AC charging of a dc battery pack of an electric vehicle using field-oriented control

Abstract

This disclosure provides a method comprising coupling a charging port to an inverter and an alternating current (AC) motor. The method further includes: performing field-oriented control (FOC) to control the inverter and motor, converting AC power received from the charging port into a first direct current (DC) power, and using the first DC power to charge a DC battery pack. Charging the DC battery pack using the first DC power may include: using a DC-DC converter to convert the first DC power into a second DC power, and using the second DC power to charge the DC battery pack.

Description

[0001] introduction The information provided in this section is for the purpose of presenting the overall context of this disclosure. The work of the currently named inventors—to the extent described in this section—and aspects of this description that may otherwise not qualify as prior art at the time of filing are neither expressly nor implicitly considered to be prior art to this disclosure.

[0002] Field-oriented control (FOC), also known as vector control, is a method for controlling the torque and speed of electric motors, particularly in applications involving alternating current (AC) motors, such as induction motors and permanent magnet synchronous motors (PMSMs). FOC is widely used in applications such as electric vehicles (EVs), robotics, and industrial automation due to its ability to provide smooth and efficient motor operation across a wide range of speeds and loads.

[0003] This disclosure generally relates to AC charging of DC battery packs in electric vehicles (EVs) using FOC. Summary of the Invention

[0004] One aspect of this disclosure provides a vehicle including an alternating current (AC) motor having a rotor, a battery pack, an inverter, a charging port, data processing hardware, and memory hardware. The battery pack is configured to provide a first direct current (DC) power. The inverter is configured to convert the first DC power provided by the battery pack into first AC power for powering the motor. The charging port is configured to receive a second AC power from an external AC power source. The memory hardware communicates with the data processing hardware and stores instructions that, when executed by the data processing hardware, cause the data processing hardware to perform operations. These operations include: selectively coupling the charging port to the inverter and the motor; performing field-oriented control (FOC) to control the inverter and the motor to convert the second AC power into a second DC power; and using the second DC power to charge the battery pack.

[0005] Implementations of this disclosure may include one or more of the following optional features. In some implementations, the vehicle further includes a DC-DC converter, wherein charging the battery pack using the second DC power includes: converting the second DC power to a third DC power using the DC-DC converter, and charging the battery pack using the third DC power. In some examples, performing FOC to control the inverter and motor to convert the second AC power to the second DC power includes: controlling the reference frame to be substantially aligned with the rotor position, controlling the d-axis current command to be sinusoidal, and controlling the q-axis current to be fixed. Additionally or alternatively, performing FOC to control the inverter and motor to convert the second AC power to the second DC power includes: performing a resonant controller to regulate the current at a predetermined frequency. Additionally or alternatively, performing FOC to control the inverter and motor to convert the second AC power to the second DC power includes: performing current control in the inner loop, wherein the outer loop performs voltage or power control.

[0006] In some examples, performing FOC to control the inverter and motor to convert a second AC power to a second DC power includes: performing a phase-locked loop (PLL) configured to provide a stable grid voltage measurement, and using that stable grid voltage measurement as a reference for aligning the grid current. In some implementations, the motor includes a permanent magnet motor, and the operation further includes pre-aligning the motor position such that the d-axis of the rotor is aligned with a phase of the motor at 0 degrees or 180 degrees, with the charging port connected to that phase.

[0007] In some implementations, performing FOC to control the inverter and motor to convert the second AC power to the second DC power includes: performing a sensorless method of pulsating vector excitation (PVE) that uses the voltage response on the q-axis of the estimated reference frame to allow alignment of the d-axis of the estimated reference frame with the d-axis of the rotor's magnetic field. Additionally or alternatively, performing FOC to control the inverter and motor to convert the second AC power to the second DC power includes: using gear lashing or a clutch to perform initial rotor alignment. Additionally or alternatively, performing FOC to control the inverter and motor to convert the second AC power to the second DC power includes: adding a small β-axis or q-axis current command to generate a small average magnetic torque, thereby repositioning the rotor when rotor movement occurs. Additionally or alternatively, performing FOC to control the inverter and motor to convert the second AC power to the second DC power includes: using average reluctance torque by injecting a small amount of AC current on the β-axis or q-axis to reposition the rotor when rotor movement occurs.

