Multi-pulse AC-DC converter fed SVM controlled NPC inverter based VCIMD

A multi-pulse AC-DC converter fed space vector modulation (SVM) controlled neutral point clamped (NPC) inverter based vector control induction motor drive (VCIMD) is proposed here for medium power rating applications. To improve the power quality at supply side, a 12-pulse AC-DC converter is used and to meet the IEEE-519 standard, a high-pass filter is also used along with it. A three-level NPC inverter is utilised on the motor side to enhance the required performances of an induction motor drive (IMD). A modified SVM strategy is proposed to balance the capacitor voltages of the NPC inverter and to switch this inverter at very low switching frequency. The neutral point voltage balancing is achieved by the time adjustment between positive and negative small vectors. The model of proposed IMD is developed using the Simulink/MATLAB platform, and simulated response is validated with test results on a developed prototype in the laboratory to demonstrate its usefulness for medium power applications.