Note: Descriptions are shown in the official language in which they were submitted.
Modular Solar Lighting and Power Management System and
Apparatus
FIELD OF THE INVENTION
The present invention relates to a system and method for selectively powering
LED lighting from various sources including a solar powered source, battery
powered
source and mains powered source.
BACKGROUND OF THE INVENTION
Improvements in solar technology have seen a dramatic increase in the number
of homes and businesses equipped with solar powered systems. Typically these
systems are capable of being connected to grid power, such that when there is
insufficient solar power available to drive a connected load, the system can
switch to
grid power.
Such hybrid systems can also be configured for powering lighting throughout a
home or business. These systems have the potential to save a great deal of
money in
lighting costs, particularly when deployed on a large scale. However,
limitations with
current technology require that hybrid lighting installations are built to
specification,
such that any changes to the lighting configuration may require substantial
modification of the associated hardware (e.g. backbone, driver circuits, etc.)
to meet
the new requirements. It would be advantageous if there was provided a hybrid
system
that readily adapted to changed lighting requirements without the need for
substantial
modification of the system itself.
CA 3017459 2018-09-14
2.
SUMMARY OF THE INVENTION
In an aspect of the present invention there is provided a modular LED lighting
system, comprising: a coordinator module comprising a coordinator
microcontroller
5 electrically coupled to a coordinator communication circuit; a slave
module
comprising: a slave microcontroller; a slave communication circuit for
communicating
with the coordinator communication module; and a driver circuit for supplying
power
to one or more electrically connected LED lights; wherein the slave
microcontroller is
operable to automatically determine a loading of any LED lights electrically
coupled to
10 the driver circuit and in response cause the driver circuit to deliver
an appropriate
current to the LED lights from a selected power source, the power source being
selected by the coordinator microcontroller from one of a solar powered source
and
mains powered source based on one or more predefined power selection rules
evaluated by the coordinator microcontroller.
1 In an embodiment a battery powered source is additionally selectable
by the
coordinator microcontroller
In an embodiment a first of the predefined power selection rules dictates that
20 the solar powered light source is selected when there is sufficient
solar power available
to deliver the appropriate current. In an embodiment where there is
insufficient solar
power available, a second of the predefined power selection rules dictates
that the
battery powered source is selected where the battery powered source has
sufficient
charge to deliver the appropriate current.
In an embodiment where there is both insufficient solar power and battery
power available, a third of the predefined power selection rules dictates that
the mains
powered source is selected where the mains powered source is operational.
30 In an embodiment the available power/charge of the various power
sources is
continuously evaluated by the coordinator microcontroller to determine which
power
source is selected for powering the LED light(s).
CA 3017459 2018-09-14
3.
In an embodiment the coordinator communication circuit and slave
communication circuit are operable to communicate with each other over a mesh
network.
In an embodiment the system further comprises a switch operable to wirelessly
communicate with one or both of the coordinator communication circuit and
slave
communication circuit for turning electrically coupled LED lights on and off.
In an embodiment the switch further comprises a dimmer control for controlling
dimming of the LED circuit.
In an embodiment the coordinator module comprises a driver circuit for
supplying power to one or more LED lights electrically connected thereto and
wherein
the coordinator microcontroller is operable to communicate with the driver
circuit for
automatically determining a loading of any electrically coupled LED lights and
in
response cause the driver circuit to deliver an appropriate current at a
predefined
voltage to the LED lights from a selected power source.
In an embodiment the system further comprises at least one additional slave
module and wherein each of the respective slave communication circuits and
coordinator communication circuit communicate over the mesh network.
In an embodiment the system further comprises a 3-core power cable to which
the coordinator and each slave module are connected and wherein the 3-core
power
cable is operable as a backbone for delivering power from a selected power
source to
the respective driver circuits.
In an embodiment the battery power is sourced from one or more batteries
which are electrically connected to individual slave modules and wherein the
microcontrollers of the respective modules are communicable with each other
for
CA 3017459 2018-09-14
4.
determining how to distribute battery power from the electrically connected
batteries to
the driver circuits.
