3-level Inverter Fed Induction Motor Drive

Abstract

Multilevel inverters have found profound applications in medium as well as high-power adjustable-speed drives (ASDs). Voltage and current quality of a two-level inverter fed induction motor is poor because of the harmonics in current wave form. These harmonics cause significant level of energy loss. For reduction of this harmonics generally multilevel inverter are used. In case of the symmetrical circuit by increasing the level of inverter voltage and power also increase. To reduce the harmonic distortion switching angle is selected very carefully. For efficient control of (ASDs) Vector control is used which has advantages like low THD and higher torque. With multilevel inverter, it is possible to reduce the harmonics at output side at low switching frequency. This report focuses on analyzing performance of various types of multilevel inverter for control of induction motor, with various multicarrier techniques phase disposition, phase opposition disposition, variable frequency PWM, carrier overlap PWM. Also, analysis is carried out for different schemes of induction motor drives. The control is achieved by generating switching pulses with Waijung for ARM cortex. For, experimental validation three-level neutral point clamped inverter controlled induction motor drive is developed. Performance of this three- level induction motor drive is analyzed by open-loop control using phase disposition technique.