开关磁阻电机低速运行无位置传感器检测方法

Position-sensorless method for switched reluctance motor in low-speed operation

针对开关磁阻电机低速运行方法中的传统脉冲注入法只利用非导通相电流信息,存在导通区间受限和续流影响估计精度的问题。本文对低速控制策略与无位置检测原理进行研究,提出了一种双电流斩波限PWM滞环控制的三相电流斜率差值无位置传感器检测方案。所提方案在导通区采用双斩波限PWM滞环控制,使导通区电流斩波次数增加,能够改善低速运行时的性能,并提高电流斜率差值的计算精度。与传统非导通相电流比较方法只利用非导通相信息相比,该方案增加了导通相电流计算。在计算导通相电流斜率差值后,与两非导通相形成三相电流斜率差值,从而估计电机的实时位置信息。以三相12/8结构的电机进行了相关仿真和实验验证,实验结果表明,该方案能够有效解决传统方法存在的导通区间固定和实时角度计算受续流影响的问题。

The conventional pulse injection method for low-speed operation of switched reluctance motors utilizes only the information of the non-conducting phase currents,which has the problems of limited conduction intervals and continuation currents affecting the estimation accuracy.In this paper,the low-speed control strategy and the principle of position-sensorless detection are investigated,and a three-phase current slope difference position-sensorless detection scheme with dual current chopper-limited PWM hysteresis loop control is proposed.The proposed scheme adopts dual chopper-limited PWM hysteresis loop control in the conduction zone,which increases the number of current chopping in the conduction zone,improves the performance during low-speed operation,and increases the calculation accuracy of the current slope difference.Compared with the traditional non-conducting phase current comparison method that utilizes only the non-conducting phase information,this scheme adds the on-phase current calculation.After calculating the on-phase current slope difference,the three-phase current slope difference is formed with the two non-conducting phases to estimate the real-time position information of the motor.The related simulation and experimental verification are carried out with a three-phase 12/8 structure motor,and the experimental results show that the scheme can effectively solve the problems of fixed on-phase intervals and real-time angle calculation affected by the continuation current that exist in the traditional method.