Method and apparatus for integrated bidirectional charging

Abstract

An electric vehicle includes a drive system that performs a method of transferring power between the vehicle and an external location. The drive system includes a battery, a rectifier, and a processor. The rectifier is one of a two-stage rectifier and a multi-stage rectifier. The processor is configured to connect the rectifier between an alternating current (AC) port of an outlet of the external location and the battery. The rectifier is configured to convert between AC power at the AC port outside the rectifier and direct current (DC) power at a vehicle side of the rectifier to transfer power bi-directionally between the external location and the battery.

Description

Technical Field

[0001] This subject matter disclosure relates to the connection between electric vehicles and the power grid, and in particular to systems and methods for bidirectional power transfer between electric vehicles and the power grid. Background Technology

[0002] Electric vehicles require frequent charging. Charging stations can be used to charge electric vehicles using both alternating current (AC) and direct current (DC). Circuitry accommodating both types of charging stations takes up space. Therefore, there is a need for a highly efficient, compact circuit capable of accommodating both types of charging. Summary of the Invention

[0003] In one exemplary embodiment, a method for transferring power between a vehicle and an external location is disclosed. A rectifier is connected between an AC port of a socket at the external location and a battery, wherein the rectifier is one of a two-stage rectifier and a multi-stage rectifier. The rectifier converts AC power at the AC port outside the rectifier and DC power on the vehicle side of the rectifier to transfer power bidirectionally between the external location and the vehicle.

[0004] In addition to one or more features described herein, the vehicle also includes a first inverter, a winding machine, and a second inverter for DC power transmission. The method further includes connecting a rectifier to the first inverter to use the first inverter, the winding machine, and the second inverter for AC power transmission, wherein the first inverter is one of a two-stage inverter and a multi-stage rectifier, and the second inverter is one of a two-stage rectifier and a multi-stage rectifier. The method also includes disconnecting the rectifier from the AC port and connecting the first inverter to the DC port of a socket for DC power transmission. The winding machine is the vehicle's electric motor, and the method further includes disconnecting the electric motor from the vehicle for power transmission. The method also includes connecting the vehicle's drive system between the AC port and the first inverter, using the drive system's inverter as a rectifier, and using the drive system's motor windings as inductors. The method also includes transmitting power using the rectifier in one of a three-phase configuration and a single-phase configuration.

[0005] In another exemplary embodiment, a drive system for an electric vehicle is disclosed. The drive system includes a battery, a rectifier, and a processor. The rectifier is one of a two-stage rectifier and a multi-stage rectifier. The processor is configured to connect the rectifier between an AC port at an external location and the battery. The rectifier is configured to convert AC power at the AC port outside the rectifier and DC power on the vehicle side of the rectifier to bidirectionally transfer power between the external location and the battery.

[0006] In addition to one or more features described herein, the drive system includes a first inverter, a winding machine, and a second inverter for DC power transfer. The processor is further configured to connect a rectifier between the AC port and the first inverter to allow AC power transfer using the first inverter, the winding machine, and the second inverter. The first inverter is one of a two-stage inverter and a multi-stage inverter, and the second inverter is also one of a two-stage inverter and a multi-stage inverter. The processor is also configured to disconnect the rectifier from the AC port and connect the first inverter to the DC port of the socket to allow DC power transfer. The winding machine is the vehicle's electric motor, and the processor is further configured to disconnect the electric motor from the vehicle for power transfer. The drive system also includes a second drive system connected in series between the AC port and the first inverter. The inverter of the second drive system acts as a rectifier, the motor windings of the second drive system act as an inductor between the AC port and the rectifier, and the inverter of the second drive system is one of a two-stage inverter and a multi-stage inverter. The rectifier operates in one of a three-phase configuration and a single-phase configuration. The neutral node or second inverter is located either between two capacitors that isolate the neutral node from the positive and negative buses of the battery, or between the first and second sub-cells connected in series. The winding machine includes battery-side windings and grid-side windings, and the turns ratio between the battery-side windings and the grid-side windings is adjustable to a selected value.

[0007] In another exemplary embodiment, an electric vehicle is disclosed. The electric vehicle includes a battery, a rectifier, and a processor. The rectifier is one of a two-stage rectifier and a multi-stage rectifier. The processor is configured to connect the rectifier between an AC port of a socket at an external location and the battery. The rectifier is configured to convert AC power at the AC port outside the rectifier and DC power on the vehicle side of the rectifier to bidirectionally transfer power between the external location and the battery.

