Closed‐loop control of the grid‐connected Z‐source inverter using hyper‐plane MIMO sliding mode

Abstract

In this study, a hyper-plane multi-input–multi-output (MIMO) sliding-mode controller (SMC) is presented for control of the grid-connected Z-source inverter (ZSI). The presented controller can simultaneously control all of the system state variables including grid-side AC current and DC-link capacitors voltage. These state variables are directly regulated by amplitude modulation index and shoot-through interval. The non-minimum phase problem of the capacitors voltage is solved by indirect regulation of the DC-side inductor current. The proposed controller is developed using non-linear MIMO model of the converter; hence, it is possible to apply the proposed controller in a wide operating range. Controller coefficients are designed using Jacobian linearisation approach to ensure stability of the system. According to application of the Lyapunov approach, it is proved that the proposed controller is asymptotically stable against changes of the system state variables. Some simulations are presented to verify the effectiveness and stability of the developed controllers by MATLAB/Simulink toolbox. Also, a laboratory prototype is implemented using a digital signal processor TMS320F28335. Experimental results are given for the presented controller in the single-phase ZSI. It is seen that the experimental and simulation results are in good agreement.