压缩机用永磁同步电机转速脉动的抑制

Suppression of speed ripples of permanent magnetic synchronous motor for compressor application

随着永磁同步电机在压缩制冷系统中的广泛应用,如何抑制其低速范围内转速脉动成为了研究的重点.本文从转速脉动产生的机理出发,针对转速脉动周期性的特点,提出了一种新的自适应控制算法.该控制算法在传统的PI控制器上并联一个可变频率谐振控制器,构成自适应比例谐振控制器.从而使得参考转矩电流是由PI控制器产生的主要参考电流与谐振控制器产生的补偿电流一起构成的.由于补偿转矩电流的作用,使得电磁转矩能够更好地跟踪负载转矩,以此达到对转速脉动的抑制.最后对使用传统PI控制器和比例谐振(PI-resonance,PI–RES)控制器的两种算法进行了对比实验分析,实验结果验证了该控制算法的有效性.

When applying the permanent magnetic synchronous motors （PMSM） to refrigerant system, the suppres- sion of speed ripples of the PMSM in low-feed range becomes the focus of consideration. We start with the generation mechanism and the periodical characteristics of the speed ripples to propose an adaptive control algorithm. In this control algorithm, we place a frequency variable resonance controller in parallel with the conditional proportion and integral （PI） controller to form a PI-resonance （PI-RES） controller. The compensation torque current generated by the resonance con- troller and the main reference current generated by the PI controller constitute the reference torque current. Because of the existence of the compensation torque current, the electromagnetic torque can follow the variation of the load torque more perfectly, thus the speed ripples are suppressed. Performance indices of the conventional PI controller and the PI-RES controller are compared and evaluated through experimental investigations. The results validate the effectiveness of the proposed algorithm.