Note: Descriptions are shown in the official language in which they were submitted.
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TITLE: Dual Voltage Charging System with an Integrated Active Filter Auxiliary
Power
Module
TECHNICAL FIELD
[0001] The described embodiments relate to a dual-voltage charging system,
and
in particular, to a dual-voltage charging system with an integrated active
filter auxiliary
power module (AFAPM) for an electrified vehicle.
BACKGROUND
[0002] In a single-phase on-board charger for electrified vehicles, second-
order
harmonic currents and corresponding ripple voltages exist on dc bus when a
battery is
charged via an AC power source. The low-frequency harmonic current is normally
filtered using a bulk film capacitor or additional active power filter (APF)
circuit.
However, such a charger consisting of a bulk capacitor may suffer from various
disadvantages, such as, low power density, high manufacturing cost, heavy
weight etc.
SUMMARY
[0003] In one aspect, at least one embodiment described herein
provides a dual-
voltage charging system comprising: an AC power source for providing power; a
charger coupled to the AC power source via a first switch, the first switch
being
operable between a connect mode to connect the charger to the AC power source
and
a disconnect mode to disconnect the charger from the AC power source; a high
voltage
battery coupled to the charger, wherein when the first switch is in the
connect mode and
the charger is connected to the AC power source, the dual-voltage charging
system
operates in filtering mode where the high voltage battery is charged using the
AC power
source; and an active filter auxiliary power module coupled to the high
voltage battery
and a low voltage battery, wherein when the first switch is in the disconnect
mode and
the charger is disconnected from the AC power source, the dual-voltage
charging
system operates in a charging mode where the high voltage battery charges the
low
voltage battery via the active filter auxiliary power module.
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[0004] In some embodiments, the charger is a single-stage charger
comprising
an AC/DC converter and a DC/DC converter in one stage. In some other
embodiments,
the charger is a two-stage charger comprising a first stage consisting of an
AC/DC PFC
boost converter and a second stage consisting of a DC/DC converter. In some
embodiments, the DC/DC converter is an isolated DC/DC converter.
[0005] In some embodiments, the active filter auxiliary power
module is located
between the first stage and the second stage.
[0006] In some embodiments, the active filter auxiliary power
module is located
between the first stage and the second stage via a second switch, and the
second
switch is operable between a first mode and a second mode, wherein in the
first mode,
the second switch is connected to the first stage and the second stage, and
the dual-
voltage charging system operates in the filtering mode, and in the second
mode, the
second switch is disconnected from the first stage and the second stage, and
connected
to the high voltage battery, and the dual-voltage charging system operates in
the
charging mode.
[0007] In some embodiments, the second switch is a mechanical
double pole
double throw switch.
[0008] In some embodiments, the active filter auxiliary power
module comprises
at least one ripple filter for filtering second-order frequency harmonics of
the AC power
source, at least one primary power switch coupled to the at least one ripple
filter and
operable to switch the dual-voltage charging system in the filtering mode; at
least one
secondary power switch operable to switch the dual-voltage charging system in
the
charging mode; at least one low voltage battery filter coupled to the at least
one
secondary power switch, the at least one low voltage battery filter and the at
least one
secondary power switch forming at least one DC/DC converter; and a transformer
coupled to the at least one primary power switch on a primary side of the
transformer
and the at least one secondary power switch on a secondary side of the
transformer.
[0009] In various embodiments, the transformer converts a high-
voltage low-
current second-order frequency harmonics to low-voltage high-current frequency
harmonics.
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[0010] In some embodiments, the AC power source is located external
to an
electrified vehicle, and the charger, the high voltage battery, the active
filter auxiliary
power module and the low voltage battery are located internal to the
electrified vehicle.
[0011] In another aspect, in at least one embodiment described
herein, there is
provided an active filter auxiliary power module for use in a dual-voltage
charging
system within an electrified vehicle, the active filter auxiliary power module
comprising:
at least one ripple filter for filtering second-order frequency harmonics of
an AC power
source located external to the electrified vehicle and providing power to
charge a high
voltage battery within the electrified vehicle; at least one primary power
switch coupled
to the at least one ripple filter and operable to switch the dual-voltage
charging system
in a filtering mode wherein when the dual-voltage charging system in the
filtering mode,
the high voltage battery is charged by the AC power source via a charger; at
least one
secondary power switch operable to switch the dual-voltage charging system in
a
charging mode wherein when the dual-voltage charging system in the charging
mode, a
low voltage battery is charged by the high voltage battery; at least one low
voltage
battery filter coupled to the at least one secondary power switch, the at
least one low
voltage battery filter and the at least one secondary power switch forming at
least one
DC/DC converter; and a transformer coupled to the at least one primary power
switch
on a primary side of the transformer and the at least one secondary power
switch on a
secondary side of the transformer.
[0012] In another aspect, in at least one embodiment described
herein, there is
provided an active filter auxiliary power module for use in a dual-voltage
charging
system within an electrified vehicle, where the dual-voltage charging system
comprises
an external AC power source for providing power, a charger coupled to the AC
power
source via a first switch, the first switch being operable between a connect
mode to
connect the charger to the AC power source and a disconnect mode to disconnect
the
charger from the AC power source, and a high voltage battery coupled to the
charger,
wherein when the first switch is in the connect mode and the charger is
connected to
the AC power source, the dual-voltage charging system operates in filtering
mode
where the high voltage battery is charged using the AC power source, and
wherein the
active filter auxiliary power module is coupled to the high voltage battery
and a low
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voltage battery, wherein when the first switch is in the disconnect mode and
the charger
is disconnected from the AC power source, the dual-voltage charging system
operates
in a charging mode where the high voltage battery charges the low voltage
battery via
the active filter auxiliary power module, the active filter auxiliary power
module
comprising: at least one ripple filter for filtering second-order frequency
harmonics of the
AC power source; at least one primary power switch coupled to the at least one
ripple
filter and operable to switch the dual-voltage charging system in the
filtering mode; at
least one secondary power switch operable to switch the dual-voltage charging
system
in the charging mode; at least one low voltage battery filter coupled to the
at least one
secondary power switch, the at least one low voltage battery filter and the at
least one
secondary power switch forming at least one DC/DC converter; and a transformer
coupled to the at least one primary power switch on a primary side of the
transformer
and the at least one secondary power switch on a secondary side of the
transformer.
