Simulation of inverter/induction-machine systems including discontinuous phase currents

The study includes the analysis and simulation of inverter-fed squirrel-cage induction-machine drives. The particular drive used for experimental validation was a 120¿¿ square-wave inverter feeding atubular axle induction motor developed for rail traction by the British Railways Board. The system and its operation in self-excited braking are described. An original analogue model of the inverter is developed that issuitable for the simulation of commonly used types of inverters. Results from the real system and from the simulation compare well for both transient and steady-state operation.