Vehicle control method and vehicle drive system

Abstract

A control method for controlling a capacitance ripple and a torque ripple of a vehicle drive system, the vehicle drive system comprising a first DC / DC converter and a second DC / DC converter, the control method comprising: setting a first resultant carrier of a first three-phase carrier generated by the first DC / DC converter in a three-phase stationary coordinate to a first direction and a second resultant carrier of a second three-phase carrier generated by the second DC / DC converter in the three-phase stationary coordinate to a second direction, so as to control the torque ripple of the vehicle drive system; wherein the first DC / DC converter is composed of a first three-phase winding of a double-winding motor, a first three-phase inverter circuit and a first DC link capacitor; and the second DC / DC converter is composed of a second three-phase winding of the double-winding motor, a second three-phase inverter circuit and a second DC link capacitor.

Description

Technical Field

[0001] This application relates to a vehicle control method and a vehicle drive system, and more particularly to a vehicle control method and a vehicle drive system that can effectively control capacitor ripple and torque ripple during the operation of a DC-DC converter. Background Technology

[0002] The rapidly growing electric vehicle industry in recent years has brought enormous challenges to the design of power management chips. Existing solutions utilize the center tap of the motor's three-phase windings as one end, connecting it to an external power supply. However, these solutions encounter two problems: firstly, the DC capacitor ripple is excessively large due to the small inductance, leading to excessive reactive power loss, reduced capacitor lifespan, and decreased system reliability. Secondly, the DC-DC conversion process generates torque ripple in the motor, causing significant vibration and noise during vehicle charging. Summary of the Invention

[0003] (I) Purpose of the Invention

[0004] One of the main objectives of this application is to provide a vehicle control method and a vehicle drive system to solve the above-mentioned problems.

[0005] (II) Technical Solution

[0006] This application provides a vehicle control method for controlling a capacitor ripple and a torque ripple in a vehicle drive system. The vehicle drive system includes a first DC-DC converter and a second DC-DC converter. The method is characterized by: setting a first composite carrier wave of a first three-phase carrier generated by the first DC-DC converter to face a first direction in a three-phase stationary coordinate system, and a second composite carrier wave of a second three-phase carrier generated by the second DC-DC converter to face a second direction in the same three-phase stationary coordinate system, to control the torque ripple of the vehicle drive system; wherein the first DC-DC converter is composed of a first three-phase winding of a dual-winding motor, a first three-phase inverter circuit, and a first DC link capacitor; and the second DC-DC converter is composed of a second three-phase winding of the dual-winding motor, a second three-phase inverter circuit, and a second DC link capacitor.

[0007] This application provides a vehicle drive system, including: a motor, the motor including a first three-phase winding and a second three-phase winding, the first three-phase winding serving as a first three-phase inductor of a first DC-DC converter, and the second three-phase winding serving as a second three-phase inductor of a second DC-DC converter; and a motor control device, the motor control device including a first three-phase inverter circuit, a second three-phase inverter circuit, a pulse width modulation controller, and a processing circuit, the first three-phase inverter circuit serving as a first switching circuit of the first DC-DC converter, and the second three-phase inverter circuit serving as a first switching circuit of the first DC-DC converter. As a second switching circuit of the second DC-DC converter, the pulse width modulation controller modulates a first three-phase current output by the first switching circuit and a second three-phase current output by the second switching circuit to generate a first three-phase carrier and a second three-phase carrier. The processing circuit sets a first composite carrier of the first three-phase carrier generated by the first DC-DC converter to be oriented in a first direction at a three-phase stationary coordinate, and a second composite carrier of the second three-phase carrier generated by the second DC-DC converter to be oriented in a second direction at the three-phase stationary coordinate, so as to control a torque ripple of the vehicle drive system. Attached Figure Description

[0008] Figure 1 This is a block diagram of a vehicle drive system according to an embodiment of this application.

[0009] Figure 2 This is a circuit diagram of a vehicle drive system according to an embodiment of this application.

[0010] Figure 3 This is a schematic diagram of the first composite carrier, the second composite carrier, and the rotor permanent magnet magnetic field in a three-phase stationary coordinate system according to an embodiment of this application.

[0011] Figure 4 This is a schematic diagram of the first composite carrier, the second composite carrier, and the rotor permanent magnet magnetic field in a three-phase stationary coordinate system according to another embodiment of this application.

