Simple Sensorless Active Damping Solution for Three-Phase PWM Rectifier with LCL Filter

摘要

Three-phase PWM (active) rectifiers are connected to the line power through inductance or LCL filter. LCL filter is more effective (better attenuates switching harmonics), however such solution causes stability problems. In order to assure stable operation either a damping resistor or active damping algorithm has to be used. However, extra resistor causes additional losses and active damping algorithm usually needs extra sensors. Therefore, this paper shows simulation and experimental results of a simple AC voltage sensorless active damping solution suitable for industrial application.