Zero-Speed Operation of CSI-Fed Induction Motor Drive

Most of the work in PWM current-source-inverter (CSI) fed induction motor drive (IMD) is focusing on the general applications, while this paper is dedicated to investigating its zero-speed operation which is vital for hoist and crane applications. Current flux model which employs the stator currents and speed signal is adopted for the rotor flux estimation. Unlike the voltage-source-inverter based drives, filter capacitors are employed at the output of the CSI for current commutation and harmonics filtering. Its influence on the system dynamic performance is comprehensively evaluated. Moreover, a classic load torque observer with feedforward control is also employed to improve the speed dynamic response. Simulation and experimental results show that the CSI-fed IMD works well at zero-speed with promising speed dynamic performance.