[0008] In addition to one or more features described herein, the electric vehicle also includes a first inverter, a winding machine, and a second inverter for DC power transmission, wherein the processor is further configured to connect a rectifier between an AC port and the first inverter to allow AC power transmission using the first inverter, the winding machine, and the second inverter, wherein the first inverter is one of a two-stage inverter and a multi-stage inverter, and the second inverter is one of a two-stage inverter and a multi-stage inverter. The processor is also configured to disconnect the rectifier from the AC port and connect the first inverter to the DC port of the socket to allow DC power transmission. The winding machine is the vehicle's electric motor, and the processor is also configured to disconnect the electric motor from the vehicle for power transmission. The electric vehicle also includes a drive system connected in series between the AC port and the first inverter, wherein the drive system's inverter acts as a rectifier, and the drive system's motor windings act as an inductor between the AC port and the rectifier, and the drive system's inverter is one of a two-stage inverter and a multi-stage inverter. The rectifier operates in one of a three-phase configuration and a single-phase configuration.

[0009] The above-described features and advantages, as well as other features and advantages, of this disclosure will become apparent from the following detailed description when taken in conjunction with the accompanying drawings. Attached Figure Description

[0010] Other features, advantages, and details appear only by way of example in the following detailed description, which refers to the accompanying drawings, wherein:

[0011] Figure 1 An electric vehicle according to an exemplary embodiment is shown.

[0012] Figure 2 The drive circuit of the drive system of the electric vehicle in the embodiment is shown;

[0013] Figure 3 An alternative drive circuit is shown, in which the AC port is connected to the front-end rectifier via a three-phase interface;

[0014] Figure 4 An alternative drive circuit for a motor, including the front-end rectifier and the AC port, is shown in a three-phase configuration.

[0015] Figure 5 An alternative drive circuit is shown, in which the motor between the front-end rectifier and the AC port is in a first single-phase configuration;

[0016] Figure 6 An alternative drive circuit is shown, in which the motor between the front-end rectifier and the AC port is in a second single-phase configuration;

[0017] Figure 7 A first DC configuration of a drive circuit for transferring power between a battery and a universal charger via a DC port is shown.

[0018] Figure 8 A second DC configuration of the drive circuitry for transferring power between the battery and a universal charger via a DC port is shown;

[0019] Figure 9 An AC configuration for a drive circuit used to transfer power between a battery and an external power grid via an AC port is shown.

[0020] Figure 10 A diagram depicting the drive circuitry in an alternative embodiment is shown;

[0021] Figure 11 A driving circuitry in another alternative embodiment is shown;

[0022] Figure 12 A diagram illustrating a winding machine along the longitudinal axis in an embodiment is shown;

[0023] Figure 13 A schematic diagram of the transmission system of an electric vehicle is shown;

[0024] Figure 14 This is a flowchart of a method for preparing a vehicle to use an electric motor for power transmission purposes;

[0025] Figure 15 This is a flowchart of a method for reconnecting an electric motor to a vehicle for driving purposes;

[0026] Figure 16 A two-stage inverter is shown in an exemplary embodiment;

[0027] Figure 17 This illustrates a branch of the fast capacitor-type multilevel inverter;

[0028] Figure 18 The branch of the X-type multilevel inverter in the embodiment is shown;

[0029] Figure 19 The branch of the H-type dual multilevel inverter in the embodiment is shown;

[0030] Figure 20A A branch of the diode-clamped multilevel inverter in the embodiment is shown;

[0031] Figure 20B A branch of the active clamped multilevel inverter in the embodiment is shown;

[0032] Figure 21 The branch of the T-type multilevel inverter in the embodiment is shown;

[0033] Figure 22 A cascaded H-bridge of a multilevel inverter is shown in the embodiment;

[0034] Figure 23 The drive circuit of the drive system of an electric vehicle in another embodiment is shown;

[0035] Figure 24 The drive circuit of the drive system of an electric vehicle in another embodiment is shown; and

[0036] Figure 25 The drive circuit of the drive system of an electric vehicle in another embodiment is shown. Detailed Implementation

[0037] The following description is exemplary in nature only and is not intended to limit this disclosure, its application, or use. It should be understood that in all the drawings, corresponding reference numerals denote the same or corresponding parts and features.

[0038] According to an exemplary embodiment, Figure 1 An electric vehicle 100 is shown. The electric vehicle 100 includes an electrical system 102 having a drive system 104 and an electric motor 106, the electric motor 106 operating using power provided by the drive system. Figure 1 As shown, electric vehicle 100 is depicted plugged into external power grid 108 or other external electrical equipment or location. External power grid 108 can be a home, residence, office, charging station, etc. Note that external power grid 108 may include more than one power source, but may also include other electrical components typically powered by external power grid 108. For example, if external power grid 108 is a home or residence, electrical components may include lights, televisions, computers, clocks, appliances such as washing machines / dryers, electric stoves, refrigerators, etc. Electricity can flow between external power grid 108 and electric vehicle 100 in either direction (i.e., bidirectionally). Therefore, external power grid 108 can be used to charge drive system 104. Alternatively, drive system 104 can be used to charge external power grid 108 or to power one or more electrical components (e.g., washing machines / dryers) of external power grid 108. It should be understood that electric vehicle 100 may have more than one electric motor, and each electric motor may have an associated drive system.