[0008] In some examples, performing FOC to control the inverter and motor to convert a second AC power to a second DC power includes: performing a rotor position controller, which includes at least one of a proportional-integral-derivative (PID) controller, a PID controller in series with an integrator, or a lead / lag compensator. Additionally or alternatively, performing FOC to control the inverter and motor to convert a second AC power to a second DC power includes: performing current regulation using a rotating or stationary reference frame, using an α-β signal, or an abc signal. Additionally or alternatively, performing FOC to control the inverter and motor to convert a second AC power to a second DC power includes: feeding forward the grid voltage to regulate the current. Additionally or alternatively, performing FOC to control the inverter and motor to convert a second AC power to a second DC power includes: performing field winding current regulation to shut off the rotor field or adjust the rotor field level to achieve at least one of a desired machine inductance level, machine saliency, or grid voltage synchronization, thereby allowing torque reduction. In some implementations, the operation also includes reversing the direction of grid power flow between grid-to-vehicle operating mode and vehicle-to-grid operating mode.

[0009] Another aspect of this disclosure provides a system comprising an alternating current (AC) motor having a rotor, a battery pack configured to provide a first direct current (DC) power, an inverter configured to convert the first DC power from the battery pack into first AC power for driving the motor, a charging port configured to receive a second AC power from an AC power source, data processing hardware, and memory hardware in communication with the data processing hardware, the memory hardware storing instructions that, when executed by the data processing hardware, cause the data processing hardware to perform operations. The operations include selectively coupling the charging port to the inverter and the motor, performing field-oriented control (FOC) to control the inverter and the motor to convert the second AC power into second DC power, and using the second DC power to charge the battery pack.

[0010] Implementations of this disclosure may include one or more of the following optional features. In some implementations, the system further includes a DC-DC converter, wherein charging the battery pack using the second DC power includes: converting the second DC power to a third DC power using the DC-DC converter, and charging the battery pack using the third DC power.

[0011] Another aspect of this disclosure provides a computer-implemented method executed by data processing hardware, which causes the data processing hardware to perform operations. The operations include: coupling a charging port to an inverter and an AC motor; performing field-oriented control (FOC) to control the inverter and the motor to convert AC power received from the charging port into a first direct current (DC) power; and using the first DC power to charge a DC battery pack.

[0012] Implementations of this disclosure may include one or more of the following optional features. In some implementations, charging the battery pack using the first DC power includes: converting the first DC power to a second DC power using a DC-DC converter, and charging the battery pack using the second DC power. Attached Figure Description

[0013] The accompanying drawings described herein are for illustrative purposes only for selected configurations and are not intended to limit the scope of this disclosure.

[0014] Figure 1 This is a view of an example electric vehicle (EV) including a charging system, based on the principles of this disclosure.

[0015] Figure 2 yes Figure 1 A schematic diagram of the charging system.

[0016] Figure 3 yes Figure 1 Another schematic diagram of the charging system.

[0017] Figure 4 This is a flowchart of another example operational arrangement for using field-oriented control (FOC) to AC charge the DC battery pack of an electric vehicle.

[0018] Throughout the accompanying drawings, the corresponding reference numerals indicate the corresponding components. Detailed Implementation

[0019] The example configuration will now be described more fully with reference to the accompanying drawings. Example configurations are provided so that this disclosure will be thorough and fully communicate the scope of this disclosure to those skilled in the art. Specific details, such as examples of specific components, devices, and methods, are set forth to provide a thorough understanding of the configurations disclosed herein. It will be apparent to those skilled in the art that the example configurations can be embodied in many different forms without the need for specific details, and the specific details and example configurations should not be construed as limiting the scope of this disclosure.

[0020] The terminology used herein is for the purpose of describing specific exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a (a, an)” and “the” may also be intended to include plural forms unless the context explicitly indicates otherwise. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein should not be construed as having to be performed in the specific order discussed or described unless specifically specified as such. Additional or alternative steps may be employed.

[0021] When an element or layer is referred to as being "on," "attached to," "connected to," "attached to," or "coupled to" another element or layer, it may be directly on, directly attached to, directly connected to, directly attached to, or directly coupled to the other element or layer, or one or more intermediate elements or layers may be present. Conversely, when an element is referred to as being "directly on," "directly attached to," "directly connected to," directly attached to, or directly coupled to another element or layer, no intermediate elements or layers may be present. Other terms used to describe relationships between elements should be interpreted in a similar manner (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the listed related items.

