ENHANCED DYNAMIC PERFORMANCE IN SINGLE-PHASE CASCADED H BRIDGE MULTILEVEL INVERTERS USING A NOVEL CONTROLLER

Abstract

Using closed loop controllers, this study examines the dynamic and steady state performance of a cascaded H-Bridge multilevel inverter (CHBMLI). A dual loop cascaded controller is suitable for an MLI system to address a range of issues. It consists of two loops: an inner loop and an outer loop. Proportional-Integral (PI) controllers are utilised as voltage controllers in the outer loop while proportional (P) controllers are used as current controllers in the inner loop. A current controller can reduce the time needed to reach steady state, or the transient/dynamic period, whereas a voltage controller can help achieve steady state voltage, or a constant output voltage. They use the same controller for both linear and nonlinear loads. The MATLAB/SIMULINK platform is used in this study to develop the closed loop CHB-MLI model, and the controller parameters integral gain (Ki) and proportional gain (Kp) are carefully selected. By varying these two parameters in both loops, the steady state and dynamic performance of a CHB-MLI for linear load may be determined.