AC charging of a DC battery pack of an electric vehicle by means of field-oriented control

Abstract

One method comprises coupling a charging port to an inverter and an alternating current electric motor (AC motor). The method further comprises performing field-oriented control (FOC) to control the inverter and the electric motor to convert the AC power received from the charging port into first direct current (DC) power and to charge a DC battery pack with the first DC power. Charging the DC battery pack using the first DC power may include converting the first DC power into second DC power using a DC-to-DC converter and charging the DC battery pack using the second DC power.

Description

INTRODUCTION

[0001] The information provided in this section serves only to give a general overview of the context of the disclosure. The work of the inventors mentioned herein, insofar as it is described in this section, as well as aspects of the description that may not be considered prior art at the time of filing, are neither expressly nor implicitly acknowledged as prior art with respect to the present disclosure.

[0002] Field-oriented control (FOC), also known as vector control, is a method for controlling the torque and speed of an electric motor, 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 ensure smooth and efficient motor operation across a wide speed and load range.

[0003] The present disclosure relates generally to charging a DC battery pack of an electric vehicle (EV) with AC current using FOC. SUMMARY

[0004] One aspect of the disclosure concerns a vehicle comprising an alternating current electric motor (AC motor) with a rotor, a battery pack, an inverter, a charging port, data processing hardware, and memory hardware. The battery pack is designed to supply initial direct current (DC) power. The inverter is designed to convert the initial DC power supplied by the battery pack into initial AC power to drive the electric motor. The charging port is designed to receive a second AC power supply from an external AC power source. The memory hardware communicates with the data processing hardware and stores instructions which, 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 electric motor, performing field-oriented control (FOC) to control the inverter and electric motor to convert the second AC power into a second DC power, and charging the battery pack using the second DC power.

[0005] Implementations of the disclosure may include one or more of the following optional features. According to some implementations, the vehicle also includes a DC-DC converter, wherein charging the battery pack using the second DC power involves 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. According to some examples, performing the FOC to control the inverter and the electric motor to convert the second AC power to the second DC power involves controlling a reference frame so that it is substantially aligned to a rotor position, controlling a d-axis current command so that it is sinusoidal, and controlling a q-axis current so that it is fixed.Additionally or alternatively, implementing the FOC to control the inverter and electric motor for converting the second AC power into the second DC power includes implementing a resonant controller to regulate the current at a predetermined frequency. Additionally or alternatively, implementing the FOC to control the inverter and electric motor for converting the second AC power into the second DC power includes implementing current control in an inner loop, with an outer loop performing voltage or power control.

[0006] According to some examples, performing the FOC to control the inverter and electric motor to convert the second AC power to the second DC power involves implementing a phase-locked loop designed to provide a stable grid voltage measurement and using the stable grid voltage measurement as a reference to align the grid current. According to some implementations, the electric motor is a permanent magnet motor, and the operations also include pre-aligning a motor position such that a d-axis of the rotor is aligned at 0 or 180 degrees with a phase of the electric motor to which the charge terminal is connected.

[0007] According to some implementations, performing the FOC to control the inverter and electric motor to convert the second AC power to the second DC power involves performing a sensorless pulsed vector excitation (PVE) method that uses a voltage response on a q-axis of an estimated reference frame to align the d-axis of the estimated reference frame with the magnetic field d-axis of the rotor. Additionally or alternatively, performing the FOC to control the inverter and electric motor to convert the second AC power to the second DC power involves performing an initial rotor alignment using a gear mesh or clutch.Additionally or alternatively, performing FOC to control the inverter and electric motor to convert the second AC power to the second DC power involves adding small β-axis or q-axis current commands to generate a small average magnetic torque to reposition the rotor when rotor movement occurs. Additionally or alternatively, performing FOC to control the inverter and electric motor to convert the second AC power to the second DC power involves using an average reluctance torque to reposition the rotor when rotor movement occurs by injecting a small amount of AC current on a β-axis or a q-axis.

