Title of Invention

ELECTRIC MOTOR SYSTEMS

Abstract Electric motor systems are provided for use in vehicles. In an embodiment, by way of example only, the system includes a first inverter, a second inverter, and a motor electrically coupled to the first and the second inverters. The motor includes a stator including a plurality of slots formed therein and a plurality of windings. The plurality of windings is disposed at least partially in the slots, and each winding includes a first coil and a second coil. The first coil has a first number of turns, and the second coil has a second number of turns that is unequal to the first number of turns. The first coil of each winding is electrically coupled to the first inverter, and the second coil of each winding is electrically coupled to the second inverter.
Full Text ELECTRIC MOTOR SYSTEMS
TECHNICAL FIELD
[0001] The inventive subject matter generally relates to electric motor
systems, and more particularly relates to electric motor systems for use in a
vehicle.
BACKGROUND OF THE INVENTIVE SUBJECT MATTER
[0002] In a DC-driven electric motor system that includes a single motor
and two voltage sources, such as in a traction drive unit, the power of the
system is typically increased by enlarging the motor, adding additional
magnets to the motor, or boosting the available DC voltage with, for example,
a conventional boost DC-DC converter. However, a larger motor requires
additional space, additional magnets provide additional complexity, and
boosting the available DC voltage burdens the motor with a higher current
rating
[0003] Accordingly, it is desirable to provide an improved electric motor
system topology capable of obtaining additional power output from a single
motor system without adding complexity to the system or increasing the motor
size. Furthermore, other desirable features and characteristics of the inventive
subject matter 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 INVENTIVE SUBJECT MATTER
[0004] Electric motor systems are provided for use in vehicles. In an
embodiment, by way of example only, the system includes a first inverter, a
second inverter, and a motor electrically coupled to the first and the second
inverters. The motor includes a stator including a plurality of slots formed
therein and a plurality of windings. The plurality of windings is disposed at
least partially in the slots and includes a first coil and a second coil. The first
coil has a first number of turns, and the second coil has a second number of
turns that is unequal to the first number of turns. The first coil of each
winding is electrically coupled to the first inverter, and the second coil of each
winding is electrically coupled to the second inverter.
DESCRIPTION OF THE DRAWINGS
[0005] The inventive subject matter will hereinafter be described in
conjunction with the following drawing figures, wherein like numerals denote
like elements, and
[0006] FIG. 1 is a schematic diagram of an electric motor system for use
in a vehicle, according to an embodiment;
[0007] FIG. 2 is a more detailed schematic of the electric motor system of
FIG. 1 including a stator assembly;
[0008] FIG. 3 is a planar view of a stator assembly of a motor, according
to an embodiment;
[0009] FIG. 4 is a planar view of the stator assembly of the motor,
according to another embodiment of FIG. 3;
[0010] FIG. 5 is a planar view of the stator assembly of the motor of FIG.
3, according to another embodiment;
[0011] FIG. 6 is planar view of the stator assembly of the motor of FIG. 3,
according to another embodiment;

[0012] FIG. 7 is a planar view of the stator assembly of the motor of FIG.
3, according to another embodiment;
[0013] FIG. 8 is a planar view of the stator assembly of the motor of FIG.
3, according to another embodiment; and
[0014] FIG. 9 is a cross section view of a slot, according to an
embodiment.
DESCRIPTION OF AN EXEMPLARY EMBODIMENT
[0015] The following detailed description is merely exemplary in nature
and is not intended to limit the inventive subject matter or the application and
uses of the inventive subject matter. 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] FIG. 1 depicts an electric motor system 100 for use in a vehicle.
The electric motor system 100 may be implemented in any electric or hybrid-
electric vehicle. In this regard, the electric motor system 100 includes at least
a motor 102, two inverters 104,106, and two voltage sources 108, 110.
[0017] In an embodiment, the motor 102 is a three-phase motor and
includes a stator assembly 111 and a rotor assembly 113. The stator assembly
111 includes three conductive windings 114, 116, 118. Turning to FIG. 2, a
more detailed schematic of the system 100 including the stator assembly is
shown. Each winding 114, 116, 118 has two legs L1 and L2. One leg L1 of
each winding 114, 116, 118 is electrically coupled to the first inverter 104,
while the other leg L2 of each winding 114, 116, 118, is electrically coupled to
the second inverter 106.
[0018] With reference back to FIG. 1, the rotor assembly 113 may be a
conventional rotor (e.g., a PM rotor or an induction machine rotor) for use in a
motor 102 and may have, for example, a stator core. In an embodiment, the