[0022] The terms “first,” “second,” “third,” etc., are used herein to describe various elements, components, regions, layers, and / or parts. These elements, components, regions, layers, and / or parts should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or part from another. Terms such as “first,” “second,” and other numerical terms do not imply order or sequence unless explicitly indicated by the context. Therefore, without departing from the teachings of the example configuration, the first element, component, region, layer, or part discussed below may be referred to as the second element, component, region, layer, or part.

[0023] In this application, including the following definitions, the term "module" may be replaced by the term "circuit". The term "module" may refer to, be part of, or include the following: application-specific integrated circuit (ASIC); digital, analog, or mixed-signal analog / digital discrete circuit; digital, analog, or mixed-signal analog / digital integrated circuit; combinational logic circuit; field-programmable gate array (FPGA); processor (shared, dedicated, or grouped) for executing code; memory (shared, dedicated, or grouped) for storing code executed by the processor; other suitable hardware components that provide the aforementioned functionality; or combinations of some or all of the foregoing, such as in a system-on-a-chip.

[0024] The term "code" as used above can include software, firmware, and / or microcode, and may refer to programs, routines, functions, classes, and / or objects. The term "shared processor" covers a single processor that executes some or all of the code from multiple modules. The term "group processor" covers a processor that, in conjunction with additional processors, executes some or all of the code from one or more modules. The term "shared memory" covers a single memory that stores some or all of the code from multiple modules. The term "group memory" covers memory that, in conjunction with additional memory, stores some or all of the code from one or more modules. The term "memory" may be a subset of the term "computer-readable medium." The term "computer-readable medium" does not cover transient electrical and electromagnetic signals propagating through a medium, and therefore can be considered tangible and non-transitory memory. Non-limiting examples of non-transitory memory include tangible computer-readable media that include non-volatile memory, magnetic storage devices, and optical storage devices.

[0025] The apparatus and methods described in this application can be implemented, in whole or in part, by one or more computer programs executed by one or more processors. The computer program includes processor-executable instructions stored on at least one non-transitory tangible computer-readable medium. The computer program may also include and / or depend on stored data.

[0026] A software application (i.e., a software resource) can refer to computer software that causes a computing device to perform a task. In some examples, a software application may be referred to as an "application," "App," or "program." Example applications include, but are not limited to, system diagnostic applications, system management applications, system maintenance applications, word processing applications, spreadsheet applications, messaging applications, media streaming applications, social networking applications, and gaming applications.

[0027] Non-transitory memory can be a physical device used to temporarily or permanently store programs (e.g., instruction sequences) or data (e.g., program state information) for use by a computing device. Non-transitory memory can be volatile and / or non-volatile addressable semiconductor memory. Examples of non-volatile memory include, but are not limited to, flash memory and read-only memory (ROM) / programmable read-only memory (PROM) / erasable programmable read-only memory (EPROM) / electrically erasable programmable read-only memory (EEPROM) (e.g., commonly used in firmware, such as boot programs). Examples of volatile memory include, but are not limited to, random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), phase-change memory (PCM), and disks or tapes.

[0028] These computer programs (also referred to as programs, software, software applications, or code) include machine instructions for a programmable processor and can be implemented using high-level procedural languages ​​and / or object-oriented programming languages, and / or assembly / machine languages. As used herein, the terms "machine-readable medium" and "computer-readable medium" refer to any computer program product, non-transitory computer-readable medium, apparatus, and / or device (e.g., disk, optical disk, memory, programmable logic device (PLD)) used to provide machine instructions and / or data to a programmable processor, including machine-readable media that receive machine instructions as machine-readable signals. The term "machine-readable signal" refers to any signal used to provide machine instructions and / or data to a programmable processor.

[0029] The various implementations of the systems and techniques described herein can be implemented in digital electronic and / or optical circuits, integrated circuits, specially designed ASICs (Application-Specific Integrated Circuits), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include implementations in one or more computer programs that are executable and / or interpretable on a programmable system including at least one programmable processor, which may be dedicated or general-purpose, coupled to receive and transmit data and instructions from a storage system, at least one input device, and at least one output device.

