Dynamic performance improvement in motor drive systems of electric vehicle by z-source inverter

This paper present an integral sliding-mode controller based on equivalent control to overcome the disadvantages of non-minimum phase system, which the z-source inverter has when it is used in the motor drive system of electric vehicles. Based on the pseudo-output, which is defined by measured capacitor voltage and inductor current on z-source network, a constant capacitor voltage control strategy for z-source inverter is given. With the reaching condition imposed, the controller can guarantee the stability of closed-loop system and the robustness of system output. The simulation results show that the closed-loop control system for z-source inverter can achieve better global robustness with zero steady error, and that the capacitor voltage on z-source network can be stabilized with good performances of motor drive system.