motor 102 may additionally include a cooling fluid (i.e., coolant) (not shown)
that circulates therethrough.
[0019] In the embodiment shown in FIG. 1, each inverter 104, 106 may be
a three-leg inverter connected to the motor 102 across the DC link by
switching elements of the inverters 104, 106. The inverters 104, 106 may each
include a first set of switching elements 120 connected between a high voltage
side 124, 125 and a low voltage side 122 of one of the voltage sources 108 and
a second set of switching elements 128 also connected between the high
voltage side 124, 125 and the low voltage side 122 of the other source 110.
The switching elements are preferably transistors, such as insulated gate
bipolar transistors (IGBTs) or Metal-Oxide-Semiconductor Field-Effect
Transistors (MOSFETs). In an embodiment, protective capacitors (not shown)
may be connected between the high voltage side 124 and the low voltage side
122 of the voltage sources 108, 110.
[0020] Transistors 130, 132, 134 of the first set of switching elements 120
are connected between the high voltage side 124, 125 and corresponding ones
of a first set of nodes 136, 138, 140, each of the nodes 136, 138, 140
connected to a first winding end of one of the plurality of windings 114, 116,
118 of the motor 102. Transistors 131, 133, 135 of the first set of switching
elements 120 are connected between the low voltage side 122 and
corresponding ones of the first set of nodes 136, 138, 140.
[0021] In accordance with the embodiment, transistors 142, 144, 146 of
the second set of switching elements 128 are connected between the high
voltage side 124, 125 and corresponding ones of a second set of nodes 148,
150, 152, each of the nodes 148, 150, 152 connected to a second winding end
of one of the plurality of windings 114, 116, 118 of the motor 102. Transistors
143, 145, 147 are connected between the low voltage side 122 and
corresponding ones of the second set of nodes 148, 150, 152.

[0022] As alluded to above, the voltage sources 108, 110 are electrically
coupled to a corresponding inverter 104, 106, respectively, and to the motor
102, and each is configured to deliver DC current to the corresponding
inverter 104, 106. In an embodiment, one voltage source ("first voltage
source") 108 may be a fuel cell and the other voltage source ("second voltage
source") 110 may be a battery. In such case, the fuel cell or first voltage
source 108 may feed power or discharge power to the motor 102 and to the
battery or second voltage source 110, while the second voltage source 110
may discharge power to the motor 102 and may be fed power from or charged
by the first voltage source 108. Because the first voltage source 108 can
discharge power and the second voltage source 110 can both discharge power
and be charged, the current rating of the windings 114, 116, 118 electrically
coupling their corresponding inverters 104, 106 to the motor 102 may be
configured such that each has a different maximum current carrying
capability. Consequently, the current ratings of the windings 114, 116, 118
may be unequal, in an embodiment.
[0023] In order to optimize power distribution and usage in the electric
motor system 100 using unequally rated windings 114, 116, 118, each winding
114, 116, 118 is split into two coils, in an embodiment where each coil end is
a leg, either L1 or L2, each coil is configured to be electrically isolated from
each other, and each coil has a different current rating. As briefly mentioned
above, the inverters 104, 106 are electrically coupled to the motor 102 such
that one leg L1 of each winding 114, 116, 118 is electrically coupled to the
first inverter 104, while the other leg L2 of each winding 114, 116, 118, is
electrically coupled to the second inverter 106.