[0030] The processes and logic flows described in this specification can be executed by one or more programmable processors (also known as data processing hardware) that execute one or more computer programs to perform functions by manipulating input data and generating output. These processes and logic flows can also be executed by special-purpose logic circuitry, such as FPGAs (Field-Programmable Gate Arrays) or ASICs (Application-Specific Integrated Circuits). For example, processors suitable for executing computer programs include both general-purpose and special-purpose microprocessors, as well as any one or more processors of any kind of digital computer. Typically, the processor receives instructions and data from read-only memory or random access memory, or both. The basic elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Typically, a computer will also include one or more mass storage devices (e.g., magnetic disks, magneto-optical disks, or optical disks) for storing data, or be operatively coupled to receive data from or transfer data to these storage devices, or both. However, a computer does not necessarily need to have such devices. Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and memory devices, including, for example, semiconductor memory devices (e.g., EPROM, EEPROM, and flash memory devices); magnetic disks (e.g., internal hard disks or removable disks); magneto-optical disks; and CD-ROMs and DVD-ROMs. Processors and memory may be supplemented by dedicated logic circuitry or incorporated into dedicated logic circuitry.

[0031] To provide interaction with a user, one or more aspects of this disclosure can be implemented on a computer having a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor or touchscreen) for displaying information to the user, and optional keyboard and pointing devices (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback, such as visual, auditory, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input. Furthermore, the computer can interact with the user by sending documents to and receiving documents from the device used by the user; for example, by sending a webpage to a web browser on the user's client device in response to a request received from a web browser.

[0032] Unless otherwise expressly stated, the phrase “at least one of A, B, or C” is intended to refer to any combination or subset of A, B, and C, such as: (1) at least one A alone; (2) at least one B alone; (3) at least one C alone; (4) at least one A and at least one B; (5) at least one A and at least one C; (6) at least one B and at least one C; and (7) at least one A and at least one B and at least one C. Furthermore, unless otherwise expressly stated, the phrase “at least one of A, B, and C” is intended to refer to any combination or subset of A, B, and C, such as: (1) at least one A alone; (2) at least one B alone; (3) at least one C alone; (4) at least one A and at least one B; (5) at least one A and at least one C; (6) at least one B and at least one C; and (7) at least one A and at least one B and at least one C. Additionally, unless otherwise expressly stated, “A or B” is intended to refer to any combination of A and B, such as: (1) at least one A alone; (2) at least one B alone; and (3) A and B.

[0033] Field-oriented control (FOC), also known as vector control, is an advanced method for controlling the torque and speed of electric motors, particularly in applications involving alternating current (AC) motors such as induction motors and permanent magnet synchronous motors (PMSMs). FOC is widely used in applications such as electric vehicles (EVs), robotics, and industrial automation due to its ability to provide smooth and efficient motor operation across a wide range of speeds and loads. FOC operates by decoupling the stator current into two orthogonal components: one that generates the magnetic field (flux), and the other that generates torque. This decoupling allows for independent control of the motor's magnetic field and torque, similar to controlling a direct current (DC) motor, resulting in improved performance, efficiency, and dynamic response. By transforming the three-phase motor current into a two-axis coordinate system (direct (d) axis and quadrature (q) axis) aligned with the rotor magnetic field, FOC enables precise and smooth control of the motor's operation, making it ideal for applications requiring high performance and precision, such as EVs, robotics, and industrial automation.

[0034] Traditionally, RV battery packs are charged using a separate On-Board Charging Module (OBCM). The OBCM is a critical component that facilitates the conversion of AC power from external sources, such as residential or public charging stations, into DC power required to charge the vehicle's battery. Integrated within the vehicle, the OBCM is designed to efficiently manage the charging process, ensuring optimal battery health and lifespan. OBCMs typically include dedicated power electronics, control systems, and safety mechanisms to regulate voltage and current, prevent overcharging, and protect the vehicle from electrical faults. By enabling convenient and reliable charging, the OBCM plays a crucial role in the overall functionality and user experience of electric vehicles. However, traditional OBCMs require additional dedicated hardware (e.g., power factor correction (PFC) circuitry), increasing the complexity and cost of EVs. Furthermore, traditional OBCMs may suffer from current regulation issues and / or distortion during zero-crossings. Therefore, an improved method and circuitry are needed to charge EV battery packs.

