Performance analysis of three phase Cascaded H-Bridge multi level inverter for under voltage and over voltage conditions

A Multilevel Inverter is a power electronic device built to synthesize a desired AC voltage from several levels of DC voltages. Nowadays, modern industrial devices are mostly based on electronic devices such as programmable logic controllers and electronic drives. The electronic devices are very sensitive to disturbances and become less tolerant to power quality problems such as under voltage and over voltage conditions. In general under voltage and over voltage conditions will occur more at source side. In this paper a closed loop Control system is designed using PI controller in order to maintain load voltage constant for under voltage and Over voltage conditions. The triggering pulses to Cascaded H-Bridge (CHB) MLI is given using multi carrier phase shifted technique and MATLAB simulations have been carried out.