带位置误差校正的开关磁阻电机电流梯度法

Current gradient sensorless control with position error calibration for switched reluctance motors

电流梯度法是一种通用性强,操作简单的无位置传感器技术。该方法对相电流进行低通滤波时导致相位后移,且转速越大,位置检测偏差越大,限制了适用的转速范围。对此采用零相移滤波方法,计算上一周波相电流因滤波产生的相移角,并对当前时刻输出的位置角进行补偿,提高位置检测精确度。分析了PWM控制方式下的相电流波形频谱,以确定合适的滤波截止频率。实验结果表明所提方法将转速对位置检测精确度的影响降低了86%,扩大了电流梯度法适用的转速范围。

The current gradient method is a position sensorless technology which is adaptable and easy op-erational. However, this method must filter the current, which causes the phases-lag and notable position detection error. This paper presented a method to calculate the phase-lag angle, which can calibrate the detected position angle, and then the detection precision of the traditional current gradient method was improved. The spectrum of the phase current with PWM ( pulse width modulation) control was analyzed, which helps to get the suitable cutoff frequency of the filter. Experimental results demonstrate the pro-posed method reduces the adverse effect of the rotation speed on the position detecting precision, and the speed range of the current gradient method is expanded.