[0008] According to some examples, implementing the FOC to control the inverter and electric motor for converting the second AC power to the second DC power involves implementing a rotor position controller, which may include a proportional-integral derivative controller (PID controller), a PID controller in series with an integrator, or a lead / follow compensator. Additionally or alternatively, implementing the FOC to control the inverter and electric motor for converting the second AC power to the second DC power involves implementing current control using a rotating or stationary reference system, either using α-β signals or abc signals.Additionally or alternatively, performing the FOC to control the inverter and electric motor for converting the second AC power to the second DC power includes forward coupling of a grid voltage to regulate the current. Additionally or alternatively, performing the FOC to control the inverter and electric motor for converting the second AC power to the second DC power includes performing field winding current control to switch off a rotor magnetic field or adjust a rotor magnetic field level to achieve a desired machine induction level, machine leginess, and / or grid voltage synchronization, which enables torque reduction. According to some implementations, the operations also include reversing the direction of grid current flow between a grid-to-vehicle operating mode and a vehicle-to-grid operating mode.

[0009] Another aspect of the disclosure relates to a system comprising an alternating current electric motor (AC motor) with a rotor, a battery pack designed to supply initial direct current (DC) power, an inverter designed to convert the initial DC power from the battery pack into initial AC power to drive the electric motor, a charging port designed to receive a second AC power from an AC power source, data processing hardware, and memory hardware communicating with the data processing hardware, wherein the memory hardware stores instructions which, when executed by the data processing hardware, cause the data processing hardware to perform operations, wherein the operations include selectively coupling the charging port to the inverter and the electric motor.This includes performing field-oriented control (FOC) to control the inverter and electric motor to convert the second AC power into a second DC power and charging the battery pack using the second DC power.

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

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

[0012] Implementations of the disclosure may include one or more of the following optional features. According to some implementations, charging the battery pack using the first DC power involves converting the first DC power into a second DC power using a DC-to-DC converter and charging the battery pack using the second DC power. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings described here serve only to illustrate selected configurations and are not intended to limit the scope of this disclosure; they show: Fig. 1 a view of an example of an electric vehicle (EV) with a charging system according to the principles of the present disclosure; Fig. 2 a schematic view of the charging system of Fig. 1; Fig. 3 Another schematic view of the charging system of Fig. 1; and Fig. 4 a flowchart of another exemplary arrangement of operations for a method for charging a DC battery pack of an EV with AC current using field-oriented control (FOC).

[0014] The corresponding reference symbols in all drawings denote the corresponding parts. DETAILED DESCRIPTION

[0015] Exemplary configurations are now described in more detail with reference to the accompanying drawings. These exemplary configurations are provided to complete this disclosure and to fully convey its scope to those skilled in the art. Specific details, such as examples of certain components, devices, and methods, are given to facilitate a comprehensive understanding of the configurations presented in this disclosure. It will be evident to those skilled in the art that certain details need not be used, that exemplary configurations can be implemented in many different forms, and that the specific details and exemplary configurations should not be interpreted as limiting the scope of the disclosure.

[0016] The terminology used here serves only to describe certain exemplary configurations and is not to be understood as a limitation. Unless the context clearly indicates otherwise, the singular forms "a / an" and "the" as used here may also include the plural forms. The terms "includes," "comprising," "exhibit," and "have" are inclusive and therefore specify the presence of features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The procedural steps, processes, and operations described here are not to be interpreted as requiring them to be carried out in the specific order described or depicted, unless this order is explicitly stated as the execution sequence.Additional or alternative steps can be used.

[0017] When an element or layer is described as "on," "interacting with," "connected with," "attached to," or "coupled with" another element or layer, it may be directly on top of, in interaction with, connected to, coupled with, or attached to that other element or layer, or there may be intervening elements or layers. Conversely, when an element is described as "directly on," "directly interacting with," "directly connected with," "directly attached to," or "directly coupled with" another element or layer, there must be no intervening elements or layers. Other terms used to describe the relationship between elements are to be interpreted similarly (e.g., "between" as opposed to "directly between," "adjacent" as opposed to "directly adjacent," etc.).As used here, the term “and / or” encompasses all combinations of one or more of the listed elements.