[0024] With additional reference to FIGs. 3-5, planar views of the stator
assembly 111 of the motor 102 is provided, according to various
embodiments. It will be appreciated that the planar view is provided for ease
of explanation to show how the unequally rated windings 114, 116, 118 may
be disposed in the stator assembly 111 and that the stator assembly 111 may
be formed as a cylinder. In any event, the stator assembly 111 includes a
stator 115, a plurality of slots 1-12, and windings 114, 116, 118. Although
thirteen slots are shown in the stator 115, it will be appreciated that a different
number of slots may alternatively be included. The windings 114, 116, 118 are
at least partially disposed in the slots 1-12 and are made up of two coils each.
Winding 114 includes coil A1 and coil A2, winding 116 includes coil B1 and
coil B2, and winding 118 includes coil C1 and coil C2. It will be appreciated
that each coil may make one or more turns between the slots.
[0025] In an embodiment, the windings 114, 116, 118 may be disposed in
the stator assembly 111 such that no phase difference exists between two coils
of the same winding. For example, as shown in FIG. 3, coil A1 of winding
114 has a leg L1 that is connected to the first inverter 104 and makes several
turns in a first pair of non-adjacent slots (e.g., slots 1 and 7). After making
turns in the first pair of non-adjacent slots (e.g., slots 1 and 7), coil Al then
makes turns in a second pair of non-adjacent slots, where a second slot (e.g.,
slot 2) is adjacent a first slot (e.g., slot 1) of the first pair of non-adjacent slots
and a second slot (e.g., slot 8) is adjacent a second slot (e.g., slot 7) of the first
pair of non-adjacent slots. Leg L2 of winding 114 is then connected to the
second inverter 106.
[0026] Coil A2 may be disposed over coil A1. It will be appreciated that
spatial terms or phrases, such as over, under, or on top of, are used simply to
provide a spatial relationship between two components and that the
components are not limited to such relationships. Thus, coil A2 similarly has
a leg L1 that is connected to the first inverter 104 and makes several turns in

the first pair of non-adjacent slots (e.g., slots 1 and 7). After making turns in
the first pair of non-adjacent slots (e.g., slots 1 and 7), coil A2 then makes
turns in the second pair of non-adjacent slots (e.g., slots 2 and 8). Leg L2 of
coil A2 is then connected to the second inverter 106.
[0027] Turning to FIG. 4, a planar view of the stator assembly 111 of the
motor 102 is provided, according to another embodiment. The stator assembly
111 includes both windings 114 and 116. As shown in FIG. 4, coil B1 of
winding 116 makes turns in a third pair of non-adjacent slots (e.g., slots 3 and
9) that are located such that the second pair of non-adjacent slots are between
the first and the third pairs of non-adjacent slots. After making turns in the
third pair of non-adjacent slots, coil B1 makes turns in a fourth pair of non-
adjacent slots (e.g., slots 4 and 10) that are located such that the third pair of
non-adjacent slots are between the second and fourth pairs of non-adjacent
slots. Leg L1 of coils B1 is connected to the first inverter 104 and leg L2 of
coil Bl is connected to the second inverter 106. Coil B2 is disposed over coil
Bl. Thus, coil B2 similarly has a leg L1 that is connected to the first inverter
104 and makes several turns in the third pair of non-adjacent slots (e.g., slots 3
and 9). After making turns in the third pair of non-adjacent slots (e.g., slots 3
and 9), coil B2 then makes turns in the fourth pair of non-adjacent slots (e.g.,
slots 4 and 10). Leg L2 of coil B2 is then connected to the second inverter
106.
[0028] FIG. 5 is another planar view of the stator assembly 111 of the
motor 102 is provided, according to an embodiment. Here, windings 114,
116, 118 are shown. Coil C1 of winding 118 makes turns in a fifth pair of
non-adjacent slots (e.g., slots 5 and 11) that are located such that the fourth
pair of non-adjacent slots are between the third and the fifth pairs of non-
adjacent slots. After making turns in the fifth pair of non-adjacent slots, coil
Cl makes turns in a sixth pair of non-adjacent slots (e.g., slots 6 and 12) that
are located such that the fourth pair of non-adjacent slots are between the third