[0039] The electric vehicle 100 also includes a controller 110. The controller 110 may include processing circuitry, which may include application-specific integrated circuits (ASICs), electronic circuitry, a processor (shared, dedicated, or grouped) executing one or more software or firmware programs, memory, combinational logic circuitry, and / or other suitable components providing the aforementioned functionality. The controller 110 may include a non-transitory computer-readable medium storing instructions that, when processed by one or more processors of the controller 110, implement a method for controlling the operation of the drive system 104.

[0040] Figure 2 A drive circuit 200 for a drive system 104 of an electric vehicle 100 in an embodiment is shown. The drive circuit 200 includes a power source or battery 202, a first inverter 204, a second inverter 206, and a winding machine 208. The first inverter 204 and the second inverter 206 are electrically isolated from each other and can be powered using separate power modules and drivers. Each of the first inverter 204 and the second inverter 206 includes multiple transistors or MOSFETs adapted to convert between direct current (DC) and alternating current (AC). The winding machine 208 includes windings divided into two electrically isolated winding groups. Each winding group has its own neutral connection. The two winding groups share the same stator core and have the same rotor. The windings can be electromagnetically symmetrical about the winding machine to avoid any imbalance, increase control convenience, etc., but in other embodiments, they can be electromagnetically asymmetrical about the winding machine. The winding machine can be of any form (i.e., a wound magnetic field synchronizing machine, a synchronous reluctance machine, an internal permanent magnet motor, a surface permanent magnet motor, an induction motor, etc.).

[0041] The first inverter 204 can be used to convert DC power at the external power grid 108 and AC power at the electric motor 106. The second inverter 206 can be used to convert DC power at the battery 202 and AC power at the electric motor 106. The drive circuit 200 can be connected to the external power grid 108 via a universal charger 210, which is a socket for the external power grid including a DC port (DC port 212) and an AC port (AC port 214). The winding machine 208 is integrated into the electric motor 106.

[0042] The drive circuit 200 includes a high-voltage DC bus 216 for connecting to a high-voltage socket of DC port 212 and a low-voltage DC bus 218 for connecting to a low-voltage socket of DC port 212. A first DC port switch 220 controls the connection between DC port 212 and the high-voltage DC bus 216. A second DC port switch 222 controls the connection between DC port 212 and the low-voltage DC bus 218. An AC bus 224 extends between AC port 214 and front-end rectifier 226. An AC port switch 228 on AC bus 224 controls the connection between AC port 214 and front-end rectifier 226. An inductor (L1) may be provided on AC bus 224. The front-end rectifier 226 decouples AC / DC power transfer between AC port 214 and other components of the drive circuit 200 (e.g., the first inverter 204).

[0043] In various embodiments, the first inverter 204 can be a two-stage inverter or a multi-stage inverter, the second inverter 206 can be a two-stage inverter or a multi-stage inverter, and the front-end rectifier 226 can be a two-stage inverter or a multi-stage inverter. The front-end rectifier 226 can also be a single-stage rectifier, a multi-stage rectifier, or a Vienna rectifier, which are types of two-stage or multi-stage inverters. Figure 16-22 Examples of two-stage or multi-stage inverters are shown.

[0044] Battery contact switch 230 is located between battery 202 and high-voltage DC bus 216. Battery contact switch 230 can be turned on (closed) during drive mode (to operate electric vehicle 100) and can be turned off (on or off) during charging mode. During AC charging, while the front-end rectifier 226 is operating, switch 232 between low-voltage DC bus 218 and battery 202 can be opened to disconnect the battery and low-voltage DC bus. Figure 2 As shown, the front-end rectifier 226 is a single-phase rectifier. However, this does not imply any limitation on the invention.

[0045] Figure 3-6 The drive circuit 200 in various alternative embodiments is shown. Figure 3-6 Each of the first inverter 204, the second inverter 206, and the front-end rectifier 226 can be a two-stage inverter or a multi-stage inverter, as exemplified in [examples omitted]. Figure 16-22 As shown in the image. Figure 3 An alternative drive circuit 300 is shown, in which AC port 214 is connected to front-end rectifier 226 via a three-phase interface including a first bus 302, a second bus 304, and a third bus 306. The first bus 302 includes a first switch 308 and a first inductor 310. The second bus 304 includes a second switch 312 and a second inductor 314. The third bus 306 includes a third switch 316 and a third inductor 318.

[0046] In various embodiments, the first inverter 204, the second inverter 206, and the winding machine 208 operate as the electrical system driving the first motor (first drive system) of the electric vehicle 100. Figure 4-6 In this context, the second motor drive (second drive system) of the electric vehicle 100 can be used to achieve [the desired connection / operation]. Figure 3 The front-end rectifier 226 in the second motor driver can function similarly to inductors 310, 314, and 318. The three-phase motor windings of the second motor driver can be used as inductors 310, 314, and 318, and the inverter of the second motor driver can be used as the front-end rectifier 226.

