Using Fuzzy Logic Self-Tuning PI Gain Controller Z-Source Inverter in Hybrid Electric Vehicles

This paper presents a new algorithm to control the peak dc-link voltage (PDV) across the inverter bridge in Z-Source inverters (ZSI) by applying self-tuning fuzzy PI controller (SFP) with robust structure and non-linear characteristic. In particular, this so-called SFP based control algorithm is applied to closed loop speed control system of induction motor, which relies on direct torque control combined with modified space vector modulation (DTC-MSVM) control strategy. More importantly, the combination of SFP based control algorithm and DTC-MSVM with many exceptional features such as: fast torque response, low steady state torque ripple, and high accurate is the best candidate for controlling the PDV in hybrid electric vehicles (HEV) applications. In this way, the PDV is more adaptive to the sudden change of dc input voltage (DIV). The transient response of PDV is thus improved with low disturbance for output voltage stabilization in the inverter bridge. As a result, we achieve higher robustness and performance of speed motor control system. Our new SFP based control algorithm is verified in both simulation and experimental implementation using MATLAB and dSPACE DS1103, respectively.