The input characteristic and stability analyse of inverter with induction motor

The connection of an inverter-motor-drive system and a rectifier may lead to instability of the DC-link voltage. As the small signal technology is an important method to the cascaded system, the input impedance of the inverter-motor-drive system and its impact on the system stability are studied. Then the effect of the input impedance was analysis from d-axis rotor flux, load torque and DC-link voltage and some conclusions useful to improve the input impedance and make the cascaded system stable were obtained. Simulation results demonstrate the correctness of the theoretical analysis.