Title of Invention	SINGLE-PHASE PHASE LOCKED LOOP SUITABLE FOR USE IN A HYBRID VEHICLE CHARGING SYSTEM AND METHOD FOR CHARGING A HYBRID VEHICLE FROM A SINGLE-PHASE POWER SOURCE
Abstract	Apparatus for charging an electric vehicle or a hybrid vehicle are provided. Particularly, apparatus for charging a hybrid vehicle from a single-phase standard (110 volt, single-phase, 60 Hz in the U.S.) are provided. In one implementation, a single-phase phase locked loop (PLL) receives a single-phase power gird voltage and delays it by one-quarter cycle to create an orthogonal imaginary second power signal. These signals are then applied to a transform matrix within a PLL to phase lock an output signal to the incoming power grid voltage.

Title of Invention

SINGLE-PHASE PHASE LOCKED LOOP SUITABLE FOR USE IN A HYBRID VEHICLE CHARGING SYSTEM AND METHOD FOR CHARGING A HYBRID VEHICLE FROM A SINGLE-PHASE POWER SOURCE

Abstract

Apparatus for charging an electric vehicle or a hybrid vehicle are provided. Particularly, apparatus for charging a hybrid vehicle from a single-phase standard (110 volt, single-phase, 60 Hz in the U.S.) are provided. In one implementation, a single-phase phase locked loop (PLL) receives a single-phase power gird voltage and delays it by one-quarter cycle to create an orthogonal imaginary second power signal. These signals are then applied to a transform matrix within a PLL to phase lock an output signal to the incoming power grid voltage.

