Integral sliding mode control of Z-source inverter for motor drive system of electric vehicles

In order 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, an integral sliding-mode controller based on equivalent control is proposed. With the reaching condition imposed, the controller can guarantee the stability of closed-loop system and the robustness of system output. 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. 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 so that good performances of motor drive system can be effectively realized.