and sixth pairs of non-adjacent slots. Leg L1 of coil C1 is connected to the
first inverter 104 and leg L2 of coils Cl is connected to the second inverter
106. Coil C2 is disposed over coil C1. Thus, coil C2 has a leg L1 that is
connected to the first inverter 104 and makes several turns in the fifth pair of
non-adjacent slots (e.g., slots 5 and 11). After making turns in the fifth pair of
non-adjacent slots (e.g., slots 5 and 11), coil C2 then makes turns in the sixth
pair of non-adjacent slots (e.g., slots 6 and 12). Leg L2 of coil C2 is then
connected to the second inverter 106.
[0029] In other embodiments shown in FIGs. 6-8, the windings 114, 116,
118 may be disposed in the stator assembly 111 where a phase difference
equivalent to one slot exists between two coils of the same winding. FIG. 6 is
a planar view of the stator assembly of the motor, according to still another
embodiment. In this embodiment, the stator assembly 111 includes a plurality
of slots 1-13 and windings 114 is shown herein. Coil A1 of winding 114 has a
leg L1 that is connected to the first inverter 104 and makes several turns in a
first pair of non-adjacent slots (e.g., slots 1 and 7). After making turns in the
first pair of non-adjacent slots (e.g., slots 1 and 7), coil Al makes turns in the
second pair of non-adjacent slots (e.g., slots 2 and 8), where a first slot (e.g.,
slot 2) is adjacent a first slot (e.g., slot 1) of the first pair of non-adjacent slots
and a second slot (e.g., slot 8) is adjacent a second slot (e.g., slot 7) of the first
pair of non-adjacent slots. Leg L2 of coil Al is then connected to the second
inverter 106. Coil A2 of winding 114 makes turns in the second pair of non-
adjacent slots (e.g., slots 2 and 8), and has a leg L1 that is connected to the
first inverter 104. Coil A2 then makes turns in the third pair of non-adjacent
slots (e.g., slots 3 and 9), where the third pair of non-adjacent slots is located
such that the second pair of non-adjacent slots are between the first and the
third pairs of non-adjacent slots. Leg L2 of coil A2 is connected to the second
inverter 106.

[0030] FIG. 7 is a planar view of the stator assembly of the motor,
according to still another embodiment. Here, windings 114 and 116 are
shown. Leg L1 of coil B1 is connected to the first inverter 104 and makes
turns in the third pair of non-adjacent slots (e.g., slots 3 and 9). Coil Bl then
continues on to make turns in a fourth pair of non-adjacent slots (e.g., slots 4
and 10) that are located such that the third pair of non-adjacent slots are
between the second and fourth pairs of non-adjacent slots. Leg of coil Bl is
connected to the second inverter 106. Coil B2 of winding 116 makes turns in
the fourth pair of non-adjacent slots, and has a leg L1 that is connected to the
first inverter 104. Coil B2 then makes turns in a fifth pair of non-adjacent
slots (e.g., slots 5 and 11), where the fifth pair of non-adjacent slots are located
such that the fourth pair of non-adjacent slots are between the third and the
fifth pairs of non-adjacent slots. Leg L2 of coil B2 is connected to the second
inverter 106.
[0031] FIG. 8 is a planar view of the stator assembly of the motor,
according to still yet another embodiment. Here, windings 114, 116, 118 are
shown. Leg L1 of coil C1 of winding 118 is connected to the first inverter 104
and makes turns in the fifth pair of non-adjacent slots (e.g., slots 5 and 11).
Coil Cl then continues on to make turns in a sixth pair of non-adjacent slots
(e.g., slots 6 and 12) that are located such that the fifth pair of non-adjacent
slots are between the fourth and sixth pairs of non-adjacent slots. Leg of coil
C1 is connected to the second inverter 106. Coil C2 of winding 118 makes
turns in the sixth pair of non-adjacent slots (e.g., slots 5 and 11), and has a leg
L1 that is connected to the first inverter 104. Coil C2 then makes turns in a
seventh pair of non-adjacent slots (e.g., slots 6 and 12), where the seventh pair
of non-adjacent slots are located such that the sixth pair of non-adjacent slots
are between the fifth and the seventh pairs of non-adjacent slots. Leg L2 of
coil C2 is connected to the second inverter 106.

