Optimization And Simulation On Control System For Variable Frequency Air-conditioner Compressor

With the greatest economic boom ever, energy consumption and environment protection have been the urgent issues for China. Being one of the main electricity consumers in family life, traditional air-conditioner has its drawbacks on energy saving and noise reduction. With the superiority on these drawbacks, the Variable Frequency Air-conditioner which always works at low-frequency is a development trend of air-conditioner.In recent years, AC Induction Motors have been widely used in the driver of air-conditioner, while Permanent Magnet Synchronous Motors (PMSM) and Brushless DC Motors (BLDCM) are becoming more and more popular due to their high performance. Comparing to BLDCM, PMSM has its superiority on both of torque ripple and speed fluctuation. However, since PMSM has problems of low-speed torque ripple with vibration and noise, as well as hall sensors which cost a lot and is hard to maintain, Variable Frequency air-conditioner still faces the limitation of high cost and immature technology. Therefore, we propose an optimal control algorithm to suppress the low-speed torque ripple of PMSM, combining with the sensorless control solution.Starting from the model of PMSM, this paper firstly proposes an optimal control algorithm based on stator current to suppress the torque ripple in low speed region. Then, the sensorless drive system is realized by sensorless control algorithm. Besides, after analyzing the model and high order harmonics of BLDCM, the optimal control algorithm is extended to the torque ripple minimization of BLDCM. Simulation results on MATLAB have shown the effectiveness and practical availability of the proposed method.