A method and device for controlling the bus current limit of a brushless DC motor for a vehicle

Abstract

The invention relates to a bus current limiting control method and device for an automotive brushless direct current motor. The method mainly comprises the following steps that: a main control chip receives current signals processed by a conditioning and filtering unit and performs PI compensation control according to a set current limiting value, an allowed maximum duty cycle for avoiding current exceeding the limit value is figured out and is compared with the duty cycle of driving willing, the allowed duty cycle takes a minimum value, and a PWM (Pulse-Width Modulation) control signal corresponding to the minimum duty cycle is output to an inverter driving motor according to the value. The device comprises a current detecting module, a signal filtering module, a main control chip and an inverter which are connected with one another in sequence, wherein the current detecting module and the inverter are all connected with the brushless direct current motor, the current detecting module is used for collecting bus current, and the inverter is used for driving the brushless direct current motor. Compared with the prior art, the method and the device are easy to implement and low in cost, can effectively solve the problem of overheating of the motor, and cannot influencing the driving of a driver under normal conditions.

Description

technical field [0001] The invention relates to a control technology of a brushless DC motor for a vehicle, in particular to a method and device for controlling the current limiting of a bus bar of a brushless DC motor for a vehicle. Background technique [0002] The problem of overheating has been one of the barriers to the application of brushless DC motor systems in vehicles. The brushless DC motor system includes two parts: the motor body and the controller. When the motor body overheats, the phase winding resistance increases, and even the winding burns out; when the controller is overheated, the control board, especially the power switch tube, will be damaged at high temperature damaged and not functioning properly. In short, severe overheating can cause damage to motor system components and prevent them from operating normally. [0003] High current is one of the most direct causes of overheating of the motor system, so the current amplitude of the motor system must...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a vehicle brushless DC motor bus current limiting control method and device in order to overcome the above defects in the prior art, the method and device can prevent the brushless DC motor system from overheating caused by excessive current At the same time, avoid the battery caused by the excessive discharge current of the power battery, and when the bus current does not exceed the current limit value, it will not affect the driver's operation

Images