Research on the Control Technique of High Power Three-Level PWM Rectifier with IGCTs

This paper is based on the high power three-level back-to-back converter system with IGCTs as its application platform. Three-phase voltage source rectifier (VSR) space vector PWM (SVPWM) control system using feedforward decoupling control strategy is built in the software of PSIM. When this SVPWM rectifier is in practical control, problems of harmonics and neutral point voltage deviation, as well as starting impulse current occur. After detailed analysis, solutions are provided respectively to each problem. Then a new PWM control method is designed to improve the situation overall. That is to say, this method can effectively eliminate even-order harmonics, balance neutral point voltage and lower the starting impulse current. So the system has a better performance which is proved by PSIM simulations and experimental waveforms.