In an embodiment, dependent on a charge state, power from one electrically
connected battery may be supplied to multiple driver circuits, via the 3-core
power
cable
In an embodiment the microcontroller for each of the slave modules connected
to a battery implements a battery management routine for controlling charging
of the
I 0 battery from one of the solar powered source and mains powered source.
In an embodiment the coordinator module is operable to directly connect to the
mains powered and solar powered source and output a regulated DC voltage to
the
respective slave driver circuits
IS
In an embodiment the controller module further comprises a boost buck
regulator for the voltage regulation
In accordance with a second aspect there is provided a coordinator module for
a
20 lighting system, comprising: a microcontroller electrically coupled to a
communication
circuit which is operable to communicate with one or more a slave modules; and
a
driver circuit for supplying power to one or more electrically connected LED
lights;
wherein the microcontroller is operable to automatically determine a loading
of any
LED lights electrically coupled to the driver circuit and in response cause
the driver
25 circuit to appropriately power the LED lights based on the determined
loading from a
selected power source, the power source being selected by the microcontroller
from
one of a solar powered source and mains powered source based on one or more
predefined power selection rules.
30 In an embodiment the coordinator module is operable to cause driver
circuits
electrically connected to the slave modules to source power from the selected
power
source for power loads electrically coupled to the driver circuits.
CA 3017459 2018-09-14
5.
In accordance with a third aspect there is provided a slave module for a
lighting
system, comprising: a microcontroller electrically coupled to a communication
circuit
which is operable to communicate with a coordinator module; and a driver
circuit for
supplying power to one or more electrically connected LED lights; wherein the
microcontroller is operable to automatically determine a loading of any LED
lights
electrically coupled to the driver circuit and in response cause the driver
circuit to
appropriately power the LED lights based on the determined loading from a
selected
power source, the power source being selected by a microcontroller of the
coordinator
module from one of a solar powered source and mains powered source based on
one or
more predefined power selection rules evaluated by the coordinator module
microcontroller.
In a fourth aspect there is provided an LED lighting module, comprising: a
driver circuit for supplying power to one or more electrically connected LED
lights; a
microcontroller which is operable to automatically determine a loading of any
LED
lights electrically coupled to the driver circuit and in response cause the
driver circuit
to deliver power to the LED lights from a selected power source, the power
source
being selected by the microcontroller from one of a solar powered source and
mains
powered source based on one or more predefined power selection rules evaluated
by
the coordinator microcontroller.
In an embodiment the microcontroller monitors an available voltage level of
the
solar power source and when the level is insufficient to deliver the required
power to
the LED lights the microcontroller selects the mains powered source for
driving the
LED lights
In an embodiment a battery power source is additionally selectable by the
coordinator microcontroller and wherein the microcontroller monitors an
available
voltage of both the battery source and the solar power source, such that when
there is
insufficient solar power available the battery power source is selected for
powering the
CA 3017459 2018-09-14
6.
LED lights until the battery power source is no longer able to provide the
necessary
power at which time the microcontroller selects the mains powered source.
In an embodiment the available power/charge of the various power sources is
continuously evaluated by the microcontroller to determine which power source
is
selected for powering the LED light(s).
In an embodiment the microcontroller is additionally configured to cause the
solar powered source to charge the battery powered source when the LED
light(s) are
not switched on and there is sufficient power available for charging the
battery
powered source and wherein the microcontroller causes the solar powered source
to
cease charging at a predetermined charge level to prevent overcharging of the
battery.
In an embodiment the microcontroller is additionally configured to cause the
solar powered source to charge the battery powered source while the solar
power
source is delivering power to the LED light(s) provided there is sufficient
power for
both charging and powering the LED light(s), as determined from the monitored
charge
and power levels.
In an embodiment the module further comprises a boost circuit which is
operable to boost an operating voltage of the solar and/or battery power to
match a
higher operating voltage for the LED light(s)
In an embodiment the driver is operable to be electrically connected to the
mains powered and solar powered source and comprises a circuit operable to
output a
regulated DC voltage for powering the LED light(s).
In an embodiment the battery powered source comprises one or more deep
charge batteries.
