基于负载转矩观测的永磁同步电机抑制转速脉动控制方法

Speed Ripple Suppression Control of PM Motor Based on Load Torque Observation

在电机调速系统中,需要抑制由负载转矩的周期性波动引起的转速脉动,单纯依靠转速调节器难以获得理想的转速脉动抑制效果。对于无法安装位置传感器的永磁同步电动机,只能通过软件观测转子的转速和位置,更加大了抑制转速脉动的控制难度。本文采用一种基于假设旋转坐标系的无位置传感器观测方法,对转子位置和转速进行观测,并通过转速信息进一步观测负载转矩中的周期性脉动分量。在此基础上,提出一种负载转矩电流前馈补偿方法,依据观测得到的负载转矩波动幅值对电动机转矩电流的给定值进行相应的前馈补偿,从而抑制转速脉动,明显提高了转速调节器的控制性能。通过带模拟空调压缩机负载实验,验证了所提方法的有效性。

It is necessary to suppress the speed ripple in the adjustable speed motor control system with apparent periodic load torque ripple.That however is difficult to realize by merely using conventional speed regulator,especially for the motors without installing rotor position sensor,in which the messages of rotor speed and position are estimated through a software observer.In this paper,a position sensorless observation method based on the hypothetical rotating coordinate system was adopted to observe the rotor position and speed,and the periodic ripple components of the load torque were observed through the speed.Futher,a method of load torque current feedforward compensation was proposed.The reference value of the motor torque current was compensated correspondingly based on the observed load torque ripple amplitudes,therefore the speed ripple was suppressed and the control performance of the speed regulator was improved obviously.The validity of the proposed method was verified by experiments with a simulated load torque of air-conditioning compressor.