POWER TRANSMISSION USING ELECTRIC RECORDING MACHINES

Abstract

A vehicle's power transmission system includes a multi-winding motor, a first inverter connected to a first set of windings, and a second inverter connected to a second set of windings. The system includes a controller configured to manage the first and second inverters to control a charging current through the multi-winding motor at a set power when the multi-winding motor is in a torque-free state.The controller is configured to control the charging current through the first inverter and the second inverter, such that a first current vector associated with the first winding set and a second vector associated with the second winding set are symmetrical about a d-axis, and the multi-winding motor operates as a transformer, with the control of the first inverter and the second inverter providing power transfer between the first winding set and the second winding set.

Description

INTRODUCTION

[0001] The disclosure of the subject matter relates to the transfer of power to and / or from an energy storage system, such as a vehicle battery system, and more specifically to the control of the transfer of power or energy using an electrical multi-winding machine.

[0002] Vehicles, including both gasoline and diesel-powered vehicles as well as electric and hybrid electric vehicles, have a battery storage system for purposes such as powering electric motors, electronics, and other vehicle subsystems. Electric and hybrid vehicles (e.g., passenger cars, trucks, construction equipment, automated factory equipment, agricultural equipment, etc.) are charged using external power sources (e.g., charging stations, an electrical grid, etc.). Charging can include alternating current (AC) charging (e.g., a Stage 1 or Stage 2 outlet connected to the grid) or direct current (DC) charging (e.g., DC fast charging (DCFC)). Additionally, the current flow can be reversed to allow a vehicle to supply power to an external energy storage system (e.g., the grid, another vehicle, etc.). Typically, charging is performed by a vehicle charger, e.g.,an onboard onboard load management module (OBCM) that includes conversion devices for performing functions such as voltage control and AC-DC power conversion. SUMMARY

[0003] According to an exemplary embodiment, a vehicle's energy transmission system includes a multi-winding motor comprising a first winding set and a second winding set, the multi-winding motor being connected to a battery system, a first inverter connected to the first winding set, and a second inverter connected to the second winding set.The system also includes a controller configured to receive a power transfer request, put the multi-winding motor into a charging mode, and control the first and second inverters to deliver a charging current through the multi-winding motor at a set power level when the motor is in a torque-free state. The controller is configured to control the charging current through the first and second inverters such that a first current vector, associated with the first winding set, and a second vector, associated with the second winding set, are symmetrical about a d-axis, allowing the multi-winding motor to operate as a transformer. Control of the first and second inverters provides power transfer between the first and second winding sets.

[0004] In addition to one or more of the features described here, the controller is configured to control the charging current based on a reference charging current value derived from a calibration of an optimal value of a d-axis current and an optimal value of a q-axis current, the optimal values ​​being determined based on a power transfer capability of the multi-winding motor.

[0005] In addition to one or more of the features described here, the charging current reference value is a minimum size of charging current that can be applied to achieve a target charging power.

[0006] In addition to one or more of the features described here, the power transfer capability is estimated based on an energy relation that specifies an energy E as a function of the d-axis current and the q-axis current.

[0007] In addition to one or more of the characteristics described here, the power transfer capability is used to determine a maximum power per ampere (MPPA) for a given motor speed.

[0008] In addition to one or more of the features described here, the MPPA specifies a minimum charging current for a given motor speed, where the minimum charging current is determined based on the optimal value of the d-axis current and the optimal value of the q-axis current.

[0009] In addition to one or more of the features described herein, the system also includes a switch configured to selectively connect the first inverter to the battery system, the switch being configured to be closed when the vehicle is in a propulsion mode.

[0010] In addition to one or more of the features described here, the charging current is an alternating current, the switch is configured to be open to put the multi-winding motor into charging mode, and includes controlling the first inverter and the second inverter, operating the first winding set and the second winding set as an isolated transformer to transfer power between the first winding set and the second winding set.

[0011] According to a further exemplary embodiment, a method for transferring energy to or from a vehicle's battery system includes receiving a request to transfer energy at a controller connected to a vehicle's charging system, wherein the charging system includes a multi-winding motor comprising a first winding set and a second winding set, a first inverter connected to the first winding set, and a second inverter connected to the second winding set, wherein the multi-winding motor is connected to the battery system.The method also includes putting the multi-winding motor into a charging mode and controlling the first and second inverters to direct a charging current through the multi-winding motor with a set power when the multi-winding motor is in a torque-free state. The charging current is controlled by the first and second inverters such that a first current vector, associated with the first winding set, and a second vector, associated with the second winding set, are symmetrical about a d-axis, and the multi-winding motor operates as a transformer. Controlling the first and second inverters provides power transfer between the first and second winding sets.

[0012] In addition to one or more of the features described here, the control of the charging current is based on a reference charging current value derived from a calibration of an optimal value of a d-axis current and an optimal value of a q-axis current, the optimal values ​​being determined based on the power transmission capability of the multi-winding motor.

