THD Reduction in Performance of Cascaded Multi-Level Inverter Fed Induction Motor Drive

The multilevel inverter power structure plays a vital role in the power industry. It is easier to produce a high-power, high-voltage inverter with the multilevel structure. The topologies of multilevel inverter have several advantages such as lower total harmonic distortion (THD), lower electromagnetic interference (EMI) generation, reduction of voltage ratings of the power semiconductor switching devices and high output voltage. This paper presents a universal control scheme based on multicarrier PWM methods and its implementation in three-level, five-level and nine-level cascaded inverters feeding a three phase induction motor. This paper compares total harmonic distortion values of voltage and current waveforms of induction motors between different levels.