
control unit 70 forms a power distribution unit and serves
a role of distributing the second DC power to observation
devices 100-1 to 100-4 (devices).
The control unit 70 includes a secondary winding
opposing the primary winding of the transformer of the main
DC/DC converter 64, a secondary winding opposing the
primary winding of the transformer of the main DC/DC
converter 66, and primary windings of transformers of the
output DC/DC converters 72-1 to 72-4.
The output DC/DC converters 72-1 to 72-4 include the
primary windings of the transformers connected to the
secondary sides of the main DC/DC converters 64 and 66,
switching elements (not illustrated), secondary windings
opposing the primary winding, and the rectifying and
smoothing circuits (not illustrated) connected to the
subsequent stages of the secondary windings.
The output DC/DC converters 72-1 to 72-4 can set each
operation to an ON/OFF state based on the control data
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received by the transmission unit 40.
[0020]
Further, the control unit 70 includes output ports
Fri and Pr2 to output surplus power out of the DC power
supplied from the secondary sides of the main DC/DC
converters 64 and 66 to the dummy load device 90, and a
functional ground terminal G.
It is possible to stabilize the potential of the
power supply line to observation devices 100-1 to 100-4 by
grounding the functional ground terminal G of the control
unit 70, which is electrically insulated and held in a
floating state, to the functional sea ground 22 via a
resistor Rl.
The output unit 80 includes output ports P1 to P4 to
output the DC power supplied from the secondary sides of
the output DC/DC converters 72-1 to 72-4, respectively.
The observation devices 100-1 to 100-4 arranged at
the seafloor are connected, respectively, to the output
ports P1 to P4 as necessary, and power is consumed in each
of the observation devices 100-1 to 100-4.
Incidentally, the transmission unit 40 and the
control unit 70 are connected via a cable 42, and the
control data is output from the transmission unit 40 to the
control unit 70 via the cable 42 as illustrated in Fig. 2.
[0021]
<Control Data>
Here, the control data transmitted from the onshore
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control device 2 to the subsea device 20 via the control
cable 4 will be described.
For example, #001 to #003 may be used as the format
of a device address unique to each of the subsea devices
20-1 to 20-3 illustrated in Fig. 1. In addition, each of
control data DO to designate a power supply state of the
device, control data D1 to designate the ON/OFF state of
the switch SW65, control data D2 to designate the ON/OFF
state of the switch SW67, and control data D3 to D6 to
designate the ON/OFF states of the operations of the output
DC/DC converters 72-1 to 72-4 that output power to the
observation devices 100-1 to 100-4, respectively, is
designated.
Incidentally, it is assumed that "1" indicates the ON
state (closed state) and "0" indicates the OFF state (open
state) in the control data DO to D2 regarding the state of
the contact point of each relay. In addition, it is
assumed that "1" indicates the ON state (operating state)
and "0" indicates the OFF state (stopped state) in the
control data D3 to D6 regarding an operating/stopped state
of each output DC/DC converter.
[0022]
[Table 1]
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,
Subsea Device Control data
device address D 0 ID 1 D 2 D 3 ID 4 D 5 D 6
1 # 0 0 1 0 0 0 1 1 1 1
2 # 0 0 2 0 0 0 1 1 1 1
3 # 0 0 3 0 0 0 1 1 1 1
[0023]
Incidentally, data examples illustrated in Table I
indicate that all the output DC/DC converters 72-1 to 72-4
of the subsea devices 20-1 to 20-3 are in the operating
state.
[0024]
Fig. 3 is a block diagram for describing a more
detailed connection relationship between the main DC/DC
converters 64 and 66 and the output DC/DC converters 72-1
to 72-4 illustrated in Fig. 2 which are used in the power
supply system 1 according to the first embodiment of the
present invention.
[0025]
<Main DC/DC Converter>
The primary sides of the main DC/DC converters 64 and
66 are connected in series to the power supply lines 32b
and 32d with the power supply line 32c interposed
therebetween. On the other hand, the secondary sides of
the main DC/DC converters 64 and 66 are connected in
parallel to terminals 01 and 02.
The switch SW65 and a converter 64i are connected in
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parallel to the primary side of the main DC/DC converter 64,
and the converter 641 is connected in parallel to a primary
winding of a transformer 64t. The converter 64i converts a
DC voltage input as the first DC power from the power
supply lines 32b and 32c when the switch SW65 is in the
open state by performing high-frequency switching using the
switching element (not illustrated) into high-frequency
power and outputs the converted power to the primary
winding of the transformer 64t.
[CO26]
A rectifying and smoothing circuit 64c is connected
in parallel to a secondary winding of the transformer 64t
on the secondary side of the main DC/DC converter 64, and
the rectifying and smoothing circuit 64c rectifies and
smoothes the high-frequency power induced in the secondary
winding of the transformer 64t using a diode and a
capacitor to generate a DC voltage, and outputs the DC
voltage to the terminal 01 as the second DC power via a
diode Dil.
The main DC/DC converter 66 has the same
configuration as that of the main DC/DC converter 64, and a
description thereof will be omitted.
The diodes Dil and Di2 provided in the main DC/DC
converters 64 and 66 are provided so as to prevent an
output current from flowing from one main DC/DC converter
to the other main DC/DC converter when the secondary sides
are connected in parallel to the terminals 01 and 02. It
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is possible to connect the outputs of the main DC/DC
converters 64 and 66 to each other in parallel via the
diodes Dil and Di2.
[0027]
As described above, the secondary sides of the main
DC/DC converters 64 and 66 are connected in parallel to the
terminals 01 and 02, the terminal 01 is connected to a
terminal Ii and the terminal 02 is connected to a terminal
12 as illustrated in Fig. 3.
The primary sides of the output DC/DC converters 72-1
to 72-4 are connected in parallel to the terminals Ii and
12, and the secondary sides of the output DC/DC converters
72-1 to 72-4 are independently connected to the output
ports P1 to P4, respectively. Incidentally, the
observation devices 100-1 to 100-4 can be connected to the
output ports 21 to P4 to be freely detachably as necessary.