[0013] In addition to one or more of the features described here, the charging current reference value is a minimum size of charging current that can be applied to achieve a target charging power.

[0014] In addition to one or more of the features described here, the power transfer capability is estimated based on an energy relation that specifies an energy E as a function of the d-axis current and the q-axis current.

[0015] In addition to one or more of the characteristics described here, the energy relationship is derived through simulation and / or experimentation.

[0016] In addition to one or more of the features described here, the power transfer capability is used to determine a maximum power per ampere (MPPA) for a given motor speed, where the MPPA prescribes a minimum charging current for a given motor speed, the minimum charging current being determined based on the optimal value of the d-axis current and the optimal value of a q-axis current.

[0017] In addition to one or more of the features described here, the charging system includes a switch configured to selectively connect the first inverter to the battery system, with the switch configured to be closed when the vehicle is in a propulsion mode.

[0018] The method of claim 16, wherein the charging current is an alternating current and putting the multi-winding motor into charging mode includes opening the switch and controlling the first inverter and the second inverter includes operating the first winding set and the second winding set as an isolated transformer to transfer power between them.

[0019] According to a further exemplary embodiment, a vehicle system includes a memory containing computer-readable instructions and a processing device for executing the computer-readable instructions, wherein the computer-readable instructions control the processing device to execute a method. The method includes receiving a request to transfer energy to a controller connected to a charging system of the vehicle, wherein the charging system includes a multi-winding motor comprising a first winding set and a second winding set, a first inverter connected to the first winding set, and a second inverter connected to the second winding set, the multi-winding motor being connected to the battery system.The method also includes putting the multi-winding motor into a charging mode and controlling the first and second inverters to direct a charging current through the multi-winding motor with a set power when the multi-winding motor is in a torque-free state. The charging current is controlled by the first and second inverters such that a first current vector, associated with the first winding set, and a second vector, associated with the second winding set, are symmetrical about a d-axis, and the multi-winding motor operates as a transformer. Controlling the first and second inverters provides power transfer between the first and second winding sets.

[0020] In addition to one or more of the features described here, the control of the charging current is based on a charging current reference value derived from a calibration of an optimal value of a d-axis current and an optimal value of a q-axis current, the optimal values ​​being determined based on the power transfer capability of the multi-winding motor, where the charging current reference value is a minimum size of charging current that can be applied to achieve a target charging power.

[0021] In addition to one or more of the features described here, the power transfer capability is estimated based on an energy relation that specifies an energy E as a function of the d-axis current and the q-axis current.

[0022] In addition to one or more of the features described here, the power transfer capability is used to determine a maximum power per ampere (MPPA) for a given motor speed, where the MPPA prescribes a minimum charging current for a given motor speed, the minimum charging current being determined based on the optimal value of the d-axis current and the optimal value of the q-axis current.

[0023] The above features and advantages and other features and advantages of the disclosure are easily evident from the following detailed description when considered in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Further features, advantages and details appear in the following detailed description only as examples, the detailed description referring to the drawings; they show: Fig. 1 a top view of a motor vehicle comprising a battery assembly or battery system and a multiple drive system according to an exemplary embodiment; Fig. 2 a charging system comprising components of a vehicle drive system with an electric double-winding machine, according to an exemplary embodiment; Fig. 3 a section of an electrical double or multi-winding machine and the properties of the current vectors according to an exemplary embodiment; Fig. 4 a flowchart illustrating aspects of a procedure for controlling a vehicle charging system and / or charging an energy storage system according to an exemplary embodiment; Fig. 5A and Fig. 5B Contour diagrams showing aspects of an example of the procedure according to Fig. Figure 4 illustrates the estimation of optimal d-axis and q-axis currents used to supply a charging current to a vehicle battery system; and Fig. 6 a computer system according to an exemplary embodiment. DETAILED DESCRIPTION

[0025] The following description is merely exemplary and is not intended to limit the present disclosure, its application, or use. It should be recognized that throughout the drawings, corresponding reference numerals denote identical or corresponding parts and features.

[0026] According to exemplary embodiments, methods, devices, and systems are provided for supplying electrical power from a vehicle's battery system (e.g., an electric or hybrid vehicle) to an energy storage system, such as a battery in another vehicle. The embodiments can also be used to receive electrical power from a power source (e.g., a charging station) to provide charging to the battery system.

[0027] The embodiments of a charging system utilize a double-winding electric machine, such as an electric motor / generator with segmented windings. According to one embodiment, the electric machine is part of a vehicle's drive system (e.g., an electric or hybrid vehicle). The electric machine is, for example, a three-phase (or multi-phase) motor with two sets of three-phase (or multi-phase) windings. The winding sets are electrically isolated from each other, with each winding set connected to a corresponding inverter. For vehicle propulsion, one or both inverters are operated to provide alternating current (AC) to each phase of one or both winding sets.

