A Fuzzy Based Control Strategy for a Cascaded Multi Level Converter

Abstract

In this paper, Fuzzy based pulse width modulation (PWM) technique specially designed for signle phase (or four wire three-phase) multilevel Cascaded H-Bridge Converters is presented. The main theme of the proposed technique is to reduce the DC-link voltage unbalance independently from the amplitude of the DC-link voltage reference compensate the switching device voltage drops and on-state resistances,and distorted currents in terms of THD. Such type of reduction can be used for increasing the quality of the waveform from the converter. This is widely used in high-power low supply voltage applications where low switching frequency is used. The DC-voltage balance capability of the method removes the requirement of additional control loops to actively balance the DC-link voltage on each H-bridge , simplifying the control strategy. The proposed Fuzzy Based Control strategy is verified in MATLAB/ simulink and results are presented .
Index terms—Multi level converters; Predictive control; and smart grid.