[0013] In another aspect, in at least one embodiment described
herein, there is
provided a method for operating a dual-voltage charging system within an
electrified
vehicle, the method comprising: connecting a charger to an external AC power
source
via a first switch, the first switch being operable between a connect mode to
connect the
charger to the AC power source and a disconnect mode to disconnect the charger
from
the AC power source; coupling a high voltage battery to the charger, wherein
when the
first switch is in the connect mode and the charger is connected to the AC
power
source, the dual-voltage charging system operates in filtering mode where the
high
voltage battery is charged using the AC power source; and coupling an active
filter
auxiliary power module to the high voltage battery and a low voltage battery,
wherein
when the first switch is in the disconnect mode and the charger is
disconnected from the
AC power source, the dual-voltage charging system operates in a charging mode
where
the high voltage battery charges the low voltage battery via the active filter
auxiliary
power module.
[0014] In some embodiments, the charger is a single-stage charger
comprising
an AC/DC converter and a DC/DC converter in one stage.
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[0015] In some embodiments, the charger is a two-stage charger
comprising a
first stage consisting of an AC/DC PFC boost converter and a second stage
consisting
of a DC/DC converter.
[0016] In some embodiments, the method further comprises coupling the
active
filter auxiliary power module to the first stage and the second stage.
[0017] In some embodiments, the method further comprises coupling the
active
filter auxiliary power module to the first stage and the second stage via a
second switch,
wherein the second switch is operable between a first mode and a second mode,
and
wherein in the first mode, the second switch is connected to the first stage
and the
second stage, and the dual-voltage charging system operates in the filtering
mode, and
in the second mode, the second switch is disconnected from the first stage and
the
second stage, and connected to the high voltage battery, and the dual-voltage
charging
system operates in the charging mode.
[0018] In some embodiments, the active filter auxiliary power module
comprises:
at least one ripple filter for filtering second-order frequency harmonics of
the AC power
source; at least one primary power switch coupled to the at least one ripple
filter and
operable to switch the dual-voltage charging system in the filtering mode; at
least one
secondary power switch operable to switch the dual-voltage charging system in
the
filtering mode; at least one low voltage battery filter coupled to the at
least one
secondary power switch, the at least one low voltage battery filter and the at
least one
secondary power switch forming at least one DC/DC converter; and a transformer
coupled to the at least one primary power switch on a primary side of the
transformer
and the at least one secondary power switch on a secondary side of the
transformer.
[0019] In various embodiments, the transformer converts a high-
voltage low-
current second-order frequency harmonics to low-voltage high-current frequency
harmonics.
[0020] In various embodiments, the AC power source is located
external to an
electrified vehicle, and the charger, the high voltage battery, the active
filter auxiliary
power module and the low voltage battery are located internal to the
electrified vehicle.
[0021] Other features and advantages of the present application will
become
apparent from the following detailed description taken together with the
accompanying
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drawings. It should be understood, however, that the detailed description and
the
specific examples, while indicating preferred embodiments of the application,
are given
by way of illustration only, since various changes and modifications within
the spirit and
scope of the application will become apparent to those skilled in the art from
this
detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Several embodiments of the present invention will now be
described in
detail with reference to the drawings, in which:
FIG. 1A is a dual-voltage charging system for an electrified vehicle according
to
an example embodiment;
FIG. 2A is a dual-voltage charging system for an electrified vehicle according
to
another example embodiment;
FIG. 2B is block diagram of an integrated active filter auxiliary power module
(AFAPM) according to an example embodiment;
FIG. 3A is a dual-voltage charging system for an electrified vehicle according
to
an example embodiment;
FIG. 3B is block diagram of an integrated AFAPM according to another example
embodiment;
FIG. 4A is a dual-voltage charging system for an electrified vehicle according
to
another example embodiment;
FIG. 4B is block diagram of an integrated AFAPM according to an example
embodiment;
FIG. 5A is a dual-voltage charging system for an electrified vehicle according
to
an example embodiment;
FIG. 5B is block diagram of an integrated AFAPM according to another example
embodiment;
FIG. 6 is block diagram of an integrated AFAPM according to an example
embodiment;
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FIG. 7 illustrates a graphical representation of cost of components of various
filtering methods used for mitigating the harmonics on DC-link according to an
example embodiment;
FIG. 8 illustrates a circuit diagram of an integrated AFAPM according to an
example embodiment;
FIG. 9A illustrates a circuit diagram of operation of an integrated AFAPM in a
buck mode with inductor current rising according to an example embodiment;
FIG. 9B illustrates a circuit diagram of operation of an integrated AFAPM in a
buck mode with inductor current falling according to an example embodiment;
FIG. 9C illustrates a circuit diagram of operation of an integrated AFAPM in a
boost mode with inductor current rising according to an example embodiment;
FIG. 9D illustrates a circuit diagram of operation of an integrated AFAPM in a
boost mode with inductor current falling according to an example embodiment;
FIG. 10A illustrates a graphical representation of an integrated AFAPM working
as an active power filter (APF) according to an example embodiment;
FIG. 10B illustrates a graphical representation of an integrated AFAPM working
as an APF according to another example embodiment;
FIG. 11 illustrates a graphical representation of an integrated AFAPM working
as
a low voltage battery charger according to an example embodiment;
FIG. 12A illustrates a graphical representation of an integrated AFAPM acting
in
a low voltage battery charging mode according to another example embodiment;
and
FIG. 12B illustrates a graphical representation of an integrated AFAPM acting
in
an active filtering mode according to another example embodiment.
[0023] The drawings are provided for the purposes of illustrating various
aspects
and features of the example embodiments described herein. For simplicity and
clarity of
illustration, elements shown in the FIGS. have not necessarily been drawn to
scale.
Further, where considered appropriate, reference numerals may be repeated
among the
FIGS.to indicate corresponding or analogous elements.
DETAILED DESCRIPTION
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[0024]
Various apparatuses or processes will be described below to provide an
example of at least one embodiment of the claimed subject matter. No
embodiment
described below limits any claimed subject matter and any claimed subject
matter may
cover processes, apparatuses, devices or systems that differ from those
described
below. The claimed subject matter is not limited to apparatuses, devices,
systems or
processes having all of the features of any one apparatus, device, system or
process
described below or to features common to multiple or all of the apparatuses,
devices,
systems or processes described below. It is possible that an apparatus,
device, system
or process described below is not an embodiment of any claimed subject matter.
Any
subject matter that is disclosed in an apparatus, device, system or process
described
below that is not claimed in this document may be the subject matter of
another
protective instrument, for example, a continuing patent application, and the
applicants,
inventors or owners do not intend to abandon, disclaim or dedicate to the
public any
such subject matter by its disclosure in this document.
