Design of the Robust Hybrid Controller for Three-Phase Four-Leg Voltage Source Inverter under the Unbalance Load

불평형 부하에서 강인한 3상4족 전압형 인버터를 위한 하이브리드 제어기의 설계

The three-phase four-leg voltage source inverter (VSI) topology can be an interesting option for the three phase-four wire system. With an additional leg, this topology can achieve superior performance with unbalanced and/or nonlinear load. This paper proposes a new hybrid controller which combines PI controller and resonant controller in synchronous frame for three phase four leg inverter. The hybrid controller is simple in structure and easy to implement. The performance of proposed controller is verified by the experiments and compared with that of the conventional PI controller.