[0032] Regardless of the embodiment, because the windings 114, 116, 118
are configured to have different current rating, the number of turns made by
each coil A1, A2, B1, B2, C1, C2 may vary. Specifically, the stator assembly
111 is configured such that the first coils A1, B1, C1 make a first number of
turns in the slots 1-12, and the second coils A2, B2, C2 make a second number
of turns in the slots 1-12 that is unequal to the first number of turns. In an
embodiment illustrated in FIG. 9, a cross-section view of a slot 900 is
provided. The slot 900 includes a first layer 902 made up of coil A1 and a
second layer 904 made up of A2. As can be seen, coil Al is wound such that
it has three turns in the slot 900. Coil A2 is wound such that it has nine turns
in the slot 900. It will be appreciated that although coil A2 is depicted as
being disposed over coil A1, this may not always be the case. Moreover, coil
B1 may be disposed over or under coil B2, and coil Cl may be disposed over
or under coil C2. Additionally, the number of turns may be different than
shown.
[0033] An electric motor system topology has now been provided that
may be capable of obtaining additional power output from a single motor
system without adding complexity to the system. Additionally, the system
topology may be implemented in a vehicle and may not increase the motor
size. The topology may also provide capabilities similar to those of a
conventional traction drive system having a three phase power converter fed
from a single dc voltage source and a three phase traction motor, without the
inclusion of the converter.

[0034] 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 inventive
subject matter 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 inventive subject matter
as set forth in the appended claims and the legal equivalents thereof.

CLAIMS
What is claimed is:
1. An electric motor system for use in a vehicle, comprising:
a first inverter;
a second inverter;
a motor electrically coupled to the first and the second inverters,
the motor comprising:
a stator including a plurality of slots formed therein; and
a plurality of windings disposed at least partially in the slots and
including a first coil and a second coil, the first coil having a first number of
turns, the second coil having a second number of turns that is unequal to the
first number of turns, the first coil of each winding electrically coupled to the
first inverter, and the second coil of each winding electrically coupled to the
second inverter.
2. The electric motor system of claim 1, wherein:
the plurality of windings includes a first winding comprising a first
coil and a second coil;
at least a portion of the first winding first coil is disposed in a first
pair of non-adjacent slots and a second pair of non-adjacent slots, where a first
slot of the second pair of non-adjacent slots is located adjacent a first slot of
the first pair of non-adjacent slots and a second slot of the second pair of non-
adjacent slots is adjacent a second slot of the first pair of non-adjacent slots;
and
at least a portion of the first winding second coil is disposed in the
first and the second pairs of non-adjacent slots over the first winding first coil.

3. The electric motor system of claim 2, wherein:
the plurality of windings further includes a second winding
comprising a first coil and a second coil;
at least a portion of the second winding first coil is disposed in a
third pair of non-adjacent slots and a fourth pair of non-adjacent slots, the third
pair of non-adjacent slots located such that the second pair of non-adjacent
slots is located between the first and third pairs of non-adjacent slots, and the
fourth pair of non-adjacent slots located such that the third pair of non-
adjacent slots is located between the second and fourth pairs of non-adjacent
slots; and
at least a portion of the second winding second coil is disposed in
the third and fourth pairs of non-adjacent slots over the second winding first
coil.
4. The electric motor system of claim 3, wherein:
the plurality of windings further includes a third winding having a
first coil and a second coil;
at least a portion of the third winding first coil is disposed in a fifth
pair of non-adjacent slots and a sixth pair of non-adjacent slots, the fifth pair
of non-adjacent slots located such that the fourth pair of non-adjacent slots is
located between the third and fifth pairs of non-adjacent slots, and the sixth
pair of non-adjacent slots located such that the fifth pair of non-adjacent slots
is located between the fourth and sixth pairs of non-adjacent slots; and
at least a portion of the third winding second coil is disposed in the
fifth and sixth pairs of non-adjacent slots over the third winding first coil.