[0025]
Furthermore, it will be appreciated that for simplicity and clarity of
illustration, where considered appropriate, reference numerals may be repeated
among
the figures to indicate corresponding or analogous elements. In addition,
numerous
specific details are set forth in order to provide a thorough understanding of
the example
embodiments described herein. However, it will be understood by those of
ordinary skill
in the art that the example embodiments described herein may be practiced
without
these specific details. In other instances, well-known methods, procedures and
components have not been described in detail so as not to obscure the example
embodiments described herein. Also, the description is not to be considered as
limiting
the scope of the example embodiments described herein.
[0026]
It should also be noted that the terms "coupled" or "coupling" as used
herein can have several different meanings depending in the context in which
the term
is used. For example, the term coupling can have a mechanical, electrical or
magnetic
connotation. For example, as used herein, the terms "coupled" or "coupling"
can
indicate that two elements or devices can be directly connected to one another
or
connected to one another through one or more intermediate elements or devices
via an
electrical element, electrical signal, a mechanical element or magnetic flux
such as but
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not limited to, a wire, a cable, or magnetic field, for example, depending on
the
particular context.
[0027] It should be noted that terms of degree such as
"substantially", "about"
and "approximately" as used herein mean a reasonable amount of deviation of
the
modified term such that the end result is not significantly changed. These
terms of
degree should be construed as including a deviation of the modified term if
this
deviation would not negate the meaning of the term it modifies.
[0028] Furthermore, the recitation of any numerical ranges by
endpoints herein
includes all numbers and fractions subsumed within that range (e.g. 1 to 5
includes 1,
1.5, 2, 2.75, 3, 3.90, 4, and 5). It is also to be understood that all numbers
and fractions
thereof are presumed to be modified by the term "about" which means a
variation up to
a certain amount of the number to which reference is being made if the end
result is not
significantly changed.
[0029] The various embodiments disclosed herein relate to a dual-
voltage
charging system with an integrated active filter auxiliary power module
(AFAPM). In
particular, the various embodiments disclosed herein relate to a dual-voltage
charging
system that applies the integrated AFAPM as an active filter (APF) to
compensate the
low frequency harmonics in the high voltage (HV) battery charger when the HV
battery
is charging, and applies the integrated AFAPM as a low voltage (LV) battery
charger
auxiliary power module (APM) when the HV battery stops charging and starts to
charge
the LV battery.
[0030] Typically, in a single-phase high voltage (HV) battery charger
of electrified
vehicles, large capacitance is required to filter the low frequency current
harmonics,
especially the second-order harmonics. These low frequency current harmonics
are
mainly introduced by the fluctuation of the instantaneous input power. A
typical value of
such a bulk capacitor can be around 1500pF/600V.
[0031] The DC-link capacitor typically used in the power electronics
converters
can be either electrolytic or film capacitors. Compared to film capacitors,
the ratio
between capacitance and volume of electrolytic capacitors is much higher.
However the
HV electrolytic capacitor tends to have many disadvantages, such as short
lifetime and
safety issues, when used in power systems in automotive applications.
Accordingly, in
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various applications, film capacitors with low power density are preferred to
be installed
in the electrified vehicles rather than electrolytic capacitors. However,
addition of bulk
film capacitor in power electronics converters may result in large converter
volume and
low power density. These disadvantages may become more stringent for the on-
board
charger which is focused on light weight, small size and low cost.
[0032] The dual-voltage charging system according to the various
embodiments
disclosed herein eliminates the need for a bulk DC-link capacitor in the HV
battery
charger. This may provide the advantages of reduced cost and weight of the
dual-
voltage charging system.
[0033] In the various embodiments disclosed herein, a low voltage (LV)
battery
charger auxiliary power module (APM) is disclosed. The low voltage APM is
proposed
to be used as the active power filter (APF) to reduce the second-order
harmonic current
of the single-phase power factor correction when the high voltage (HV) battery
is
charging. An advantage of this low voltage APM is that the bulk capacitor can
be
removed.
[0034] In the various embodiments disclosed herein, two integration
methods for
the AFAPM are provided. In a half-integrated AFAPM, power switch components
are
shared between the active power filter or the APF and the auxiliary power
module or the
APM. In such embodiments, the dual-voltage charging system can operate as an
APF
to fulfill the active filtering function while no extra power switches, heat
sinks and
corresponding gate drivers may be required. In a full-integrated AFAPM, all
the power
switch components and filter components are shared between the APF and the
APM. In
such embodiments, the dual-voltage charging system can operate as an APF to
fulfil the
active filtering function while no extra power electronic components may be
required.
Such half-integrated and full-integrated AFAPM may provide the advantages of
improved power density of the dual-voltage charging system, as well as reduced
cost
and weight of the dual-voltage charging system.
[0035] In the various embodiments disclosed herein, the HV battery
charger can
either be a single-stage charger, a two-stage charger with non-isolated DC/DC
converter or a two-stage charger with isolated DC/DC converter. In the various
embodiments disclosed herein, the integrated AFAPM is configured to be
isolated or
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non-isolated depending on the HV battery charger structure and customer needs.
In one
example, any APF can be integrated into any APM DC/DC converter to form the
integrated AFAPM.
[0036] Reference is first made to FIG. 1, which illustrates a dual-
voltage charging
system 100 for an electrified vehicle 105 according to an example embodiment.
The
dual-voltage charging system 100 comprises an external power charger 110, a
high
voltage (HV) battery 115, a low voltage (LV) battery 125, a high voltage (HV)
battery
charger 120, a switch 145 and an integrated AFAPM 130.
[0037] The external power charger 110 may be located at any electric
vehicle
charging station and when plugged into the vehicle 105, it charges the HV
battery 115.
The external power charger 110 charges the HV battery 115 through the HV
battery
charger 120. This is referred to herein as the filtering mode 135. In the
illustrated
embodiment, the external power charger 110 is a single-phase AC power source.
In
various other embodiments, the external power charger 110 may be a three-phase
AC
power source.
[0038] As illustrated in FIG. 1, in the filtering mode 135, the
external power
charger 110 is connected to the vehicle 105 at the HV battery charger 120.
