BLDCM Torque Ripple Suppression Method Based on Improved Quasi-Z Source Network

The torque ripple produced by brushless DC motor in the process of commutation seriously hinders its application in aerospace and other fields. By analyzing the causes of commutation torque ripple of Brushless DC motor, a new escl-qzsi (enhanced switched capacitor inductor Quad Z-source inverter) topology is used. The topology replaces the traditional DC power supply through the front-stage power converter, which effectively improves the output DC bus voltage range, The topology works normally by adjusting the delay time of high-level output on the rising and falling edges of Hall signal. The control strategy of escl-qzsi topology is to make the decline rate of off phase current equal to the rise rate of on phase current, so as to make the non commutation current stable and achieve the purpose of restraining torque ripple. The experimental results show that when the new topology is applied to the commutation torque ripple suppression of Brushless DC motor, the torque ripple is reduced by 19.8% and the stability of the system is improved.