TNPC型逆变器无死区载波层叠PWM控制

Carrier Disposition PWM Control with No Dead Zone for TNPC Inverter

载波层叠PWM(Carrier Disposition Pulse Width Modulation)调制法在实际应用中加入死区后会引起电流波形畸变及电压利用率降低等问题,以TNPC(T-type Neutral Point Clamped)型三相三电平逆变器拓扑结构作为研究对象,提出一种应用于三电平逆变器的无死区载波层叠PWM调制法。该调制法采用三重载波生成三路PWM调制信号,通过分析不同工作状态时死区引起的效应,推导出功率开关管的导通和关断规律。在MATLAB/Simulink环境下进行仿真,结果表明该方法可降低电流中的谐波含量、提高电流的基波幅值和电压利用率,实现TNPC型三电平逆变器无死区控制。

After the addition of dead zone, the carrier disposition PWM modulation method could have some problems, such as distortion of current waveform and decreasing of voltage utilization ratio. Taking the TNPC type three-level inverter as a researching object, a novel method of the carrier disposition PWM modulation with no dead zone for three-level inverter was proposed, in which three PWM modulation signals were generated by using triple carrier wave. By analyzing the effect caused by the dead zone in different operating states, on and off rules of power switches were derived. Simulation results in MATLAB/Simulink environment show that the proposed method can reduce harmonic content of the current, and increase the amplitude of the fundamental current and the voltage utilization ratio, which realizes no-dead-zone control of the TNPC type three-level inverter.