线电压确定无刷直流电动机转子位置新方法

A Novel Scheme of Sensing Rotor Position of BLDCM Based on the Line Voltage

针对无位置传感器无刷直流电动机控制问题,提出一种基于线电压的转子位置检测新方法。依据绕组电压方程,给出了电机反电动势计算方法。通过采样电机线电压,得出反电动势计算值,确定电机换相时刻。为解决反电动势计算值中窄脉冲引起过零点误判的问题,依据反电动势变化率在换相时刻远大于非换相时刻的原理,采用反电动势变化率检测法判断过零点时刻。仿真和实验结果显示该方法能够准确提供转子位置信息,在负载转矩恒定和突变情况下无换相错误等异常情况,表明该方法具有良好的适应性和可靠性。

A novel rotor position detection method based on the line voltage was presented in the sensorless brushless DC motor control problems. Back-EMF was calculated based on the motor winding voltage equation. Thus, the commuta- tion time was defined by sampling the motor line voltage. In order to solve the zero-crossing point problem which was caused by narrow pulse, the method of Back-EMF change rate detection method was proposed based on that the change rate of Back-EMF at commutation time is much larger than the non-commutation time principle. Simulation and experiments show that this method can accurately provide rotor position information and does not appears unusual circumstances such as false commutation at load torque identical and abrupt change situation. This indicates that this method has better adaptability and reliability.