In this manner, the secondary sides of the main DC/DC
converters 64 and 66 are connected in parallel to the
terminals 01 and 02, the primary sides of the output DC/DC
converters 72-1 to 72-4 are connected in parallel to each
other from the terminals 01 and 02 via the terminals Il and
12, and accordingly, it is possible to distribute the
second DC power converted by the main DC/DC converters 64
and 66 to the output DC/DC converters 72-1 to 72-4.
Since the operation of the converter and the
rectifying and smoothing circuit provided in each of the
output DC/DC converters 72-1 to 72-4 are the same as the
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converter 64i and the converter 64c of the main DC/DC
converter 64, a description thereof will be omitted.
Incidentally, the terminals 02 and 12 are connected
to the functional ground terminal G (Fig. 2) provided in
the control unit 70, and is connected from the functional
ground terminal G to the functional sea ground 22 via the
resistor R1 as illustrated in Fig. 2.
[0028]
The dummy load device 90 illustrated in Fig. 3 is
configured by connecting n dummy load units 92-1 to 92-n in
series.
The dummy load device 90 can form a dummy load device
corresponding to a load voltage of 400 V, for example, by
connecting fifty dummy load units each of which has a load
voltage of 8 V in series.
[0029]
Fig. 4 is a block diagram illustrating the dummy load
unit as one unit of the dummy load device 90 used in the
power supply system 1 according to the first embodiment of
the present invention.
As illustrated in Fig. 4, a terminal A of a dummy
load unit 92-k is connected to a terminal B of a dummy load
unit 92-(k-1), and a terminal B of the dummy load unit 92-k
is connected to a terminal A of a dummy load unit 92-(k+1).
The dummy load unit 92-k includes an inter-terminal
voltage monitoring unit 94, a control voltage amplification
unit 96, and a power consumption unit 98, and the
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respective units are connected in parallel between both the
terminals A and B.
The inter-terminal voltage monitoring unit 94 is
constituted by a semiconductor used for monitoring a
voltage VAB applied between the terminals A and B
(hereinafter referred to as a semiconductor) and
accompanying passive components thereof, monitors the
voltage VAB between the terminals A and B, and adjusts the
amount of a current flowing through the semiconductor such
that the voltage VAB between the terminals A and B becomes
constant without depending on a current Id flowing through
the power consumption unit 98.
[0030]
The inter-terminal voltage monitoring unit 94
generates a control voltage Vs by the current flowing
through the above-described semiconductor, and transmits
the control voltage Vs to the control voltage amplification
unit 96. The inter-terminal voltage monitoring unit 94
changes the amount of the current flowing through the
semiconductor such that the voltage between the terminals A
and B becomes constant and adjusts a level of the control
voltage Vs to be transmitted to the control voltage
amplification unit 96.
The control voltage amplification unit 96 is
constituted by a signal amplification semiconductor used
for signal amplification and passive components
accompanying this signal amplification, amplifies the
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control voltage Vs generated by the inter-terminal voltage
monitoring unit 94 by g times (g > 1), and transmits a
control voltage g x Vs to the power consumption unit 98.
The power consumption unit 98 is constituted by a
power semiconductor and causes the power semiconductor to
consume power by causing the required current Id to flow to
the power semiconductor according to the control voltage g
x Vs amplified by the control voltage amplification unit 96.
Incidentally, any one of a power transistor, a field effect
transistor, and an insulated gate bipolar transistor (IGBT)
may be used as the power semiconductor provided in the
power consumption unit 98.
In addition, it is preferable to attach a heat sink,
configured to dissipate heat generated by power consumption,
to the power semiconductor.
[0031]
Next, an operation of the dummy load unit 92-k
illustrated in Fig. 4 will be described.
The inter-terminal voltage monitoring unit 94
monitors the voltage VAB applied between the terminals A
and B, generates the control voltage Vs by the current
flowing through the semiconductor, and transmits the
generated control voltage Vs to the control voltage
amplification unit 96, and further, changes the amount of
the current flowing through the semiconductor such that the
voltage VAB between the terminals A and B becomes constant,
and adjusts the level of the control voltage Vs to be
CA 02994098 2018-01-29
transmitted to the control voltage amplification unit 96.
The control voltage amplification unit 96 amplifies
the control voltage Vs generated by the inter-terminal
voltage monitoring unit 94 by g times and transmits the
control voltage g x Vs to the power consumption unit 98.
The power consumption unit 98 causes the power
semiconductor to consume power by causing the required
current Id to flow to the power semiconductor according to
the control voltage g x Vs amplified by the control voltage
amplification unit 96.
[0032]
Fig. 5 is a graph regarding a voltage, time, and a
current that represents an operation when the voltage VAB
applied between the terminals A and B is input to the dummy
load unit 92-k which is one unit of the dummy load device
90 used in the power supply system 1 according to the first
embodiment of the present invention while changing the
voltage VAB.
The voltage on the vertical axis (left side)
illustrated in Fig. 5 represents the voltage VAB input
between the terminals A and B of the dummy load unit 92-k
illustrated in Fig. 4, the current on the vertical axis
(right side) illustrated in Fig. 5 represents the current
Id flowing through the power semiconductor provided in the
power consumption unit 98, and a potential at a point B (at
a level of 0 V) illustrated in Fig. 4 is set as a relative
reference.
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A current waveform of the current Id flowing through
the power semiconductor provided in the power consumption
unit 98 represents 0.0 A in a range from time tl to t2 and
in a range where a voltage waveform of the voltage VA13
applied between the terminals A and B gradually rises from
0 V to 7.7 V (< g X Vs).
At this time, the power semiconductor is turned off
when the control voltage g X Vs for controlling the power
semiconductor is less than 7.7 V, and thus, the current Id
remains at 0.0 A.
Next, the current waveform of the current Id flowing
through the power semiconductor provided in the power
consumption unit 98 steeply rises up to about 0.0 A to 3.4
A in a range from time t2 to t3 and in a range where the
voltage waveform of the voltage VAB applied between the
terminals A and B rises to 7.7 V g X Vs) or
higher, but
the voltage waveform of the voltage VAB applied between the
terminals A and B is substantially constant at 7.7 V (> g x
Vs).
At this time, the power semiconductor is turned on
since the control voltage g X Vs for controlling the power
semiconductor is 7.7 V or higher, and accordingly, the
current Id steeply rises up to about 0.0 A to 3.4 A
according to the control voltage g x Vs.
