Control methods for drive motors, electric drive systems, motor controllers

Abstract

This application relates to a control method for a drive motor, an electric drive system, a motor controller, a storage medium, and a computer program product. The method includes: during vehicle operation, determining the winding connection method of the drive motor for the current charging phase; the winding connection method being related to a target value for the drive motor windings; determining a target rotor angle of the drive motor when the vehicle is parked based on the winding connection method; and during the parking phase, controlling the rotor angle of the drive motor to the target rotor angle. This method ensures that during the charging phase, the torque generated when current flows through the drive motor windings is almost zero, resulting in near-zero output torque for the drive motor. This avoids vehicle vibration during charging and improves user satisfaction.

Description

Technical Field

[0001] This application relates to the field of new energy vehicle charging technology, and in particular to a control method for a drive motor, an electric drive system, a motor controller, a computer-readable storage medium, and a computer program product. Background Technology

[0002] Electric vehicles are currently developing towards longer range and greater driving range. Many high-voltage electric vehicles with voltages of 800V or higher have already appeared on the market.

[0003] However, most mainstream charging stations cannot currently supply charging for vehicles with voltages above 800V. Currently, electric drive systems are often used to boost the output voltage of the charging station before charging the battery. However, in the electric drive system, when current flows through the motor, there is a torque related to the motor rotor angle. This torque causes current fluctuations, affecting the motor's output torque and causing vibrations in the vehicle's transmission system. These vibrations can be transmitted throughout the vehicle, causing it to shake during charging. Summary of the Invention

[0004] Therefore, it is necessary to provide a control method for a drive motor, an electric drive system, a motor controller, a computer-readable storage medium, and a computer program product that can avoid vehicle vibration during charging when using an electric drive system for boost charging to address the above-mentioned technical problems.

[0005] In a first aspect, this application provides a control method for a drive motor, the method comprising:

[0006] During vehicle operation, the winding connection method of the drive motor for this charging phase is determined; the winding connection method is related to the target of the drive motor winding.

[0007] The target rotor angle of the drive motor when the vehicle is stopped is determined based on the winding connection method.

[0008] During the parking phase, the rotor angle of the drive motor is controlled to the target rotor angle.

[0009] In one embodiment, the drive motor includes a U-phase winding, a V-phase winding, and a W-phase winding, wherein the target phase is the U-phase, and the winding connection method includes one of the following: a series connection of the U-phase winding and the V-phase winding, a series connection of the U-phase winding and the W-phase winding, and a series connection of the V-phase winding and the W-phase winding after being connected in parallel with the U-phase winding.

[0010] In one embodiment, determining the winding connection method of the drive motor windings during the vehicle operation phase includes:

[0011] During vehicle operation, any connection method is randomly selected as the winding connection method.

[0012] In one embodiment, determining the winding connection method of the drive motor windings during the vehicle operation phase includes:

[0013] During vehicle operation, the winding connection method of the drive motor winding is determined based on the previous historical winding connection method.

[0014] In one embodiment, determining the target rotor angle of the drive motor when the vehicle is stopped based on the winding connection method includes:

[0015] The charging current during the charging stage is determined based on the winding connection method.

[0016] The target rotor angle is determined based on the motor torque and the charging current.

[0017] In one embodiment, controlling the rotor angle of the drive motor to the target rotor angle during the parking phase includes:

[0018] Obtain the current actual rotor angle of the drive motor;

[0019] The actual rotor angle is adjusted based on the target rotor angle feedback to achieve the target rotor angle.

[0020] Secondly, this application also provides an electric drive system, comprising:

[0021] Drive motor;

[0022] A motor controller, connected to the drive motor, is used to determine the winding connection method of the drive motor during the current charging phase when the vehicle is running; the winding connection method includes a target related to the windings of the drive motor; the target rotor angle of the drive motor is determined according to the winding connection method when the vehicle is stopped; and the rotor angle of the drive motor is controlled to be the target rotor angle during the stopping phase.

[0023] Thirdly, this application also provides a motor controller. The motor controller includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the motor control method described in any of the above embodiments.

