Mobile QR Code QR CODE : The Korean Institute of Power Electronics
Title Active Damping of LCL Filter for Three-phase PWM Inverter without Additional Hardware Sensors
Authors Byoung-Woong An ; Hee-Keun Shin ; Hag-Wone Kim ; Kwan-Yuhl Cho ; Byoung-Moon Han
DOI 10.6113/TKPE/2013.18.1.10
Page pp.10-17
ISSN 1229-2214
Keywords PWM inverter; active damping; MRAS(Model Reference Adaptive System) observer
Abstract In this paper, a new active damping method of LCL filter without capacitor voltage sensors is proposed for 3 phase PWM Inverter. Normally, L filter or LCL filter is used as an output filter of grid connected PWM inverter. An LCL filter has more excellent performance than L filter to reduce harmonic current, so the small inductance value can be used. However, the resonance problem in LCL filter is happen due to the zero impedance by the addition of LC branch. To solve the resonance problem, the various active damping method has been proposed so far. Generally, the virtual resistor active damping methods is required to additional hardware sensors for measurement of capacitor voltage and current. In this paper, the new active damping method is proposed without any capacitor voltage or current sensors. In the proposed method, the resonance component of the capacitor voltage of LCL filter can be observed by a simple MRAS(Model Reference Adaptive System) observer without additional hardware sensors, and this component is suppressed by feedforward compensation. The validity of the proposed method is proven by simulation and experiment on the 3-phase PWM inverter system.