[0047] Figure 4An alternative drive circuit 400 in a three-phase configuration is shown, comprising a motor 402 between a front-end rectifier 226 and an AC port 214. The motor 402 includes three winding branches 404, 406, and 408. Switches 410, 412, and 414 connect each of the three winding branches 404, 406, and 408 of the motor 402 to a socket in the AC port 214, respectively. When switches 410, 412, and 414 are closed, the motor 402 can operate with AC power transmitted between the AC port 214 and the front-end rectifier 226. A disconnect switch between the three winding branches 404, 406, and 408 can be opened during power transmission operation to disconnect the neutral connection between the three winding branches 404, 406, and 408, and can be closed when the electric vehicle is operating in propulsion mode.

[0048] Figure 5 An alternative drive circuit 500 is shown, in which the motor 402 between the front-end rectifier 226 and the AC port 214 is in a first single-phase configuration. A first switch 504 is located between the AC port 214 and the upstream ends of the three winding branches 404, 406, and 408 of the motor 402. A second switch 506 connects the downstream end of the motor 402 back to the AC port 214. When the first switch 504 and the second switch 506 are closed, the motor 402 can operate with all three winding branches 404, 406, and 408 tapped into a single phase.

[0049] Figure 6 An alternative drive circuit 600 is shown, in which the motor 402 between the front-end rectifier 226 and AC port 214 is in a second single-phase configuration. A first switch 604 is connected between AC port 214 and a first winding branch 404, and a second switch 606 is connected between AC port 214 and a third winding branch 408. The first switch 604 and the second switch 606 are closed to operate the motor 402 connected to the neutral point.

[0050] Figure 7A first DC configuration 700 of the drive circuit 200 for transferring power between battery 202 and universal charger 210 via DC port 212 is shown. A controller 110 or processor can control the configuration of switches to select the first DC configuration 700. The controller 110 can select the DC configuration when DC power transfer is required and when the voltage of battery 202 is the same as the voltage of DC port 212. In the first DC configuration 700, the first DC port switch 220, the second DC port switch 222, and the battery contact switch 230 are closed, while the AC port switch 228 is open, thereby disabling the front-end rectifier 226, the first inverter 204, and the second inverter 206. As a result, from the perspective of front-end functionality, the first inverter 204 and the second inverter 206, the winding machine 208, and the front-end rectifier 226 are removed from the drive circuit. Battery 202 is thus directly connected to DC port 212. Power can be transferred via… Figure 7 The current path 702 shown flows between the battery 202 and the universal charger 210 in either direction. Figure 7 Each of the first inverter 204, the second inverter 206, and the front-end rectifier 226 can be a two-stage inverter or a multi-stage inverter, as exemplified in [examples omitted]. Figure 16-22 As shown in the image.

[0051] Figure 8 A second DC configuration 800 of the drive circuit 200 for transferring power between battery 202 and universal charger 210 via DC port 212 is shown. The controller 110 or processor selects the second DC configuration 800 when DC power transfer is required and when the voltage of battery 202 differs from the voltage of DC port 212. In the second DC configuration 800, the first DC port switch 220 and the second DC port switch 222 are closed, while the battery contact switch 230 and the AC port switch 228 are open. As a result, from a functional perspective, the first inverter 204, the second inverter 206, and the winding machine 208 are included in the drive circuit 200, while the front-end rectifier 226 is not included in the drive circuit. Figure 8 Each of the first inverter 204, the second inverter 206, and the front-end rectifier 226 can be a two-stage inverter or a multi-stage inverter, as exemplified in [examples omitted]. Figure 16-22 As shown in the image.

[0052] like Figure 8As shown in the diagram, the grid-side DC current 802 and AC current 804 can flow through the circuit in either direction. The first inverter 204 and the second inverter 206 function as a dual active bridge DC-DC converter, LLC converter, or CLLC converter. The grid-side DC current 802 is converted into AC current 804 at the first inverter 204. The AC current 804 flows between the first inverter 204 and the grid-side winding of a winding machine 208, which includes a first set of coils. On the grid side of the winding machine 208, the AC current 804 flows between the second inverter 206 and the battery-side winding of the winding machine 208, which includes a second set of coils. The second inverter 206 converts the DC current from the battery into AC current flowing to the winding machine 208. The first and second sets of coils enable the winding machine 208 to act as a transformer, electrically isolating the AC current 804 from the grid-side DC current 802. Electricity can flow in either direction through the winding machine 208 between the battery 202 and the DC port 212.

[0053] Figure 9 An AC configuration 900 of the drive circuit 200 is shown for transferring power between the battery 202 and the external power grid 108 via AC port 214. In AC configuration 900, the battery contact switch 230 is open, and the first DC port switch 220 and the second DC port switch 222 are also open. The AC port switch 228 is closed, thereby connecting the front-end rectifier 226 to the AC port 214.