Full Text	SINGLE-PHASE PHASE LOCKED LOOP SUITABLE FOR USE IN A HYBRID VEHICLE CHARGING SYSTEM AND METHOD FOR CHARGING A HYBRID VEHICLE FROM A SINGLE-PHASE POWER SOURCE TECHNICAL FIELD [0001] The present invention generally relates to electric and hybrid vehicles and more particularly relates to charging systems for electric and hybrid vehicles and more specifically relates to a single-phase phase locked loop suitable for use in an electric or hybrid vehicle charging system. BACKGROUND OF THE INVENTION [0002] Contemporary commercially available hybrid vehicles are generally of the dual-mode type having a liquid fueled (gas) powered engine that drives a generator for charging a battery array. The battery array powers one or more electric motors that propel the vehicle using direct current (DC) power alone or in cooperation with the gas engine. [0003] A potential alternate or supplemental charging source for the battery array of a hybrid vehicle is to "plug in" the vehicle to a public or private utility company power grid. This can be done in a driveway, a garage or in a public parking structure. However, to properly charge the battery array, the charging power waveform must be phase locked to the incoming power grid voltage. This can be done for commercial 3-phase (or multi-phase) power signals, however, most home power arrangements do not have 3-phase power systems available and most home owners will not undergo the expense to install them just to charge a hybrid vehicle. [0004] Accordingly, it is desirable to provide a single-phase charging arrangement for a hybrid vehicle so that a hybrid vehicle can be charged from a home line current. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background. SUMMARY OF THE INVENTION [0005] In one embodiment, a charging system for a hybrid vehicle includes a single-phase phase locked loop (PLL) coupled to a standard (110 volt, 60 Hz in the United States) power grid voltage. The incoming phase voltage is delayed one quarter cycle to create an imaginary phase, which is orthogonal to the power grid voltage and considered as a second phase signal for the PLL. By applying a transform matrix (discussed below), the present invention is able to phase lock to a single-phase power grid voltage and efficiently and safely charge a hybrid vehicle. DESCRIPTION OF THE DRAWINGS [0006] The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and [0007] FIG. 1A illustrates a hybrid vehicle having a single-phase power grid charging system according to one exemplary implementation of the present invention; [0008] FIG. 1B illustrates the chassis of the hybrid vehicle of FIG 1A, include the major drive train components thereof; [0009] FIG. 2 illustrates a block diagram of a single-phase phase locked loop (PLL) system according to one exemplary implementation of the present invention; [0010] FIG. 3A and FIG. 3B illustrate a preferred transformation matrix of FIG. 2. [0011] FIG. 4 illustrates a charging system suitable for use in a hybrid vehicle and employing the PLL of FIG. 2; [0012] FIG. 5 is an illustration of power grid frequency variation standards for the United States; [0013] FIG. 6A and 6B illustrate the phase tracking ability of the PLL of FIG. 2 according to one exemplary implementation of the present invention; and [0014] FIG. 7 illustrates the linearity of phase tracking across a wide range of frequency variations according to an exemplary implementation of the present invention. DESCRIPTION OF AN EXEMPLARY EMBODIMENT [0015] As used herein, the word "exemplary" means "serving as an example, instance, or illustration." The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. All of the embodiments described in this Detailed Description are exemplary embodiments provided to enable persons skilled in the art to make or use the invention and not to limit the scope of the invention which is defined by the claims. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. [0016] Referring now to FIG. 1A, a hybrid vehicle 2 is shown which employs the single-phase phase locked loop (PLL) charging system of the present invention. According to the present invention, the hybrid vehicle 2 can have an internal battery array charged by being electrically coupled via a cable 4 to a public or private utility power grid (not shown). In this way, the present invention affords the advantage of being able to charge the battery array of the hybrid vehicle without operating the vehicle or consuming fuel (gas). [0017] In this regard, any of the concepts disclosed here can be applied generally to "vehicles," and as used herein, the term "vehicle" broadly refers to a non-living transport mechanism. Examples of such vehicles include automobiles such as buses, cars, trucks, sport utility vehicles, vans, vehicles that do not travel on land such as mechanical water vehicles including watercraft, hovercraft, boats and ships, and mechanical rail vehicles such as trains, trams and trolleys, etc. In addition, the term "gas engine" is not limited by any specific propulsion technology such as gasoline or diesel fuel. Rather, gas engine also include hydrogen vehicles, ethanol vehicles and vehicles which operate using various other alternative fuels. [0018] Referring now to FIG. 1B, a chassis 6 of the hybrid vehicle 2 is shown along with major drive train components. Generally, contemporary hybrid vehicles have a battery array 8 (typically a 300 volt battery array for a standard sized automobile) and a gas engine 10. Alternately, the present invention could be used with an entirely direct current (DC) propulsion system (i.e., a vehicle without a gas engine). For electric (DC) power, an electric motor 9 (more than one can be used) provides front-wheel drive propulsion for the hybrid vehicle 2. In on embodiment, the electric motor 9 is powered by alternating current (AC) generated by a switching circuit as is known in the art. Alternately, the electric motor 9 can be a DC motor powered directly from the battery array 8. [0019] In one embodiment, the gas engine 10 drives a generator 12, which can recharge the battery array 8 when required while the vehicle is operating. A dual-mode transmission 14 allows the gas engine to provide rear-wheel propulsion via a drive shaft 16 and a differential 18. As discussed in conjunction with FIG. 1A, battery array 8 charging circuitry 20 is coupled to a power grid voltage via cable 4. Thus, the present invention affords the opportunity for the hybrid vehicle 2 to be charged from a standard (single- phase, 110 volts, 60 Hz in the U.S.) power grid voltage available generally in homes and businesses. [0020] Referring now to FIG. 2, the single-phase phased locked loop (PLL) 22 in accordance with one embodiment of the present invention is shown in block diagram form. The single-phase power grid voltage 24 (Va) is delayed (26) preferably by one-quarter cycle and the phase delayed signal 28 (Vb) is applied to a transform matrix 30. The phase delayed signal 28 is orthogonal to the power grid voltage 24 and can be used as an imaginary second phase signal for phase locking purposes as will be explained below. The transform matrix 30 produces Vd 32 and Vq 34 and Vq is multiplied by a gain factor (1/Vm) where: [0023] Referring now to FIG. 3A and FIG. 3B, an illustration of how the transformation matrix 30 modifies Va and Vb to create Vd and Vq in accordance with one embodiment of the present invention. As can be seen, Vd (/d) is phase shifted (9 31) from Va (/a) and Vq (/q) is phase shifted from Vb (fb) as follows: [0027] Equation 5 demonstrates that the phase difference can be reduced to zero by using the transform matrix 30 along with phase lock elements 32, loop filter 34 and integrator (1/S) 36 such that an output signal 38 can be phased locked to the power grid voltage 24. [0028] Referring now to FIG. 4, a charging control system 40 is shown in block diagram form. The charging control system 40 includes the single- phase PLL 22 of FIG. 2 and operates to afford the present invention an alternative or supplemental charging ability for the battery array 8 of the hybrid vehicle 2. As shown in FIG. 4, a DC power source 42 (which in one embodiment can be the battery array 8 of FIB. 1B) is coupled by an H-Bridge circuit 44 to a public or private utility company 46 that provides a single-phase power grid voltage 24 to the PLL 22. As shown in conjunction with FIG. 2, the PLL 22 provides a phase locked output signal 38 to the charging controller 48 that monitors and charges the battery array 8. [0029] Referring now to FIG. 5, there is shown an illustration of the nominal frequency of utility power available in the United States. As can be seen, the nominal frequency resides in the range of 59.95 Hz to 60.05 Hz with the normal frequency deviation (50) residing between 59.99 Hz to 60.01 Hz. Phase error in the incoming power grid voltage can damage equipment or cause equipment malfunctions. Accordingly, phase error in the power grid is tightly regulated. Accordingly the normal frequency deviation 50 sets a minimum operating performance specification for any charging system for a hybrid vehicle that intends to offer battery array charging from a standard home (single-phase) grid voltage. [0030] Referring now to FIG. 6A and FIG. 6B, the phase tracking operation of the present invention can be seen. FIG. 6A represents the ideal case of zero degrees of phase difference (51) between the incoming power grid voltage 24 and the output phase locked signal (38). After a quarter cycle time delay 52, the phase locked loop tracking waveform 38 demonstrates that the PLL 22 has achieved phase lock with the incoming power grid voltage as can be seen at all of the zero-crossings 56. As another example, FIG. 6B illustrates a power grid voltage arriving thirty degrees out of phase (58), however, after the same quarter cycle delay 52, the PLL 22 of the present invention has achieved phase lock with the incoming power grid voltage as can be seen from the zero-crossings 56. However, it will be understood by those skilled in the art that the PLL 22 of the present invention can acquire phase lock across any phase shift of the incoming power grid signal within a quarter cycle of the incoming waveform. [0031] While rapid phase locking performance is provided by the present invention, the PLL 22 of the present invention must be able to maintain a phase lock over a wide range of incoming power grid voltage phase error (as discussed above in reference to FIG. 5). Referring now to FIG. 7, the phase lock performance of the present invention over a wide range of incoming power grid phase error can be seen. The present invention provides reliable phase lock performance from 58 Hz to 62 Hz; well beyond the nominal frequency deviation discussed in conjunction with FIG. 5. More particularly, as can be seen (60) around the normal deviation, the present invention reliably achieves phase lock after only one-quarter cycle given the normal incoming power grid voltage phase error to be able to charge an electric vehicle or a hybrid vehicle from a standard single-phase power grid voltage. Accordingly, the present invention affords the opportunity to recharge the battery array of an electric vehicle or a hybrid vehicle from a standard single-phase power grid voltage without