[0028] The charging system and the drive system can be switched to different charging modes for charging the vehicle battery system or for providing charge to an external energy storage system (e.g., another vehicle or an electrical grid). One embodiment of a charging method involves determining a target or optimal combination of the q-axis and d-axis currents based on a model of the electric machine and a power transfer index. The power transfer index is calculated based on the active power parameters of the electric machine and corresponds to an energy output of the machine that is independent of the machine speed. This energy is a function of the d-axis and q-axis currents.According to one embodiment, the optimal d-axis and q-axis currents are calibrated by determining a maximum power per ampere (MPPA), with a charging current based on the optimal d-axis and q-axis current being fed into a winding set.

[0029] The embodiments described here offer numerous advantages and technical benefits. By operating a double-winding machine in an optimized manner that increases efficiency, these embodiments provide effective charging and discharging capabilities. Such increases are achieved, for example, by minimizing or reducing the current required to influence the target charging parameters (e.g., the charging power). Furthermore, these embodiments are applicable to a wide variety of charging and discharging operations.

[0030] In addition, the embodiments can utilize existing components and simplify vehicle systems, thereby reducing the number of components and the complexity of such systems. For example, the embodiments can eliminate the need for components such as an onboard charging module (OBCM) and a vehicle-to-load module, and allow for a reduction in the size of devices used to heat the vehicle battery systems. The OBCM can be eliminated because it has been found that the charging efficiency using the embodiments is at least as high as that of existing OBCMs.

[0031] The embodiments are not limited to use with any specific vehicle and can be applicable to various contexts. For example, the embodiments can be used with passenger cars, trucks, aircraft, construction machinery, agricultural equipment, automated factory equipment, and / or any other device or system that incorporates multiple drives and / or multiple conversion devices.

[0032] Fig. Figure 1 shows an embodiment of a motor vehicle 10 comprising a vehicle body 12 that at least partially defines a passenger compartment 14. The vehicle body 12 also carries various vehicle subsystems, including a drive system 16 and other subsystems to support the functions of the drive system 16 and other vehicle components, such as a brake subsystem, a suspension system, a steering subsystem, and, if the vehicle is a hybrid electric vehicle, a fuel injection subsystem, an exhaust subsystem, and others.

[0033] The vehicle 10 can be an electric vehicle (EV), a hybrid vehicle, or any other vehicle having multiple electric motors or drive systems. According to one embodiment, the vehicle 10 is an electric vehicle containing multiple motors and / or drive systems. The drive system 16, for example, is a multiple drive system comprising a first drive system 20 and a second drive system 30. The first drive system 20 includes a first electric motor 22 and a first inverter module 24, as well as other components, such as a cooling system 26. The second drive system 30 includes a second electric motor 32 and a second inverter module 34, and other components, such as a cooling system 26. B. a cooling system 36. The inverter modules 24 and 34 (e.g. the drive power inverter units or TPIMs) convert any direct current power (DC power) from a high-voltage battery pack (HV battery pack) 34 into multi-phase (e.g.Two-phase, three-phase, six-phase, etc.) alternating current power (AC power) to drive motors 22 and 32.

[0034] As in Fig. As shown in Figure 1, the drive systems are configured such that the first electric motor 22 drives the (not shown) front wheels and the second electric motor 32 drives the (not shown) rear wheels. However, the embodiments are not limited in this way, as there can be any number of drive systems and / or motors at different locations (e.g., one motor driving each wheel, dual motors per axle, etc.). Furthermore, the embodiments are not limited to a dual drive system, as they can be used with a vehicle with any number of motors and / or power inverters.

[0035] According to one embodiment, the motor 20 and / or the motor 30 are multi-winding or double-winding electric machines. The motor 20 and the motor 30 are, for example, machines with segmented windings with at least two sets of electrically insulated windings. Each inverter module 24 and 34 contains at least two inverter circuits (inverters) so that each inverter can control the current through a corresponding set of windings.

[0036] The drive system 20 and the drive system 30 are electrically connected to a battery system 40 and can also be electrically connected to other components, such as the vehicle electronics (e.g., via an auxiliary power module or APM 32). The battery system 40 can be configured as a rechargeable energy storage system (RESS).

[0037] According to one embodiment, the battery system 40 includes a battery assembly, such as the battery pack 44. The battery pack 44 contains several battery modules 46, each battery module 46 containing a number of (not shown) individual cells. The battery system 40 may also include a monitoring unit 48 configured to receive measured values ​​from the sensors 50. Each sensor 50 may be an array or system with one or more sensors for measuring various battery and environmental parameters, such as temperature, current, and voltages.

[0038] The vehicle 10 can include a charging system that can be used to charge the battery pack 44 and / or to supply power from the battery pack 44 to charge another energy storage system (e.g., V2V charging). The charging system includes at least one dual inverter and an associated multi-winding electric machine that can be selectively connected to a charging port 58. The motor 20 and / or the motor 30 are, for example, multi-winding electric machines, such as machines with segmented windings, wherein the inverter 24 and / or the inverter 34 are configured as dual or multi-inverter modules.