[0035] In the disclosed configuration, a Field-Oriented Charge (FOC) is used to reuse the EV's inverter and one or more AC motors to convert grid-based AC power to DC power. The DC power can then be converted to DC power suitable for charging the EV's battery pack using a DC-DC converter. By using an FOC to reuse one or more motors and the inverter, the additional dedicated hardware of a traditional On-Balance Module (OBCM) is eliminated, reducing the complexity and cost of the EV. Furthermore, using an FOC for AC charging of the battery pack utilizes the FOC logic and modules already used to control the AC motor to propel the EV. Additionally, using an FOC for AC charging ensures proper alignment of stator flux with rotor position during AC charging, avoiding unwanted motor rotation or torque.

[0036] While the configurations shown and described herein relate to electric vehicles (e.g., cars, trucks, airplanes, trains, motorcycles, etc.), it should be understood that the disclosed configurations can be additionally or alternatively used to AC charge the DC battery packs of electric vehicles for any other type of equipment (e.g., drones, robots, bicycles, automated equipment, industrial equipment, etc.) using FOC. Here, the vehicle or equipment may be operated by personnel or independently.

[0037] Special Reference Figure 1Figures 2 and 3, together with charging system 12, illustrate an electric vehicle (EV) 10 (e.g., a car, truck, airplane, train, motorcycle, etc.). Vehicle 10 includes: one or more AC motors 14 (also referred to herein as motor 14), each motor including a corresponding rotor; a DC battery pack 15 configured to store and provide DC power; and an inverter 16 configured to convert the DC power provided by the battery pack 15 into AC power for powering motor(s)(s). FOC control module 20 performs FOC to control motor(s)(s), inverter 16, and battery pack 15 to power motor(s)(s) to propel vehicle 10. Specifically, FOC control module 20 decouples the stator current into two orthogonal components: one generates a magnetic field (flux), and the other generates torque. This decoupling allows for independent control of the motor's magnetic field and torque, similar to control of a DC motor, thereby improving performance, efficiency, and dynamic response. By transforming the three-phase motor current into a two-axis coordinate system (d-axis and q-axis) aligned with the rotor magnetic field, the FOC control module 20 enables precise and smooth control of the motor operation. The FOC control module 20 utilizes one or more sensors 17 to measure the motor's phase current, rotor position, and rotor speed, applies necessary mathematical transformations and control algorithms to the sensed phase current, rotor position, and rotor speed, and controls power electronics (e.g., inverter 16) to drive one or more motors 14 based on the calculated control signals.

[0038] The battery pack 15 may include any number and / or (one or more) types of battery cells. The FOC control module 20 may be stored and executed by, for example, the motor control module (MCM) 22 of the vehicle 10. Specifically, the MCM 22 may store, for example, memory hardware 24, information for execution. Figure 4 Instructions for operations shown or described herein. These instructions can be executed by the data processing hardware of the MCM 22 (e.g., processor 26) to perform the operations.

[0039] Charging system 12 can be used to AC charge the DC battery pack 14 of vehicle 10 using FOC. Charging system 12 includes a charging port 18 configured to receive AC power from an external AC power source 30 (such as a residential or public charging station). For charging battery pack 15, MCM 22 selectively couples charging port 18 to inverter 16 and one or more motors 14. Figure 3As shown, the MCM 22 connects one phase of the AC power received from the external power source 30 (e.g., between 85 volts and 270 volts) to one phase of motor(s) 14 by closing switches 321 and 322 and controlling relay 323, thereby selectively coupling the charging port 18 to the inverter 16 and motor(s) 14. Although Figure 3 It is described that one phase of the external power supply 30 is connected to a specific phase of the motor(s) 14, but that phase of the external power supply 30 may be connected to different phases of the motor(s) 14, or multiple phases of the external power supply 30 may be connected to multiple phases of the motor(s) 14.

[0040] Subsequently, the FOC control module 20 performs FOC to control the inverter 16 and the motor 14 to convert the AC power received from the external AC power source 30 into DC power at capacitor C2. The MCM 22 then uses this DC power to charge the battery pack 14. In the illustrated example, the MCM 22 charges the battery pack 14 by closing switches 331 and 322 of the battery disconnect unit (BDU) 330. In some implementations, a DC-DC converter 340 (see...) Figure 3 The DC power generated using inverter 16 and motor 14 is converted at capacitor C3 into DC power for charging battery pack 14. In particular, the DC power generated using inverter 16 and motor 14 may have a different voltage than the DC power generated by DC-DC converter 320.

