十二相三电平H桥变频器共模电压抑制方法

Twelve-phase open-end winding motor systems are preferred for high-power marine propulsion, but their PWM strategies generate high common-mode and zero-sequence voltages, degrading insulation and harmonic performance. This paper proposes a 120° decoupled SVPWM to eliminate zero-sequence voltage, and optimizes switching sequence across phase groups to reduce common-mode voltage by >50% without compromising output harmonics or neutral-point control. Validated via simulation and experiment.

十二相开绕组电机系统是船舶大容量推进的首选方案,但电机系统脉宽调制(pulse width modulation,PWM)策略不可避免地会产生高幅值共模电压和零序电压,影响了电机系统绝缘和输出谐波性能.文中首先根据多相开绕组电机特点,将十二相开绕组电机配套H桥变频器等效为 8 个三相单端变频器,并利用 120º 解耦的简化空间矢量调制方法,实现零序电压的完全消除;其次,调整多相电机不同三相绕组的开关矢量作用次序来抑制共模电压幅值,实现十二相三电平H桥变频器共模电压幅值降低超过 50%,且不影响H桥变频器原有输出谐波和中点电压控制性能;最后,通过仿真和实验验证所提算法正确性、可行性.