级联型高压变频器死区效应分析

设计电压型PWM变频器时死区时间的设定会造成输出谐波增加、负载电动机转矩脉动，严重时甚至引起电动机震荡。针对电压胞级联型结构的高压变频器，通过理论推导和仿真分析，较为详细的探讨了其死区效应的特点和影响因素。研究证明，电压胞级联型高压变频器死区效应与电压胞个数无关，随频率调制比和死区时间的变化而同步变化，且总的看来死区的影响不很严重，但从高性能调速的角度，适当的死区补偿也是必要的。

Analysis of dead-time effect in cascaded multi-level medium-voltage inverters

In the design of voltage PWM inverter,the existence of dead-time will arouse the in-crease of output harmonic,the pulsation of the motor torque,and even the oscillation of the motor.The dead-time effect on the cascaded multi-level medium-voltage inverters and its affection factors are discussed by theoretic calculation and simulated analysis.The research reveals that the dead-time effect of the cascaded multi-level medium-voltage inverter has nothing to do with the number of multi-cascaded power-cell,but varies synchronously with the altering of the frequency modulation ratio and dead-time.The result also shows that the dead-time effect is not serious,but the appro-priate dead-time compensation is necessary for better performance of the inverters.