operating the vehicle or consuming fuel. [0032] Some of the embodiments and implementations are described above in terms of functional and/or logical block components and various processing steps. However, it should be appreciated that such block components may be realized by any number of hardware, software, and/or firmware components configured to perform the specified functions. For example, an embodiment of a system or a component may employ various integrated circuit components, e.g., memory elements, digital signal processing elements, logic elements, look-up tables, or the like, which may carry out a variety of functions under the control of one or more microprocessors or other control devices. In addition, those skilled in the art will appreciate that embodiments described herein are merely exemplary implementations. [0033] In this document, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Furthermore, depending on the context, words such as "connect" or "coupled to" used in describing a relationship between different elements do not imply that a direct physical connection must be made between these elements. For example, two elements may be connected to each other physically, electronically, logically, or in any other manner, through one or more additional elements. While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the invention as set forth in the appended claims and the legal equivalents thereof. CLAIMS What is claimed is: 1. A hybrid vehicle, comprising: a gas engine; a battery array powering a electric motor to propel the hybrid vehicle in a first mode; 5 a generator, driven by the gas engine, for recharging the battery array; and a charging control circuit coupled to a single phase power grid voltage for recharging the battery array from a charging signal phase locked to the single phase power grid voltage, the charging 10 control circuit including a phase locked loop for receiving the single phase power grid voltage and generating a delayed signal therefrom, each of the power control voltage and the delayed signal being processed by the phase locked loop circuit to provide the charging signal for recharging the battery array. 2. The hybrid vehicle of claim 1, wherein the delayed signal is delayed by one-quarter cycle from the single phase power grid voltage. 3. The hybrid vehicle of claim 1, wherein the delayed signal is orthogonal to the single phase power grid voltage. 4. The hybrid vehicle of claim 1, wherein the electric motor is an alternating current motor. 5. The hybrid vehicle of claim 1, wherein the electric motor is a direct current motor. 6. A method of charging a battery array in an electrically propelled vehicle, comprising the steps of: receiving a single phase power grid voltage; delaying the single phase power grid voltage to provide a delayed 5 signal; processing the single phase power grid voltage and the delayed signal in a phase locked loop to provide a charging signal phase locked to the single phase power grid voltage; and utilizing the charging signal to recharge a battery array of the 10 electrically powered vehicle. 7. The method of claim 6, wherein the delayed signal is delayed by one-quarter cycle. 8. The method of claim 6 which includes the step of generating a second charging signal from a generator powered by a gas engine for charging the battery array while the electrically propelled vehicle is in motion. 9. A phase locked loop suitable for use in a vehicle at least partially propelled by a battery array, comprising: a delay circuit providing a delayed signal representing a delayed version of a single phase power grid voltage to a transformation matrix of a 5 phase locked loop circuit; and the transformation matrix receiving the delayed signal and the single phase power control voltage and processing each signal to provide a charging signal phase locked to the single phase power grid voltage; wherein, the charging signal can be used to recharge the battery array 10 while the vehicle is not in motion. 10. The phase locked loop of claim 9, wherein the delaying circuit delays the single phase power grid voltage by one-quarter cycle. 11. A vehicle powered by at least an electric motor, comprising: a charging control circuit coupled to a single phase power grid voltage for recharging a battery array from a phase locked signal, the charging control circuit including a phase locked loop for receiving the single phase power grid voltage and generating a delayed signal therefrom, each of the single phase power grid voltage and the delayed signal being processed by the phase locked loop to provide the phase locked signal for recharging the battery array. 12. The vehicle of claim 11, including: a gas engine and a generator for charging the battery array while the vehicle is in operation. 13. The vehicle of claim 11, wherein the electric motor is an alternating current motor. 14. The vehicle of claim 11, wherein the electric motor is a direct current motor. 15. The vehicle of claim 11, wherein the delayed signal is delayed from the single phase power grid voltage by one-quarter cycle. Apparatus for charging an electric vehicle or a hybrid vehicle are provided. Particularly, apparatus for charging a hybrid vehicle from a single-phase standard (110 volt, single-phase, 60 Hz in the U.S.) are provided. In one implementation, a single-phase phase locked loop (PLL) receives a single-phase power gird voltage and delays it by one-quarter cycle to create an orthogonal imaginary second power signal. These signals are then applied to a transform matrix within a PLL to phase lock an output signal to the incoming power grid voltage.