[0039] The charging port 58 contains or is connected to a bidirectional charger that enables bidirectional power transfer. The charging system can be used to transfer power from the battery pack 44 to charge an external energy storage system (e.g., another vehicle, a portable energy storage system, a utility grid, etc.). The charging system is configured, for example, for vehicle-to-vehicle (V2V), vehicle-to-utility grid (V2G), and / or vehicle-to-everything (V2X) charging.

[0040] The charging system can be used to transfer power from an external energy storage system (e.g., a charging station, a utility grid, a donor vehicle battery system) to charge the battery pack 44. The charging system is configured, for example, for legacy or conventional charging, DC fast charging (DCFC), V2V charging, utility-to-vehicle charging (G2V charging), and / or load-to-vehicle charging (L2V charging). Such power transfers can be referred to as discharge operations or processes.

[0041] Any number of different controllers can be used to control the functions of the charging system and / or other vehicle systems. A controller contains any suitable processing device or unit and can utilize an existing controller, such as a battery system controller (e.g., a RESS or battery management system controller) and / or the controllers in the powertrain systems. A Controller 60, for example, may be used to control charging operations, as discussed here.

[0042] The vehicle 10 also includes a computer system 62, which contains one or more processing devices 64 and a user interface 66. The computer system 62 can, for example, communicate with the charging system controller to provide it with commands in response to user input. The various processing devices, modules, and units can communicate with each other via a communication device or system, such as a CAN bus or a TCP bus.

[0043] Each of the switches described here can be any suitable type of switch, such as a mechanical contactor, an electronic switch, or a semiconductor switching device. Any suitable semiconductor or electronic device can be used as a switch. The switches can include, for example, semiconductor relays or transistors, such as insulated-gate silicon bipolar transistors (IGBTs) and field-effect transistors (FETs). Examples of FETs include metal-oxide-semiconductor FETs (MOSFETs), silicon-based MOSFETs (Si-MOSFETs), silicon-carbide MOSFETs (Sic-MOSFETs), high-electron-mobility gallium-nitride transistors (HEMTs) (GaN transistors), and silicon-carbon junction FETs (SiC-JFETs). Other examples of switches that can be used include diamond, gallium oxide, and other wide bandgap (WBG) semiconductor-based power switching devices.

[0044] Fig. Figure 2 represents the components of the drive system and the battery system that form part of the charging system. Although only the motor 20 and the inverter module 24 are shown and discussed, it should be noted that the motor 30 and the inverter 34 (in addition to or instead of the motor 20 and the inverter module 24) can be configured similarly.

[0045] According to one embodiment, the electric motor 20 is a double-winding motor comprising two three-phase (or multi-phase) winding sets. The motor 20 is, for example, a machine with segmented windings having at least two winding sets. The winding sets comprise a primary winding 70 with a first set of phase windings A1, B1, C1 and a secondary winding 72 with a second set of phase windings A2, B2, C2. The primary winding 70 is electrically insulated from the secondary winding 72, with the windings 70 and 72 having their respective neutral points N1 and N2.

[0046] The inverter module 24 contains a first or primary inverter circuit (inverter) 74, which is electrically connected to the first winding 70, and a second or secondary inverter 76, which is electrically connected to the second winding 72. The inverters contain switch sets in half-bridge configurations for controlling the windings. The primary inverter 74 contains switches S1 and S2, which are connected to phase winding A1, switches S3 and S4, which are connected to phase winding B1, and switches S5 and S6, which are connected to phase winding C1. A capacitor Cp is connected in parallel to the switch sets of inverter 76.

[0047] The secondary inverter 76 contains switches S7 and S8, which are connected to phase winding A2, switches S9 and S10, which are connected to phase winding B2, and switches S11 and S12, which are connected to phase winding C2. A capacitor Cs is connected in parallel to the switch sets in inverter 76.

[0048] Capacitors Cp and Cs operate to stabilize the voltage and limit current fluctuations and ripple. According to one embodiment, inverters 74 and 76 share a common capacitor.

[0049] The drive system, which includes the motor 20, can be switched to a drive operating mode in which the primary inverter 74 and / or the secondary inverter 76 drive the motor 20. In one exemplary drive operating mode, a switch 78 is closed, and both inverters 74 and 76 drive the motor 20. In another drive operating mode, the switch 78 is open, and the inverters 74 and 76 can be used independently to drive the motor.

[0050] The drive system can be set to any of the various charging modes. When the system is in a charging mode, the motor 20 is in a torque-free state, and the switch 78 can be open to disconnect the inverter 76 from the battery pack 44. During charging of the battery pack 44, the inverter 74 and the inverter 76 are used to control a charging current. The windings 70 and 72 act as an insulated transformer for power transmission. The amount of power provided during charging or discharging can be controlled based on the motor speed.