During this
mode, switch 145 is turned on and the HV battery 115 starts charging. In the
filtering
mode 135, the integrated active filter auxiliary power module or AFAPM 130 is
configured to be an active power filter or APF to compensate the second-order
harmonics caused during the HV battery charging. As will be discussed in
detail below,
the AFAPM 130 may comprise a small capacitor, among other things, to filter
the high
frequency harmonic current. In some other cases, the AFAPM 130 may comprise a
small inductor to filter the high frequency harmonic current. This may provide
the
advantage of eliminating the bulk capacitor typically found in battery
chargers of
electrified vehicles to filter the second-order harmonic during the charging
of the HV
battery 115.
[0039] When the switch 145 turns off, the external power charger 110
is
disconnected from the vehicle 105 and the dual-voltage charging system 100
enters a
charging mode. This is typically the case when the electrified vehicle 105
starts running
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on the road. During the charging mode 140, the HV battery 115 stops charging,
and
instead starts charging the LV battery 135 through the integrated AFAPM 130.
[0040] Even though the embodiments illustrated herein refer to an
electrified
vehicle, it is noted that the various embodiments disclosed herein can apply
to other
electrical transportation devices, and accordingly can be used in other
applications,
such as electrified ships, airplanes and aerospace applications.
[0041] Reference is next made to FIG. 2A, which illustrates a dual-
voltage
charging system 200 according to another example embodiment. Dual-voltage
charging
system 200 comprises an AC power source 210, a HV battery 215, a LV battery
225, a
HV battery charger 220, a switch 245 and an integrated AFAPM 230.
[0042] During a filtering mode, switch 245 turns on, and the AC power
source
210 charges the HV battery 215 through the HV battery charger 220. This is
illustrated
by power flow 235a. As well in the filtering mode, the integrated AFAPM 230 is
configured to be an APF to compensate the low frequency harmonics caused by
the AC
power source 210. This is illustrated by power flows 235b and 235c.
[0043] In the illustrated embodiment, the HV battery charger 220 is a
single-stage
charger that combines both AC/DC and DC/DC converters in one stage. A single-
stage
charger compared to a double-stage charger, discussed below, may provide an
advantage of compactness to the dual-voltage charging system 200.
[0044] During a charging mode, switch 245 is turned off and the AC power
source 210 is disconnected from the HV battery charger 220. In this mode, the
HV
battery 215 charges the LV battery 225 via the integrated AFAPM 230, as
illustrated by
power flow 240.
[0045] In some embodiments, the HV battery charger, such as the FIV
battery
charger 120 of FIG. 1 and HV battery charger 220 of FIG. 2A, may consist of an
AC/DC
rectifier and a DC/DC boost PFC (power factor correction) converter. In some
other
embodiments, the HV battery charger, such as the HV battery charger 120 of
FIG. 1
and HV battery charger 220 of FIG. 2A, may consist of an AC/DC boost PFC
converter.
In some further embodiments, the HV battery charger, such as the HV battery
charger
120 of FIG. 1 and HV battery charger 220 of FIG. 2A, may consist of an
integrated
AC/DC boost PFC converter and DC/DC converter.
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[0046] In some embodiments, as illustrated in FIG. 1 and FIG. 2A,
only one
instance of HV battery charger is used in a dual-voltage charging system, such
as the
dual-voltage charging system 100 of FIG.1 or the dual-voltage charging system
200 of
FIG. 2A. In some other embodiments, multiple instances of HV battery chargers
may be
used in the dual-voltage charging system to achieve interleaving.
[0047] Reference is next made to FIG. 2B, which illustrates an
integrated AFAPM
230 according to an example embodiment. Integrated AFAPM 230 comprises a
ripple
filter 250, a primary power switch 255, a transformer 260, a secondary power
switch
265 and a LV battery filter 270. In the illustrated embodiment, the ripple
filter 250 and
the primary power switch 255 forms the APF 275, which is configured to filter
the
second-order harmonics during the charging of the HV battery, such as the HV
battery
215. The primary power switch 255, the transformer 260, the secondary power
switch
265 and the LV battery filter 270 forms the APM 280, which is configured to
facilitate the
charging of the LV battery, such as the LV battery 225 by the HV battery, such
as the
HV battery 215. As illustrated, the primary power switch 255 is shared by the
APF 275
and the APM 280. This is referred to herein as a half-integration method.
[0048] In the various embodiments illustrated herein, the ripple
filter 250 may
comprise one or more inductor(s), one or more capacitor(s), or a combination
of both,
and is configured to filter the low order harmonics during the charging of the
HV battery.
[0049] In the various embodiment illustrated herein, the primary power
switch 255
and the secondary power switch 265 may comprise one or more diode(s), one or
more
thyristor(s), one or more BJT(s), one or more MOSFET(s) or one or more
IGBT(s), or a
combination of these with each other or with any other switching device. The
primary
power switch 255 is configured to switch the integrated AFAPM 230, and
accordingly
the dual-voltage charging system, in the filtering mode. The secondary power
switch
265 is configured to switch the integrated AFAPM 230, and accordingly the dual-
voltage
charging system, in the charging mode.
[0050] Furthermore, in the integrated AFAPM 230, any number of
primary power
switches 255 may be used to form one or more DC/AC inverter(s) and one or more
active power filter(s). Similarly, in the integrated AFAPM 230, any number of
secondary
power switches 265 and LV battery filters 270 may be used to form one or more
AC/DC
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rectifier(s). In addition, in the integrated AFAPM 230, a combination of one
or more
DC/AC inverter(s) and AC/DC rectifier(s) may be used to achieve interleaving.
[0051] The transformer 260 is coupled to the primary power switch 255
on its
primary side and the secondary power switch 265 on its secondary side. The
transformer 260 is configured to convert high-voltage low-current second-order
frequency harmonics to low-voltage high-current frequency harmonics. In the
various
embodiments illustrated herein, the transformer 260 may be any transformer of
any
size, shape or configuration.
[0052] Reference is next made to FIG. 3A, which illustrates a dual-
voltage
charging system 300 according to another example embodiment. Dual-voltage
charging
system 300 comprises an AC power source 310, a HV battery 315, a LV battery
325, a
switch 345, an integrated AFAPM 330, an AC/DC PFC boost converter 385 and
DC/DC
converter 390.
[0053] In the embodiment of FIG. 3A, in the filtering mode, switch
345 is tuned on
and the AC power source 310 charges the HV battery 315 through the AC/DC PFC
boost converter 385 and DC/DC converter 390. This is illustrated by power flow
335a.
As well in the filtering mode, the integrated AFAPM 330 is configured to be an
APF to
compensate the low frequency harmonics caused by the AC power source 310. This
is
illustrated by power flows 335b and 335c.