[0012] The reference numerals in the attached figures are explained as follows:

[0013] 1. Vehicle drive system

[0014] 10 Dual-winding motor

[0015] 102, 104 Three-phase windings

[0016] 12 Motor control device

[0017] 122 Processing Circuit

[0018] 124, 126 Three-phase inverter circuits

[0019] 20 and 26 batteries

[0020] 22, 24 DC link capacitors Detailed Implementation

[0021] Certain terms are used in this specification and the following claims to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and the following claims do not distinguish components by differences in name, but rather by differences in function. The term "comprising" as used throughout this specification and the following claims is an open-ended term and should be interpreted as "comprising but not limited to." Furthermore, the term "coupled" here includes any direct and indirect electrical connection means. Therefore, if the text describes a first device coupled to a second device, it means that the first device can be directly electrically connected to the second device, or indirectly electrically connected to the second device through other devices or connection means.

[0022] Please refer to Figure 1 , Figure 1 This is a block diagram of a vehicle drive system 1 according to an embodiment of this application. The vehicle drive system 1 includes a dual-winding motor 10 and a motor control device 12. The motor control device 12 can generate control signals to control the motor 10 to drive the vehicle.

[0023] Please refer to Figure 2 , Figure 2 This is a circuit diagram of a vehicle drive system 1 according to an embodiment of this application. The dual-winding motor 10 includes a first three-phase winding 102 and a second three-phase winding 104. The first three-phase winding 102 and the second three-phase winding 104 can be stator windings including a center tap and a star connection. The motor control device 12 may include a processing circuit 122, a first three-phase inverter circuit 124, and a second three-phase inverter circuit 126. The first three-phase inverter circuit 124 can generate a first three-phase current, and the second three-phase inverter circuit 126 can generate a second three-phase current. A pulse width modulation controller modulates the first three-phase current and the second three-phase current to generate a first three-phase carrier wave and a second three-phase carrier wave to control the first three-phase winding 102 and the second three-phase winding 104 of the dual-winding motor 10 to drive the vehicle.

[0024] In one embodiment, please refer to Figure 2The processing circuit 122 is used to control the vehicle drive system 1 as a first DC-DC converter and a second DC-DC converter. Specifically, the processing circuit 122 uses the first three-phase inverter circuit 124 of the motor control device 12 as a first switching circuit of the first DC-DC converter and the first three-phase winding 102 of the dual-winding motor 10 as a first three-phase inductor of the first DC-DC converter; on the other hand, the processing circuit 122 uses the second three-phase inverter circuit 126 of the motor control device 12 as a second switching circuit of the second DC-DC converter and the second three-phase winding 104 of the dual-winding motor 10 as a second three-phase inductor of the second DC-DC converter. Furthermore, this application couples a low-voltage battery 20 to the center tap of the first three-phase winding 102 and the second three-phase winding 104, couples a DC link capacitor 22 and a high-voltage battery 24 to the first three-phase inverter circuit 124, and couples the DC link capacitor 24 and the high-voltage battery 24 to the second three-phase inverter circuit 126. Accordingly, a DC-DC voltage boost converter (Boost circuit) from the low-voltage battery 20 to the high-voltage battery 24 can be realized, as well as a DC-DC voltage buck converter (Buck circuit) from the high-voltage battery 24 to the low-voltage battery 20, allowing bidirectional flow of electrical energy. It should be noted that... Figure 1 , Figure 2 The vehicle drive system 1 mentioned in this application is merely a necessary component required for a DC-DC converter. Its basic architecture and operation method should be well known to those skilled in the art, and therefore will not be described in detail.