CA 3017459 2018-09-14
7
Any publications mentioned in this specification are herein incorporated by
reference. Any discussion of documents, acts, materials, devices, articles or
the like
which has been included in this specification is solely for the purpose of
providing a
context for the present invention. It is not to be taken as an admission that
any or all of
these matters form part of the prior art base or were common general knowledge
in the
field relevant to the present invention as it existed in Australia or
elsewhere before the
priority date of this application.
Throughout this specification the word "comprise", or variations such as
"comprises" or "comprising", will be understood to imply the inclusion of a
stated
element, integer or step, or group of elements, integers or steps, but not the
exclusion
of any other element, integer or step, or group of elements, integers,
integers or steps.
The features and advantages of methods of the present invention will become
further apparent from the following detailed description of preferred
embodiments and
the accompanying figures.
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
Figure 1 is a schematic view of a modular lighting system in accordance with
an embodiment of the present invention;
Figure 2 is a schematic view of the coordinator and slave modules shown in
Figure I;
Figure 3 is a schematic showing various connections for a coordinator module,
in accordance with an embodiment;
Figure 4 is a schematic illustrating power distribution among the various
modules of Figure I, in accordance with an embodiment; and
Figure 5 is a base power distribution flow chart, according to an embodiment.
CA 3017459 2018-09-14
8.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE
INVENTION
With reference to Figures 1 to 3, there is shown a modular LED lighting
system 10 comprising a coordinator module 12 and a plurality of slave modules
14
communicable therewith Both the coordinator module 12 and slave modules 14
comprise driver circuits 16 for driving electrical loads connected thereto,
According to
embodiments of the present invention, the electrical loads take the form of
one or more
energy efficient LED lights 13. Also shown in Figure 1 are wireless switches I
5 that
are communicable with the modules 12, 14 for turning on/off and controlling
dimming
of selected LED lights 13.
The coordinator module 12 is electrically connected to various power sources,
including a solar powered source 18 and a backup mains powered source 20 (in
this
case taking the form of a 12-36 volt low voltage power supply). According to
embodiments described herein, the solar powered source takes the form of one
or more
250 Watt photovoltaic solar panels 19. An energy storage device in the form of
one or
more batteries 22 may also be provided. The coordinator module 12 is operable
to
implement a power management program. The program evaluates various power
selection rules to determine which of the electrically connected power sources
18, 20,
22 is to be used for powering the respective driver circuits 16 of connected
modules 12, 14. According to embodiments described herein, power from the
solar
powered source 18, backup mains powered source 20 (and optionally the battery
sources 22) is distributed via a power backbone 24.
An advantage of the system 10 described herein is that it may accommodate
any number of slave modules 14 and switches 15, dependent only on the power
available from the respective power sources and total power usage/loading of
LED
lights coupled to the respective slave modules 14. Thus, slave modules 14 can
readily
be added or removed at any time to cater for varying lighting requirements
over time,
simply by connecting/removing the slave modules 14 to/from the power backbone
24.
CA 3017459 2018-09-14
9.
A further advantage is that solar panels 19 and batteries 22 can be
dynamically added
for increasing the total power available from these sources.
In more detail, and with additional particular reference to Figure 2, each of
the
coordinator module 12 and slave modules 14 (noting that only one slave module
is
shown for ease of description) implement a microcontroller 30 for performing
various
communication, automated load determination and power management functions, as
will be described in more detail in subsequent paragraphs. In addition, the
coordinator
module 12 and slave modules 14 each implement a transceiver circuit 32 for
communicating with each other. According to embodiments described herein, the
transceiver circuits 32 take the form of 2.4Ghz wireless transceivers that are
communicable with one another (as well as any wirelessly "paired" switches 15)
over a
mesh network, using known wireless mesh protocol communication techniques. The
initial configuration process will now be described in more detail.
When a coordinator module 12 is to be configured with one or multiple slave
modules 14 (i.e. over the same backbone 24) they first need to be "grouped".
