A Study on an Unbalanced Ac Source Three-Phase Converter Power Controllability Using Fuzzy Logic Controller

Abstract

This paper explains the power controllability of three phase converter with an unbalanced AC source by using fuzzy logic controller. Three-phase DC-AC power converters suffer from power oscillation and over current problems in case of unbalanced AC source voltage that can be caused by grid/generator faults. Existing solutions to handle these problems are properly selecting and controlling the positive and negative sequence currents. In this work a new series of control strategies which utilize the zero-sequence components are proposed to enhance the power control ability under this adverse condition. A fuzzy logic controller is rule based logic; it is having more advantages than other controllers. By using fuzzy logic controller we get required output. It is concluded that by introducing proper zero sequence current controls and corresponding circuit configurations, the power converter can enable more flexible control targets, achieving better performances in the delivered power and load current when suffering from unbalanced AC source.