Incidentally, the above-described control voltage g x
Vs may be appropriately designed according to a type of the
power semiconductor.
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[0033]
Fig. 6 is a graph regarding a voltage, time, and a
current that represents an operation when a load change is
applied to the dummy load unit 92-k as one unit of the
dummy load device 90 used in the power supply system 1
according to the first embodiment of the present invention.
The voltage on the vertical axis (left side)
illustrated in Fig. 6 represents the voltage VA B input
between the terminals A and B of the dummy load unit 92-k
illustrated in Fig. 4, the current on the vertical axis
(right side) illustrated in Fig. 6 represents the current
Id flowing through the power semiconductor provided in the
power consumption unit 98, and a potential at a point B (at
a level of 0 V) illustrated in Fig. 4 is set as a relative
reference.
In the load change test, a pulsating current having
an offset voltage of 7.7 V or higher and having a frequency
of about 4 Hz is applied as the voltage VAB between the
terminals A and B.
At this time, the power semiconductor is always in
the on-state since the control voltage g x Vs for
controlling the power semiconductor is 7.7 V or higher, and
accordingly, the current waveform of the current Id flowing
through the power semiconductor varies between about 2.55 A
and 3.375 A around 3.0 A according to the control voltage g
X vs. At this time, the voltage waveform of the voltage VAB
applied between the terminals A and B falls within a range
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of 7.70 V to 7.71 V.
[0034]
<Operation of Power Supply System>
Next, a description will be given regarding a start-
up operation of each device provided in the power supply
system 1 according to the first embodiment of the present
invention with reference to Figs. 7(a) to 7(f) and Figs.
8(a) to 8(g). Figs. 7(a) to 7(g) and Figs. 8(a) to 8(g)
are sequence diagrams for describing the start-up operation
of each device provided in the power supply system 1
according to the first embodiment of the present invention.
[0035]
<Activating Operation of Subsea device>
When activating the power supply system 1 illustrated
in Fig. 1, power is supplied to the onshore power supply
device 10 arranged on the shore side, and a constant
current is supplied from the onshore power supply device 10
to the subsea devices 20-1 to 20-3 via the subsea cable 16-
1.
When the onshore power supply device 10 is activated,
the current supplied from the onshore power supply device
10 rises to 0.0 A to 3.0 A from time tO to ti, and then, a
constant current of 3.0 A is supplied to the onshore power
supply device 10 as illustrated in Fig. 7(a).
For example, the constant current is supplied
sequentially to the subsea cable 16, the power supply line
32a, the power supply line pass relay 62, the power supply
29
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line 32e, the drive power supply unit 50, the power supply
line 32f, and the subsea cable 16 in the subsea device 20
illustrated in Fig. 2.
Hereinafter, an operation of the subsea device 20
will be described.
As described above, the DC/DC converter 52 of about
W to 30 W is provided in the drive power supply unit 50,
and this DC/DC converter 52 is activated when the constant
current is supplied at time tO. As illustrated in Fig.
10 7(b), a supply voltage of, for example, 16 V is applied to
the transmission unit 40 at time tO. Further, a current of
0.0 A to 3.0 A is supplied from the DC/DC converter 52 to
the transmission unit 40 according to a circuit load from
time tO to ti as illustrated in Fig. 7(c).
15 [0036]
The onshore control device 2 transmits the device
address and the control data (DO = 0, D1 = 0, and D2 = 0)
for controlling the power supply line pass relay 62 and the
switches SW 65 and 67 provided in each of the subsea
devices 20-1 to 20-3 from the closed state to the open
state to the subsea devices 20-1 to 20-3 from the
transmission unit 2a via the subsea cable 16-1 at time t2
illustrated in Fig. 7(d).
The transmission units 40 of the subsea devices 20-1
to 20-3 that have received the device address and control
data from the onshore control device 2 via the subsea cable
16-1 output the control data DO to the receiving unit 60
when the received device address coincides with the device
address of the relevant device.
The receiving unit 60 generates a pass relay ON
signal based on the control data DO = 0 input from the
transmission unit 40, and supplies power to the solenoid
coil provided in the power supply line pass relay 62 at
time t2 illustrated in Fig. 7(d). Accordingly, the contact
point of the power supply line pass relay 62 provided in
the receiving unit 60 is switched from the closed state to
the open state at time t2 illustrated in Fig. 7(e).
[0037]
Fig. 7(f) illustrates that the amount of a current
flowing through the main DC/DC converters 64 and 66, the
output DC/DC converters 72-1 to 72-4, and the dummy load
device 90 connected to the receiving unit 60 and the
control unit 70 is 3.0 A and that this current amount is
equal to the amount (3.0 A) of power supplied from the
onshore power supply device 10.
Specifically, the current flowing between the contact
points of the power supply line pass relay 62 in the closed
state from time tO to t2 is illustrated.
The amount of a current, which flows through the main
DC/DC converters 64 and 66 as contact points of the
switches SW 65 and SW 67 of the main DC/DC converters 64
and 66 in the non-operating state are switched from the
closed state to the open state and power is supplied to the
main DC/DC converters 64 and 66 from the power
31
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= ,
supply lines 32b and 32d and the main DC/DC converters 64
and 66 are switched to the activated state, is illustrated
from time t2 to t3.
The amount of a current, which flows through the main
DC/DC converters 64 and 66 as an input voltage rises to
about 80% of input rating in the main DC/DC converters 64
and 66 so that a current resonance circuit starts to be
activated and the switching element is switched to the high
frequency, is illustrated from time t3 to t4.
The amount of a current flowing through the dummy
load device 90 and the observation device in the middle of
operating is illustrated at time t4 and the subsequent time.
[0038]
<Activation of Main DC/DC Converter>
The supply of power to the primary winding of the
transformer of the main DC/DC converters 64 and 66
connected in series between the power supply lines 32b and
32d and the switching element (not illustrated) is started
from time t2 to t4 illustrated in Fig. 8(a) when the
contact point of the power supply line pass relay 62 is
switched from the closed state to the open state in the
receiving unit 60 in Fig. 2.
At the same time, the switch SW65 is switched from
the closed state to the open state based on the control
data D1 = 0 input from the transmission unit 40 in the main
DC/DC converter 64 in Fig. 3.