[0018] The terms "first," "second," "third," etc., may be used here to describe different elements, components, areas, layers, and / or sections. These elements, components, areas, layers, and / or sections are not intended to be restricted by these terms. These terms may only be used to distinguish one element, component, area, layer, or section from another. Terms such as "first," "second," and other numerical terms do not imply any sequence or order unless clearly indicated by the context.Thus, a first element, a first component, a first area, a first layer or a first section described below could be referred to as a second element, second component, second area, second layer or second section without deviating from the lessons of the exemplary configurations.

[0019] In this application, including the definitions below, the term "module" may be replaced by the term "circuit". The term "module" may refer to, be part of, or include: an application-specific integrated circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinational logic circuit; a field-programmable gate array (FPGA); a processor (shared, dedicated, or grouped) that executes code; a memory (shared, dedicated, or grouped) that stores code executed by the processor; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, such as in a system-on-a-chip.

[0020] The term "code," as used above, can include software, firmware, and / or microcode, and can refer to programs, routines, functions, classes, and / or objects. The term "shared processor" includes a single processor that executes some or all of the code from multiple modules. The term "group processor" includes a processor that, in combination with additional processors, executes some or all of the code from one or more modules. The term "shared memory" includes a single memory that stores some or all of the code from multiple modules. The term "group memory" includes memory that, in combination with additional memory, stores some or all of the code from one or more modules. The term "memory" can be a subset of the term "computer-readable medium."The term "computer-readable medium" excludes transitory electrical and electromagnetic signals propagating through a medium and can therefore be considered tangible, non-transient storage. Non-restrictive examples of non-transient storage include tangible computer-readable media, including non-volatile memory, magnetic storage, and optical storage.

[0021] The devices 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 programs comprise processor-executable instructions stored on at least one non-transient, tangible, computer-readable medium. The computer programs may also contain and / or access stored data.

[0022] A software application (i.e., a software resource) can refer to computer software that causes a computing device to perform a task. Depending on the context, a software application may be called an "application," "app," or "program." Examples of applications include system diagnostic applications, system administration applications, system maintenance applications, word processing applications, spreadsheet applications, messaging applications, media streaming applications, social networking applications, and gaming applications.

[0023] Non-transient memory can be physical devices 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-transient 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) / electronically erasable programmable read-only memory (EEPROM) (typically used, for example, for firmware such as boot programs). Examples of volatile memory include random-access memory (RAM), dynamic random-access memory (DRAM), static random-access memory (SRAM), phase-change memory (PCM), and floppy disks or tapes.

[0024] These computer programs (also referred to as programs, software, software applications, or code) comprise machine instructions for a programmable processor and may be implemented in a higher-level procedural and / or object-oriented programming language and / or in assembly / machine language. As used here, the terms "machine-readable medium" and "computer-readable medium" refer to any computer program product, non-volatile computer-readable medium, any device and / or apparatus (e.g., magnetic disks, optical disks, memory, programmable logic devices (PLDs)) used to deliver machine instructions and / or data to a programmable processor that includes a machine-readable medium receiving machine instructions as a machine-readable signal.The term "machine-readable signal" refers to any signal used to deliver machine instructions and / or data to a programmable processor.

[0025] Various implementations of the systems and techniques described herein can be realized in digital electronic and / or optical circuit arrangements, integrated circuit arrangements, specially designed ASICs (application-specific integrated circuits), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include implementation in one or more computer programs that are executable and / or interpretable on a programmable system comprising at least one programmable processor, which may be of a specific or general design and is coupled such that it receives data and instructions from and sends data and instructions to a storage system, at least one input device, and at least one output device.

[0026] The processes and logic sequences described in this description can be executed by one or more programmable processors, also known as data processing hardware, which run one or more computer programs to perform functions by processing input data and generating output data. The processes and logic sequences can also be executed by specialized logic circuit arrangements, such as an FPGA (field-programmable gate array) or an ASIC (application-specific integrated circuit). Processors suitable for executing a computer program include, for example, general-purpose and specialized microprocessors, and one or more processors of any type of digital computer. Generally, a processor receives instructions and data from read-only memory, random-access memory, or both.The essential elements of a computer are a processor for executing instructions and one or more storage devices for storing instructions and data. Generally, a computer also includes one or more mass storage devices for storing data, such as magnetic, magneto-optical, or optical disks, or is operationally coupled to them to receive data from or send data to them, or both. However, a computer need not have such devices. Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and storage devices, including, for example, semiconductor memory devices such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks or removable hard disks; magneto-optical disks; and CD-ROM and DVD-ROM discs.The processor and memory can be supplemented by or integrated into special logic circuit arrangements.

