一种EPS系统电机母线电源的控制电路设计及控制方法

A Control Circuit Design and Control Method of Motor Bus Power Supply for Vehicle EPS System

在汽车电动助力转向(EPS)系统中,对电机母线电源的控制大部分采用继电器的技术方案,小部分采用金属-氧化物-半导体场效应晶体管(MOSFET)的技术方案,并且驱动电路基本是采用非隔离控制信号方式。在MOSFET技术方案中,还需要DC-DC升压电路或集成升压芯片作为MOSFET的驱动电压源。但是,这两种技术方案在EPS系统出现崩溃等特定情况下无法切断电机母线电源控制电路。针对此问题,提出了一种采用电容器隔离传输控制信号并同时进行自举升压来驱动MOSFET的方案,提高了EPS系统的安全性能。

In the vehicle electric power steering(EPS)system,most of the motor bus power supply uses relay technology solutions,and a small part uses the metal-oxide-semiconductor field effect transistor(MOSFET)technology solutions,and basically the drive circuit is a non-isolated control signal.DC-DC boost circuit or integrated booster chip is needed to be used as the MOSFET driving voltage source in the MOSFET technology solutions.However,these two technology solutions will not be able to cut off the control circuit of motor bus power supply under certain circumstances such as collapse of the EPS system.In response to this issue,a solution is proposed that uses capacitor to isolate and transmit the control signal,and bootstrap boost to drive the MOSFET to be realized at the same time,which improves the safety performance of the EPS system.