The
grouping process is a sequence completed by an installer, involving an
initiation
sequence whereby each of the modules 14 is controlled to broadcast a signal
and the
radio signal strength (RSS) of each module is measured by the coordinator 12
for
determining which modules are to be included in the grouping. When the
initiation
sequence is complete, the coordinator and slave modules 12, 14 may communicate
as a
single system and recognise that they are operating on the same solar circuit,
As
previously mentioned, the modules 12, 14 may also be paired to wireless
switches 15
which form the end devices on the mesh network. Switches IS are paired with
the
relevant coordinator and/or slave modules based on the light control required
(e g.
switching the light(s) on or off, and dimming). It will be understood that a
single
switch 15 could be paired to multiple modules 12, 14 so as to manage any
number of
connected lights, switching them on or off, or controlling the LED light
intensity
"dimming". The wireless communication of the grouped and paired network of
modules 12, 14 and switches 15 described above may also transparently relay or
CA 3017459 2018-09-14
10,
forward communications from modules 12, 14 and switches 15 connected to other
groups creating a true mesh network
The subsequent communications between the modules 12, 14 over the mesh
network include exchanging status information and commands relating to power
availability, power consumption/loading, light status (i.e. on/off), battery
charge and
storage levels. In a particular embodiment, the slave modules 14 are each
configured to
broadcast the following information for electrically connected lights: (a)
on/off status;
(b) intensity (c) driver power status (d) input voltage level. This exchange
of
information allows the coordinator module 12 to manage the available solar
power,
either stored in batteries 22 or direct from the photovoltaic panels 19 in the
most
efficient manner, while at all times delivering uninterrupted light on demand.
According to the preferred embodiment, the backup mains power source 20 is
only
used when all green power sources 18, 22 are unavailable or depleted.
Each of the modules 12, 14 are additionally operable to implement an auto load
detection capability for automatically determining a loading of any LED lights
13
electrically coupled to the corresponding driver 16. In a particular
embodiment, auto
load detection comprises a first step of switching on a connected LED light.
The
microcontroller 30 is operable to take multiple high frequency samples of
current and
voltage as the connected LED light starts to conduct. It will be understood by
persons
skilled in the art that an LED light 13 will typically contain multiple LEDs,
often
referred to as an "LED array". The number of LEDs in the array that are
connected in
series (referred to herein as a "string") can be used determine the "turn on"
voltage for
the LED light array. By way of example, the microcontroller 30 may be
programmed
to recognise that an individual LED has a forward voltage of between 2.7-3,0
Volt. By
determining the voltage of the LED light at the point where current starts to
ramp up
(i e. as determined by the microcontroller 30 through the sampling step
discussed
above), the number of LED in the string can be determined. For example, where
the
sampling indicates a ramping up of current at 29 volts, the microcontroller 30
can
determine that the series string contains 10 individual LEDs. This information
along
with the current draw sampled at the same time is subsequently used by the
CA 3017459 2018-09-14
11.
microcontroller 30 to determine the number of LED strings that are connected
in
parallel within the array. Once the above parameters of the LED array are
known, the
microcontroller 30 can determine the effective LED array wattage which in turn
is
utilised to set the corresponding operational parameters for the LED driver 16
so as to
optimize power delivered to the detected LED light through constant current
regulation. Where multiple LED lights 13 of the same type are connected to the
same
driver, the microcontroller 30 can determine the loading or combined wattage
in the
same manner.
The driver circuits 16 subsequently select and regulate the power supplied to
the electrically connected LED light(s) based on constant current drawn from
the
electrically connected LED load. According to embodiments described herein,
current
regulation is achieved using a Buck Boost pulse width regulator 36. Such a
configuration advantageously compensates for the different power sources and
I 5 potentially wide fluctuations in the power output by the solar power
source. The load
determinations are also communicated to the microcontroller 30 of the
coordinator
module 12 for evaluation by the power management program, as will be described
in
more detail in subsequent paragraphs.
The auto load detection capability of the modules 12, 14 is particularly
advantageous as it provides the overall system 10 with the flexibility to add
or remove
LED lights to/from the system as required, without having to manually adjust
operational drive parameters or modify the associated driver hardware (as is
required
for conventional systems which employ dedicated LED drivers for specific LED
light
arrays). Instead, loading of connected lights can be automatically determined
avoiding
any mismatch between LED Drivers and LED light capacity (i.e. which can be
detrimental to both light output and reliability of the LED array).
