阅读说明：本技术 越野车轮毂电机双电压供电系统控制方法 (Control method of dual-voltage power supply system of wheel hub motor of off-road vehicle ) 是由 汪振晓 付邦璀 黄松 李进伟 李�杰 于 2020-07-01 设计创作，主要内容包括：本发明公开了一种越野车轮毂电机双电压供电系统控制方法,其特征在于,包括以下步骤：1)获取车辆运行参数,得到轮毂电机目标转速和目标扭矩；2)根据轮毂电机目标转速判断电池组的串并联方式；3)控制轮毂电机输出目标转速和目标扭矩。本发明通过电池组串并联的切换控制轮毂电机的输入电压,可根据驾驶需求实现在低速大扭矩工况和高速低扭矩工况之间切换。(The invention discloses a control method of a dual-voltage power supply system of a wheel hub motor of a cross-country vehicle, which is characterized by comprising the following steps of: 1) obtaining vehicle operation parameters to obtain a target rotating speed and a target torque of a hub motor; 2) judging the series-parallel connection mode of the battery pack according to the target rotating speed of the hub motor; 3) and controlling the hub motor to output a target rotating speed and a target torque. The invention controls the input voltage of the hub motor through the switching of the series-parallel connection of the battery pack, and can realize the switching between the low-speed large-torque working condition and the high-speed low-torque working condition according to the driving requirement.)

1. A control method of a dual-voltage power supply system of a wheel hub motor of a cross-country vehicle is characterized by comprising the following steps: the dual-voltage power supply system comprises a battery pack and a hub motor, wherein a series-parallel switching circuit is connected between the battery pack and the hub motor.

2. The off-road vehicle wheel hub motor dual-voltage power supply system control method of claim 1, characterized in that: the vehicle operation parameters include accelerator pedal opening, brake pedal opening and vehicle speed.

3. The off-road vehicle wheel hub motor dual-voltage power supply system control method of claim 1, characterized in that: the battery pack comprises at least two battery packs with equal output voltage and output current.

4. The off-road vehicle wheel hub motor dual-voltage power supply system control method of claim 1, characterized in that: when the target rotating speed is less than or equal to the rated rotating speed, the battery packs are connected in parallel; and when the target rotating speed is greater than the rated rotating speed, the battery packs are connected in series.

Technical Field

The invention relates to the technical field of hub motors, in particular to a control method of a dual-voltage power supply system of a cross-country wheel hub motor.

Background

The special cross-country vehicle has the condition of long-time low-speed large-torque running or high-speed low-torque running under the use condition, and in the traditional power vehicle, in order to solve the problems, a general method adopts a high-power engine and a multi-speed-ratio gearbox, and the speed ratio of a transmission system is reasonably adjusted. In the wheel hub motor vehicle, the wheel hub motor is arranged in the wheel hub, the wheel hub motor cannot be enlarged due to space limitation, the input voltage of the wheel hub motor is a fixed value, the maximum output torque of the wheel hub motor is limited, and the dynamic property of the special off-road vehicle is difficult to meet the performance requirement.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a control method of a dual-voltage power supply system of a wheel hub motor of an off-road vehicle.

In order to achieve the purpose, the invention provides a control method of a dual-voltage power supply system of a wheel hub motor of a cross-country vehicle, which is characterized by comprising the following steps of: the dual-voltage power supply system comprises a battery pack and a hub motor, wherein a series-parallel switching circuit is connected between the battery pack and the hub motor.

Further, the vehicle operating parameters include accelerator pedal opening, brake pedal opening, and vehicle speed.

Further, the battery pack comprises at least two battery packs with equal output voltage and output current.

Further, when the target rotating speed is less than the rated rotating speed, the battery packs are connected in parallel; and when the target rotating speed is greater than or equal to the rated rotating speed, the battery packs are connected in series.

The invention has the beneficial effects that: according to the invention, the mode of series-parallel connection of the battery packs is determined through the target rotating speed, so that the input voltage and the input current of the hub motor are controlled, the output rotating speed and the output torque of the hub motor are further controlled, and switching between a low-speed large-torque working condition and a high-speed low-torque working condition can be realized according to the driving requirement.

Drawings

FIG. 1 is a schematic diagram of a dual voltage power supply system for a hub motor of a cross-country vehicle.

FIG. 2 is a flow chart of the control method of the present invention.