[0051] The charging modes include, for example, a mode in which the battery pack 44 is charged by an external power source. The external power source can be a charging station, a portable charger, an electrical grid, or the battery system of another vehicle (V2V charging). The charging system can provide a comprehensive variety of charging modalities, including conventional or legacy charging and DC fast charging (DCFC).

[0052] The charging modes can include one or more discharging modes, in which energy is supplied from the battery pack 44 to charge an external energy storage system. Examples of discharging modes include V2G charging, vehicle-to-trailer charging, V2V charging, V2X charging, and others.

[0053] The charging port 58 contains or is connected to a charger 80. According to one embodiment, the charger 80 is a universal charger that includes capabilities for transmitting and controlling alternating or direct current during charging and discharging.

[0054] As in Fig. As shown in Figure 2, the charger 80 includes, for example, an AC charger 82 connected to a switch set 84. The AC charger 82 contains components for controlling the magnitude of the AC current through the charging port 58. The charger 80 also includes a DC charger 86 and a pair of switches 88.

[0055] The switch set 84 enables bidirectional AC charging. By actuating the appropriate switches, single-phase, two-phase, or three-phase current can be fed into the AC charger 82. An additional converter 90 for controlling the AC current may be included, containing the switch sets for each phase and a capacitor Ca. A first switch set S14 and S15 controls a first AC phase, a second switch set S16 and S17 controls a second AC phase, and a third switch set S18 and S19 controls a third AC phase. Each half-bridge of the additional converter 90 is connected to one of the switch sets 84.

[0056] According to one embodiment, the drive system is used to control the energy transfer to and from a vehicle battery system via a control method that is used to supply the charging current according to a reference current value. According to one embodiment, the reference current value is a minimum charging current that can be applied to achieve or maintain a target charging power. The method provides charging or discharging at a maximum or target power while reducing or minimizing power loss or energy loss.

[0057] The aspects of the procedure are discussed in connection with Fig. 2 and also in connection with an example of a model of engine 20, which is in Fig. 3 is shown, described.

[0058] Fig. Figure 3 represents a section of a stator 100, a segment of the primary winding 70, and a segment of the secondary winding 72. A segment of a tertiary winding 102 is also shown, which may be included, for example, to reduce the asymmetry in the primary winding 70 and to redistribute the flow of fault currents. Fig. 3 also represents a section of a rotor 104 which contains a set of permanent magnets 106.

[0059] Fig. Figure 3 also represents the current vectors associated with windings 70 and 72. The current vectors contain a vector i2, representing the current through secondary winding 72, and a vector i1, representing the current through primary winding 70. Each vector has a q-axis component (a q-axis current) and a d-axis component (a d-axis current). The primary current vector i1 has a d-axis current i d1 and a q-axis current i q1on, while the secondary current vector i2 carries a d-axis current i d2 and a q-axis current i q2 exhibits the following. The current vectors i1 and i2 are symmetrical about the d-axis. The d-axis currents i d1 and id2 are both positive and have the same amplitude. The q-axis currents i q1 and iq2 have the same amplitude, but opposite signs.

[0060] During rotation, when the motor 20 is in a drive mode, the voltage and current of the primary winding 70 are in phase with the voltage and current of the secondary winding 72, and the motor 20 converts electrical power into mechanical power. The motor 20 can be switched to a regeneration mode, in which it converts mechanical power into electrical power. When the motor 20 is in a charging mode, the voltages of the primary winding 70 and the secondary winding 72 are in phase, while the current of the primary winding 70 is out of phase with the current of the secondary winding 72 (e.g., shifted by 180 degrees). In the charging mode, power flows from one winding to another, with the motor 20 acting as a transformer.

[0061] During power transmission at zero torque, the motor 20 is in a charging mode, with the current vectors i1 and i2 rotating at synchronous speeds when the rotor 104 rotates. The speed of the rotor 104 can be varied based on the power demand.

[0062] Fig. Figure 4 illustrates embodiments of a method 200 for controlling energy transfer. The energy transfer can be carried out to charge a battery system in a vehicle by controlling the charging current supplied by an external power source and / or by controlling the charging current supplied by the battery system to an external energy storage system.

[0063] Aspects of Method 200 can be executed by a single processor or a combination of processors. For example, if the method is used to supply power to a load from multiple battery systems in a vehicle, one or more controllers can be used in the vehicle. According to other examples, such as charging one or more vehicles from a charging station, the method can be executed by a controller in the charging station and / or one or more controllers within one or more connected vehicles.

[0064] It is stated that the process 200 is not so restricted and can be carried out by any suitable processing device or processing system or combination of processing devices.

[0065] Procedure 200 contains a number of steps or phases represented by blocks 201-205. Procedure 200 is not restricted in the number or order of its steps, as some of the steps represented by blocks 201-205 may be performed in a different order than described below, or fewer than all of the steps may be performed.

