基于端电压对称的高速磁悬浮无刷直流电机换相延时误差补偿方法

A Novel Control Method to Correct Commutation Error of BLDC Motor Without Position Sensor Based on Symmetric Phase Voltage Difference

针对压缩机用高速磁悬浮无传感器无刷直流电机换相误差问题,分析了低通滤波器延时、器件延时、软件延时等对换相的影响,得出了由各种延时导致的换相延时角度的精确表达式,结合换相前后端电压信号变化以及"60°-α"及"120°-α"延时补偿方法,提出了一种基于端电压对称的无刷直流电机换相延时误差补偿方法,该方法以换相表切换为基础,以换相前后端电压对称为目标,将换相前后相电压差值作为反馈量,通过PI调解来减小换相信号的相位误差。仿真及实验表明,所提出的补偿方法在20000 r/min范围内能够有效对换相信号的延时误差进行实时补偿,提高了电机性能。

This paper analyzed the commutation error of high-speed magnetically suspended brushless DC motor, and analysis of the low-pass filter delay, delay devices, software delay commutation effects showed the delay will cause the exact expressions for the delay angle. Then this paper proposed a new closed loop control method to correct the commutation error based on phase voltage changes before and after commutation and ＂60~ -or＂, ＂120~ -or＂ commutation methods. This method was based on the voltage symmetry of the front end of the commutation, and took the phase voltage integration difference of non-commutation phase as the feedback amount, and corrects the commutation error automatically through the PI regulator. Simulation and experimental results show that the proposed compensation method in 20000 r/min range can effectively swapping believe, compensating the error in real time, improve the performance of the motor.