Voltage control of a single distributed generation unite in autonomous mode operation under unbalance and non-linear load conditions

摘要

This paper propose a voltage control of a single distributed generation (DG) unit powered local load. The DG system utilizes three phase four wire voltage source inverter VSI with split DC link as the medium interface and LC filter to attenuate the switching frequency harmonics, A dual loop scheme is employed. Dead beat current controller in inner loop, which achieve fast dynamic response. In the outer loop, Multi-generalized resonant filter with feedback state is employed to track reference voltage and eliminate the low order harmonics, and to make the dynamic of the system greatly adjustable via pole-placement strategy. The proposed controller provides a set balanced three phase voltage with low THD equal to 1.80% in worse case (non linear load) for a locale load, despite unbalanced and distorted current load, guarantee a robust stability, fast dynamic response to disturbance, zero study state error. Effectiveness of the proposed control strategy is evaluated based on time domain simulation studies in Matlab/Simulink™ environment.