[0054] In one embodiment, AC power is transmitted from an external power grid 108 to an electric vehicle 100. AC current 902 flows from AC port 214 to a front-end rectifier 226. The front-end rectifier 226 converts the AC current 902 into a DC current 904 flowing to a first inverter 204. The first inverter 204 converts the DC current 904 into a grid-side AC current 906 flowing to a winding machine 208. At the winding machine 208, the grid-side AC current 906 flows through the grid-side windings (i.e., the first set of coils) to induce a battery-side AC current 908 in the battery-side windings (i.e., the second set of coils). The battery-side AC current 908 flows to a second inverter 206, which converts the battery-side AC current into a DC current 910 for charging the battery 202.

[0055] In another embodiment, AC power is transmitted from electric vehicle 100 to external power grid 108. DC current 910 flows from battery 202 to second inverter 206. Second inverter 206 converts DC current 910 into battery-side AC current 908, which is sent to winding machine 208. At winding machine 208, battery-side AC current 908 flows through battery-side windings (i.e., the second set of coils) to induce grid-side AC current 906 in grid-side windings (i.e., the first set of coils). Grid-side AC current 906 is sent to first inverter 204, which converts grid-side AC current into DC current 904. DC current 904 is sent from first inverter 204 to front-end rectifier 226. Front-end rectifier 226 converts DC current 904 into AC current 902 flowing to AC port 214. Figure 9 Each of the first inverter 204, the second inverter 206, and the front-end rectifier 226 can be a two-stage inverter or a multi-stage inverter, as exemplified in [examples omitted]. Figure 16-22 As shown in the image.

[0056] Figure 10 Figure 1000 illustrates a drive circuit 200 in an alternative embodiment. A first set of Y capacitors 1002 extends across the electrodes of the battery 202 to isolate the second inverter 206 from ground 1004. Furthermore, a second set of Y capacitors 1006 is located between the high-voltage DC bus 216 and the low-voltage DC bus 218 to isolate the first inverter 204 from ground 1004. The first set 1002 and the second set 1006 further provide electrical isolation across the winding machine 208. Figure 10 Each of the first inverter 204, the second inverter 206, and the front-end rectifier 226 can be a two-stage inverter or a multi-stage inverter, as exemplified in [examples omitted]. Figure 16-22 As shown in the image.

[0057] Figure 11 A matrix converter that can be used within the drive circuit 200 in the embodiment is shown. The matrix converter 1102 converts AC current to AC current and can be inserted into the drive circuit 200 in place of the front-end rectifier 226 and the first inverter 204. For a three-phase winding, the matrix converter 1102 can be operated using nine switches instead of the twelve or more switches it replaces (i.e., six or more transistors of the front-end rectifier 266 and six or more transistors of the first inverter 204). When using the matrix converter 1102, the input inductor L1 is not required. Figure 4 The front-end rectifier 226 can be a two-stage inverter or a multi-stage inverter, as exemplified in... Figure 16-22 As shown in the image.

[0058] Figure 12Figure 1200 illustrates a winding machine 208 depicted along a longitudinal axis in an embodiment. In this embodiment, the winding machine 208 is a three-phase permanent magnet motor and includes a stator 1202 and a rotor 1204. The rotor 1204 includes one or more permanent magnets 1238 forming a D-axis 1222 (direct axis). The stator 1202 includes a grid-side winding containing a first set of coils and a battery-side winding containing a second set of coils. The first and second sets of coils are interleaved. Because the winding machine 208 is a three-phase permanent magnet motor, the grid-side winding includes a first grid-side coil 1206, a second grid-side coil 1208, and a third grid-side coil 1210, and the battery-side winding includes a first battery-side coil 1216, a second battery-side coil 1218, and a third battery-side coil 1220.

[0059] The first grid-side coil 1206 and the first battery-side coil 1216 form a first electrode pair 1240. The second grid-side coil 1208 and the second battery-side coil 1218 form a second electrode pair 1244. The third grid-side coil 1210 and the third battery-side coil 1220 winding W2 form a third electrode pair 1246. The A-axis is the flux axis of the coil. The first A-axis 1224 is shown for the grid-side winding, and the second A-axis 1226 is shown for the battery-side winding. The rotation direction 1228 of the rotor 1204 is shown. The grid-side winding uses +i q 1230 consumes power from the grid. Battery-side winding W2 uses -i q 1232 supplies power to the battery.

[0060] Figure 13 A schematic diagram 1300 of the drivetrain of an electric vehicle 100 is shown. When power is transmitted to or from the electric vehicle 100, the electric motor 106 (i.e., the winding machine 208) is disconnected from the rest of the vehicle, so that the rotation of the electric motor during power transmission does not cause the vehicle to move. The electric motor 106 is shown connected to the axle 1302 of the electric vehicle 100 via a first clutch 1304, a first gear set 1306, a second clutch 1308, and a second gear set 1310. The first clutch 1304 can be disengaged to separate the winding machine 208 from the rest of the electric vehicle 100.