Full Text

SINGLE-PHASE PHASE LOCKED LOOP SUITABLE FOR USE IN A
HYBRID VEHICLE CHARGING SYSTEM AND METHOD FOR
CHARGING A HYBRID VEHICLE FROM A SINGLE-PHASE POWER
SOURCE
TECHNICAL FIELD
[0001] The present invention generally relates to electric and hybrid
vehicles and more particularly relates to charging systems for electric and
hybrid vehicles and more specifically relates to a single-phase phase locked
loop suitable for use in an electric or hybrid vehicle charging system.
BACKGROUND OF THE INVENTION
[0002] Contemporary commercially available hybrid vehicles are
generally of the dual-mode type having a liquid fueled (gas) powered engine
that drives a generator for charging a battery array. The battery array powers
one or more electric motors that propel the vehicle using direct current (DC)
power alone or in cooperation with the gas engine.
[0003] A potential alternate or supplemental charging source for the
battery array of a hybrid vehicle is to "plug in" the vehicle to a public or
private utility company power grid. This can be done in a driveway, a garage
or in a public parking structure. However, to properly charge the battery
array, the charging power waveform must be phase locked to the incoming
power grid voltage. This can be done for commercial 3-phase (or multi-phase)
power signals, however, most home power arrangements do not have 3-phase
power systems available and most home owners will not undergo the expense
to install them just to charge a hybrid vehicle.
[0004] Accordingly, it is desirable to provide a single-phase charging
arrangement for a hybrid vehicle so that a hybrid vehicle can be charged from
a home line current. Furthermore, other desirable features and characteristics

of the present invention will become apparent from the subsequent detailed
description and the appended claims, taken in conjunction with the
accompanying drawings and the foregoing technical field and background.
SUMMARY OF THE INVENTION
[0005] In one embodiment, a charging system for a hybrid vehicle
includes a single-phase phase locked loop (PLL) coupled to a standard (110
volt, 60 Hz in the United States) power grid voltage. The incoming phase
voltage is delayed one quarter cycle to create an imaginary phase, which is
orthogonal to the power grid voltage and considered as a second phase signal
for the PLL. By applying a transform matrix (discussed below), the present
invention is able to phase lock to a single-phase power grid voltage and
efficiently and safely charge a hybrid vehicle.
DESCRIPTION OF THE DRAWINGS
[0006] The present invention will hereinafter be described in conjunction
with the following drawing figures, wherein like numerals denote like
elements, and
[0007] FIG. 1A illustrates a hybrid vehicle having a single-phase power
grid charging system according to one exemplary implementation of the
present invention;
[0008] FIG. 1B illustrates the chassis of the hybrid vehicle of FIG 1A,
include the major drive train components thereof;
[0009] FIG. 2 illustrates a block diagram of a single-phase phase locked
loop (PLL) system according to one exemplary implementation of the present
invention;
[0010] FIG. 3A and FIG. 3B illustrate a preferred transformation matrix of
FIG. 2.
[0011] FIG. 4 illustrates a charging system suitable for use in a hybrid
vehicle and employing the PLL of FIG. 2;

[0012] FIG. 5 is an illustration of power grid frequency variation standards
for the United States;
[0013] FIG. 6A and 6B illustrate the phase tracking ability of the PLL of
FIG. 2 according to one exemplary implementation of the present invention;
and
[0014] FIG. 7 illustrates the linearity of phase tracking across a wide
range of frequency variations according to an exemplary implementation of
the present invention.
DESCRIPTION OF AN EXEMPLARY EMBODIMENT
[0015] As used herein, the word "exemplary" means "serving as an
example, instance, or illustration." The following detailed description is
merely exemplary in nature and is not intended to limit the invention or the
application and uses of the invention. Any embodiment described herein as
"exemplary" is not necessarily to be construed as preferred or advantageous
over other embodiments. All of the embodiments described in this Detailed
Description are exemplary embodiments provided to enable persons skilled in
the art to make or use the invention and not to limit the scope of the invention
which is defined by the claims. Furthermore, there is no intention to be bound
by any expressed or implied theory presented in the preceding technical field,
background, brief summary or the following detailed description.
[0016] Referring now to FIG. 1A, a hybrid vehicle 2 is shown which
employs the single-phase phase locked loop (PLL) charging system of the
present invention. According to the present invention, the hybrid vehicle 2
can have an internal battery array charged by being electrically coupled via a
cable 4 to a public or private utility power grid (not shown). In this way, the
present invention affords the advantage of being able to charge the battery
array of the hybrid vehicle without operating the vehicle or consuming fuel
(gas).
[0017] In this regard, any of the concepts disclosed here can be applied
generally to "vehicles," and as used herein, the term "vehicle" broadly refers

