Torque Ripple Reduction Strategy for Brushless DC Motor Based on Output Mode Reconstruction of Cuk Converter

To solve the problem of torque ripple of brushless dc motor (BLDCM) caused by nonideal back-electromotive force (EMF) and the commutation process, a new method for torque ripple suppression of BLDCM based on output mode reconstruction of the Cuk converter is proposed. This article uses the output Modes I and II of the Cuk converter. In the normal conduction stage, the output Mode I of the Cuk converter is adopted, and the inverter works in the chopping mode to realize the current control. Meanwhile, the torque ripple caused by the change of back-EMF can be suppressed by reasonably controlling the switch duty cycle of the inverter. The output Modes I and II of the Cuk converter are adopted in the low-speed commutation stage and the high-speed commutation stage, respectively, which can effectively suppress the commutation torque ripple of BLDCM. In addition, the proposed method improves the efficiency of the motor converter and effectively reduces the influence of the dc-dc intermediate stage on the system efficiency. Experimental results verify the feasibility and effectiveness of the proposed method.