[0024] Fourthly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements the control method for the drive motor described in any of the above embodiments.

[0025] Fifthly, this application also provides a computer program product. The computer program product includes a computer program that, when executed by a processor, implements the control method for the drive motor described in any of the above embodiments.

[0026] The aforementioned drive motor control method, electric drive system, motor controller, storage medium, and computer program product determine the winding connection method of the drive motor during the charging phase in the vehicle operation phase, and determine the target rotor angle of the drive motor when parking based on the winding connection method. Furthermore, during the parking phase, the rotor angle of the drive motor is controlled to be the target rotor angle, so that the torque generated when current flows through the windings of the drive motor during the charging phase is almost zero, making the output torque of the drive motor almost zero. This can avoid the occurrence of vehicle vibration during charging and improve user satisfaction. Attached Figure Description

[0027] Figure 1 This is an application environment diagram of the control method for the drive motor in one embodiment;

[0028] Figure 2 This is a flowchart illustrating a control method for a drive motor in one embodiment;

[0029] Figure 3 This is a circuit topology of the motor controller and drive motor in one embodiment;

[0030] Figure 4 This is a flowchart illustrating the control method for the drive motor in another embodiment;

[0031] Figure 5 This is a schematic diagram showing the flow of charging current in a certain winding connection method during the charging stage in one embodiment.

[0032] Figure 6 This is a structural block diagram of the control device for the drive motor in one embodiment;

[0033] Figure 7 This is a block diagram of the electric drive system in one embodiment;

[0034] Figure 8 This is an internal structural diagram of the motor controller in one embodiment. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0036] The drive motor control method provided in this application embodiment can be applied to, for example... Figure 1 In the application environment shown, the motor controller 104 can be connected to both the battery 102 and the drive motor 106, and the charging pile 108 can be connected to the drive motor 106. When the vehicle is running, the connection between the charging pile 108 and the drive motor 106 is disconnected. The DC voltage output from the battery 102 is inverted into AC voltage by the motor controller 104 and flows into the drive motor 106 to drive the vehicle. When the battery 102 is low on power, the user can connect the charging pile 108 to the vehicle after parking. That is, the charging pile 108 and the drive motor 106 are connected, and the output voltage of the charging pile 108 is boosted by the drive motor 106 and the motor controller 104 to charge the battery 102.

[0037] In one embodiment, such as Figure 2 As shown, a controller method for driving a motor is provided, which is applied to... Figure 1 The following explanation uses the motor controller as an example, including steps S202-S206.

[0038] S202, During the vehicle operation phase, determine the winding connection method of the drive motor for this charging phase.

[0039] For example, the DC-AC conversion module of the motor controller and the circuit topology of the drive motor are as follows: Figure 3 As shown.

[0040] During vehicle operation, the direct current (DC) from the power battery is converted to alternating current (AC) by the DC-AC converter module of the motor controller, and then flows into the three-phase windings of the drive motor, enabling the drive motor to propel the vehicle. Furthermore, after starting operation, the motor controller determines the winding connection method of the drive motor windings for this charging phase. The winding connection method is related to the target configuration of the drive motor windings. Figure 3 In the circuit structure shown, the motor windings of the drive motor include a U-phase winding, a V-phase winding, and a W-phase winding. The U-phase winding can be used as the target phase, and the winding connection methods can include a series connection of the U-phase and V-phase windings, a series connection of the U-phase and W-phase windings, or a parallel connection of the V-phase and W-phase windings followed by a series connection with the U-phase winding. Optionally, the V-phase can be used as the target phase, and the winding connection methods can include a series connection of the V-phase and U-phase windings, or a series connection of the V-phase and W-phase windings. Optionally, the W-phase can be used as the target phase, and the winding connection methods can include a series connection of the W-phase and V-phase windings, or a series connection of the W-phase and U-phase windings.

[0041] S204, determine the target rotor angle of the drive motor when the vehicle is stopped based on the winding connection method.