Accordingly, the main DC/DC converter 64 is activated.
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Further, when the input voltage rises to 400 V which is
about 80% of the input rating at time t3 in the main DC/DC
converter 64, the current resonance circuit provided in the
converter 64i starts to be activated, and the switching
element is switched to the high frequency. Accordingly,
magnetic energy generated in the primary winding induces
the voltage in the secondary winding, a DC voltage is
generated by the rectifying and smoothing circuit 64c
connected to the subsequent stage of the secondary winding,
and the DC voltage is output to the output DC/DC converters
72-1 to 72-4 from time t3 to t5 illustrated in Fig. 8(a).
In addition, the main DC/DC converter 66 is also
activated in the same manner as the activation of the main
DC/DC converter 64.
As a result, an output voltage of 400 V is output
between the output ports Prl and Pr2 at time t5 illustrated
in Fig. 8(b).
[0(339]
<Operation of Dummy Load Device>
At time t5 illustrated in Fig. 8(c), when the
activation of the main DC/DC converters 64 and 66 is
completed, the output voltage of 400 V is output between
the output ports Fri and Pr2 of the control unit 70, the
voltage of 400 V is applied between both terminals of the
dummy load device 90, and a current of 3.40 A flows.
Specifically, since the fifty dummy load units are
connected in series to the dummy load device 90, for
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CA 02994098 2018-01-29
example, the voltage VAB applied between both the terminals
A and B of one dummy load unit is 8 V (= 400 V/50).
Here, an operation using each dummy load unit
provided in the dummy load device 90 will be described with
reference to Fig. 4.
The inter-terminal voltage monitoring unit 94
monitors the voltage VAB applied between the terminals A
and B, generates the control voltage Vs by the current
flowing through the semiconductor, and transmits the
generated control voltage Vs to the control voltage
amplification unit 96 in the dummy load unit, and further,
changes the amount of the current flowing through the
semiconductor such that the voltage VAB between the
terminals A and B becomes constant, and adjusts the level
of the control voltage Vs to be transmitted to the control
voltage amplification unit 96.
The control voltage amplification unit 96 amplifies
the control voltage Vs generated by the inter-terminal
voltage monitoring unit 94 by g times and generates and
transmits the control voltage g x Vs to the power
consumption unit 98.
The power consumption unit 98 causes the power
semiconductor to consume power by causing the required
current Id to flow to the power semiconductor according to
the control voltage g X Vs amplified by the control voltage
amplification unit 96.
[0040]
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CA 02994098 2018-01-29
As a result, it is possible to consume the surplus
power that is no longer consumed in the observation device
switched from the power supply state to the non-power
supply state by the dummy load device 90 in which the
plurality of dummy load units 92 is connected in series.
Further, it is possible to adjust the amount of the
current flowing through the semiconductor such that the
voltage VAB applied between both the terminals A and B is
constant without depending on the current Id flowing
through the power semiconductor provided in the power
consumption unit 98, and it is possible to consume the
surplus power that is no longer consumed in the observation
device switched from the power supply state to the non-
power supply state by the dummy load device 90 in which the
plurality of dummy load units 92 is connected in series.
[0041]
<Activation of Output DC/DC Converter 72-1>
Next, a description will be given regarding an
operation of activating only the output DC/DC converter 72-
1 to supply power only to the observation device 100-1 in
the subsea device 20-1.
For example, the control data of the subsea device
20-1 may be changed such that D3 = 1, D4 - 0, D5 = 0, and
DO = 0 as shown in Table 2.
[0042]
[Table 2]
Subsea Device Control data
device address DO D1 E)2 E)3 E)4 E)5 ID6
1 o o 1 1 1 1 1
[0043]
First, the onshore control device 2 illustrated in
Fig. 1 transmits a device address (#001) unique to the
subsea device 20-1 and the control data to the subsea
device 20-1 via the subsea cable 16-1 in order to control
the subsea device 20-1 at time t6 illustrated in Figs. 8(d).
Next, when the received device address (#001)
coincides with the device address (#001) of the relevant
device, the transmission unit 40 of the subsea device 20
illustrated in Fig. 2 outputs the control data to the
control unit 70. The control unit 70 illustrated in Fig. 3
switches the output DC/DC converters 72-1 from the stopped
state to the operating state based on the control data D3 =
1, D4 = 0, D5 = 0, and D6 = 0 input from the transmission
unit 40.
[0044]
Specifically, in Fig. 3, the converter is switched
from the stopped state to the activated state based on the
control data D3 = 1 input from the transmission unit 40 in
the output DC/DC converters 72-1 from time t6 to t7
illustrated in Fig. 8 (d). Accordingly, the output DC/DC
converter 72-1 is activated.
That is, as the switching element provided in the
36
CA 2994098 2018-05-01
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converter is subjected to ON/OFF control in the output
DC/DC converter 72-1, magnetic energy generated in the
primary winding induces a voltage in the secondary winding,
and a DC voltage is generated by the rectifying and
smoothing circuit connected to the subsequent stage of the
secondary winding.
The output DC/DC converter 72-1 is activated so that
the DC voltage is output from the output port P1 to the
observation device 100-1, the output voltage of the output
port P1 gradually rises from 0 V to 300 V at time t6 to t7,
and the current flowing through the dummy load device 90
drops to 3.4 A to 2.55 A at time t7.
[0045]
That is, when the DC voltage output from the output
DC/DC converter 72-1 to the observation device 100-1 via
the output port P1 reaches 300 V and the power consumed by
the observation device 100-1 reaches a specified value at
time t7, the voltage across both ends of the input-side
terminals Ii and 12 of the output DC/Dc converter 72-1
drops (only by a minute level). Accordingly, the current
flowing through the dummy load device 90 drops from 3.4 A
to 2.55 A.
At this time, the DC power is supplied from the
output DC/DC converter 72-1 to the output port P1, the
power is supplied from the output port P1 to the
observation device 100-1 arranged on the seafloor, and
observation is started in the observation device 100-1.
37
CA 02994098 2018-01-29
[0046]
<Activation of Output DC/DC Converter 72-2>
Next, a description will be given regarding an
operation of activating the output DC/DC converter 72-2 to
supply power to the observation device 100-2 in the subsea
device 20-1.