[0027] To enable interaction with a user, one or more aspects of the disclosure can be implemented on a computer that has a display device, such as a CRT (cathode ray tube) monitor, an LCD (liquid crystal display) monitor, or a touchscreen, to display information to the user, and optionally a keyboard and a pointing device, such as a mouse or trackball, through which the user can input information to the computer. Other types of devices can also be used to enable interaction with a user; for example, feedback to the user can be any form of sensory feedback, such as visual, auditory, or tactile feedback; and user input can be received in any form, including auditory, verbal, or tactile input.Furthermore, a computer can interact with a user by sending and receiving documents to a device used by the user, for example, by sending web pages to a web browser on a user's client device in response to requests received from the web browser.

[0028] Unless expressly stated otherwise, the phrase "at least one of A, B or C" refers to any combination or subset of A, B, 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 with at least one B; (5) at least one A with at least one C; (6) at least one B with at least C; and (7) at least one A with at least one B and at least one C. Unless expressly stated otherwise, the phrase "at least one of A, B and C" refers to any combination or subset of A, B, 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 with at least one B; (5) at least one A with at least one C; (6) at least one B with at least one C; and (7) at least one A with at least one B and at least one C.Unless expressly stated otherwise, “A or B” refers to any combination of A and B, such as: (1) A alone; (2) B alone; and (3) A and B.

[0029] Field-oriented control (FOC), also known as vector control, is an advanced method for controlling the torque and speed of an electric motor, particularly in applications with alternating current (AC) electric 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 ensure smooth and efficient motor operation over a wide speed and load range. FOC decouples the stator current into two orthogonal components: one that generates the magnetic field (magnetic flux) and another that generates the torque. This decoupling allows for independent control of the electric motor's magnetic field and torque, similar to the control of a direct current (DC) motor, thereby improving performance, efficiency, and dynamic response.By transforming the three-phase motor currents into a two-axis coordinate system (a direct axis (d-axis) and a quadrature axis (q-axis)) aligned with the rotor's magnetic field, the FOC enables precise and smooth control of the electric motor's operation, making it particularly suitable for applications requiring high performance and precision, such as electric vehicles, robotics, and industrial automation.

[0030] Traditionally, an electric vehicle's battery pack is charged via a separate onboard charging module (OBCM). The OBCM is a crucial component that converts alternating current (AC) power from an external power source, such as a private or public charging station, into direct current (DC) power, which is needed to charge the vehicle's battery. Integrated into the vehicle, the OBCM is designed to efficiently manage the charging process and ensure optimal battery condition and longevity. The OBCM typically includes specialized power electronics, control systems, and safety mechanisms to regulate voltage and current, prevent overcharging, and protect against electrical failures. By enabling a convenient and reliable charging process, the OBCM plays a vital role in the overall functionality and driving experience of electric vehicles.However, a conventional OBCM requires additional specialized hardware (e.g., a power factor correction (PFC) circuit), which increases the complexity and cost of an electric vehicle. Furthermore, a conventional OBCM can exhibit current regulation issues and / or distortion during zero crossings. Therefore, there is a need for improved methods and circuits for charging electric vehicle battery packs.

[0031] According to the disclosed configurations, the one or more AC electric motors and the inverter of an electric vehicle are reused using FOC to convert grid-based AC power into DC power. This DC power can then be converted by a DC-to-DC converter into DC power suitable for charging the electric vehicle's battery pack. By reusing the one or more motors and the inverter using FOC, the additional specialized hardware of a conventional OBCM can be omitted, reducing the complexity and cost of the electric vehicle. Furthermore, using FOC to charge a battery pack with AC power also utilizes the FOC logic and modules already used to control the AC electric motor that drives the electric vehicle.Furthermore, by using FOC for AC charging, correct alignment of the stator flux to the rotor position can be ensured during AC charging to avoid unwanted motor rotation or unwanted motor torque.