[0066] The following discussion concerns the process 200 in conjunction with the motor 20, the drive system and the battery system 40, which are located in Fig. 2 and Fig. Figure 3 is shown for illustration. Method 200 can be implemented similarly in conjunction with motor 30. Additionally, method 200 can be implemented with any suitable system comprising an electric multi-winding machine and an energy storage device, and is therefore not limited to the systems described here.

[0067] In block 201, the controller 60 (and / or another processing device, such as a RESS controller, a battery management system controller (BMS controller), etc.) receives a request for power transfer between the battery system 40 and an external power source or energy storage system.

[0068] The requirement can be to provide power for an external energy storage system, such as another vehicle for V2V charging. According to other embodiments, the requirement is to charge the battery system 40 from a charging station or another energy source.

[0069] In block 202, the controller 60 receives or determines the power transmission or charging parameters, such as the target charging voltage or maximum voltage, the target charging power and the motor parameters (e.g., the winding characteristics, such as the number of turns in each winding set 70 and 72).

[0070] In block 203, the controller 60 evaluates the power transfer capability of the motor 20 when the motor 20 is in a charging mode (power transfer mode). This evaluation is based on the active power output of the motor 20.

[0071] The power transfer capability can be determined by measuring or calculating a power transfer index. According to one embodiment, the power transfer index is an energy E (i.e., the amount of energy transferred as a function of the electric angle) that is a function of the d-axis and q-axis currents.

[0072] According to one embodiment, the energy E is derived from the following equation for active power (P): P=ωre32(λd2iq2−λq2id2), or P=ωre32((Lmdid1+Ldid2+λpm)iq2−(Lmqiq1+Lqiq2)id2) where ω re The engine speed is 20. λ d2is the d-axis flux linkage of the secondary winding 72, k q2 is the q-axis flux linkage of the secondary winding 72 and λ pm The flux linkage of the permanent magnets is 106. L md is the d-axis mutual inductance between the two windings, L mq is the q-axis mutual inductance between the two windings, L d is the d-axis winding inductance and L q is the q-axis winding inductance.

[0073] E can be derived from the equation above as follows: E=Pωre=32(λd2iq2−λq2id2), or E=32((Lmdid1+Ldid2+λpm)iq2−(Lmqiq1+Lqiq2)id2)

[0074] The energy E can be calibrated, for example, by experimentally operating the motor 20 and / or via a simulation. A model of the motor 20, such as a dq model (whose aspects in Fig. Figure 3 shows the process used to simulate operation and determine or calibrate the optimal values ​​of the d-axis current and the q-axis current for different stages of energy transfer. The optimal values ​​can be stored as a lookup table or other data structure for use when calibrating an optimal charging current to achieve a target power output.

[0075] The index is used to determine an optimal combination of the d-axis and q-axis currents. According to one embodiment, the optimal combination refers to the d-axis and q-axis currents that provide a target power to be transmitted with minimal power consumption.

[0076] In block 204, the motor 20 is put into a charging mode by electrically connecting the charger 80 to the external source or the external storage system. For DC power transmission, the switch pair 88 is closed, with all switches of the switch set 84 being open. For AC power transmission, the switch pair 88 is open, with at least one switch of the switch set 84 being closed.

[0077] In block 205, energy transfer (charging or discharging) is initiated by receiving a charging current (if energy transfer is used to charge battery pack 44) or generating a charging current (if energy transfer is used to charge an external energy storage system).

[0078] Power transfer is controlled by setting or controlling the magnitude of the charging current based on a maximum power per ampere (MPPA) control methodology to supply a charging current based on minimum values. For example, the Controller 60 periodically receives voltage and current measurements, determines the actual d-axis and q-axis currents, and compares them to a limit value that includes the minimum d-axis and q-axis currents required to produce a target power level. An example of MPPA control is shown in the Fig. 5A and Fig. 5B shown, which will be discussed further here.

[0079] The charging current can be controlled in real time. Comparison with target values ​​and control of the charging current can be performed continuously in real time (e.g., generating current sensor and other sensor outputs at each sampling point).

[0080] To control AC charging (receiving AC power from a power supply network or other external source), AC power is received via the charger 82, with the charging current being set via the charger 82 according to the setpoints.

[0081] The charging current flows through the auxiliary converter 90, which can be controlled to adjust parameters such as phase and voltage. The charging current then flows through the inverter 76 to the phase windings A2, B2 and / or C2, with windings 70 and 72 operating as an isolated transformer.

[0082] Inverter 74 is used as a synchronous active pulse-width modulation rectifier (PWM rectifier) ​​to convert alternating current to direct current for charging the battery pack and controlling power. Additionally, the switches in the auxiliary converter 90 can be used to perform power factor correction (PFC), which reduces the harmonic distortion of the alternating current supplied to the inverter module 24 (i.e., shapes the mains current to produce a current waveform close to a sine wave fundamental and aligns the phase with the voltage from the external source).