[0025] Please refer to Figure 3 , Figure 3 This is a schematic diagram of the first synthetic carrier Is1, the second synthetic carrier Is2, and the rotor permanent magnet magnetic field Ψf in Embodiment 1 of this application, on a three-phase stationary coordinate system (A, B, C). Figure 3 As shown, the first composite carrier Is1 of the first three-phase carrier generated by the first DC-DC converter is oriented in a first direction in the three-phase stationary coordinate system, and the second composite carrier Is2 of the second three-phase carrier generated by the second DC-DC converter is oriented in a second direction in the same three-phase stationary coordinate system. A torque ripple in the vehicle drive system 1 is the dot product of the rotor permanent magnet magnetic field Ψf and the first composite carrier Is1 and the second composite carrier Is2. Accordingly, the processing circuit 122 sets the first composite carrier Is1 in a first direction in the three-phase stationary coordinate system and the second composite carrier in a second direction in the same three-phase stationary coordinate system to control the torque ripple in the vehicle drive system 1. For example, as... Figure 3As shown, the first direction and the rotor permanent magnet magnetic field direction are at a first angle θ1 and a second direction and the rotor permanent magnet magnetic field direction are at a second angle θ2. The processing circuit 122 sets the first and second angles to have the same angle value and opposite angle directions, and sets the amplitude of the first composite carrier Is1 to be equal to the amplitude of the second composite carrier Is2. At this time, the third composite carrier Is of the first composite carrier Is1 and the second composite carrier Is2 is oriented in a third direction in the three-phase stationary coordinate system. This third direction is parallel to the rotor permanent magnet magnetic field direction. That is, the angle between the third direction and the rotor permanent magnet magnetic field direction is 0 degrees or 180 degrees. The torque ripple of the vehicle drive system 1 is the dot product of the rotor permanent magnet magnetic field Ψf and the third composite carrier Is. Therefore, the torque ripple of the vehicle drive system 1 is 0, achieving the purpose of reducing torque ripple.

[0026] Please refer to Figure 4 , Figure 4 This is a schematic diagram of the first synthesized carrier Is1, the second synthesized carrier Is2, and the rotor permanent magnet magnetic field Ψf in three-phase stationary coordinates (A, B, C) according to an embodiment of this application. The processing circuit 122 sets the first synthesized carrier Is1 in a first direction in the three-phase stationary coordinates and the second synthesized carrier Is2 in a second direction in the same three-phase stationary coordinates to control a torque ripple in the vehicle drive system 1. For example, as... Figure 4 As shown, the processing circuit 122 sets the sum of the angles of the first included angle and the second included angle to be 180 degrees, which means the phase difference between the first direction and the second direction is 180 degrees. Therefore, the amplitude of the third composite carrier Is is the amplitude of the first composite carrier Is1 minus the amplitude of the second composite carrier Is2. When the processing circuit 122 sets the amplitude of the first composite carrier Is1 to be equal to the amplitude of the second composite carrier Is2, the amplitude of the third composite carrier Is is equal to 0. Since the torque ripple of the vehicle drive system 1 is the dot product of the rotor permanent magnet magnetic field Ψf and the third composite carrier Is, the torque ripple of the vehicle drive system 1 is 0, thus achieving the purpose of reducing torque ripple.

[0027] In one embodiment, the processing circuit 122 sets the phase difference of each phase carrier in the first three-phase carrier to 120 degrees and sets the phase difference of each phase carrier in the second three-phase carrier to 120 degrees, thereby reducing the capacitor ripple of the vehicle drive system 1, thereby reducing reactive power loss, avoiding a decrease in capacitor life and a decrease in system reliability.

[0028] Those skilled in the art can combine, modify, or change the embodiments described above in accordance with the spirit of this application, but are not limited thereto. All the statements, steps, and / or processes (including suggested steps) above can be implemented by hardware, software, firmware (i.e., a combination of hardware devices and computer instructions, where the data in the hardware device is read-only software data), electronic systems, or combinations of the above devices. Hardware may include analog, digital, and mixed circuits (i.e., microcircuits, microchips, or silicon chips). Electronic systems may include system-on-chip (SoC), system-in-package (SiP), computer-on-module (CoM), and vehicle drive system 1. The process steps and embodiments of this application may exist in the form of program code or instructions and be stored in a computer-readable recording medium. Computer-readable recording media may include read-only memory (ROM), flash memory, random-access memory (RAM), subscriber identity module (SIM), hard disk, floppy disk, or optical disk read-only memory (CD-ROM / DVD-ROM / BD-ROM), but are not limited thereto. The processor can be used to read and execute program code or instructions stored on computer-readable media to perform all the aforementioned steps and functions.

[0029] In summary, in this embodiment, the first composite carrier of the first three-phase carrier generated by the first DC-DC converter is positioned in a first direction in the three-phase stationary coordinate system, and the second composite carrier of the second three-phase carrier generated by the second DC-DC converter is positioned in a second direction in the three-phase stationary coordinate system, to control the torque ripple of the vehicle drive system; and the phase difference between each phase carrier in the first three-phase carrier and the phase difference between each phase carrier in the second three-phase carrier are both set to 120 degrees to control the capacitance ripple of the vehicle drive system. This achieves the optimal solution for controlling the torque ripple and capacitance ripple of the vehicle drive system.