As particularly shown in Figures 3 & 4, the coordinator module 12 is directly
connected to both the solar power source 18 and mains power source 20. Power
from
each of these sources 18, 20 is subsequently distributed to the respective
slave driver
circuits 16 over the power backbone 24, which according to the illustrated
embodiment
CA 3017459 2018-09-14
12.
takes the form of a 3-core power cable. More particularly, the 3-core backbone
has one
conductor as a common ground, one conductor allocated to distributing low
voltage
mains (i.e. as backup power) and the remaining conductor allocated to
distributing
solar power and battery power, as controlled by the coordinator module 12.
=
As previously mentioned, each of the modules 12, 14 may additionally be
electrically connected to individual batteries 22. In this regard, each of the
microcontrollers 30 are operable to implement a battery management routine
that
monitors a charge state of an electrically connected battery 22 and controls
the
appropriate charging thereof. The charge state is additionally communicated to
the
microprocessor 30 of the coordinator module 12 for evaluation by the power
management program.
In more detail, any batteries connected to the slave modules 14 are used as
energy storage and supply devices and thus configured as deep cycle devices
The
battery connected to the coordinator module 12 is used in a slightly different
manner.
To avoid constant switching between power sources caused by load (i.e. when
solar
power is still available), the battery connected to the coordinator module 12
may be
used as a dampener or buffer for the solar source 18, thereby improving the
power
efficiency of the system 10. When there is insufficient or no solar power
available (e.g.
caused through cloud and/or shadows, or when the angle of the sun is
insufficient to
satisfy the power needs of the system) the coordinator module 12 will cause
the system
to switch to battery power (i.e. provided by the respective slave module
batteries which
are individually switched and gated by diodes to the backbone 24 as needed).
Once
switched, the respective slave driver circuits 16 are able to draw from the
cumulative
battery capacity of the system 10 The coordinator module 12 is the last to
switch its
power to the backbone 24. Once the batteries have been drained, the driver
circuits 16
of both the slave and coordinator modules 12, 14 will switch to backup
mains power 20, which is available on the backbone 24 at all times (i.e. via
the
dedicated conductor).
=
CA 3017459 2018-09-14
13
With additional reference to Figure 5, there is shown a flow chart
illustrating
various determinations/rules implemented by the power management program of
the
coordinator module 12
In a first step SI, the program determines whether there is sufficient solar
power available for powering connected drivers 16. The coordinator 12 monitors
the
solar output and loads the solar source (i.e using the electrically connected
lights) to
determine solar power availability.
At step S2, responsive to determining that there is sufficient solar power
available, the power management module evaluates whether the required light
current
can be maintained. This involves evaluating the loading of the LED light(s)
connected
to the coordinator module 12 and any slave modules 14 (communicated from the
respective slave microcontrol ler 30, as previously described). More
specifically, each
of the driver circuits 16 are operable to continuously monitor for a low
voltage level
indicator, which is an indicator that current cannot be maintained and that
either a
power boost or switch of power sources is required.
At step S3, if light current can be maintained (i.e. no low voltage level
indications have been detected), the microcontroller 30 of the coordinator
module 12
determines whether the mains backup 20 is on and if so disables it at step S4.
If at
step S3 the mains backup 20 is determined to be off, the process proceeds
directly to
step S5, which involves determining whether the lights are switched on for
each of the
connected drivers 16. In this regard it will be understood that the
coordinator and slave
modules 12, 14 are each responsible for the management and control of their
respective
LED driver. For those driver circuits 16 that do not have any lights switched
on,
batteries 22 electrically connected thereto are charged (if required) from the
selected
power source (step S6). Battery charging is managed by the microcontrollers of
the
individual modules 12, 14 to which the batteries are connected. If the lights
are
switched on, then at step S7 the corresponding driver circuits enable/adjust
light
current and operation, as required. The process then returns to step SI
CA 3017459 2018-09-14
14
Returning to steps Si and S2, if either determination results in a negative
output, then the coordinator module 12 causes the driver circuit(s) 16 to
switch to
battery power supply (step S8). The available battery charge is evaluated at
step S9
and if there is sufficient voltage the process returns to step S5, as
previously described.