[0054] In the illustrated embodiment, the HV battery 315 is charged by the
AC
power source 310 using a two-stage charger, which includes the AC/DC PFC boost
converter 385 followed by the DC/DC converter 390. A two-stage charger may
provide
the advantages of a high power factor, wide line regulation performance and
clean
charge current, compared to a single-stage charger, such as the single-stage
charger
used in FIG. 2A.
[0055] In some embodiments, the DC/DC converter 390 is a non-isolated
DC/DC
converter. In some other embodiments, the DC/DC converter 390 is an isolated
DC/DC
converter. The non-isolated DC/DC converter may provide the advantages of a
smaller
size, lower cost and higher efficiency of the dual-voltage charging system 300
compared to an isolated DC/DC converter. On the other hand, an isolated DC/DC
CA 02911984 2015-11-13
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converter may provide the advantage of higher safety compared to a non-
isolated
DC/DC converter.
[0056] During a charging mode, switch 345 is turned off and the AC
power
source 310 is disconnected from the HV battery 315. In this mode, the HV
battery 315
charges the LV battery 325 via the DC/DC converter 390 and the integrated
AFAPM
330, as illustrated by power flow 340.
[0057] In the illustrated embodiment, the integrated AFAPM 330 is
positioned
between the AC/DC PFC boost converter 385 and the DC/DC converter 390. As a
result, during the filtering mode, the integrated AFAPM 330 compensates the
second-
order harmonic on the DC-link without any hardware change, and during the
charging
mode, the charging current flows through the DC/DC converter 390 and then
through
the integrated AFAPM 330 acting as an APM to charge the LV battery 325. In the
embodiments where the DC/DC converter 390 is non-isolated, the integrated
AFAPM
330 is isolated. And in the embodiments where the DC/DC converter 390 is
isolated, the
integrated AFAPM 330 can be non-isolated since the isolated DC/DC converter
390
provides enough isolation between the HV battery 315 and the LV battery 325.
[0058] In some embodiments, the AC/DC PFC boost converter 385
consists of an
AC/DC rectifier and a DC/DC boost PFC converter. In some other embodiments,
the
AC/DC PFC boost converter 385 consists of an integrated AC/DC boost PFC
converter.
In some embodiments, the DC/DC converter 390 can be either isolated or non-
isolated.
In various embodiments illustrated herein, the dual-voltage charging system
300 may
comprise one or more AC/DC PFC boost converter(s) 385 and one or more DC/DC
converter(s) 390 to achieve interleaving.
[0059] Reference is next made to FIG. 3B, which illustrates an
integrated AFAPM
330 according to an example embodiment. Integrated AFAPM 330 comprises a
primary
power switch 355, a transformer 360, a secondary power switch 365 and a LV
battery
filter 370. In the illustrated embodiment, the primary power switch 355, the
transformer
360, the secondary power switch 365 and the LV battery filter 370 are shared
by both
the APF 375 and the APM 380. This is referred to herein as a full-integration
method. In
the charging mode, the low frequency harmonics are transformed to the
secondary side
of the integrated AFAPM 330 and the ripple energy is stored in the filter 370.
CA 02911984 2015-11-13
. - 16 -
[0060] In the
various embodiments illustrated herein, the filter 370 may comprise
of one or more inductor(s), one or more capacitor(s), or a combination of
these.
Similarly, in the various embodiments illustrated herein, the transformer 360
may be any
transformer of any size, shape or configuration.
[0061] In the
various embodiment illustrated herein, the primary power switch 355
and the secondary power switch 365 may comprise of one or more diode(s), one
or
more thyristor(s), one or more BJT(s), one or more MOSFET(s) or one or more
IGBT(s),
or a combination of these with each other or with any other material.
[0062]
Furthermore, in the integrated AFAPM 330, any number of primary power
switches 355, any number of secondary power switches 365 and any number of
filters
370 may be used to form one or more DC/AC inverter(s), one or more AC/DC
rectifier(s)
and one or more active filter(s). In addition, in the integrated AFAPM 330, a
combination
of one or more DC/AC inverter(s) and one or more AC/DC rectifier(s) may be
used to
achieve interleaving.
[0063] Reference
is next made to FIG. 4A, which illustrates a dual-voltage
charging system 400 according to another example embodiment. Dual-voltage
charging
system 400 comprises an AC power source 410, a HV battery 415, a LV battery
425, a
first switch 445, an integrated AFAPM 430, an AC/DC PFC boost converter 485, a
DC/DC converter 490, and a second switch 495.
[0064] The
second switch 495 couples the integrated AFAPM 430 between the
first stage and the second stage on one side and to the HV battery 415 on the
other
side. The second switch 495 is operable between a first mode and a second
mode. In
the first mode, the second switch 495 is connected to the first stage and the
second
stage, and the dual-voltage charging system operates in the filtering mode. In
the
second mode, the second switch 495 is disconnected from the first stage and
the
second stage, and connected to the high voltage battery 415, and the dual-
voltage
charging system operates in the charging mode.
[0065] In the
embodiment of FIG. 4A, in the filtering mode, the first switch 445 is
tuned on and the second switch 495 is in the first mode, and the AC power
source 410
charges the HV battery 415 through the AC/DC PFC boost converter 485 and DC/DC
converter 490. This is illustrated by power flow 435a. As well in the
filtering mode, the
CA 02911984 2015-11-13
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=
integrated AFAPM 430 is configured to be an APF to compensate the low
frequency
harmonics caused by the AC power source 410. This is illustrated by power
flows 435b
and 435c.
[0066] During a charging mode, the first switch 445 is turned off
and the second
switch 495 turns to a second mode (i.e. a LV charging mode) for the integrated
AFAPM
430. In this mode, the AC power source 410 is disconnected from the HV battery
415,
and the HV battery 415 charges the LV battery 425 via the integrated AFAPM
430, as
illustrated by power flow 440.
[0067] In the various embodiments illustrated herein, the second
switch 495 may
be a mechanical double pole double throw (DPDT) switch. In some other
embodiments,
other types of switches may be used to switch the integrated AFAPM 430 between
the
filtering mode and the charging mode. In the illustrated embodiment, the
integrated
AFAPM 430 is isolated irrespective of whether the DC/DC converter 490 is
isolated or
non-isolated.
[0068] In some embodiments, the AC/DC PFC boost converter 485 consists of
an
AC/DC rectifier and a DC/DC boost PFC converter. In some other embodiments,
the
AC/DC PFC boost converter 485 consists of an integrated AC/DC boost PFC
converter.