The components in the figures are numbered as follows: the device comprises a first battery pack 1, a second battery pack 2, a first diode 3, a second diode 4, a change-over switch 5, an anode contactor 6, a cathode contactor 7, a filter capacitor 8, a three-phase inverter bridge 9 and a hub motor 10.

Detailed Description

The invention will be described in more detail below with reference to the accompanying drawings, which are included to provide a more clear understanding of the invention, but are not intended to limit the invention.

As shown in fig. 1, a cross-country vehicle hub motor dual-voltage power supply system comprises a battery pack and a wheel hub motor 10, wherein the battery pack is composed of a first battery pack 1 and a second battery pack 2 with equal output voltage and output current, the system further comprises a series-parallel switching circuit, one end of the series-parallel switching circuit is connected with the battery pack to control series connection or parallel connection of the first battery pack 1 and the second battery pack 2, and the other end of the series-parallel switching circuit is connected with the wheel hub motor 10 through a filter capacitor 8 and a three-phase inverter bridge 9 which are sequentially connected in series.

In the above technical scheme, the series-parallel switching circuit includes a first diode 3 and a second diode 4, a cathode of the first diode 3 is connected with a cathode of the first battery pack 1, an anode of the second diode 4 is connected with an anode of the second battery pack 2, a change-over switch 5 is further connected between the cathode of the first diode 3 and the anode of the second diode 4, the anode of the first battery pack 1 and the cathode of the second diode are both connected to a P-end of the three-phase inverter bridge through a positive contactor 6, and the cathode of the second battery pack 2 and the anode of the first diode 4 are both connected to an N-end of the three-phase inverter bridge through a negative contactor 7. Therefore, when the change-over switch is closed, the first battery pack and the second battery pack are connected in series, the output current is unchanged, and the output voltage is increased to twice of the original voltage; when the change-over switch is switched off, the first battery pack and the second battery pack are connected in parallel, the output voltage is unchanged, and the output current is increased by two times.

The power supply system also comprises a vehicle control unit, wherein the signal input end of the vehicle control unit is respectively connected with signals of the opening degree of an accelerator pedal, the opening degree of a brake pedal, the speed of the vehicle and the like; the signal output end of the motor controller is respectively connected with the motor controller and the battery pack controller, the motor controller controls the output rotating speed and the output torque of the hub motor, and the battery pack controller controls the series-parallel switching circuit to realize the series connection or the parallel connection of the two battery packs.

As shown in fig. 2, the control method of the dual-voltage power supply system of the off-road vehicle hub motor comprises the following steps:

1. the vehicle control unit obtains vehicle operation parameters including accelerator pedal opening, brake pedal opening and vehicle speed, and obtains a target rotating speed and a target torque of the hub motor according to the parameters.

2. When the target rotating speed is lower than the rated rotating speed, the vehicle control unit sends an instruction to the battery pack controller, the battery pack controller enables the battery packs to be connected in parallel by controlling the series-parallel connection switching circuit, at the moment, the input voltage of the hub motor is the voltage of a single battery pack, and the input current is twice of the voltage of the single battery pack; when the target rotating speed is greater than or equal to the rated rotating speed, the battery pack controller controls the series-parallel connection switching circuit to enable the battery packs to be connected in series, the input voltage of the hub motor is twice of the voltage of a single battery pack, and the input current is the current of the voltage of the single battery pack.

3. After the series-parallel connection switching of the battery pack, the motor controller controls the output target rotating speed and the target torque of the hub motor by adjusting the frequency of the hub motor. The battery pack is connected in parallel when the vehicle normally runs under the working condition of low rotating speed and large torque, the target rotating speed is less than or equal to the rated rotating speed, the input current of the hub motor is increased to be twice of that of a single battery pack, and the frequency of the hub motor is adjusted to enable the output rotating speed to be equal to the target rotating speed; when the vehicle needs to run at a high speed and a low torque working condition, the target rotating speed is greater than the rated rotating speed, the battery packs are connected in series, the input voltage of the hub motor is increased to be twice of that of a single battery pack, the frequency of the hub motor is adjusted, the output rotating speed can be increased to be twice of that of the hub motor, and the output rotating speed is equal to the target rotating speed.

According to the invention, on the basis of not changing the structure of the hub motor, the input voltage of the hub motor is adjusted through the series-parallel connection switching of the battery pack, so that the output rotating speed and the output torque of the hub motor are controlled, and the switching of a vehicle between a low-rotating-speed large-torque working condition and a high-speed low-torque working condition is realized.