A variable speed single-phase induction motor drive using a smart power module

A variable-speed single-phase induction motor drive which utilises just one smart (intelligent) power module (IPM) incorporating six switches has been described. The main and auxiliary windings of a single-phase motor are driven by a two-phase inverter with unbalanced voltage/frequency control to produce smooth torque. The remaining leg of the IPM is used as a current-forced reversible rectifier which supplies the required DC link voltage to drive the two windings up to the full voltage ratings. The drive system has a wide speed range in both directions and operates with near unity power factor regenerative braking. Simulation and experimental results are presented.