In some embodiments, the DC/DC converter 490 can be either isolated or non-
isolated.
In various embodiments illustrated herein, the dual-voltage charging system
400 may
comprise one or more AC/DC PFC boost converter(s) 485 and one or more DC/DC
converter(s) 490 to achieve interleaving.
[0069] Reference is next made to FIG. 4B, which illustrates an
integrated AFAPM
430 according to an example embodiment. Integrated AFAPM 430 comprises a
ripple
filter 450, a power switch 460 and a LV battery filter 470. In the illustrated
embodiment,
the ripple filter 450 and the power switch 460 forms the APF 475. The power
switch 460
and the LV battery filter 470 forms the APM 480. In the illustrated
embodiment, the
power switch 460 is shared by both the APF 475 and the APM 480.
[0070] In the various embodiments illustrated herein, the ripple
filter 450 may
comprise of one or more inductor(s), one or more capacitor(s), or a
combination of
these. Similarly, in the various embodiments illustrated herein, the power
switch 460
may comprise of one or more diode(s), one or more thyristor(s), one or more
BJT(s),
CA 02911984 2015-11-13
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one or more MOSFET(s) or one or more IGBT(s), or a combination of these with
each
other or with any other material.
[0071] Furthermore, in the integrated AFAPM 430, any number of power
switches
460 and any number of LV battery filters 470 may be used to form one or more
DC/DC
converter(s), and any number of power switches 460 and the ripple filters 450
may be
used to form one or more active filter(s). In addition, in the integrated
AFAPM 430, any
number of power switches 460 may be used to achieve interleaving.
[0072] Reference is next made to FIG. 5A, which illustrates a dual-
voltage
charging system 500 according to another example embodiment. Dual-voltage
charging
system 500 comprises an AC power source 510, a HV battery 515, a LV battery
525, a
first switch 545, an integrated AFAPM 530, an AC/DC PFC boost converter 585, a
DC/DC converter 590, a second switch 505 and a third switch 595.
[0073] In the embodiment of FIG. 5A, in the filtering mode, the first
switch 545
turns on, the second switch turns on and the third switch turns off, and
accordingly the
AC power source 510 charges the HV battery 515 through the AC/DC PFC boost
converter 585 and DC/DC converter 590. This is illustrated by power flow 535a.
As well
in the filtering mode, the integrated AFAPM 530 is configured to be an APF to
compensate the low frequency harmonics caused by the AC power source 510. This
is
illustrated by power flows 535b and 535c.
[0074] During an operation mode, the first switch 545 is turned off, the
second
switch 505 is turned off and the third switch 595 is turned on. In this mode,
the AC
power source 510 is disconnected from the HV battery 515, and the HV battery
515
charges the LV battery 525 via the integrated AFAPM 530, as illustrated by
power flow
540.
[0075] In some embodiments, the AC/DC PFC boost converter 585 consists of
an
AC/DC rectifier and a DC/DC boost PFC converter. In some other embodiments,
the
AC/DC PFC boost converter 585 consists of an integrated AC/DC boost PFC
converter.
In various embodiments illustrated herein, the dual-voltage charging system
500 may
comprise one or more AC/DC PFC boost converter(s) 585 and one or more DC/DC
converter(s) 590 to achieve interleaving.
CA 02911984 2015-11-13
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[0076] Reference is next made to FIG. 5B, which illustrates an
integrated AFAPM
530 according to an example embodiment. Integrated AFAPM 530 comprises a
primary
power switch 555, a transformer 560, a secondary power switch 565 and a filter
570. In
the illustrated embodiment, the secondary power switch 565 and the filter 570
forms the
APF 575. The primary power switch 555, the transformer 560, the secondary
power
switch 565 and the filter 570 forms the APM 580. The secondary power switch
565 and
the filter 570 are shared by the APF 575 and the APM 580.
[0077] In the various embodiments illustrated herein, the filter 570
may comprise
one or more inductor(s), one or more capacitor(s), or a combination of both.
Similarly, in
the various embodiments illustrated herein, the transformer 560 may be any
transformer
of any size, shape or configuration.
[0078] In the various embodiment illustrated herein, the primary
power switch 555
and the secondary power switch 565 may comprise one or more diode(s), one or
more
thyristor(s), one or more BJT(s), one or more MOSFET(s) or one or more
IGBT(s), or a
combination of these with each other or with any other material.
[0079] Furthermore, in the integrated AFAPM 530, any number of
primary power
switches 555 may be used to form one or more DC/AC inverter(s). Similarly, in
the
integrated AFAPM 530, any number of secondary power switches 565 and filters
570
may be used to form one or more AC/DC rectifier(s) and active filter(s). In
addition, in
the integrated AFAPM 530, a combination of one or more DC/AC inverter(s) and
AC/DC
rectifier(s) may be used to achieve interleaving.
[0080] Reference is next made to FIG. 6, which illustrates a non-
isolated
integrated AFAPM 630 according to an example embodiment. The non-isolated
integrated AFAPM 630 comprises a power switch 660 and a filter 670. In the
illustrated
embodiment, the power switch 660 and the filter 670 are shared by the APF 676
and
the APM 680.
[0081] In the various embodiments illustrated herein, the filter 670
may comprise
one or more inductor(s), one or more capacitor(s), or a combination of both.
In the
various embodiment illustrated herein, the power switch 660 may comprise one
or more
diode(s), one or more thyristor(s), one or more BJT(s), one or more MOSFET(s)
or one
or more IGBT(s), or a combination of these with each other or with any other
material.
CA 02911984 2015-11-13
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[0082] In the
integrated AFAPM 630, any number of power switches 660 may be
used to form one or more DC/DC converter(s) and active filter(s). Similarly,
in the
integrated AFAPM 630, one or more DC/DC converter(s) may be used to achieve
interleaving.
[0083]
Reference is next made to FIG. 7, which illustrates a graphical
representation 700 comparing the cost of the components of various filtering
methods
used for mitigating the harmonics on the DC-link according to an example
embodiment.
As illustrated, plot 705 corresponds to the passive filter method for
mitigating the
harmonics on the DC link, plot 710 corresponds to the active filter method for
mitigating
the harmonics on the DC link, and plot 715 corresponds to the primary-
integrated
AFAPM method for mitigating the harmonics on the DC link.
[0084] As
illustrated, the passive filter method is a traditional system that only
uses a DC link capacitor 720 to mitigate the harmonics on the DC-link.