[0042] During vehicle charging, the voltage from the charging station needs to be boosted using the drive motor and motor controller before being output to the power battery. Different winding connection methods of the drive motor result in different circuit structures for the boost circuit formed by the drive motor and motor controller, affecting the current flowing through the drive motor windings and thus generating different torques. Therefore, it is necessary to determine the target rotor angle of the drive motor when the vehicle is parked based on the winding connection method. This ensures that, under this target rotor angle and winding connection method, the torque generated by the drive motor during vehicle charging is almost zero.

[0043] S206, During the parking phase, the rotor angle of the drive motor is controlled to the target rotor angle.

[0044] During the parking phase, the motor controller adjusts the rotor angle of the drive motor to the target rotor angle. During the charging phase, the vehicle is stationary, therefore the rotor angle of the drive motor needs to be at the target rotor angle when the user parks the vehicle.

[0045] In this embodiment, by determining the winding connection method of the drive motor during the current charging phase during vehicle operation, and determining the target rotor angle of the drive motor when parking based on the winding connection method, and further, controlling the rotor angle of the drive motor to the target rotor angle during parking, the torque generated when current flows through the windings of the drive motor during the charging phase is almost zero, so that the output torque of the drive motor is almost zero, which can avoid the occurrence of vehicle vibration during charging and improve user satisfaction.

[0046] In one embodiment, during vehicle operation, determining the winding connection method of the drive motor for this charging phase includes the step of randomly determining any connection method as the winding connection method during vehicle operation.

[0047] A random module can be set within the motor controller, with multiple winding connection methods selected with equal probability. During vehicle operation, the motor controller can invoke this random module to generate the winding connection method for the current charging phase.

[0048] In one embodiment, during vehicle operation, determining the winding connection method of the drive motor winding for the current charging phase includes the step of determining the winding connection method of the drive motor winding for the current charging phase based on the previous historical winding connection method during vehicle operation.

[0049] This allows the winding connection method in each charging stage to remain the same as the previous historical winding connection method.

[0050] Optionally, a sequence list can be built within the motor controller to sort various winding connection methods, and the winding connection method for the current charging stage can be determined based on the previous historical winding connection method and the order of the sequence list.

[0051] In this embodiment of the application, by determining the winding connection method of the drive motor winding in the current charging stage based on the previous historical winding connection method during the vehicle operation stage, different circuit elements can be used in turn to form the boost branch, avoiding the situation where the same circuit elements are continuously used to form the boost branch, which would lead to excessive losses in the circuit and extend the service life of the circuit elements.

[0052] In one embodiment, determining the target rotor angle of the drive motor when it is stopped based on the winding connection method includes determining the charging current during the charging phase based on the winding connection method, and determining the target rotor angle based on the motor torque and the charging current.

[0053] The charging current during the charging phase can be obtained by transforming the current flowing through the U-phase winding, V-phase winding, and W-phase winding. During the charging phase, with a fixed output voltage from the charging pile but different winding connection methods, the current values ​​flowing through the U-phase, V-phase, and W-phase windings of the drive motor will differ, resulting in different charging currents.

[0054] The torque, charging current, and rotor angle of the drive motor have the following relationship:

[0055]

[0056] Among them, p, L md i f L d L q These are all fixed parameters related to the motor, where p is the number of pole pairs and L is the number of pole pairs. md For the d-axis mutual inductance between the stator and rotor, i f The equivalent excitation current of the permanent magnet, L d For the d-axis inductance of the stator winding, L q i is the q-axis inductance of the stator winding. s Let β be the charging current, and i be the current. s The angle with the d-axis is the rotor angle. From formula (1), it can be seen that when the motor parameters are fixed, the motor torque is related to the charging current and the rotor angle. When the motor parameters are known, the charging current is known, and the motor torque is approximately zero, the target rotor angle can be obtained through the above formula (1).

[0057] In one embodiment, during the parking phase, controlling the rotor angle of the drive motor to a target rotor angle includes the steps of acquiring the current actual rotor angle of the drive motor and adjusting the actual rotor angle based on the target rotor angle feedback to achieve the target rotor angle.

