基于汽车EPS系统电机相线切断功能的驱动电路分析与改进

Analysis and Improvement of Driving Circuit Based on Motor Phase Cut-Off Function of Vehicle EPS System

为了提高汽车的安全性能,基于电动助力转向(EPS)系统的电子控制单元(ECU),要求电机的各个相线可以切断,以保证EPS在发生故障时,驾驶员仍可以较顺畅地操控方向盘,防止事故发生。基于TLE9183QK预驱动芯片的激活相线切断电路(APC)功能的推荐应用电路进行了测试及仿真,分析了电机相线切断驱动电路失效的原因,并在其基础上对电路进行了改进,解决了控制信号通过电容器进行隔离传输时产生的相对电势反向的问题。试验及仿真结果表明:通过对电容器信号输出端的控制信号进行电荷补偿,可使TLE9183QK的APC引脚正常驱动EPS电机相线切断电路。

In order to improve the safety performance of the vehicle,the electronic control unit(ECU)based on the electric power steering(EPS)system is required to cut off each phase of the motor to ensure that the driver can still operate the steering wheel smoothly when the EPS system fails to prevent accidents.The test and simulation of the recommended application circuit of the activation phase cut-off circuit(APC)function based on the TLE9183QK pre-driver chip are carried out,and the failure reason of the phase cut-off driver circuit is analyzed,based on which the circuit is improved.It solves the problem of relative electromotive force reverse when the control signal is transmitted through the capacitor in isolation.The experimental and simulation results show that the APC pin of TLE9183QK can drive the EPS motor phase cut-off circuit normally by means of charge compensation to the control signal of the capacitance signal output port.