5. The electric motor system of claim 1, wherein:
the plurality of windings further includes a first winding having a
first coil and a second coil;
at least a portion of the first winding first coil is disposed in a first
pair of non-adjacent slots and a second pair of non-adjacent slots, where a first
slot of the second pair of non-adjacent slots is located adjacent a first slot of
the first pair of non-adjacent slots and a second slot of the second pair of non-
adjacent slots is adjacent a second slot of the first pair of non-adjacent slots;
and
at least a portion of the first winding second coil disposed in the
second pair of non-adjacent slots and a third pair of non-adjacent slots, the
third pair of non-adjacent slots located such that the second pair of non-
adjacent is disposed between the first and third non-adjacent pairs of slots.
6. The electric motor system of claim 5, wherein:
the plurality of windings further includes a second winding having
a first coil and a second coil;
at least a portion of the second winding first coil is disposed in the
third pair of non-adjacent slots and a fourth pair of non-adjacent slots located
such that the third pair of non-adjacent slots is located between the second and
fourth pairs of non-adjacent slots; and
at least a portion of the second winding second coil is disposed in
the fourth pair of non-adjacent slots and a fifth pair of non-adjacent slots
located such that the fourth pair of non-adjacent slots is between the third and
fifth pairs of non-adjacent slots.

7. The electric motor system of claim 6, wherein:
the plurality of windings further includes a third winding having a
first coil and a second coil;
at least a portion of the third winding first coil is disposed in the
fifth pair of non-adjacent slots and a sixth pair of non-adjacent slots located
such that the fifth pair of non-adjacent slots is located between the fourth and
sixth pairs of non-adjacent slots; and
at least a portion of the second winding second coil is disposed in
the sixth pair of non-adjacent slots and a seventh pair of non-adjacent slots
located such that the sixth pair of non-adjacent slots is between the fifth and
seventh pairs of non-adjacent slots.
8. The electric motor system of claim 1, wherein the first and
the second inverters have a common ground
9. The electric motor system of claim 1, further comprising:
a first voltage source electrically coupled to the first inverter; and
a second voltage source electrically coupled to the second inverter.
10. The electric motor system of claim 1, wherein:
the first voltage source comprises a fuel cell; and
the second voltage source comprises a battery.

11. An electric motor system for use in a vehicle, comprising:
a first inverter;
a second inverter;
a motor electrically coupled to the first and the second inverters,
the motor comprising:
a stator including a plurality of slots formed therein; and
a plurality of windings disposed at least partially in the slots, the
plurality of windings including a first winding comprising a first coil and a
second coil, at least a portion of the first winding first disposed in a first pair
of non-adjacent slots and a second pair of non-adjacent slots, where a first slot
of the second pair of non-adjacent slots is located adjacent a first slot of the
first pair of non-adjacent slots and a second slot of the second pair of non-
adjacent slots is adjacent a second slot of the first pair of non-adjacent slots,
and at least a portion of the first winding second coil disposed in the first and
the second pairs of non-adjacent slots over the first winding first coil, the first
coil having a first number of turns and electrically coupled to the first inverter,
and the second coil having a second number of turns that is unequal to the first
number of turns and electrically coupled to the second inverter.
12. The electric motor system of claim 11, wherein:
the plurality of windings further includes a second winding
comprising a first coil and a second coil;
at least a portion of the second winding first coil is disposed in a
third pair of non-adjacent slots and a fourth pair of non-adjacent slots, the third
pair of non-adjacent slots located such that the second pair of non-adjacent
slots is located between the first and the third pairs of non-adjacent slots, and
the fourth pair of non-adjacent slots located such that the third pair of non-
adjacent slots is located between the second and fourth pairs of non-adjacent
slots; and

