A novel SOSMC based SVPWM control of Z-source inverter for AC microgrid applications

In this paper, analysis and control of Single stage Z-Source Inverter (ZSI) using Particle Swarm Optimization (PSO) tuned Proportional Integral (PI) based Space Vector Pulse Width Modulation (SVPWM) and Second Order Sliding Mode Control (SOSMC) based SVPWM for harmonic reduction and load voltage regulation are presented. To increase the reliability and to enhance the output voltage of ZSI, the Shoot-Through (ST) state is implemented. To decrease the number of sensors and to simplify the controller design, sixth order model of ZSI is transformed into second order model using Pade's approximation method. To analyse the steady state and transient response of the proposed system, the closed loop implementation is carried out using proposed control techniques. PSO tuned PI controller is utilized for outer voltage control to obtain the Shoot Through Duty Ratio (STDR). Inner current loop utilizes PSO tuned PI controller based SVPWM/SOSMC based SVPWM techniques. MATLAB/SIMULINK software tool is used to simulate the proposed system. From the simulation results, it is inferred that the SOSMC based SVPWM technique offers fast transient response, low % Total Harmonic Distortion (THD) and regulated output voltage when compared to PSO tuned PI based SVPWM control scheme. Hence, an experimental prototype model of 2 kW controlled by the SOSMC based SVPWM using Field Programmable Gate Array (FPGA) is constructed to validate the simulation results with the experimental results.