[0083] To control the power transfer from battery pack 44 to an external system (i.e., the discharging), the direct current from battery pack 44 is converted into alternating current by inverter 74, with the alternating current being fed into phase windings A1, B1 and / or C1. Windings 70 and 72, in turn, act as a transformer (optionally for stepping up or stepping down the voltage), with the alternating current flowing through inverter 76 and being output to supply charge to the external system.

[0084] To control DC charging (e.g., DCFC charging) or discharging (e.g., V2V), all switches 84 are open and the switch pair 88 is closed. If the voltage of the battery pack 44 is the same as the received voltage, switch 78 is closed, and the received DC power is fed directly into the battery pack 44.

[0085] If the voltages are different, switch 78 is open, with the two winding sets operating as an isolated transformer and the two inverters 74 and 76 being used as an active double-bridge DC-DC converter to control the power in both directions. The voltage can be increased, for example, by appropriately controlling the switches in inverters 74 and 76.

[0086] The Fig. 5A and Fig. 5B presents aspects of an example of procedure 200 and illustrates how the optimal d-axis and q-axis currents are determined. Fig. 5A is a contour diagram 210 of the energy E as a function of the d-axis current (i d2 ) in winding 72 (e.g. through one or more phases A2, B2 and C2) and the q-axis current (i q2) in winding 72, as determined by modeling and / or calibration. The currents are expressed in amperes (A), while the energy E is expressed in kilowatt-seconds per radian (kWs / rad).

[0087] The contours reflect the values ​​of E for different combinations of i. d2 - and i q2 -Sizes are represented and are color-coded, as shown by legend 212. A contour 214, for example, represents the combinations of the i d2 - and i q2 -values ​​corresponding to an energy of 40 kW / s, while a contour 216 represents the combinations of the i d2 - and i q2 -values ​​represented that correspond to an energy of 20 kW / s.

[0088] Fig. Figure 5B presents an example of the results of the estimation of the d- and q-axis currents shown in contour diagram 220. Contour diagram 220 represents the power P as a function of the d-axis current (i d) and the q-axis current (i q2 ) represents. Lines 222 represent different current amplitudes.

[0089] Diagram 220 also shows different power levels for different motor speeds. Diagram 220 can be interpreted by converting energy E into power P based on the motor speed (i.e., P = E * ω). re ) are generated. Such power limits can be nominal limits or limits determined through modeling or experimentation. Curve 224, for example, represents the power P as a function of i. d and i q2 for a motor speed (i.e., the mechanical speed of a rotor) of approximately 1000 min -1 (revolutions per minute), curve 226 represents the power P for an engine speed of approximately 2000 rpm -1 Curve 228 represents the power P for an engine speed of approximately 4000 rpm. -1and curve 230 represents the power P for an engine speed of approximately 6000 rpm -1 .

[0090] A curve 232 represents a maximum power per ampere (MPPA) determined as part of a control procedure, as discussed above. The relationship shown by curve 232 is used by the controller in this example to determine the magnitude of an applied charging current.

[0091] Fig. Figure 6 illustrates the aspects of an embodiment of a computer system 240 that can perform various aspects of the embodiments described herein. The computer system 240 includes at least one processing device 242, which generally contains one or more processors, for performing the aspects of the image acquisition and analysis methods described herein.

[0092] The components of the computer system 240 include the processing device 242 (such as one or more processors or one or more processing units), a memory 244, and a bus 246 that connects various system components, including the system memory 244, to the processing device 242. The system memory 244 can be a non-transient, computer-readable medium and can contain various media readable by a computer system. Such media can be any available media accessible through the processing device 242 and include both volatile and non-volatile media, as well as removable and non-removable media.

[0093] The system memory 244 contains, for example, non-volatile memory 248, such as a hard disk drive, and may also contain volatile memory 250, such as read / write memory (RAM) and / or cache memory. The computer system 240 may also contain other removable / non-removable, volatile / non-volatile computer system storage media.

[0094] System memory 244 can contain at least one program product with a set (e.g., at least one) of program modules configured to perform the functions of the embodiments described herein. System memory 244 stores, for example, various program modules that generally perform the functions and / or methodologies of the embodiments described herein. A module 252 can be included for performing the functions relating to acquiring signals and data, while a module 254 can be included for performing the functions relating to controlling power transmission, as discussed herein. System 244 is not so restricted, as it can contain other modules.As the term "module" is used here, it refers to a processing circuit arrangement that may include an application-specific integrated circuit (ASIC), an electronic circuit, a (shared, dedicated or grouped) processor and memory that executes one or more software or firmware programs, a combinational logic circuit and / or other suitable components that provide the described functionality.

[0095] The processing device 242 can also communicate with one or more external devices 256, such as a keyboard, a pointing device, and / or any other devices (e.g., a network card, a modem, etc.), which enable the processing device 242 to communicate with one or more other computing devices. Communication with various devices can take place via the input / output (I / O) interfaces 264 and 265.