to a non-living transport mechanism. Examples of such vehicles include
automobiles such as buses, cars, trucks, sport utility vehicles, vans, vehicles
that do not travel on land such as mechanical water vehicles including
watercraft, hovercraft, boats and ships, and mechanical rail vehicles such as
trains, trams and trolleys, etc. In addition, the term "gas engine" is not limited
by any specific propulsion technology such as gasoline or diesel fuel. Rather,
gas engine also include hydrogen vehicles, ethanol vehicles and vehicles
which operate using various other alternative fuels.
[0018] Referring now to FIG. 1B, a chassis 6 of the hybrid vehicle 2 is
shown along with major drive train components. Generally, contemporary
hybrid vehicles have a battery array 8 (typically a 300 volt battery array for a
standard sized automobile) and a gas engine 10. Alternately, the present
invention could be used with an entirely direct current (DC) propulsion system
(i.e., a vehicle without a gas engine). For electric (DC) power, an electric
motor 9 (more than one can be used) provides front-wheel drive propulsion for
the hybrid vehicle 2. In on embodiment, the electric motor 9 is powered by
alternating current (AC) generated by a switching circuit as is known in the
art. Alternately, the electric motor 9 can be a DC motor powered directly from
the battery array 8.
[0019] In one embodiment, the gas engine 10 drives a generator 12, which
can recharge the battery array 8 when required while the vehicle is operating.
A dual-mode transmission 14 allows the gas engine to provide rear-wheel
propulsion via a drive shaft 16 and a differential 18. As discussed in
conjunction with FIG. 1A, battery array 8 charging circuitry 20 is coupled to a
power grid voltage via cable 4. Thus, the present invention affords the
opportunity for the hybrid vehicle 2 to be charged from a standard (single-
phase, 110 volts, 60 Hz in the U.S.) power grid voltage available generally in
homes and businesses.
[0020] Referring now to FIG. 2, the single-phase phased locked loop
(PLL) 22 in accordance with one embodiment of the present invention is
shown in block diagram form. The single-phase power grid voltage 24 (Va) is

delayed (26) preferably by one-quarter cycle and the phase delayed signal 28
(Vb) is applied to a transform matrix 30. The phase delayed signal 28 is
orthogonal to the power grid voltage 24 and can be used as an imaginary
second phase signal for phase locking purposes as will be explained below.
The transform matrix 30 produces Vd 32 and Vq 34 and Vq is multiplied by a
gain factor (1/Vm) where:

[0023] Referring now to FIG. 3A and FIG. 3B, an illustration of how the
transformation matrix 30 modifies Va and Vb to create Vd and Vq in
accordance with one embodiment of the present invention. As can be seen,
Vd (/d) is phase shifted (9 31) from Va (/a) and Vq (/q) is phase shifted from
Vb (fb) as follows:

[0027] Equation 5 demonstrates that the phase difference can be reduced
to zero by using the transform matrix 30 along with phase lock elements 32,
loop filter 34 and integrator (1/S) 36 such that an output signal 38 can be
phased locked to the power grid voltage 24.
[0028] Referring now to FIG. 4, a charging control system 40 is shown in
block diagram form. The charging control system 40 includes the single-
phase PLL 22 of FIG. 2 and operates to afford the present invention an
alternative or supplemental charging ability for the battery array 8 of the
hybrid vehicle 2. As shown in FIG. 4, a DC power source 42 (which in one
embodiment can be the battery array 8 of FIB. 1B) is coupled by an H-Bridge