For example, the control data of the subsea device
20-1 shown in Table 2 may be changed such that D3 = 1, D4 =
1, D5 = 0, and D6 = 0.
Incidentally, operations of the onshore control
device 2 illustrated in Fig. 1, the transmission unit 40 of
the subsea device 20 illustrated in Fig. 2, the control
unit 70 illustrated in Fig. 3, and the output DC/DC
converter 72-2 from time t8 to t9 illustrated in Fig. 8(e)
are substantially the same as the description regarding the
"activation of the output DC/DC converter 72-1", and thus,
a description thereof will be omitted.
When the DC voltage output from the output DC/DC
converter 72-2 to the observation device 100-2 via the
output port P2 reaches 300 V and the power consumed by the
observation device 100-2 reaches a specified value at time
t9, the voltage across both ends of the input-side
terminals I1 and 12 of the output DC/DC converter 72-2
drops (only by a minute level). Accordingly, the current
flowing through the dummy load device 90 drops from 2.55 A
to 1.70 A.
[0047]
38
<Activation of Output DC/DC Converter 72-3>
Next, a description will be given regarding an
operation of activating the output DC/DC converter 72-3 to
supply power to the observation device 100-3 in the subsea
device 20-1.
For example, the control data of the subsea device
20-1 shown in Table 2 may be changed such that D3 = 1, D4 --
1, D5 = 1, and D6 = 0.
Incidentally, operations of the onshore control
device 2 illustrated in Fig. 1, the transmission unit 40 of
the subsea device 20 illustrated in Fig. 2, the control
unit 70 illustrated in Fig. 3, and the output DC/DC
converter 72-3 from time t10 to tll illustrated in Fig.
8(f) are substantially the same as the description
regarding the "activation of the output DC/DC converter 72-
2", and thus, a description thereof will be omitted.
When the DC voltage output from the output DC/DC
converter 72-3 to the observation device 100-3 via the
output port P3 reaches 300 V and the power consumed by the
observation device 100-3 reaches a specified value at time
t11, the voltage across both ends of the input-side
terminals Ii and 12 of the output DC/DC converter 72-3
drops (only by a minute level). Accordingly, the current
flowing through the dummy load device 90 drops from 1.70 A
to 0.85 A.
[0048]
<Activation of Output DC/DC Converter 72-4>
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CA 2994098 2018-05-01
Next, a description will be given regarding an
operation of activating the output DC/DC converter 72-4 to
supply power to the observation device 100-4 in the subsea
device 20-1.
For example, the control data of the subsea device
20-1 shown in Table 2 may be changed such that D3 = 1, D4 =
1, D5 = 1, and D6 = 1.
Incidentally, operations of the onshore control
device 2 illustrated in Fig. 1, the transmission unit 40 of
the subsea device 20 illustrated in Fig. 2, the control
unit 70 illustrated in Fig. 3, and the output DC/DC
converter 72-4 from time t12 to t13 illustrated in Fig.
8(g) are substantially the same as the description
regarding the "activation of the output DC/DC converter 72-
2", and thus, a description thereof will be omitted.
When the DC voltage output from the output DC/DC
converter 72-4 to the observation device 100-4 via the
output port P4 reaches 300 V and the power consumed by the
observation device 100-4 reaches a specified value at time
t13, the voltage across both ends of the input-side
terminals Ii and 12 of the output DC/DC converter 72-4
drops (only by a minute level). Accordingly, the current
flowing through the dummy load device 90 drops from 0.85 A
to 0.00 A.
[0049]
As a result, it is possible to consume the surplus
power that is no longer consumed in the observation device,
CA 2994098 2018-05-01
CA 02994098 2018-019
switched from the power supply state to the non-power
supply state, by the dummy load device, and it is possible
to provide the power supply system capable of consuming the
surplus power that is no longer consumed with the simple
configuration.
In addition, it is possible to cover the power to be
consumed in the observation device, switched from the non-
power supply state to the power supply state, with the
power that is being consumed in the dummy load device, and
it is possible to provide the power supply system capable
of easily performing exchange of the surplus power between
the observation device and the dummy load device with the
simple configuration.
[0050]
<Second Embodiment>
Fig. 9 is a block diagram illustrating a dummy load
unit as one unit of a dummy load device 90 used in a power
supply system 1 according to a second embodiment of the
present invention.
As illustrated in Fig. 9, a terminal A of a dummy
load unit 92-k is connected to a terminal B of a dummy load
unit 92-(k-1), and a terminal B of the dummy load unit 92-k
is connected to a terminal A of a dummy load unit 92-(k+1).
As illustrated in Fig. 9, the dummy load unit 92-k
includes an inter-terminal voltage monitoring unit 104, a
control voltage generation unit 106, and a power
consumption unit 108, and the respective units are
41
CA 02994098 2018-01-29
connected in parallel between the terminals A and B.
The inter-terminal voltage monitoring unit 104 is
constituted by a semiconductor used for monitoring a
voltage VAB applied between the terminals A and B, a
voltage control semiconductor used for voltage control, and
accompanying passive components of the voltage control
semiconductor, monitors the voltage VAB between the
terminals A and B, generates a monitoring voltage Vw to
make the voltage VAE between the terminals A and B constant
without depending on a current Id flowing through the power
consumption unit 108, and transmits the monitoring voltage
Vw to the control voltage generation unit 106.
The control voltage generation unit 106 is
constituted by a signal amplification semiconductor used
for signal amplification and passive components
accompanying the signal amplification semiconductor,
amplifies the monitoring voltage Vw generated by the inter-
terminal voltage monitoring unit 104 by g times, generates
a required control voltage g x Vw, and transmits the
control voltage g x Vw to the power consumption unit 108.
The power consumption unit 108 is constituted by a
power semiconductor and causes the power semiconductor to
consume power by causing a required current to flow to the
power semiconductor according to the control voltage g x Vw
generated by the control voltage generation unit 106.
Incidentally, any one of a power transistor, a field effect
transistor, and an IGBT may be used as the power
42
CA 02994098 2018-01-29
semiconductor provided in the power consumption unit 108.
[0051]
Next, an operation of the dummy load unit 92-k
illustrated in Fig. 9 will be described.
