Analysis of Distributed Generators with Fuzzy logic Controller Based Inverter at un-balanced loads

Abstract

The design of a fuzzy logic controller using the voltage as feedback for significantly improving the dynamic performance of converter. Renewable energy resources (RES) are being increasingly connected in distribution systems utilizing power electronic converters. This paper presents a new control strategy for achieving maximum benefits from these grid-interfacing inverters using the closed loop P-I controller and fuzzy logic controller, when installed in 3-phase 4-wire distribution systems. The inverter is controlled to perform as a multi-function device by incorporating active power filter functionality. The inverter can thus be utilized as: 1) power converter to inject power generated from RES to the grid, and 2) shunt APF to compensate current unbalance, load current harmonics, load reactive power demand and load neutral current. All of these functions may be accomplished either individually or simultaneously. The THD and power factor variations for both PI-controller and fuzzy logic controller are also shown. This new control concept is demonstrated with extensive MATLAB/Simulink .Finally the proposed scheme is applied for both balanced, unbalanced linear and non linear loads. The proposed concept can be implemented to Fuzzy logic controller by using Matlab/Simulink software.