Multi-loop Control Strategy for Parallel Distributed Generation Units in Standalone Applications

This paper presents a suitable output voltage control approach for parallel distributed generation (DG) units working in standalone operating mode. Indeed, an Adaptive Multi Resonant controller with weighted State Feedbacks is optimally designed for the voltage control loop while a Proportional regulator is proposed for the inner current loop. Thankful to its frequency adjusting ability, the proposed multi loop controller is also expanded to a wireless power sharing controlled parallel inverters. A co-simulation is carried out combining Matlab/Simulink and PSIM environments in order to highlight the effectiveness of the global control structure which ensures high tracking performance with reduced rate of harmonic distortion, deals efficiently with any load disturbances and may face large frequency deviation while an accurate power sharing is maintained among the parallel DG units.