The inter-terminal voltage monitoring unit 104
monitors the voltage VAB between the terminals A and B,
generates the monitoring voltage Vw to make the voltage VAS
between the terminals A and B constant without depending on
the current Id flowing through the power consumption unit
108, and transmits the monitoring voltage Vw to the control
voltage generation unit 106.
The control voltage generation unit 106 amplifies the
monitoring voltage Vw received from the inter-terminal
voltage monitoring unit 104 by g times, generates the
required control voltage g X Vw, and supplies the control
voltage g x Vw to the power consumption unit 108.
The power consumption unit 108 is constituted by the
power semiconductor and causes the power semiconductor to
consume power by causing the required current to flow to
the power semiconductor according to the control voltage g
X Vw generated by the control voltage generation unit 106.
In this manner, the dummy load device 90 is
configured by connecting, for example, fifty dummy load
units each of which has the voltage VAB applied between
both terminals A and B of 8 V in series.
[0052]
As a result, it is possible to consume the surplus
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power that is no longer consumed in an observation device
switched from a power supply state to a non-power supply
state by the dummy load device 90 in which the plurality of
dummy load units 92 is connected in series.
Further, it is possible to adjust the amount of the
current flowing through the semiconductor such that the
voltage VAB applied between both the terminals A and B is
constant without depending on the current Id flowing
through the power semiconductor provided in the power
consumption unit 108, and it is possible to consume the
surplus power that is no longer consumed in the observation
device switched from the power supply state to the non-
power supply state by the dummy load device 90 in which the
plurality of dummy load units 92 is connected in series.
[0053]
<Third Embodiment>
Fig. 10 is a block diagram illustrating a dummy load
unit as one unit of a dummy load device 90 used in a power
supply system 1 according to a third embodiment of the
present invention.
As illustrated in Fig. 10, a terminal A of a dummy
load unit 92-k is connected to a terminal B of a dummy load
unit 92-(k-1), and a terminal B of the dummy load unit 92-k
is connected to a terminal A of a dummy load unit 92-(k+1).
The dummy load unit 92-k includes a control unit 114,
an amplification unit 116, and a power consumption unit 118,
and the respective units are connected in parallel between
44
the terminals A and B.
The control unit 114 is constituted by a voltage
control semiconductor used for voltage control and
accompanying passive components thereof, monitors a voltage
VAB applied between the terminals A and B, generates a
control voltage Vs to make the voltage VAB between the
terminals A and B constant without depending on a current
flowing through the power consumption unit 118, and
transmits the control voltage Vs to the amplification unit
116.
The amplification unit 116 is constituted by a signal
amplification semiconductor used for signal amplification
and passive components accompanying the signal
amplification, amplifies the control voltage generated by
the control unit 114 by g times, generates a control
voltage g x Vs, and transmits the control voltage g x Vs to
the power consumption unit 118.
The power consumption unit 118 is constituted by a
power semiconductor and causes the power semiconductor to
consume power by causing a current to flow to the power
semiconductor according to the control voltage g x Vs
generated by the amplification unit 116. Incidentally, any
one of a power transistor, a field effect transistor, and
an IGBT may be used as the power semiconductor provided in
the power consumption unit 118.
[0054]
Next, an operation of the dummy load unit 92-k
CA 2994098 2018-05-01
CA 02994098 2018-01-29
illustrated in Fig. 10 will be described.
The control unit 114 monitors the voltage VAB applied
between the terminals A and B and transmits the control
voltage Vs to the amplification unit 116 such that the
voltage VAB between the terminals A and=B is constant
without depending on the current flowing through the power
consumption unit 118.
The amplification unit 116 amplifies the control
voltage received from the control unit 114 by g times and
transmits the control voltage g X VS to the power
consumption unit 118.
The power consumption unit 118 causes the power
semiconductor to consume the power by causing the current
to flow to the power semiconductor according to the control
voltage g x Vs received from the amplification unit 116.
In this manner, the dummy load device 90 is
configured by connecting, for example, fifty dummy load
units each of which has the voltage VAB applied between
both terminals A and B of 8V in series.
[0055]
As a result, it is possible to consume the surplus
power that is no longer consumed in the observation device
switched from the power supply state to the non-power
supply state by the dummy load device 90 in which the
plurality of dummy load units 92 is connected in series.
Further, it is possible to adjust the amount of the
current flowing through the semiconductor such that the
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CA 02994098 2018-01-29
voltage VAB applied between both the terminals A and B is
constant without depending on the current Id flowing
through the power semiconductor provided in the power
consumption unit 118, and it is possible to consume the
surplus power that is no longer consumed in the observation
device switched from the power supply state to the non-
power supply state by the dummy load device 90 in which the
plurality of dummy load units 92 is connected in series.
[0056]
<Fourth Embodiment>
Fig. 11 is a block diagram for describing a
configuration of a subsea device 20 provided in a power
supply system 1 according to a fourth embodiment of the
present invention. Incidentally, the same reference signs
as those illustrated in Fig. 2 among reference signs
illustrated in Fig. 11 have the same configurations as
those in Fig. 2, and a description thereof will be omitted.
The subsea device 20 according to the fourth
embodiment is different from the first embodiment in which
the dummy load device 90 is connected to the control
portion 70 in that a dummy load device 90 is connected to a
receiving unit 60.
Specifically, the dummy load device 90 is connected
to both contact points of a power supply line pass relay 62
via output ports Prl and Pr2.
[0057]
Fig. 12 is a block diagram for describing a more
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CA 02994098 2018-01-29
detailed connection relationship between main DC/DC
converters 64 and 66 and output DC/DC converters 72-1 to
72-4 illustrated in Fig. 11 which are used in the power
supply system 1 according to the fourth embodiment of the
present invention.
Specifically, the dummy load device 90 is connected
to power supply lines 32b and 32d and is connected to each
primary side of the main DC/DC converters 64 and 66. The
dummy load device 90 can consume surplus power that has not
been consumed in observation devices 100-1 to 100-4, which
can be connected to the respective ports P1 to P4 of an
output unit 80, when the contact point of the power supply
line pass relay 62, and a contact point the switch SW65
and/or the switch SW67 are switched from a closed state to
an open state according to the control by an onshore
control device 4.