circuit 44 to a public or private utility company 46 that provides a single-phase
power grid voltage 24 to the PLL 22. As shown in conjunction with FIG. 2,
the PLL 22 provides a phase locked output signal 38 to the charging controller
48 that monitors and charges the battery array 8.
[0029] Referring now to FIG. 5, there is shown an illustration of the
nominal frequency of utility power available in the United States. As can be
seen, the nominal frequency resides in the range of 59.95 Hz to 60.05 Hz with
the normal frequency deviation (50) residing between 59.99 Hz to 60.01 Hz.
Phase error in the incoming power grid voltage can damage equipment or
cause equipment malfunctions. Accordingly, phase error in the power grid is
tightly regulated. Accordingly the normal frequency deviation 50 sets a
minimum operating performance specification for any charging system for a
hybrid vehicle that intends to offer battery array charging from a standard
home (single-phase) grid voltage.
[0030] Referring now to FIG. 6A and FIG. 6B, the phase tracking
operation of the present invention can be seen. FIG. 6A represents the ideal
case of zero degrees of phase difference (51) between the incoming power grid
voltage 24 and the output phase locked signal (38). After a quarter cycle time
delay 52, the phase locked loop tracking waveform 38 demonstrates that the
PLL 22 has achieved phase lock with the incoming power grid voltage as can
be seen at all of the zero-crossings 56. As another example, FIG. 6B
illustrates a power grid voltage arriving thirty degrees out of phase (58),
however, after the same quarter cycle delay 52, the PLL 22 of the present
invention has achieved phase lock with the incoming power grid voltage as
can be seen from the zero-crossings 56. However, it will be understood by
those skilled in the art that the PLL 22 of the present invention can acquire
phase lock across any phase shift of the incoming power grid signal within a
quarter cycle of the incoming waveform.
[0031] While rapid phase locking performance is provided by the present
invention, the PLL 22 of the present invention must be able to maintain a
phase lock over a wide range of incoming power grid voltage phase error (as

discussed above in reference to FIG. 5). Referring now to FIG. 7, the phase
lock performance of the present invention over a wide range of incoming
power grid phase error can be seen. The present invention provides reliable
phase lock performance from 58 Hz to 62 Hz; well beyond the nominal
frequency deviation discussed in conjunction with FIG. 5. More particularly,
as can be seen (60) around the normal deviation, the present invention reliably
achieves phase lock after only one-quarter cycle given the normal incoming
power grid voltage phase error to be able to charge an electric vehicle or a
hybrid vehicle from a standard single-phase power grid voltage. Accordingly,
the present invention affords the opportunity to recharge the battery array of
an electric vehicle or a hybrid vehicle from a standard single-phase power grid
voltage without operating the vehicle or consuming fuel.
[0032] Some of the embodiments and implementations are described
above in terms of functional and/or logical block components and various
processing steps. However, it should be appreciated that such block
components may be realized by any number of hardware, software, and/or
firmware components configured to perform the specified functions. For
example, an embodiment of a system or a component may employ various
integrated circuit components, e.g., memory elements, digital signal
processing elements, logic elements, look-up tables, or the like, which may
carry out a variety of functions under the control of one or more
microprocessors or other control devices. In addition, those skilled in the art
will appreciate that embodiments described herein are merely exemplary
implementations.
[0033] In this document, relational terms such as first and second, and the
like may be used solely to distinguish one entity or action from another entity
or action without necessarily requiring or implying any actual such
relationship or order between such entities or actions. Furthermore, depending
on the context, words such as "connect" or "coupled to" used in describing a
relationship between different elements do not imply that a direct physical
connection must be made between these elements. For example, two elements

may be connected to each other physically, electronically, logically, or in any
other manner, through one or more additional elements.
While at least one exemplary embodiment has been presented in the foregoing
detailed description, it should be appreciated that a vast number of variations
exist. It should also be appreciated that the exemplary embodiment or
exemplary embodiments are only examples, and are not intended to limit the
scope, applicability, or configuration of the invention in any way. Rather, the
foregoing detailed description will provide those skilled in the art with a
convenient road map for implementing the exemplary embodiment or
exemplary embodiments. It should be understood that various changes can be
made in the function and arrangement of elements without departing from the
scope of the invention as set forth in the appended claims and the legal
equivalents thereof.