[0030] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A vehicle control method for controlling a capacitor ripple and a torque ripple in a vehicle drive system, the vehicle drive system comprising a first DC-DC converter and a second DC-DC converter, characterized in that, include: The torque ripple of the vehicle drive system is controlled by setting a first composite carrier of a first three-phase carrier generated by the first DC-DC converter in a first direction at a three-phase stationary coordinate and a second composite carrier of a second three-phase carrier generated by the second DC-DC converter in a second direction at the same three-phase stationary coordinate. The first DC-DC converter consists of a first three-phase winding of a dual-winding motor, a first three-phase inverter circuit, and a first DC link capacitor; and the second DC-DC converter consists of a second three-phase winding of the same dual-winding motor, a second three-phase inverter circuit, and a second DC link capacitor. The method further includes setting a first angle between the first direction and the direction of the rotor permanent magnet magnetic field and a second angle between the second direction and the direction of the rotor permanent magnet magnetic field, based on the direction of the rotor of the dual-winding motor in the three-phase stationary coordinate system. When the angle values ​​of the first angle and the second angle are the same, the first angle and the second angle are symmetrically distributed on both sides of the rotor permanent magnet magnetic field, and the amplitudes of the first composite carrier wave and the second composite carrier wave are equal, the torque ripple is minimized.

2. The vehicle control method according to claim 1, characterized in that, The capacitor ripple is minimized when the phase difference between each phase of the first three-phase carrier and the phase difference between each phase of the second three-phase carrier is 120 degrees.

3. The vehicle control method according to claim 1, characterized in that, include: The first three-phase inverter circuit is used as a first switching circuit of the first DC-DC converter, and the second three-phase inverter circuit is used as a second switching circuit of the second DC-DC converter; and The first three-phase winding of the dual-winding motor is used as a first three-phase inductor of the first DC-DC converter, and the second three-phase winding of the dual-winding motor is used as a second three-phase inductor of the second DC-DC converter.

4. The vehicle control method according to claim 3, characterized in that, include: The pulse width modulation controller of the vehicle drive system modulates a first three-phase current output from the first switching circuit to generate a first three-phase carrier wave, and the pulse width modulation controller modulates a second three-phase current output from the second switching circuit to generate a second three-phase carrier wave.

5. A vehicle drive system, comprising: A dual-winding motor, comprising a first three-phase winding and a second three-phase winding, wherein the first three-phase winding serves as a first three-phase inductor of a first DC-DC converter, and the second three-phase winding serves as a second three-phase inductor of a second DC-DC converter; and A motor control device includes a first three-phase inverter circuit, a second three-phase inverter circuit, a pulse width modulation controller, and a processing circuit. The first three-phase inverter circuit serves as a first switching circuit for a first DC-DC converter, and the second three-phase inverter circuit serves as a second switching circuit for a second DC-DC converter. The pulse width modulation controller modulates a first three-phase current output from the first switching circuit and a second three-phase current output from the second switching circuit to generate a first three-phase carrier wave and a second three-phase carrier wave. The processing circuit sets a first composite carrier wave of the first three-phase carrier wave generated by the first DC-DC converter to oriented towards a three-phase stationary coordinate. A second composite carrier of the second three-phase carrier generated by the first direction and the second DC-DC converter is directed in a second direction at the three-phase stationary coordinates to control a torque ripple of the vehicle drive system. This further includes setting a first angle between the first direction and the direction of the rotor permanent magnet field, and a second angle between the second direction and the direction of the rotor permanent magnet field, based on the rotor of the dual-winding motor at the three-phase stationary coordinates in the direction of the rotor permanent magnet field. The torque ripple is minimized when the first angle and the second angle have the same angle value, are symmetrically distributed on both sides of the rotor permanent magnet field, and have equal amplitudes of the first composite carrier and the second composite carrier.

6. The vehicle drive system according to claim 5, characterized in that, When the phase difference between each phase of the first three-phase carrier and the phase difference between each phase of the second three-phase carrier are 120 degrees, the capacitor ripple of the vehicle drive system is minimized.

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