LAUSR

In this paper, a novel multiobjective control strategy for the three-phase quasi Z-source inverter (q-ZSI) is proposed. A sliding mode control (SMC)-based controller is proposed to regulate inductor current through shoot-through ratio, and DC-link voltage reference is considered as an additional control input to keep q-ZS network capacitor voltage at a desired constant level. The load current is regulated by a proportional resonant controller whose output is then divided by DC-link voltage reference to obtain a modulation signal. With these three control inputs, the system is no longer underactuated, thus to eliminate probable steady-state error, which always happens in the underactuated system. The SMC-based controller for inductor current has the advantages of easy implementation, strong robustness, fast response, and low current ripple. The capacitor voltage is kept constant by the proportional integral-based variable DC-link voltage reference theme with negligible steady-state error and load current is pure sinusoidal with low THD. Simulations and experimental results both verify the effectiveness of the proposed control strategy.