[0061] Figure 14 This is a flowchart 1400 of a method for preparing a vehicle for use with an electric motor 106 for power transmission purposes. In box 1402, the vehicle is in parking gear. In box 1404, the electric motor 106 is disconnected from the rest of the vehicle, for example, by disengaging the first clutch 1304. In box 1406, the power level, speed, and operating frequency for power transmission are selected. In box 1408, a winding machine is used for power transmission.

[0062] Figure 15Flowchart 1500 shows a method for reconnecting electric motor 106 to the vehicle for driving purposes. In block 1502, power transfer between the vehicle and the external power grid is stopped. In block 1504, the electric motor is switched to electric mode using either a first inverter (externally powered) or a second inverter (battery powered). In block 1506, the speed of electric motor 106 is reduced or decreased to restore its kinetic energy. In block 1508, the clutch is engaged when the electric motor speed drops below a selected speed threshold. In block 1510, the battery contact switch 230 is disconnected to discharge the high-voltage DC bus. In block 1512, the vehicle returns to a safe mechanical and electrical state.

[0063] Figure 16 A two-stage inverter 1600 is illustrated in an exemplary embodiment. The two-stage inverter 1600 includes at least one branch (e.g., a first branch 1602, a second branch 1604, and a third branch 1606) extending from a positive bus 1608 to a negative bus 1610. Each branch includes two switches connected in series between the positive bus 1608 and the negative bus 1610. For example, the first branch 1602 includes switch S1 and switch S2. A phase winding is connected to the branch between the two switches. For example, a phase winding 1612 is connected to the first branch 1602 between switch S1 and switch S2.

[0064] Figure 17 Branch 1700 of a fast capacitor type multilevel inverter is shown. Branch 1700 includes four switches (labeled S1, S2, S3, and S4) that are sequentially connected in series between the positive bus 1608 and the negative bus 1610. The node between switch S1 and switch S2 is connected to the node between switch S3 and switch S4 via a fast capacitor 1702.

[0065] Figure 18 Branch 1800 of the X-type multilevel inverter in the embodiment is shown. Branch 1800 includes a first sub-branch 1802 and a second sub-branch 1804. The first sub-branch 1802 includes switches S1, S2, S3, and S4 connected in series between the positive bus 1608 and the negative bus 1610. The second sub-branch 1804 includes switches S5, S6, S7, and S8 connected in series between the positive bus and the negative bus. A first diode D1 is connected between the node between switches S3 and S4 and the node between switches S5 and S6. A second diode D2 is connected between the node between switches S7 and S8 and the node between switches S1 and S2.

[0066] Figure 19Branch 1900 of the H-type dual multilevel inverter in the embodiment is shown. Branch 1900 includes a first sub-branch 1902 and a second sub-branch 1904. The first sub-branch 1902 includes switches S1 and S2 connected in series between the positive bus 1608 and the negative bus 1610. The second sub-branch 1904 includes switches S5 and S6 connected in series between the positive bus and the negative bus. A third sub-branch 1906 is connected from the node between switches S1 and S2 and the node between switches S5 and S6. In the embodiment, the third sub-branch may include additional switches S3 and S4 or bidirectional switches; however, this is not intended to be limiting.

[0067] Figure 20A A branch 2000 of a diode-clamped multilevel inverter in an embodiment is shown. Branch 2000 includes four switches (labeled S1, S2, S3, and S4) sequentially connected in series between the positive bus 1608 and the negative bus 1610. A first diode D1 connects the neutral node N to the node between switches S1 and S2. Similarly, a second diode D2 connects the neutral node N to the node between switches S3 and S4. The neutral node N is located outside the inverter and is isolated from the positive bus 1608 by a first capacitor 2002 and from the negative bus by a second capacitor 2004. In another embodiment, the battery (i.e. Figure 2 The battery 202) can be divided into a first sub-battery and a second sub-battery connected in series, and the neutral node N can be located between the first sub-battery and the second sub-battery.

[0068] Figure 20B Branch 2010 of the active clamped multilevel inverter in the embodiment is shown. The active clamped multilevel inverter includes switches S1, S2, S3, and S4. A first clamping switch 2012 replaces... Figure 20A The first diode D1, the second clamping switch 2014 replaces Figure 20A The second diode, D2.

[0069] Figure 21 Branch 2100 of the T-type multilevel inverter in the embodiment is shown. Branch 2100 includes a first switch S1 and a second switch S2 connected in series between the positive bus 1608 and the negative bus 1610. Neutral line 2102 connects the node between the first switch S1 and the second switch S2 to the neutral node N. Neutral line 2102 includes switches S3 and S4 or bidirectional switches; however, this is not intended to be limiting.

[0070] Figure 22A cascaded H-bridge 2200 of multilevel inverters in an embodiment is shown. For illustrative purposes, the cascaded H-bridge 2200 includes a first H-type dual multilevel inverter 2202 and a second H-type dual multilevel inverter 2204. A first cascading line 2206 connects between the switch of a first branch 2208 of the first H-type dual multilevel inverter 2202 and the second branch 2214 of the second H-type dual multilevel inverter 2204. A second cascading line 2216 connects between the switch of a first branch 2212 of the second H-type dual multilevel inverter 2204 and the second branch 2210 of the first H-type dual multilevel inverter 2202.