[0096] The processing device 242 can also communicate via a network adapter 268 with one or more networks 266, such as a local area network (LAN), a wide area network (WAN), a bus network, and / or a public network (e.g., the Internet). It should be recognized that, although not shown, other hardware and / or software components can be used in conjunction with the computer system 40. Examples include, but are not limited to: microcode, device drivers, redundant processing units, external disk drive arrangements, RAID systems, and data archive storage systems, etc.

[0097] The terms "one" and "an" do not denote a quantity limitation, but rather indicate the presence of at least one of the designated element. The term "or" means "and / or" unless the context clearly indicates otherwise. References throughout the patent specification to "an aspect" mean that a particular element (e.g., a feature, a structure, a step, or a property) described in connection with that aspect is contained in at least one aspect described therein and may or may not be present in other aspects. Furthermore, it should be understood that the described elements in the various aspects can be combined in any suitable manner.

[0098] When an element, such as a layer, film, area, or substrate, is described as being "on" another element, it may be located directly on top of that element, or there may be intervening elements. Conversely, when an element is described as being "directly on" another element, there are no intervening elements.

[0099] Unless otherwise specified herein, all testing standards are the most recent standard in force since the date of filing of this application or, if priority is claimed, the date of filing of the earliest priority application in which the testing standard appears.

[0100] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as they are generally understood by a person skilled in the art in the field to which this invention belongs.

[0101] While the above disclosure has described exemplary embodiments, those skilled in the art recognize that various modifications can be made and elements can be replaced by their equivalents without altering its scope of protection. Furthermore, many modifications can be made to adapt a particular situation or material to the teachings of the disclosure without altering its essential scope of protection. Therefore, it is intended that the present disclosure is not limited to the specific embodiments disclosed, but includes all embodiments that fall within its scope of protection.

Claims

[1] Energy transmission system of a vehicle, comprising: a multi-winding motor including a first set of windings and a second set of windings, the multi-winding motor connected to a battery system; a first inverter connected to the first set of windings; a second inverter connected to the second set of windings; and a controller configured to receive a request for power transfer, place the multi-winding motor in a charging mode, and control the first inverter and the second inverter to control a charging current through the multi-winding motor at a target power when the multi-winding motor is in a no-torque state, wherein the controller is configured to control the charging current through the first inverter and the second inverter such that a first current vector associated with the first set of windings and a second vector associated with the second set of windings are symmetric about a d-axis and the multi-winding motor operates as a transformer, wherein the control of the first inverter and the second inverter provides power transfer between the first set of windings and the second set of windings. [2] The system of claim 1, wherein the controller is configured to control the charging current based on a charging current reference value derived from a calibration of an optimum value of a d-axis current and an optimum value of a q-axis current, the optimum values being determined based on a power transmission capability of the multi-winding motor. [3] The system of claim 2, wherein the charging current reference value is a minimum magnitude of the charging current that can be supplied to achieve a target charging power. [4] The system of claim 2, wherein the power transfer capability is estimated based on an energy relation indicating an energy E as a function of the d-axis current and the q-axis current. [5] The system of claim 4, wherein the power transfer capability is used to determine a maximum power per ampere (MPPA) for a given engine speed. [6] The system of claim 5, wherein the MPPA dictates a minimum charging current for a given engine speed, the minimum charging current being determined based on the optimum value of the d-axis current and the optimum value of the q-axis current. [7] The system of claim 1, further comprising a switch configured to selectively connect the first inverter to the battery system, the switch configured to be closed when the vehicle is in a propulsion mode. [8] The system of claim 7, wherein the charging current is an alternating current, the switch is configured to be open to place the multi-winding motor in the charging mode, and controlling the first inverter and the second inverter includes operating the first set of windings and the second set of windings as an isolated transformer to transfer power between the first set of windings and the second set of windings. [9] A method for transferring energy to or from a battery system of a vehicle, the method comprising: Receiving a request for energy transfer at a controller connected to a charging system of the vehicle, the charging system including a multi-winding motor including a first set of windings and a second set of windings, a first inverter connected to the first set of windings, and a second inverter connected to the second set of windings, the multi-winding motor being connected to the battery system; Putting the multi-winding motor into a charging mode; and Controlling the first inverter and the second inverter to control a charging current through the multi-winding motor at a target power when the multi-winding motor is in a no-torque state, wherein the charging current is controlled by the first inverter and the second inverter such that a first current vector associated with the first set of windings and a second vector associated with the second set of windings are symmetric about a d-axis and the multi-winding motor operates as a transformer, wherein controlling the first inverter and the second inverter provides power transfer between the first set of windings and the second set of windings. [10] The method of claim 9, wherein the control of the charging current is based on a reference charging current value derived from a calibration of an optimum value of a d-axis current and an optimum value of a q-axis current, the optimum values being determined based on a power transmission capability of the multi-winding motor, and the reference charging current value being a minimum magnitude of the charging current that can be supplied to achieve a target charging power.

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