Speed Ripple Suppression Strategy for Space Vector Modulation Based Direct Torque Control of Permanent Magnet Compressors

In the direct torque control (DTC) based permanent magnet compressors, the speed fluctuates greatly due to the periodic ripple of load. In order to reduce the speed ripples and improve the operation stability, a speed ripple suppression strategy based on quasi-resonant controller is proposed. The space vector modulation-based DTC oriented in stator field using PI controller achieves controlling the direct and alternating current component separately through the proposed quasi-resonant controller. By combining the sensorless algorithm based on extended flux linkage, the speed ripples can be effectively suppressed. The effectiveness of the above algorithm is verified on the 1.5kW air conditioning experiment platform.