[0041] In the illustrated example, BDU 330 also includes switches 333 and 334 for pre-charging inverter 16 and capacitor C1; and switches 333 and 335 for supplying power to inverter 16 to provide AC power to motor(s) 14 to propel vehicle 10.

[0042] In some implementations, performing FOC to control the inverter 16 and motor 14 to convert AC power received via charging port 18 to DC power includes: controlling the rotor reference frame to be substantially fixed, controlling the d-axis current command to be sinusoidal, and in some examples, controlling the q-axis current to be fixed (e.g., zero) to avoid torque generation. Additionally or alternatively, performing FOC to control the inverter 16 and motor 14 to convert AC power received via charging port 18 to DC power includes: performing a resonant controller to regulate the current at a predetermined frequency. Performing FOC to control the inverter 16 and motor 14 to convert AC power received via charging port 18 to DC power may also include: in addition to performing a conventional controller (e.g., a proportional-integral-derivative (PID) controller or a lead / lag compensator) in some examples, performing a resonant controller to regulate the current at a predetermined frequency for performing current control, wherein the current control may be performed in an inner loop, while the outer loop controls power or voltage. Performing FOC to control the inverter 16 and the motor 14 to convert AC power received via the charging port 18 into DC power may also include: performing a phase-locked loop, the phase-locked loop being configured to provide a stable grid voltage measurement, and using the stable grid voltage measurement as a reference for aligning the grid current.

[0043] In some examples, the motor includes a permanent magnet motor, and the FOC control module 20 pre-aligns the motor position such that the d-axis of the rotor is aligned with a phase of the motor 14 (e.g., the phase to which the charging port is connected). In some implementations, performing FOC to control the inverter 16 and the motor 14 to convert AC power to DC power includes aligning the motor 14 with the α-axis. Additionally or alternatively, performing FOC to control the inverter 16 and the motor 14 to convert AC power received via the charging port 18 to DC power includes using gear backlash or a clutch to perform initial rotor alignment. Additionally or alternatively, performing FOC to control the inverter 16 and the motor 14 to convert AC power received via the charging port 18 to DC power includes adding a small β-axis or q-axis current command to generate a small magnetic torque, thereby repositioning the rotor when rotor movement occurs. Performing FOC to control the inverter 16 and the motor 14 to convert AC power received via the charging port 18 into DC power may also include using average reluctance torque to reposition the rotor when rotor movement occurs by injecting a small amount of AC current on the β-axis or q-axis.

[0044] In some implementations, performing FOC to control the inverter 16 and motor 14 to convert AC power received via charging port 18 to DC power includes: performing a rotor position controller, which includes at least one of a PID controller, a PID controller in series with an integrator, or a lead / lag compensator. Additionally or alternatively, performing FOC to control the inverter 16 and motor 14 to convert AC power received via charging port 18 to DC power includes: performing current regulation using a rotating or stationary reference frame, using an α-β signal, or an abc signal.

[0045] In some examples, the FOC control module 20 reverses the direction of grid power flow between grid-to-vehicle operating mode and vehicle-to-grid operating mode. In some implementations, performing FOC to control the inverter 16 and motor 14 to convert AC power received via charging port 18 to DC power includes: feeding forward the grid voltage to regulate the current. Additionally or alternatively, performing FOC to control the inverter 16 and motor 14 to convert AC power received via charging port 18 to DC power includes: performing field winding current regulation to shut off the rotor magnetic field or adjust the rotor magnetic field level to achieve at least one of a desired machine inductance level, machine salient polarity, or grid voltage synchronization, thereby allowing torque mitigation. In some implementations, performing FOC to control the inverter and motor to convert a second AC power to a second DC power may also include: performing a pulsed vector excitation (PVE) sensorless method that uses the voltage response on the q-axis of the estimated reference frame to allow alignment of the d-axis of the estimated reference frame with the d-axis of the rotor magnetic field.