CLAIMS
What is claimed is:
1. A hybrid vehicle, comprising:
a gas engine;
a battery array powering a electric motor to propel the hybrid
vehicle in a first mode;
5 a generator, driven by the gas engine, for recharging the battery
array; and
a charging control circuit coupled to a single phase power grid
voltage for recharging the battery array from a charging signal
phase locked to the single phase power grid voltage, the charging
10 control circuit including a phase locked loop for receiving the
single phase power grid voltage and generating a delayed signal
therefrom, each of the power control voltage and the delayed
signal being processed by the phase locked loop circuit to provide
the charging signal for recharging the battery array.
2. The hybrid vehicle of claim 1, wherein the delayed signal is delayed
by one-quarter cycle from the single phase power grid voltage.
3. The hybrid vehicle of claim 1, wherein the delayed signal is
orthogonal to the single phase power grid voltage.
4. The hybrid vehicle of claim 1, wherein the electric motor is an
alternating current motor.
5. The hybrid vehicle of claim 1, wherein the electric motor is a direct
current motor.

6. A method of charging a battery array in an electrically propelled
vehicle, comprising the steps of:
receiving a single phase power grid voltage;
delaying the single phase power grid voltage to provide a delayed
5 signal;
processing the single phase power grid voltage and the delayed signal
in a phase locked loop to provide a charging signal phase locked to the single
phase power grid voltage; and
utilizing the charging signal to recharge a battery array of the
10 electrically powered vehicle.
7. The method of claim 6, wherein the delayed signal is delayed by
one-quarter cycle.
8. The method of claim 6 which includes the step of generating a
second charging signal from a generator powered by a gas engine for charging
the battery array while the electrically propelled vehicle is in motion.
9. A phase locked loop suitable for use in a vehicle at least partially
propelled by a battery array, comprising:
a delay circuit providing a delayed signal representing a delayed
version of a single phase power grid voltage to a transformation matrix of a
5 phase locked loop circuit; and
the transformation matrix receiving the delayed signal and the single
phase power control voltage and processing each signal to provide a charging
signal phase locked to the single phase power grid voltage;
wherein, the charging signal can be used to recharge the battery array
10 while the vehicle is not in motion.

10. The phase locked loop of claim 9, wherein the delaying circuit
delays the single phase power grid voltage by one-quarter cycle.
11. A vehicle powered by at least an electric motor, comprising:
a charging control circuit coupled to a single phase power grid voltage
for recharging a battery array from a phase locked signal, the charging control
circuit including a phase locked loop for receiving the single phase power grid
voltage and generating a delayed signal therefrom, each of the single phase
power grid voltage and the delayed signal being processed by the phase locked
loop to provide the phase locked signal for recharging the battery array.
12. The vehicle of claim 11, including:
a gas engine and a generator for charging the battery array while the
vehicle is in operation.
13. The vehicle of claim 11, wherein the electric motor is an
alternating current motor.
14. The vehicle of claim 11, wherein the electric motor is a direct
current motor.
15. The vehicle of claim 11, wherein the delayed signal is delayed
from the single phase power grid voltage by one-quarter cycle.

Apparatus for charging an electric vehicle or a hybrid vehicle are provided. Particularly, apparatus for charging a hybrid vehicle from a single-phase standard (110 volt, single-phase, 60 Hz in the U.S.) are provided. In one implementation, a single-phase phase locked loop (PLL) receives a single-phase power gird voltage and delays it by one-quarter cycle to create an
orthogonal imaginary second power signal. These signals are then applied to a transform matrix within a PLL to phase lock an output signal to the incoming power grid voltage.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=/HjrX5ob1j907Vtd2mJK+A==&loc=wDBSZCsAt7zoiVrqcFJsRw==

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Patent Number

271978

Indian Patent Application Number

750/KOL/2009

PG Journal Number

12/2016

Publication Date

18-Mar-2016

Grant Date

11-Mar-2016

Date of Filing

18-May-2009

Name of Patentee

GM GLOBAL TECHNOLOGY OPERATIONS, INC.

Applicant Address

300 RENAISSANCE CENTER, DETROIT, MICHIGAN

Inventors:

#	Inventor's Name	Inventor's Address
1	GHOLAMREZA ESMAILI	23115 SAMUEL STREET, APT. 3 TORRANCE, CA 90505
2	MILUN PERISIC	20710 ANZA AVE APT. 20 TORRANCE, CA 90503-2976

PCT International Classification Number

H02J7/14; H03L7/08

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	12/184078	2008-07-31	U.S.A.