[0032] Although the configurations shown and described here are related to an electric vehicle (e.g., a car, truck, aircraft, train, motorcycle, etc.), it should be understood that the disclosed configurations can additionally or alternatively be used for charging a DC battery pack of an electric vehicle with AC current using FOC for any other type of device (e.g., a drone, robot, bicycle, automated equipment, industrial equipment, etc.). The vehicle or device can be operated by a person or operate independently.

[0033] With particular reference to Fig. 1, Fig. 2 and Fig. Figure 3 shows an electric vehicle (EV) 10 (e.g., a car, truck, airplane, train, motorcycle, etc.) in conjunction with a charging system 12. The vehicle 10 comprises one or more AC electric motors 14 (here also referred to as motors 14), each comprising a rotor, a DC battery pack 15 for storing and supplying DC power, and an inverter 16 for converting the DC power supplied by the battery pack 15 into AC power to supply the one or more motors 14. A field-of-control (FOC) control module 20 performs FOC to control the one or more motors 14, the inverter 16, and the battery pack 15 to supply the one or more motors 14 to drive the vehicle 10.In particular, the FOC control module 20 decouples the stator current into two orthogonal components: one that generates the magnetic field (magnetic flux) and another that generates the torque. This decoupling enables independent control of the electric motor's magnetic field and torque, similar to the control of a direct current (DC) motor, thereby improving performance, efficiency, and dynamic response. By transforming the three-phase motor currents into a two-axis coordinate system (a d-axis and a q-axis) aligned with the rotor's magnetic field, the FOC control module 20 enables precise and smooth control of the electric motor's operation.The FOC control module 20 uses one or more sensors 17 to measure the phase currents, rotor position and rotor speed of the electric motor, applies the required mathematical transformations and control algorithms to the detected phase currents, rotor positions and rotor speeds and controls the power electronics (e.g. the inverter 16) to drive the one or more electric motors 14 on the basis of the calculated control signals.

[0034] The battery pack 15 can comprise any number and / or any type of battery cells. The FOC control module 20 can, for example, be stored and executed in an engine control module (MCM) 22 of the vehicle 10. In particular, the MCM 22 can issue commands to execute the Fig. The operations shown or described here are stored, for example, in a memory hardware 24. The instructions can be executed by a data processing hardware (e.g., a processor 26) of the MCM 22 to perform the operations.

[0035] The charging system 12 can be used to charge the vehicle 10's DC battery pack 14 with AC using FOC. The charging system 12 includes a charging port 18 designed to receive AC from an external AC power source 30, such as a private or public charging station. To charge the battery pack 15, the MCM 22 selectively connects the charging port 18 to the inverter 16 and the one or more electric motors 14. As shown in Fig. As shown in Figure 3, the MCM 22 selectively couples the charging port 18 to the inverter 16 and the one or more electric motors 14 by closing switches 321 and 322 and controlling a relay 323 to connect one phase of the AC power received from the external power source 30 (e.g., between 85 and 270 volts) to one phase of the one or more motors 14. Although Fig. Figure 3 shows that one phase of the external power source 30 is connected to a specific phase of the one or more motors 14, the phase of the external power source 30 can be connected to another phase of the one or more motors 14, or several phases of the external power source 30 can be connected to several phases of the one or more motors 14.

[0036] The FOC control module 20 then performs an FOC to control the inverter 16 and the electric motor 14, converting the AC power received from the external AC power source 30 into DC power at a capacitor C2. The MCM 22 then charges the battery pack 14 using the DC power. In the example shown, the MCM 22 charges the battery pack 14 by closing switches 331 and 322 of a battery disconnect unit (BDU) 330. According to some implementations, a DC-DC converter 340 (see Fig. 3) The DC power generated by the inverter 16 and the electric motor 14 is converted at a capacitor C3 into DC power, which is used to charge the battery pack 14. In particular, the DC power generated by the inverter 16 and the electric motor 14 can have a different voltage than the DC power generated by the DC-DC converter 320.

[0037] According to the example shown, the BDU 330 also includes switches 333 and 334 for pre-charging the inverter 16 and a capacitor C1, as well as switches 333 and 335 for supplying the inverter 16 to provide alternating current power to the one or more electric motors 14 for driving the vehicle 10.

