A Fuzzy Based Three-Phase Inverter for a Unified Controller in Distributed Generation

Abstract

This paper presents a novel fuzzy based three-phase inverter for a unified controller in distributed generation (DG) which enables both islanded and grid-tied modes, no need for switching between two corresponding controllers or critical islanding detection. This paper describes inner inductor current loop, and a voltage loop in the synchronous reference frame. It addresses a current source by regulating the inner current loop in grid-tied operation, and the voltage controller is automatically activated to regulate the load voltage upon the occurrence of islanding. With the conventional strategy, the current in grid-tied mode the load voltage in the islanding mode are distorted under nonlinear local load. The same is addressed by proposing a load current feed forward in this paper. The effectiveness of the techniques proposed in this paper is demonstrated by MATLAB Simulation and results are presented here.

Index Terms- Fuzzy Logic; Distributed generation (DG); islanding; load current; seamless transfer; three-phase inverter; unified control