[0058]
As a result, it is possible to consume the surplus
power that is no longer consumed in the observation device,
switched from the power supply state to the non-power
supply state, by the dummy load device, and it is possible
to provide the power supply system capable of consuming the
surplus power that is no longer consumed with the simple
configuration.
In addition, it is possible to cover the power to be
consumed in the observation device, switched from the non-
power supply state to the power supply state, with the
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CA 02994098 201.8-01-29
=
power that is being consumed in the dummy load device, and
it is possible to provide the power supply system capable
of easily performing exchange of the surplus power between
the observation device and the dummy load device with the
simple configuration.
[0059]
<Effect of Invention>
In the dummy load unit of the present invention, the
inter-terminal voltage monitoring unit, the control voltage
amplification unit, and the power consumption unit are
constituted by semiconductor elements and accompanying
passive elements thereof, and it is possible to accurately
design and manufacture (adjust) each block.
Accordingly, it is possible to implement the dummy
load unit having small characteristic variation at
relatively low cost, and thus, it is possible to obtain the
characteristics as expected even in the case of multi-stage
connection. In this regard, it is superior in terms of
characteristics to the configuration in which the Zener
diodes are connected in multiple stages used in the related
art.
In addition, there is an advantage that it is
remarkably superior in terms of voltage stability to the
configuration in which the Zener diode is simply caused to
consume the surplus power as in the related art since the
dummy load unit of the present invention is constituted by
the inter-terminal voltage monitoring unit, the control
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CA 02994098 2018-01-29
voltage amplification unit, and the power consumption unit.
[0060]
<Configuration, Action, and Effect of Exemplary Embodiment
of Present Invention>
<First Aspect>
A power supply system 1 of this aspect is a power
supply system 1 including: a parent device which has an
onshore power supply device 10 (power supply means) and an
onshore control device 2 (control means); and a subsea
device 20 (child device) which is connected to the parent
device via a subsea cable 16, and is characterized in that
the subsea device 20 (child device) includes: main DC/DC
converters 64 and 66 (DC power conversion unit) that
convert first DC power supplied to a primary side into
second DC power and output the second DC power to a
secondary side; and a control unit 70 (power distribution
unit) and an output unit 80 which distribute the second DC
power to a dummy load device 90 and at least one of
observation devices 100 (devices), and the dummy load
device 90 is connected to the primary side or the secondary
side of the main DC/DC converters 64 and 66 and consumes
surplus power out of the first DC power or the second DC
power in accordance with an increase or a decrease of the
number of the observation devices 100 connected to the
control unit 70 and the output unit 80.
According to this aspect, the main DC/DC converters
64 and 66 convert the first DC power supplied to the
CA 02994098 2018-019
primary side into the second DC power and output the second
DC power to the secondary side, the control unit 70 and the
output unit 80 distribute the second DC power to the dummy
load device 90 and at least one of the observation devices
100 (devices), the dummy load device 90 is connected to the
primary side or the secondary side of the main DC/DC
converters 64 and 66 and consumes the surplus power out of
the first DC power or the second DC power in accordance
with the increase or decrease of the number of the
observation devices 100 connected to the control unit 70
and the output unit 80 in the subsea device 20 (child
device).
As a result, it is possible to consume the surplus
power that is no longer consumed in the observation device,
switched from the power supply state to the non-power
supply state, by the dummy load device, and it is possible
to provide the power supply system capable of consuming the
surplus power that is no longer consumed with the simple
configuration.
In addition, it is possible to cover the power to be
consumed in the observation device, switched from the non-
power supply state to the power supply state, with the
power that is being consumed in the dummy load device, and
it is possible to provide the power supply system capable
of easily performing exchange of the surplus power between
the observation device and the dummy load device with the
simple configuration.
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CA 02994098 2018-01-29
[0061]
<Second Aspect>
A dummy load device 90 of this aspect includes a
plurality of dummy load units 92 connected in series, and
each of the dummy load units 92 is characterized by
including: an inter-terminal voltage monitoring unit 94
which monitors a voltage VAB applied between both terminals
A and B of the dummy load unit 92 to generate a control
voltage Vs and adjusts a level of the control voltage Vs
such that the voltage VAB applied between both the
terminals A and B is constant; a control voltage
amplification unit 96 which amplifies the control voltage
Vs generated by the inter-terminal voltage monitoring unit
94 by g times to generate a control voltage g x Vs; and a
power consumption unit 98 which causes a power
semiconductor to consume power by causing a required
current Id to flow to the power semiconductor according to
the control voltage g x Vs generated by the control voltage
amplification unit 96.
According to this aspect, the inter-terminal voltage
monitoring unit 94 monitors the voltage VAB applied between
both the terminals A and B of the dummy load unit 92 to
generate the control voltage Vs and adjusts the level of
the control voltage Vs such that the voltage VAB applied
between both the terminals A and B is constant, the control
voltage amplification unit 96 amplifies the control voltage
Vs generated by the inter-terminal voltage monitoring unit
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CA 02994098 2018-01-29
94 by g times to generate the control voltage g X Vs, and
the power consumption unit 98 causes the power
semiconductor to consume power by causing the required
current Id to flow to the power semiconductor according to
the control voltage g X Vs generated by the control voltage
amplification unit 96 in each of the dummy load units 92.
As a result, it is possible to consume the surplus
power that is no longer consumed in an observation device
switched from a power supply state to a non-power supply
state by the dummy load device 90 in which the plurality of
dummy load units 92 is connected in series.
In addition, it is possible to cover the power to be
consumed in the observation device, switched from the non-
power supply state to the power supply state, with the
power that is being consumed in the dummy load device, and
it is possible to easily perform the exchange of the
surplus power between the observation device and the dummy
load device with the simple configuration.
[0062]
<Third Aspect>
An inter-terminal voltage monitoring unit 94 of this
aspect is characterized by having a semiconductor for
monitoring a voltage VAB applied between both terminals A
and B and generating a control voltage Vs by adjusting the
amount of a current flowing through the semiconductor such
that the voltage VAE applied between both the terminals A
and B is constant without depending on a current Id flowing
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CA 02994098 2018-01-29
through a power semiconductor provided in a power
consumption unit 98.