at least a portion of the second winding second coil is disposed in
the third and fourth pairs of non-adjacent slots over the second winding first
coil.
13. The electric motor system of claim 12, wherein:
the plurality of windings further includes a third winding having a
first coil and a second coil;
at least a portion of the third winding first coil is disposed in a fifth
pair of non-adjacent slots and a sixth pair of non-adjacent slots, the fifth pair
of non-adjacent slots located adjacent such that the fourth pair of non-adjacent
slots is located between the third and the fifth pairs of non-adjacent slots, and
the sixth pair of non-adjacent slots located such that the fifth pair of non-
adjacent slots is located between the fourth and sixth pairs of non-adjacent
slots; and
at least a portion of the third winding second coil is disposed in the
fifth and sixth pairs of non-adjacent slots over the third winding first coil.
14. The electric motor system of claim 11, wherein the first and
the second inverters have a common ground.
15. An electric motor system for use in a vehicle, comprising:
a first inverter;
a second inverter;
a motor electrically coupled to the first and the second inverters,
the motor comprising:
a stator including a plurality of slots formed therein; and
a plurality of windings disposed at least partially in the slots, the
plurality of windings includes a first winding comprising a first coil and a
second coil, at least a portion of the first winding first coil disposed in a first

pair of non-adjacent slots and a second pair of non-adjacent slots, where a first
slot of the second pair of non-adjacent slots is located adjacent a first slot of
the first pair of non-adjacent slots and a second slot of the second pair of non-
adjacent slots is adjacent a second slot of the first pair of non-adjacent slots, at
least a portion of the first winding second coil disposed in the second pair of
non-adjacent slots and a third pair of non-adjacent slots, the third pair of non-
adjacent slots located such that the second pair of non-adjacent is disposed
between the first and third non-adjacent pairs of slot, the first coil having a
first number of turns and electrically coupled to the first inverter, and the
second coil having a second number of turns that is unequal to the first number
of turns and electrically coupled to the second inverter.
16. The electric motor system of claim 15, wherein:
the plurality of windings further includes a second winding having
a first coil and a second coil;
at least a portion of the second winding first coil is disposed in the
third pair of non-adjacent slots and a fourth pair of non-adjacent slots located
such that the third pair of non-adjacent slots is located between the second and
fourth pairs of non-adjacent slots; and
at least a portion of the second winding second coil is disposed in
the fourth pair of non-adjacent slots and a fifth pair of non-adjacent slots
located such that the fourth pair of non-adjacent slots is between the third and
fifth pairs of non-adjacent slots.

17. The electric motor system of claim 16, wherein:
the plurality of windings further includes a third winding having a
first coil and a second coil;
at least a portion of the third winding first coil is disposed in the
fifth pair of non-adjacent slots and a sixth pair of non-adjacent slots located
such that the fifth pair of non-adjacent slots is located between the fourth and
sixth pairs of non-adjacent slots; and
at least a portion of the second winding second coil is disposed in
the sixth pair of non-adjacent slots and a seventh pair of non-adjacent slots
located such that the sixth pair of non-adjacent slots is between the fifth and
seventh pairs of non-adjacent slots.
18. The electric motor system of claim 15, wherein the first and
the second inverters have a common ground.

Electric motor systems are provided for use in vehicles. In an
embodiment, by way of example only, the system includes a first inverter, a
second inverter, and a motor electrically coupled to the first and the second
inverters. The motor includes a stator including a plurality of slots formed
therein and a plurality of windings. The plurality of windings is disposed at
least partially in the slots, and each winding includes a first coil and a second
coil. The first coil has a first number of turns, and the second coil has a second
number of turns that is unequal to the first number of turns. The first coil of
each winding is electrically coupled to the first inverter, and the second coil of
each winding is electrically coupled to the second inverter.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=OQ2e0s+MAcOCfvjWedtLtQ==&loc=wDBSZCsAt7zoiVrqcFJsRw==


Patent Number 270596
Indian Patent Application Number 1107/KOL/2008
PG Journal Number 02/2016
Publication Date 08-Jan-2016
Grant Date 31-Dec-2015
Date of Filing 25-Jun-2008
Name of Patentee GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Applicant Address 300 GM RENAISSANCE CENTER, DETROIT, MICHIGAN
Inventors:
# Inventor's Name Inventor's Address
1 SIBAPRASAD CHAKRABARTI 23905 LOS CODONA AVENUE #216 TORRANCE, CALIFORNIA 90505
2 SILVA HITI 205 PASEO DE LAS DELICIAS REDONDO BEACH, CALIFORNIA 90277
PCT International Classification Number H02P27/06; B60L15/00; B60L15/20
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 11/829,275 2007-07-27 U.S.A.