Dual Closed-Loop Scheme with Lead Compensator and Proportional Controller for Quasi Z-Source Inverter Based STATCOM

Over the last decade, numerous control schemes have been proposed by researchers for quasi Z source inverter (qZSI) to provide fast dynamic response and good transient performances. This paper proposed a novelty and an effective tuning method of dual-loop controller based on lead compensator and proportional (P) controller for single-phase qZSI to ensure reliable DC-link power regulation. Specifically, lead compensator and P controller act as voltage control and current control loop, respectively, to generate the desired shoot-through duty cycle feeding towards the unipolar carrier based pulse width modulation (CB-PWM). The lead compensator contributes to move the system poles from the left to the right half of the s-plane while the P controller damps any high frequency oscillation occurrence caused by the newly sited complex conjugate pole pair. To demonstrate the effectiveness and the feasibility of the proposed controller, the qZSI is utilized as a static synchronous compensator (STATCOM) system to provide reactive current compensation at the point of common coupling (PCC). All simulation models and results which documented in this paper are carried out using MATLAB/Simulink software.