Consequently,
the cost associated with this method is the highest. The active filter method
is a
conventional process that uses additional active filter circuits to mitigate
the harmonics
on the DC-link current. As illustrated, the active filter method uses DC link
capacitors
720, auxiliary capacitors 725, auxiliary inductors 730, power switches 745,
drivers 750
and heat sinks 755. The primary-integrated AFAPM method, as illustrated in the
various
embodiments disclosed herein, uses DC link capacitors 720, auxiliary
capacitors 725,
auxiliary inductors 730 and relays 740. As illustrated, the most cost
efficient method is
the primary-integrated AFAPM.
[0085]
Reference is next made to FIG. 8, which illustrates a topology of an
integrated AFAPM 800 according to an example embodiment. The integrated AFAPM
800 of the illustrated embodiment is formed by a full bridge current doubler
circuit
comprising an inductor Lao. 805, a capacitor Caux 810, a relay G2 815, a first
switch Si
820, a second switch S2825, a third switch S3 830, a fourth switch S4 835, a
fifth switch
S5 840, a sixth switch S6 845, a first inductor 850, a second inductor 850, an
output
capacitor Co 860, an output resistor Ro 865 and a transformer 870. The output
resistor
Ro 865 may be an optional feature.
[0086] In the
illustrated embodiment, the inductor Laux 805, the capacitor Caux 810,
the relay G2 815, the first switch Si 820, the second switch S2825, the third
switch S3
CA 02911984 2015-11-13
,
-21-
830 and the fourth switch S4835 form the primary side of the integrated AFAPM
800,
and the first inductor 850, the second inductor 850, the fifth switch S5 840,
the sixth
switch S6 845, the output capacitor Co 860 and the output resistor Ro 865 form
the
secondary side of the AFAPM 800. The primary side is isolated from the
secondary side
via transformer 870.
[0087] On the primary side, the first switch Si 820 and the second
switch S2825
are connected in series with each other, and the third switch 53 830 and the
fourth
switch S4835 are connected in series with each other. Each of these series
connections
are in parallel to each other, i.e. the series combination of the first switch
Si 820 and the
second switch S2 825 is in parallel with the series combination of the third
switch S3 830
and the fourth switch S4 835. The capacitor Caux 810 is connected with the
point of
connection between the first switch Si 820 and the second switch S2 825 via
the
inductor Laux 805 and the relay G2 815.
[0088] On the secondary side, the first inductor 850 and the second
inductor 850
are connected in series with each other, the fifth switch S5840 and the sixth
switch S6
845 are connected in series with each other, and the series combination of the
first
inductor 850 and the second inductor 850 is connected in parallel to the
series
combination of the fifth switch S5 840 and the sixth switch S6 845. The output
capacitor
Co 860 and the output resistor Ro 865 are connected in parallel to each other,
both of
which are connected in parallel to the first inductor 850 and the fifth switch
S5840.
[0089] In the illustrated embodiment, the inductor Laux 805, the
capacitor Caux
810, and the first switch Si 820 and the second switch S2 825 compose a
bidirectional
buck-boost converter to store the ripple energy. In the illustrated
embodiment, the
inductor La. 805 is used only to transfer the harmonic energy and the
capacitor Caux
810 is used to store the harmonic energy. The relay G2 is turned on when the
HV
battery is charging and turned off when the LV battery is charging. The
integrated APM
800 of FIG. 8 may have the advantage of eliminating additional MOSFET
switches, gate
drivers and heat sinks to achieve active filtering function.
[0090] Reference is next made to FIGS. 9A ¨ 9D, which illustrate the
operation of
the integrated AFAPM 800 of FIG. 8 in different modes. FIG. 9A illustrates a
circuit
diagram 900A corresponding to the operation of the integrated AFAPM 800 of
FIG. 8 in
CA 02911984 2015-11-13
- 22 -
=
a buck mode with inductor current rising. FIG. 9B illustrates a circuit
diagram 900B
corresponding to the operation of the integrated AFAPM 800 of FIG. 8 in a buck
mode
with inductor current falling. FIG. 9C illustrates a circuit diagram 900C
corresponding to
the operation of the integrated AFAPM 800 of FIG. 8 in a boost mode with
inductor
current rising. FIG. 9D illustrates a circuit diagram 900D corresponding to
the operation
of the integrated AFAPM 800 of FIG. 8 in the boost mode with inductor current
falling. In
the embodiments of FIGS. 9A ¨ 9D, the respective circuit diagrams 900A ¨ 900D
comprise an inductor Laux 905, a capacitor Caux 910, a relay G2 915, a first
switch S1
920, a second switch S2 925, a third switch S3 930 and a fourth switch S4 935,
which
correspond to and are arranged analogously to the inductor Lux 805, the
capacitor Caux
810, the relay G2 815, the first switch Si 820, the second switch S2825, the
third switch
S3830 and the fourth switch S4835 of the integrated AFAPM 800 of FIG. 8.
[0091] Reference is again made to FIG. 9A, which illustrates the
circuit diagram
900A of an integrated AFAPM in a buck mode with an increasing inductor
current. In
this mode, the vehicle is at a charging station and the HV battery is
charging. The relay
G2 915 is turned on in this mode. Once the second harmonic current ripple is
higher
than the DC component current, the integrated AFAPM assimilates harmonic
current
and turns the first switch Si 920 on. In this mode, the harmonic current
charges both the
inductor Laux 905 and the capacitor Caux 910. The inductor current rising rate
can be
calculated using equation 1.
oc ¨ _______________________________________________________________________
(1)
L.
[0092] Reference is again made to FIG. 9B, which illustrates the
circuit diagram
900B of an integrated AFAPM in a buck mode with a falling inductor current. In
this
mode, the first switch Si 920 is turned off, and the inductor Laux 905
transfers its energy
to capacitor Caux 910 through the second switch S2 925. In this mode, the
inductor
current falling rate can be calculated using equation 2.
cc2= aux
(2)
[0093] Reference is again made to FIG. 9C, which illustrates the
circuit diagram
900C of an integrated AFAPM in a boost mode with an increasing inductor
current. In
this mode, when the second-order harmonic current ripple is lower than the DC
CA 02911984 2015-11-13
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component current, the integrated AFAPM releases energy back to the DC-link.
In this
mode, the second switch S2 925 is used to control the circuit in boost mode.
During the
turn-on interval of the second switch S2 925, the inductor Laux 905 is charged
by the
capacitor Caux 910. In this mode, the inductor current rising rate can be
calculated using
equation 3.
a v.
