A Pulse Width Modulation Method Applicable to Vehicle Motor Controller

A pulse width modulation, motor controller technology, applied in the direction of AC motor control, general control strategy, motor, etc., can solve the problem that the temperature of the power switching device, the low output voltage/current sine, and the reduction of the switching frequency cannot be guaranteed. It can minimize the control delay, improve safety, and reduce harmonic losses and torque fluctuations.

Active Publication Date: 2022-07-05
LEADRIVE TECH (SHANGHAI) CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The efficiency of the motor controller and the temperature of the power switching device are affected by many factors, so relying solely on the motor speed cannot guarantee the efficiency of the motor controller, nor can it guarantee that the temperature of the power switching device is within a reliable range
Second, the degree of reduction in switching frequency is not clear
The problem with this control method is that the duty cycle is only updated once per switching cycle. When the motor speed is high, the output voltage / current sine degree is not high, and the harmonic content is large.
Therefore, when the carrier frequency is at the rated value, there is also the problem of high harmonic content of the output voltage / current

Method used

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  • A Pulse Width Modulation Method Applicable to Vehicle Motor Controller
  • A Pulse Width Modulation Method Applicable to Vehicle Motor Controller
  • A Pulse Width Modulation Method Applicable to Vehicle Motor Controller

Examples

Experimental program
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Effect test

Embodiment 1

[0071] The following are when the switching frequency is the rated value, and only when sampling and calculation are triggered at the start / end of the rated switching (carrier) cycle, combined with figure 2 , the specific implementation steps of the pulse width modulation method provided by the present invention are described:

[0072] (1) At the moment shown in trigger sampling and operation 4, that is, at the beginning of the rated carrier cycle (the lowest point of the carrier), the instantaneous value of the three-phase output current of the motor controller is exactly equal to the average value in one switching cycle. At this point, the motor controller starts to collect the state quantities and command values ​​of the motor controller and the motor.

[0073] (2) Further, within the time window shown in the sampling sum operation 5, the switching frequency is determined according to the variable information collected in step (1).

[0074] (3) After that, within the time w...

Embodiment 2

[0080] The following is when the switching frequency is the rated value, and the sampling and calculation can only be triggered at the midpoint of the rated switching (carrier) cycle, combined with image 3 , the specific implementation steps of the pulse width modulation method provided by the present invention are described:

[0081] Different from the above Embodiment 1, at the moment shown in trigger sampling and operation 4, that is, at the midpoint of the rated carrier cycle (the highest point of the carrier), the instantaneous value of the three-phase output current of the motor controller is exactly equal to one switching cycle. average of. At this point, the motor controller starts to collect the state quantities and command values ​​of the motor controller and the motor. The rest of the execution flow sequence is delayed by half a carrier cycle. In one switching (carrier) cycle, sample once, calculate the voltage command value in the rotating coordinate system once...

Embodiment 3

[0084] The following is when the switching frequency is the rated value, and the sampling and calculation can be triggered at the start / stop time and midpoint of the rated switching (carrier) cycle, combined with Figure 4 , the specific implementation steps of the pulse width modulation method provided by the present invention are described:

[0085] Different from Embodiment 1 and Embodiment 2, the motor controller starts to collect the state quantities and command values ​​of the motor controller and the motor at the start time and the midpoint time of the rated carrier cycle. After that, the motor controller should complete all the information collection and operation within half the carrier cycle, and update the duty cycle value at the next start time or midpoint time. In one switching (carrier) cycle, sample twice, calculate the voltage command value in the rotating coordinate system twice, obtain the voltage command value in the static coordinate system twice, and updat...

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PUM

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Abstract

The present invention provides a pulse width modulation method suitable for a vehicle-mounted motor controller, comprising: taking the instructions of the motor controller, the state quantities of the motor controller and the motor as factors, and taking the temperature of the power switching device and the efficiency of the motor controller as factors At least one of them is used as the optimization target, according to the relationship between the factors and the optimization target, set the weight positive / negative sign and weight value of the corresponding factor; according to each factor and the corresponding weight value, determine whether to adjust the switching frequency; The adjustment degree is set according to the gear position. According to the sampling and operation timing of the motor controller, the switching frequency corresponding to each gear position is set. Finally, the switching frequency is adjusted to the switching frequency of the corresponding gear position according to each factor and the corresponding weight value. The method aims at minimizing the control delay, determines the reduction degree of the switching frequency, improves the update rate of the output duty cycle, improves the sine degree of the output voltage / current, and reduces the harmonic content.

Description

technical field [0001] The present disclosure relates to the technical field of electric vehicle control systems, and in particular, to a pulse width modulation method suitable for an on-board motor controller. Background technique [0002] Motor controller is one of the important components in electric vehicles. One of the core components of the motor controller is the power switching device. By controlling the power switching device to perform high-speed switching actions, the required output voltage / current waveform can be generated. When a power switching device performs a switching action, a certain energy loss will be generated, and the energy loss will be dissipated in the switching device in the form of heat energy. Therefore, the higher the switching frequency, the greater the switching losses and the higher the temperature of the switching device. In order to improve the energy conversion efficiency of the motor controller and ensure that the temperature of the s...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H02P23/28H02P23/00
CPCH02P23/28H02P23/0004Y02T10/72
Inventor 刘光远沈捷韩娜朱骏余浩
Owner LEADRIVE TECH (SHANGHAI) CO LTD
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