[0058] During the parking phase, the motor controller obtains the current actual rotor angle of the drive motor and compares it with the target rotor angle. In fact, there may be more than one target rotor angle calculated according to formula (1). The motor controller can use the target rotor angle with the smallest difference from the actual rotor angle as the reference value for feedback adjustment. For example, the difference between the actual rotor angle and the target rotor angle can be calculated by a PI controller, and the corresponding torque command can be output to make the motor controller control the rotor of the drive motor to rotate to the target rotor angle.

[0059] In this embodiment, by obtaining the current actual rotor angle of the drive motor during the parking phase, the rotor of the drive motor is controlled to rotate to the target rotor angle through feedback adjustment. This ensures that the torque generated when the charging current flows through the drive motor during the charging phase is almost zero, thus avoiding vehicle vibration.

[0060] In one embodiment, such as Figure 4 As shown, the control method for the drive motor includes steps S402-S408.

[0061] S402, during the vehicle operation phase, determine the winding connection method of the drive motor for this charging phase.

[0062] S404 determines the target rotor angle of the drive motor when the vehicle is stopped, based on the winding connection method.

[0063] S406, during the parking phase, controls the rotor angle of the drive motor to the target rotor angle.

[0064] Steps S402-S406 correspond one-to-one with steps S202-S206, and will not be repeated here.

[0065] S408, during the charging phase, controls the conduction of the bridge arm connecting the windings of the drive motor according to the winding connection method to achieve boost charging.

[0066] refer to Figure 3 and Figure 5 During the charging phase, the motor controller can control the conduction of the corresponding bridge arm according to the winding connection method. For example, in... Figure 3 In the circuit shown, power switches UH and UL form the first bridge arm connected to the U-phase winding, power switches VH and VL form the second bridge arm connected to the V-phase winding, and power switches WH and WL form the third bridge arm connected to the W-phase winding. When the winding connection is a series connection between the U-phase and V-phase windings, the motor controller can control the second bridge arm to conduct and, by controlling the duty cycle of power switch VL, ensure the charging current follows the specified parameters. Figure 5 The flow direction indicated by the middle arrow enables boost charging.

[0067] In this embodiment, by determining the winding connection method of the drive motor during the charging phase while the vehicle is running, and determining the target rotor angle of the drive motor when the vehicle is parked based on the winding connection method, and further, controlling the rotor angle of the drive motor to the target rotor angle during the parking phase, the torque generated when current flows through the windings of the drive motor during the charging phase is almost zero, resulting in almost zero output torque of the drive motor, thus avoiding vehicle vibration during charging. Simultaneously, by controlling the conduction of the bridge arm connecting the drive motor windings based on the winding connection method during the charging phase, boost charging can be achieved.

[0068] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0069] Based on the same inventive concept, this application also provides a control device for a drive motor to implement the control method for the drive motor described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more drive motor control device embodiments provided below can be found in the limitations of the drive motor control method described above, and will not be repeated here.

[0070] In one embodiment, such as Figure 6 As shown, a control device for a drive motor is provided, including: a winding determination module 602, a rotor angle determination module 604, and a control module 606, wherein:

[0071] The winding determination module 602 is used to determine the winding connection method of the drive motor during the current charging phase in the vehicle operation phase.

[0072] The rotor angle determination module 604 is used to determine the target rotor angle of the drive motor when the vehicle is stopped, based on the winding connection method.

[0073] The control module 606 is used to control the rotor angle of the drive motor to the target rotor angle during the parking phase.

[0074] Each module in the aforementioned drive motor control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of the motor controller in hardware form or independent of it, or stored in the memory of the motor controller in software form, so that the processor can call and execute the corresponding operations of each module.

[0075] In one embodiment, such as Figure 7 As shown, an electric drive system is provided, including a drive motor 702 and a motor controller 704.

[0076] The motor controller 704 is connected to the drive motor 702. During vehicle operation, it can determine the winding connection method of the drive motor for the current charging phase and determine the target rotor angle of the drive motor when the vehicle is parked based on the winding connection method. Furthermore, during the parking phase, the motor controller 704 can control the rotor angle of the drive motor 702 to the target rotor angle, so that the output torque of the drive motor 702 during the charging phase is almost zero, avoiding vehicle vibration during charging and improving the user experience.