[0038] According to some implementations, performing the FOC to control the inverter 16 and the electric motor 14 to convert the AC power received via the charging port 18 into DC power involves controlling a rotor reference system such that it is essentially fixed, controlling a d-axis current command such that it is sinusoidal, and, according to some examples, controlling a q-axis current such that it is fixed (e.g., zero) to prevent torque generation. Additionally or alternatively, performing the FOC to control the inverter 16 and the electric motor 14 to convert AC power received via the charging port 18 into DC power involves executing a resonant controller to regulate the current at a predetermined frequency.Performing the FOC to control the inverter 16 and the electric motor 14 to convert AC power received via the charging port 18 into DC power can also include performing a resonant controller to regulate the current at a predetermined frequency, and additionally, according to some examples, performing a conventional controller, such as a proportional-integral derivative controller (PID controller) or a lead / follow compensator to perform current control, wherein the current control can be performed within an inner loop, with an outer loop controlling either the power or the voltage.Performing the FOC to control the inverter 16 and the electric motor 14 to convert AC power received via the charging port 18 into DC power may also include performing a phase-controlled loop designed to provide a stable mains voltage measurement and using the stable mains voltage measurement as a reference to align the mains current.

[0039] According to some examples, the electric motor comprises a permanent magnet motor, and the FOC control module 20 pre-aligns a motor position such that a d-axis of the rotor is aligned with a phase of the electric motor 14, for example, the phase to which the charging port is connected. According to some implementations, performing the FOC to control the inverter 16 and the electric motor 14 to convert AC power to DC power involves aligning the electric motor 14 with an α-axis. Additionally or alternatively, performing the FOC to control the inverter 16 and the electric motor 14 to convert AC power received via the charging port 18 to DC power involves performing an initial rotor alignment using a gear mesh or clutch.Additionally or alternatively, performing the FOC to control the inverter 16 and the electric motor 14 to convert AC power received via the charging port 18 into DC power involves adding small β-axis or q-axis current commands to generate a small magnetic torque to reposition the rotor when rotor movement occurs. Performing the FOC to control the inverter 16 and the electric motor 14 to convert the AC power received via the charging port 18 into DC power may also involve using an average reluctance torque to reposition the rotor when rotor movement occurs by injecting a small amount of AC current on a β-axis or a q-axis.

[0040] According to some implementations, performing the FOC to control the inverter 16 and the electric motor 14 to convert the AC power received via the charging port 18 into DC power involves implementing a position controller, which may include a PID controller, a PID controller in series with an integrator, or a pre- / post-roll compensator. Additionally or alternatively, performing the FOC to control the inverter 16 and the electric motor 14 to convert the AC power received via the charging port 18 into DC power involves implementing current control using a rotating or stationary reference system, either using α-β signals or abc signals.

[0041] According to some examples, the FOC control module 20 reverses the direction of the grid current flow between a grid-to-vehicle operating mode and a vehicle-to-grid operating mode. According to some implementations, performing the FOC to control the inverter 16 and the electric motor 14 to convert AC power received via the charging port 18 into DC power involves forward coupling of a grid voltage to regulate the current. Additionally or alternatively, performing the FOC to control the inverter 16 and the electric motor 14 to convert AC power received via the charging port 18 into DC power involves performing field winding current control to switch off a rotor magnetic field or adjust a rotor magnetic field level to achieve a desired machine induction level, machine legness, and / or grid voltage synchronization, thus enabling torque reduction.According to some implementations, performing the FOC to control the inverter and electric motor to convert the second AC power into the second DC power may also involve performing a sensorless pulsed vector excitation (PVE) method, which uses a voltage response on a q-axis of an estimated reference frame to enable the alignment of the d-axis of the estimated reference frame to the magnetic field d-axis of the rotor.

[0042] Fig. Figure 4 is a flowchart of an exemplary sequence of operations for a procedure for charging an electric vehicle battery pack with alternating current using FOC. The operations can be performed by data processing hardware (e.g., processor 26) based on the execution of instructions stored in memory (e.g., memory hardware 24). Many other ways can be used to implement procedure 400. For example, the order in which the operations are performed can be changed, and / or one or more of the operations and / or interactions can be modified, eliminated, subdivided, or combined. Additionally, the operations can be performed by Fig. 4. can be executed sequentially and / or in parallel, for example by separate processing lines, processors, devices, discrete logic, circuits, etc.