[0071] exist Figure 16-22 In the inverter shown, the switch can be a transistor or a diode, such as, but not limited to, Si IGBT transistors, anti-parallel diodes, SiC MOSFETs, SiC Schottky diodes, GaN switches / diodes, Ga2O3 switches / diodes, diamond-based power devices, etc.

[0072] Figure 23 A drive circuit 2300 for a drive system 104 of an electric vehicle 100 in another embodiment is shown. The drive circuit 2300 supports single-phase and three-phase AC charging. The drive circuit 2300 includes a power source or battery 202, a first inverter 204, a second inverter 206, and a winding machine 208. The first inverter 204 and the second inverter 206 are electrically isolated from each other and can be powered using separate power modules and drivers. Each of the first inverter 204 and the second inverter 206 includes multiple transistors or MOSFETs adapted to convert between direct current (DC) and alternating current (AC). Each of the first inverter 204, the second inverter 206, and the front-end rectifier 226 can be a two-stage inverter or a multi-stage inverter, such as a Vienna rectifier, examples of which are shown in [examples omitted]. Figure 16-22 As shown in the image.

[0073] The first inverter 204 can be used in the external power grid 108 ( Figure 1 DC power at ) and electric motor 106 ( Figure 1 The second inverter 206 can be used to convert between DC power at battery 202 and AC power at electric motor 106. Drive circuit 200 can be connected to external power grid 108 via universal charger 210, which is a socket for the external power grid including a DC port (DC port 212) and an AC port (AC port 214). Winding machine 208 is integrated within electric motor 106.

[0074] The drive circuit 2300 includes a high-voltage DC bus 216 for connection to a high-voltage socket of DC port 212 and a low-voltage DC bus 218 for connection to a low-voltage socket of DC port 212. A first DC port switch 220 controls the connection between DC port 212 and the high-voltage DC bus 216. A second DC port switch 222 controls the connection between DC port 212 and the low-voltage DC bus 218. AC port 214 is connected to front-end rectifier 226 via a three-phase interface including a first bus 302, a second bus 304, and a third bus 306. The first bus 302 includes a first switch 308 and a first inductor 310. The second bus 304 includes a second switch 312 and a second inductor 314. The third bus 306 includes a third switch 316 and a third inductor 318.

[0075] The first pair of isolation capacitors 2302 and 2304 establish a first neutral node N1 between the high-voltage DC bus 216 and the low-voltage DC bus 218, thereby allowing the first inverter 204 to operate as a multi-stage inverter employing a neutral point (e.g., T-type, diode clamping, active clamping, etc.).

[0076] The second pair of isolation capacitors 2306 and 2308 establish a second neutral node N2 between the positive and negative buses of battery 202, thereby allowing the second inverter 206 to operate as a multi-stage inverter employing a neutral point (e.g., T-type, diode clamping, active clamping, etc.).

[0077] The front-end rectifier 226 outputs a positive voltage line 2310 connected to the high-voltage DC bus 216, a negative voltage line 2312 connected to the low-voltage DC bus 218, and a neutral voltage line 2314 connected to the first neutral node N1. During operation of the front-end rectifier 226 during AC charging, a switch 2320 between the low-voltage DC bus 218 and the battery 202 can be opened to disconnect the battery from the low-voltage DC bus.

[0078] Figure 24 A drive circuit 2400 for a drive system 104 of an electric vehicle 100 in another embodiment is shown. The drive circuit 2400 supports single-phase and three-phase AC charging, wherein the neutral grid is directly connected to the neutral point of the DC-linked capacitor to eliminate leakage current and improve electromagnetic charging. The drive circuit 2400 includes... Figure 23 The components of the drive circuit 2300 and the neutral line 2402, which is connected from the neutral node of the universal charger 210 to the neutral voltage line 2314 and thus to the first neutral node N1, are included. The neutral line 2402 can also be connected as an input to the front-end rectifier 226. A switch 2404 on the neutral line 2402 can open or close the connection to the first neutral node N1. Another switch 2406 on the neutral line 2402 can open or close the connection to the front-end rectifier 226.

[0079] Figure 25 A drive circuit 2500 for a drive system 104 of an electric vehicle 100 in another embodiment is shown. The drive circuit 2500 includes... Figure 2 The components of the drive circuit 200. The winding machine 208 includes a first interconnect 2502 connected to a first inverter 204 and a second interconnect 2504 connected to a second inverter 206. The winding machine 208 includes a winding 2506 connected between the first interconnect 2502 and the second interconnect 2504. The windings are grouped according to battery-side windings and grid-side windings, with each battery-side winding paired with a grid-side winding. The windings may be adjustable windings, wherein the turns ratio (e.g., the turns ratio between a battery-side winding and its associated grid-side winding A2) can be adjusted to increase or decrease the voltage transmission through the winding machine 208. For example, winding pairs may be configured and interconnected to have different turns ratios (i.e., two integer turns ratios, such as 1:1, 2:3, 3:2, 1:3, 3:1, etc., and fractional turns ratios, such as 1:1.2, 2.5:1, etc.). The turns ratio can be selected to allow the battery 202 to be charged at different states of charge (SOC) from different grid-side voltages at AC port 214.