If there is insufficient voltage, the mains backup 20 is turned on (step S10)
and the
driver circuits (16) are instructed to source power from the regulated mains
power
supply. Step Sit is the same as for step S5, which involves determining
whether lights
are switched on and, if yes, process flow returns to step S7. Otherwise, the
process
returns directly to step S I
As shown in Figure 4, a smart phone or PC can connect to the wireless mesh
network for controlling operation of (i e. switching on/off and dimming) LED
lights
electrically connected thereto. This is achieved through a suitable user
interface and
programming language which is communicable with the coordinator
microcontroller 30.
In an alternative embodiment to that described above, the slave modules are
operable to each perform the functions of the coordinator module and have
direct
access to the various connectable power sources 18, 20, 22. In other words,
the slave
modules (which can now be considered and will hereafter be referred to as
"independent controller modules") each implement a microcontroller 30 which is
operable to automatically determine a loading of any LED lights electrically
coupled to
the driver circuit and in response cause the driver circuit to deliver power
to the LED
lights from a connected power source (i.e. one of a solar powered source,
mains power
source or batter power source), based on one or more predefined power
selection rules
evaluated by the microcontroller 30. Such an embodiment is particularly suited
for
home or office lighting and optimises the green power resources at any point
in time,
extending battery life while minimising wire losses through reduced current
levels.
In more detail, each of the independent controller module microprocessors 30
monitors the voltage levels of both solar source 18 and battery source 22,
while also
monitoring charge and draw currents. Based on these readings the
microprocessor 30 is
CA 3017459 2018-09-14
15
programmed to calculate the most effective and efficient power usage, while
preventing overcharge and /or discharge battery states. Based on battery
status the solar
power (i.e. from source 18) is gated to a charge circuit / charge boost
circuit (not
shown), or direct supply to the driver 16. This not only utilises the green
power
resources in the most efficient way, but also enhances the life of the battery
22 by
minimising the battery cycle count and depth of discharge. A battery
management
routine implemented by the microprocessor 30 can safely charge a variety of
deep
charge batteries and batteries of different chemistry, including lead acid,
AGM, lithium
ion and LiFePO4. In a particular embodiment, the battery 22 comprises a 24VDC
(+3/- 2) lithium ion battery and the and preferred Solar Panel is 24V type.
According
to a particular embodiment, the operating voltage of the system 10 and driver
16 is 30
¨45VDC. This allows the system 10 to operate at reduced current levels
reducing cable
losses. If there is a situation where solar power is not available and the
battery
resources have been depleted, the microprocessor gates the 12-18VDC mains
backup
source 20 to the boost circuit ensuring the system delivers seamless lighting
in all
situations 24/7 365 days of the year.
In an office environment the preferred configuration may not require a
battery.
In this case the independent controller module may be configured with solar
panels and
mains back-up. This allows the solar power 18 to be used during office hours.
The
mains backup 20 would be gated in during cloudy periods or late evenings again
delivering seamless efficient lighting at all times. Alternatively, the
independent
controller module could be configured with a smaller battery system to further
improve
efficiency allowing extend green power operation. An advantage of the
independent
controller module is seamless lighting while delivering that lighting with the
highest
possible green power content.
The independent controller modules may advantageously be connected to the
master/slave system 10 of Figure 1 (i.e. such that they operate as slave
modules), if
desired. In this scenario, the modules may each implement a boost circuit that
. matches/boost the battery voltage from 24V to the same voltage as the
Figure I system.
CA 3017459 2018-09-14
16.
It will be understood by persons skilled in the art that numerous variations
and/or
modifications may be made to the invention without departing from the spirit
or scope of
the invention as broadly described. For example, the skilled addressee would
be able to
readily modify the control system yet still obtain clamping of the blade of
the saw. The
present embodiments are, therefore, to be considered in all respects as
illustrative and not
restrictive.
CA 3017459 2018-09-14