[0043] In Operation 402, Procedure 400 comprises coupling the charging port 18 to the inverter 16 and the one or more AC electric motors 14. In Operation 404, Procedure 400 comprises performing the FOC to control the inverter 16 and the one or more electric motors 14 to convert AC power received from the charging port 18 into a first DC power. In Operation 406, Procedure 400 comprises converting the first DC power into a second DC power using the DC-to-DC converter 330. In Operation 408, Procedure 400 comprises charging the battery pack 15 using the second DC power.

[0044] Several implementations have been described. However, it is understood that various modifications can be made without deviating from the concept and scope of the disclosure. Accordingly, other implementations fall within the scope of the following claims.

[0045] The foregoing description has been given for illustrative and descriptive purposes only. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular configuration are generally not restricted to that particular configuration, but are interchangeable and may be used in a selected configuration, even if not specifically shown or described. They may also be varied in many ways. Such variations are not to be considered a deviation from the disclosure, and all such modifications are to be considered within the scope of the disclosure.

Claims

[1] Vehicle comprising: an alternating current electric motor (AC electric motor) that has a rotor; a battery pack designed to provide initial direct current (DC) power; an inverter designed to convert the initial DC power supplied by the battery pack into an initial AC power to power the electric motor; a charging port designed to receive a second AC power supply from an external AC power source; Data processing hardware; and Storage hardware that communicates with data processing hardware, wherein the storage hardware stores instructions which, when executed by the data processing hardware, cause the data processing hardware to perform operations that include: selective coupling of the charging port with the inverter and the electric motor; Implementing field-oriented control (FOC) to control the inverter and electric motor to convert the second AC power into a second DC power; and Charging the battery pack using the second DC power supply. [2] Vehicle according to claim 1, further comprising a DC-DC converter, wherein charging the battery pack using the second DC power comprises: Converting the second DC power into a third DC power using the DC-DC converter; and Charging the battery pack using the third DC power supply. [3] Vehicle according to claim 1, wherein performing the FOC comprises controlling the inverter and the electric motor to convert the second AC power into the second DC power: Controlling a reference system such that it is essentially aligned with a rotor position; Controlling a d-axis current command such that it is sinusoidal; and Controlling a q-axis current such that it is fixed. [4] Vehicle according to claim 1, wherein the implementation of the FOC for controlling the inverter and the electric motor for converting the second AC power into the second DC power includes the implementation of a resonant controller for regulating the current at a predetermined frequency. [5] Vehicle according to claim 1, wherein performing the FOC to control the inverter and the electric motor to convert the second AC power into the second DC power comprises performing current control in an inner loop, wherein an outer loop performs voltage or power control. [6] Vehicle according to claim 1, wherein performing the FOC comprises controlling the inverter and the electric motor to convert the second AC power into the second DC power: Implementing a phase-locked loop designed to provide a stable mains voltage measurement; and Using stable mains voltage measurement as a reference to align the mains current. [7] Vehicle according to claim 1, wherein the electric motor includes a permanent magnet motor; and The operations further include: pre-aligning a motor position such that a d-axis of the rotor is aligned at 0 or 180 degrees to a phase of the electric motor to which the charge terminal is connected. [8] Vehicle according to claim 1, wherein performing the FOC to control the inverter and electric motor to convert the second AC power into the second DC power comprises performing a sensorless pulsed vector excitation (PVE) method which uses a voltage response on a q-axis of an estimated reference system to enable alignment of the d-axis of the estimated reference system to the magnetic field d-axis of the rotor. [9] Vehicle according to claim 1, wherein performing the FOC to control the inverter and electric motor to convert the second AC power into the second DC power includes performing an initial rotor alignment using a gear mesh or a clutch. [10] Vehicle according to claim 1, wherein performing the FOC to control the inverter and electric motor to convert the second AC power into the second DC power includes adding small β-axis or q-axis current commands to generate a small average magnetic torque to reposition the rotor when rotor movement occurs.

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