[0046] Figure 4 This is a flowchart of an example operational arrangement for a method of AC charging an electric vehicle's battery pack using FOC. These operations can be performed by data processing hardware (e.g., processor 26) based on instructions stored in memory (e.g., memory hardware 24). Many other ways of implementing method 400 can be adopted. For example, the execution order of operations can be changed, and / or one or more operations and / or interactions can be changed, eliminated, subdivided, or combined. Additionally, Figure 4 The operations can be performed sequentially and / or in parallel by, for example, separate processing threads, processors, devices, discrete logic, circuits, etc.

[0047] At operation 402, method 400 includes coupling charging port 18 to inverter 16 and (one or more) AC motors 14. At operation 404, method 400 includes performing FOC to control inverter 16 and (one or more) motors 14 to convert AC power received from charging port 18 into first DC power. At operation 406, method 400 includes using DC-DC converter 330 to convert the first DC power into second DC power. At operation 408, method 400 includes using the second DC power to charge battery pack 15.

[0048] Various implementations have been described. However, it should be understood that various modifications can be made without departing from the spirit and scope of this disclosure. Therefore, other implementations are also within the scope of the following claims.

[0049] The foregoing description is provided for illustrative purposes only. It is not intended to be exhaustive or limiting of this disclosure. Individual elements or features of a particular configuration are generally not limited to that particular configuration, but where applicable, they are interchangeable and can be used in the selected configuration, even if not specifically shown or described. This can also be varied in many ways. Such variations should not be considered a departure from this disclosure, and all such modifications are intended to be included within the scope of this disclosure.

Claims

1. A vehicle comprising: An AC motor with a rotor; The battery pack is configured to provide the first direct current (DC) power; An inverter is configured to convert first DC power supplied by a battery pack into first AC power for powering a motor. The charging port is configured to receive a second AC power from an external AC power source; Data processing hardware; as well as Memory hardware that communicates with data processing hardware, the memory hardware storing instructions that, when executed by the data processing hardware, cause the data processing hardware to perform operations, the operations including: The charging port can be selectively coupled to the inverter and the motor. Perform field-oriented control (FOC) to control the inverter and motor to convert the second AC power into a second DC power; and The battery pack is charged using a second DC power source.

2. The vehicle of claim 1, further comprising a DC-DC converter, wherein charging the battery pack using the second DC power comprises: Use a DC-DC converter to convert the second DC power into the third DC power; as well as The battery pack is charged using a third DC power source.

3. The vehicle of claim 1, wherein performing FOC to control the inverter and motor to convert the second AC power to the second DC power comprises: The reference frame is controlled to be substantially aligned with the rotor position; Control the d-axis current command to be sinusoidal, and The q-axis current is controlled to be fixed.

4. The vehicle of claim 1, wherein performing FOC to control the inverter and motor to convert the second AC power to the second DC power comprises: The resonant controller is activated to regulate the current at a predetermined frequency.

5. The vehicle of claim 1, wherein performing FOC to control the inverter and motor to convert the second AC power to the second DC power comprises: Current control is performed in the inner loop, while voltage or power control is performed in the outer loop.

6. The vehicle of claim 1, wherein performing FOC to control the inverter and motor to convert the second AC power to the second DC power comprises: A phase-locked loop is executed, which is configured to provide stable grid voltage measurement; as well as The stable grid voltage measurement is used as a reference for aligning the grid current.

7. The vehicle according to claim 1, wherein: Electric motors include permanent magnet motors; and The operation further includes pre-aligning the motor position so that the d-axis of the rotor is aligned with the phase of the motor at 0 degrees or 180 degrees, and the charging port is connected to the phase.

8. The vehicle of claim 1, wherein performing FOC to control the inverter and motor to convert the second AC power to the second DC power comprises: A sensorless method of pulsating vector excitation (PVE) is implemented, which uses the voltage response on the q-axis of the estimated reference frame to allow the d-axis of the estimated reference frame to be aligned with the d-axis of the rotor's magnetic field.

9. The vehicle of claim 1, wherein performing FOC to control the inverter and motor to convert the second AC power to the second DC power comprises: Use gear backlash or a clutch to perform initial rotor alignment.

10. The vehicle of claim 1, wherein performing FOC to control the inverter and motor to convert the second AC power to the second DC power comprises: Add small β-axis or q-axis current commands to generate small average magnetic torque, thereby repositioning the rotor when rotor movement occurs.

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