An Optimized Modulation of Torque and Current Harmonics Suppression for Dual Three-Phase PMSM
Ge Liang, Sheng Huang, Wu Liao, Zhaoyang Zhang, Yu Liu, Congqi Feng, Xuan Wu, Shoudao Huang
Abstract
Although dual three-phase permanent magnet synchronous motor (DTP-PMSM) exhibits smoother output torque compared to traditional three-phase PMSM, the limitation of switching frequency in high-power industrial equipment can cause a decrease in the carrier ratio, which can lead to greater torque and current harmonics. This paper proposes a novel torque and current harmonics suppression pulse width modulation (TCHSPWM) method for DTP-PMSM that reduces torque and current harmonics under low carrier ratio. In this paper, the analytical formula of electromagnetic torque is derived by deriving the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> -axis current formula under optimized synchronous modulation. The torque analytical formula can be used to directly calculate torque harmonics for different existing optimized synchronous modulation methods. Then, a comprehensive optimization index is proposed using the derived torque and current analytical formulas. Based on this comprehensive optimization index value, the TCHSPWM is constructed to simultaneously suppress the torque and current harmonics of DTP-PMSM by regulating the switching angles of each phase. Comparative experiments have verified the effectiveness of the proposed method, which achieves good torque harmonics suppression while maintaining the ability to suppress current harmonics effectively.