[0080] Note that this invention is primarily discussed in relation to power grids, but can be used with any external device. When this invention is used with any external device, "power grid side" can refer to "external side".

[0081] The terms “a” and “an” do not indicate a limitation of quantity, but rather that at least one of the referenced items is present. The term “or” means “and / or”, unless the context clearly indicates otherwise. A reference to “an aspect” throughout the specification means that a particular element (e.g., feature, structure, step, or characteristic) described in connection with that aspect is included in at least one aspect described herein and may or may not be present in other aspects. Furthermore, it should be understood that the described elements may be combined in any suitable manner across the aspects.

[0082] When an element, such as a layer, film, region, or substrate, is referred to as being "on" another element, it can be directly on the other element, or there may be intermediate elements present. Conversely, when an element is referred to as being "directly on" another element, there are no intermediate elements present.

[0083] Unless otherwise stated herein, all test standards are the most recent valid standards up to the filing date of this application, or, if priority is claimed, the filing date of the earliest priority application in which the test standard appears.

[0084] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0085] While the foregoing disclosure has been described with reference to exemplary embodiments, those skilled in the art will understand that various changes can be made and equivalents can replace its elements without departing from its scope. Furthermore, many modifications can be made to adapt particular situations or materials to the teachings of this disclosure without departing from its essential scope. Therefore, it is intended that this disclosure be limited to the specific embodiments disclosed, but will include all embodiments falling within its scope.

Claims

1. A method for transmitting power between a vehicle and an external location, comprising: Connect the rectifier to the AC port of an external outlet, where the rectifier is one of a two-stage rectifier or a multi-stage rectifier; The DC side of the rectifier is connected to the DC side of the first inverter, wherein the AC side of the first inverter is connected to the first winding group of the winding machine; The DC side of the second inverter is connected to the vehicle's battery, and the AC side of the second inverter is connected to the second winding group of the winding machine. It converts the AC power at the AC port on the outside of the rectifier and the DC power on the vehicle side of the rectifier. DC power is converted to AC power at the first inverter and the first winding; The AC power in the second winding is induced from the AC power in the first winding; and The AC power at the second winding is converted into DC power at the second inverter to power the battery.

2. The method according to claim 1, wherein, The first inverter is one of a two-stage inverter and a multi-stage rectifier, and the second inverter is one of a two-stage rectifier and a multi-stage rectifier.

3. The method of claim 2, further comprising disconnecting the rectifier from the AC port and connecting the first inverter to the DC port of the socket for DC power transmission.

4. The method according to claim 2, wherein, The winding machine is the electric motor of the vehicle, and the method further includes disconnecting the electric motor from the vehicle for power transmission.

5. The method of claim 2, further comprising connecting the vehicle's drive system between the AC port and the first inverter, and using the inverter of the drive system as the rectifier, and using the motor windings of the drive system as inductors.

6. A drive system for an electric vehicle, comprising: Battery; A winding machine having a first winding group and a second winding group; A rectifier that can be connected to the AC port of an outlet in an external location, wherein the rectifier is one of a two-stage rectifier and a multi-stage rectifier; The first inverter has a DC side connected to the rectifier and an AC side connected to the first winding group; The second inverter has an AC side connected to the second winding group and a DC side connected to the battery; as well as The processor is configured to establish a connection between the rectifier and the AC port, thereby allowing conversion between AC power at the AC port outside the rectifier and DC power on the vehicle side of the rectifier, conversion from DC power to AC power at the first inverter and the first winding, induction of AC power in the second winding from AC power in the first winding, and conversion of AC power at the second winding to DC power at the second inverter to power the battery.

7. The drive system according to claim 6, wherein, The first inverter is one of a two-stage inverter and a multi-stage inverter, and the second inverter is one of a two-stage inverter and a multi-stage inverter.

8. The drive system according to claim 7, wherein, The processor is also configured to disconnect the rectifier from the AC port and connect the first inverter to the DC port of the socket to allow DC power transfer.

9. The drive system according to claim 7, wherein, The winding machine is the electric motor of the vehicle, and the processor is also configured to decouple the electric motor from the vehicle for power transmission.

10. The drive system of claim 7 further includes a second drive system connected in series between the AC port and the first inverter, wherein the inverter of the second drive system serves as the rectifier, the motor winding of the second drive system serves as an inductor between the AC port and the rectifier, and the inverter of the second drive system is one of a two-stage inverter and a multi-stage inverter.

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