Modeling, simulation and test of a three-level voltage source inverter with output LC filter and direct torque control

This paper presents the modeling, the detailed simulation and the test of an efficient medium voltage adjustable speed drive. The system consists of a three-level neutral-point clamped (NPC) inverter supplied by a 12-pulse rectifier. To achieve a motor-friendly supply, an LC filter is inserted between inverter output terminals and induction motor terminals. A direct torque control (DTC) tunes the inverter. The full power circuits and the digital control scheme have been implemented and simulated. Simulation results have been compared successfully with measurements, in steady state and transients.