Pi
(3)
[0094]
Reference is again made to FIG. 9D, which illustrates the circuit diagram
900D of an integrated AFAPM in a boost mode with a falling inductor current.
In this
mode, the second switch S2 925 is turned off, and both the inductor Lau, 905
and the
capacitor C. 910 are discharged and release the energy back to the DC-link
through
the first switch Si 920. In this mode, the inductor current falling rate can
be calculated
using equation 4.
p2 IC= ¨Vitc (4)
[0095]
Reference is made to FIG. 10A, which illustrates a graph 1000 of an
integrated AFAPM, such as the integrated AFAPM 800 of FIG. 8, working as an
APF
according to an example embodiment. Graph 1000 illustrates a plot 1005
corresponding
to the voltage Vdc measured on the primary side of the integrated AFAPM, and
plot 1010
corresponding to voltage Vaux measured across capacitor Caux, such as
capacitor Caux
810 of FIG. 8 or 910 of FIGS. 9A ¨ 9D. Graph 1000 further illustrates plot
1015
corresponding to the switching cycle of a first switch Si, such as the first
switch Si 820
of FIG. 8 or first switch Si 920 of FIGS. 9A ¨ 9D, plot 1020 corresponding to
the
switching cycle of a second switch S2, such as the second switch S2 825 of
FIG. 8 or
second switch S2 925 of FIGS. 9A ¨ 9D, plot 1025 corresponding to the
switching cycle
of a third switch S3, such as the third switch S3 830 of FIG. 8 or third
switch S3 930 of
FIGS. 9A ¨ 9D, and plot 1030 corresponding to the switching cycle of a fourth
switch Sa,
such as the fourth switch S4 835 of FIG. 8 or fourth switch S4 935 of FIGS. 9A
¨ 9D.
[0096]
As illustrated in the graph 1000, at time before 0.2 s, the integrated
AFAPM is operating in an active filtering mode as illustrated in plot 1005,
and the first
switch Si and the second switch S2 are working with corresponding duty cycles
as
CA 02911984 2015-11-13
- 24 -
illustrated in plots 1015 and 1020 respectively. In this mode, the second-
order harmonic
energy is stored in the capacitor Caux. Under this condition, the dc bus
voltage Vdc is
equal to 400V with relatively small ripple. After 0.2s, all of the four
switches are turned
off as illustrated in plots 1015, 1020, 1025 and 1030. As illustrated in plot
1005, a large
second-order harmonics is observed on the DC-link Vdc=
[0097] Reference is made to FIG. 10B, which illustrates a graph 1050
of an
integrated AFAPM, such as the integrated AFAPM 800 of FIG. 8, working as an
APF
according to another example embodiment. Graph 1050 comprises a plot 1055
corresponding to voltage Vaux measured across capacitor Caõ, such as capacitor
Caux
810 of FIG. 8 or 910 of FIGS. 9A ¨ 9D, and plot 1060 corresponding to current
laux
measured through the capacitor Caux.
[0098] As illustrated in plot 1055, over the duration of time when
the integrated
AFAPM is operating in a charging buck mode, i.e. between a first time 1065 and
a
second time 1070, the current la" is positive, and over the duration of time
when the
integrated AFAPM is operating in a discharging boost mode, i.e. between the
second
time 1070 and a third time 1075, the current laux is negative.
[0099] Reference is made to FIG. 11, which illustrates a graph 1100
of an
integrated AFAPM, such as the integrated AFAPM 800 of FIG. 8, working as a LV
battery charger. Graph 1100 comprises a plot 1105 corresponding to output
voltage VLO
of a LV battery, plot 1110 corresponding to current lin through the LV
battery, plot 1115
corresponding to the switching cycle of a first switch S1, such as the first
switch S1 820
of FIG. 8 or first switch S1 920 of FIGS. 9A ¨ 9D, plot 1120 corresponding to
the
switching cycle of a second switch S2, such as the second switch S2 825 of
FIG. 8 or
second switch S2 925 of FIGS. 9A ¨ 9D, plot 1125 corresponding to the
switching cycle
of a third switch S3, such as the third switch S3 830 of FIG. 8 or third
switch S3 930 of
FIGS. 9A ¨ 9D, and plot 1130 corresponding to the switching cycle of a fourth
switch Sa,
such as the fourth switch S4 835 of FIG. 8 or fourth switch S4 935 of FIGS. 9A
¨ 9D. As
illustrated, all the four switches are operating as a general phase-shift full
bridge
converter and the output voltage VL0 of the LV battery is 12 V.
[00100] Reference is next made to FIGS. 12A and 12B, which illustrate
graphical
representations of an integrated AFAPM in a LV battery charging mode and an
active
CA 02911984 2015-11-13
- 25 -
filtering mode, respectively, based on a proof-of-concept prototype of a 1.2KW
integrated AFAPM.
[00101] Reference is now made to FIG. 12A, which illustrates a graph
1200 of an
integrated AFAPM acting in a LV battery charging mode according to an example
embodiment. In this embodiment, the maximum output power of the LV battery is
selected to be 12V/100A. Graph 1200 comprises a plot 1205 corresponding to a
transformer voltage of a transformer isolating the primary side of the
integrated AFAPM
from the secondary side, such as the transformer 870 of FIG. 8, plot 1210
corresponding to input voltage Vdc on the primary side of the integrated
AFAPM, plot
1215 corresponding to output current ILO through the LV battery, and plot 1220
corresponding to output voltage VLO across the LV battery.
[00102] Reference is made to FIG. 12B, which illustrates a graph 1250
of
simulation of an integrated AFAPM acting in an active filtering mode according
to an
example embodiment. In this embodiment, the active filter design part is based
on a
380W (380V/1A) power factor correction (PFC) boost converter. Graph 1250
comprises
a plot 1255 corresponding to voltage Vaux measured across capacitor Caux, such
as
capacitor Caux 810 of FIG. 8, plot 1260 corresponding to input voltage Vdc on
the primary
side of the integrated AFAPM, plot 1265 corresponding to HV battery charging
current
before the active filter, and plot 1270 corresponding to HV battery charging
current after
the active filter that charges the HV battery. As illustrated, in the active
filtering mode,
the second-order wave harmonics current in plot 1265 is assimilated by the
APE,
leaving the HV battery charging current of plot 1270 with DC component only.
[00103] The above-described embodiments and applications of the
present
invention are intended only to be examples. Alterations, modifications and
variations
may be effected to the particular embodiments by those of ordinary skill in
the art, in
light of this teaching, without departing from the spirit of or exceeding the
scope of the
claimed invention.