According to this aspect, the inter-terminal voltage
monitoring unit 94 has the semiconductor for monitoring the
voltage VAB applied between both the terminals A and B and
generates the control voltage Vs by adjusting the amount of
the current flowing through the semiconductor such that the
voltage VAB applied between both the terminals A and B is
constant without depending on the current Id flowing
through the power semiconductor provided in the power
consumption unit 98.
Accordingly, it is possible to adjust the amount of
the current flowing through the semiconductor such that the
voltage VAB applied between both the terminals A and B is
constant without depending on the current Id flowing
through the power semiconductor provided in the power
consumption unit 98, and it is possible to consume surplus
power that is no longer consumed in an observation device
switched from a power supply state to a non-power supply
state by a dummy load device 90 in which a plurality of
dummy load units 92 is connected in series.
[0063]
<Fourth Aspect>
A power semiconductor of this aspect is characterized
by being any one of a transistor, a field effect transistor,
and an IGBT.
According to this aspect, it is possible to consume
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CA 02994098 2018-01-29
power applied between two terminals by the power
semiconductor since the power semiconductor is any one of
the transistor, the field effect transistor, and the IGBT.
As a result, it is possible to consume surplus power
that is no longer consumed in an observation device,
switched from a power supply state to a non-power supply
state, by a dummy load device.
[0064]
<Fifth Aspect>
A dummy load device 90 of this aspect is
characterized in that a current flowing through the dummy
load device 90 decreases when the number of observation
devices 100 (devices) connected to a control unit 70 (power
distribution unit) increases, and the current flowing
through the dummy load device 90 increases when the number
of the observation devices 100 (devices) connected to the
control unit 70 decreases.
According to this aspect, the current flowing through
the dummy load device 90 decreases when the number of the
observation devices 100 connected to the control unit 70
increases, and the current flowing through the dummy load
device 90 increases when the number of observation devices
100 connected to the control unit 70 decreases in the dummy
load device 90.
As a result, the dummy load device 90 can consume
surplus power in accordance with an increase or a decrease
of the number of observation devices 100.
CA 02994098 2018-01-29
As a result, when the number of the observation
devices 100 connected to the control unit 70 decreases, it
is possible to consume the surplus power that is no longer
consumed in the observation device 100, switched from a
power supply state to a non-power supply state, by the
dummy load device, and it is possible to provide a power
supply system capable of consuming the surplus power that
is no longer consumed with a simple configuration.
In addition, when the number of the observation
devices 100 connected to the control unit 70 increases, it
is possible to cover the power to be consumed in the
observation device 100, switched from the non-power supply
state to the power supply state, with the power that is
being consumed in the dummy load device, and it is possible
to provide the power supply system capable of easily
performing exchange of the surplus power between the
observation device and the dummy load device with the
simple configuration.
[0065]
<Sixth Aspect>
A dummy load device 90 of this aspect is a dummy load
device including a plurality of dummy load units 92
connected in series, and each of the dummy load units 92 is
characterized by including: an inter-terminal voltage
monitoring unit 94 which monitors a voltage VAB applied
between both terminals A and B of the dummy load unit 92 to
generate a control voltage Vs and adjusts a level of the
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CA 02994098 2018-01-29
control voltage Vs such that the voltage \TAB applied
between both the terminals A and B is constant; a control
voltage amplification unit 96 which amplifies the control
voltage Vs generated by the inter-terminal voltage
monitoring unit 94 by g times to generate a control voltage
g x Vs; and a power consumption unit 98 which causes a
power semiconductor to consume power by causing a required
current Id to flow to the power semiconductor according to
the control voltage g x Vs generated by the control voltage
amplification unit 96.
According to this aspect, the inter-terminal voltage
monitoring unit 94 monitors the voltage VAB applied between
both the terminals A and B of the dummy load unit 92 to
generate the control voltage Vs and adjusts the level of
the control voltage Vs such that the voltage VAB applied
between both the terminals A and B is constant, the control
voltage amplification unit 96 amplifies the control voltage
Vs generated by the inter-terminal voltage monitoring unit
94 by g times to generate the control voltage g x Vs, and
the power consumption unit 98 causes the power
semiconductor to consume power by causing the required
current Id to flow to the power semiconductor according to
the control voltage g x Vs generated by the control voltage
amplification unit 96 in each of the dummy load units 92.
As a result, it is possible to consume the surplus
power that is no longer consumed in an observation device
switched from a power supply state to a non-power supply
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state by the dummy load device 90 in which the plurality of
dummy load units 92 is connected in series.
In addition, it is possible to cover the power to be
consumed in the observation device, switched from the non-
power supply state to the power supply state, with the
power that is being consumed in the dummy load device, and
it is possible to easily perform the exchange of the
surplus power between the observation device and the dummy
load device with the simple configuration.
[0066]
As above, the present invention has been described
with reference to the example in which the parent device on
the shore and the child device on the seafloor are
connected via the subsea cable. However, the present
invention is not limited to this example, but can be
applied to all scenes where power is supplied to a child
device installed in a remote place that is secluded, for
example, when power is supplied to an eruption monitoring
device installed near a crater of a volcano, when power is
supplied to a dam level monitoring device, and the like.
In addition, the present invention can be also
applied to a system which relates to power supply on shore
and supplies power in a DC system to each house or a room
of each house.
Description of the reference numerals
[0067]
1.. .Power supply system, 2.. .Onshore control device
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(Control means), 4. ..Control cable, 10. ..Onshore power
supply device (Power supply means), 11. ..Ground, 12...Power
line, 16. ..Subsea cable, 20.. .Subsea device (Child device),
22.. .Functional sea ground, 40.. .Transmission unit,
42.. .Cable, 62.. .Power supply line pass relay, 64,66.. .Main
DC/DC converter, 65,67.. .Switch SW, 50.. .Drive power supply
unit, 60.. .Receiving unit, 70.. .Control unit, 72.. .Output
DC/DC converter, 80.. .Output unit, 90.. .Dummy load device,
92.. .Dummy load unit, 94,104.. .Inter-terminal voltage
monitoring unit, 96.. .Control voltage amplification unit,
98,108,118.. .Power consumption unit, 100.. .Observation
device, 106...Control voltage generation unit,
114.. .Control unit, 116.. .Amplification unit
59