[0077] In one embodiment, a motor controller is provided, the internal structure diagram of which can be shown as follows: Figure 8 As shown, the motor controller includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operating system and computer programs stored in the non-volatile storage media. The database stores data such as winding connection methods and target rotor angles. The I / O interfaces are used for information exchange between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a method for controlling the drive motor.

[0078] Those skilled in the art will understand that Figure 8 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the controller to which the present application is applied. A specific motor controller may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0079] In one embodiment, a motor controller is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0080] During vehicle operation, the winding connection method of the drive motor for this charging phase is determined; the winding connection method is related to the target of the drive motor winding.

[0081] Determine the target rotor angle of the drive motor when the vehicle is stopped based on the winding connection method;

[0082] During the parking phase, the rotor angle of the drive motor is controlled to the target rotor angle.

[0083] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0084] During vehicle operation, the winding connection method of the drive motor for this charging phase is determined; the winding connection method is related to the target of the drive motor winding.

[0085] Determine the target rotor angle of the drive motor when the vehicle is stopped based on the winding connection method;

[0086] During the parking phase, the rotor angle of the drive motor is controlled to the target rotor angle.

[0087] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, performs the following steps:

[0088] During vehicle operation, the winding connection method of the drive motor for this charging phase is determined; the winding connection method is related to the target of the drive motor winding.

[0089] Determine the target rotor angle of the drive motor when the vehicle is stopped based on the winding connection method;

[0090] During the parking phase, the rotor angle of the drive motor is controlled to the target rotor angle.

[0091] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0092] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0093] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A control method for a drive motor, characterized in that, The method includes: During vehicle operation, the winding connection method of the drive motor for this charging phase is determined; the winding connection method is related to the target of the drive motor winding; the drive motor includes a U-phase winding, a V-phase winding, and a W-phase winding, and the target phase is the U-phase; wherein, the winding connection method includes one of the following: a series connection of the U-phase winding and the V-phase winding, a series connection of the U-phase winding and the W-phase winding, and a parallel connection of the V-phase winding and the W-phase winding followed by a series connection with the U-phase winding; The charging current during the charging stage is determined based on the winding connection method. The target rotor angle of the drive motor when the vehicle is stopped is determined based on the motor torque and the charging current. During the parking phase, the rotor angle of the drive motor is controlled to the target rotor angle.

2. The method according to claim 1, characterized in that, During vehicle operation, determining the winding connection method of the drive motor windings for this charging phase includes: During vehicle operation, any connection method is randomly selected as the winding connection method.

3. The method according to claim 1, characterized in that, During vehicle operation, determining the winding connection method of the drive motor windings for this charging phase includes: During vehicle operation, the winding connection method of the drive motor winding is determined based on the previous historical winding connection method.

4. The method according to claim 1, characterized in that, During the parking phase, controlling the rotor angle of the drive motor to the target rotor angle includes: Obtain the current actual rotor angle of the drive motor; The actual rotor angle is adjusted based on the target rotor angle feedback to achieve the target rotor angle.

5. An electric drive system, characterized in that, include: Drive motor; A motor controller, connected to the drive motor, is used to determine the winding connection method of the drive motor during the current charging phase in the vehicle operation phase. The winding connection method is related to the target of the drive motor winding; the charging current during the charging stage is determined according to the winding connection method; the target rotor angle of the drive motor when parking is determined according to the motor torque and the charging current; during the parking stage, the rotor angle of the drive motor is controlled to be the target rotor angle. The drive motor includes a U-phase winding, a V-phase winding, and a W-phase winding, with the target phase being the U-phase. The winding connection method includes one of the following: a series connection of the U-phase winding and the V-phase winding, a series connection of the U-phase winding and the W-phase winding, or a parallel connection of the V-phase winding and the W-phase winding followed by a series connection with the U-phase winding.

6. A motor controller, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 4.

8. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 4.

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