Continuous Time Least Square PI Control Method for Quasi-Z Source Inverter

Abstract

This paper presents the proposed model of proportional Integral (PI) controller using continuous time least square method (CT-LSM) for a quasi-Z source inverter (qZSI). PI control is one of the most applicable control methods in power systems. Then, CT-LSM is mainly a statistical optimization method including parameter estimation for nonlinear systems to control. The proposed model is designed to set a control structure without using the nonlinear loads of qZSI and also improve PI control applications against the nonlinear system dynamics. Controller design for qZSI is divided into two parts which are explained as dc side and ac side in both two mode operations. For the dc side of the system, PI controller is designed according to approved system and its estimated parameters which are calculated from state space analysis of qZSI. As for the ac side, the voltage and current regulations are controlled in order to transfer the power to inverter legs based on design criteria. Simulation results by using the current qZSI model on Matlab/Simulink are used to research and analyze the effectiveness and efficiency of the proposed control design.

Keywords

• continuous time least square method
• quasi Z source inverter
• system estimation