Significance of Capacitor Voltage Balancing in Multilevel Inverter

Abstract

In the recent trends, the use of multilevel inverter is rapidly increasing due to its good performance compared to conventional inverter. In this paper, the performance of Nested Neutral Point Clamped Multilevel inverter (NNPC) is presented. NNPC is a Hybrid type of Multilevel inerter which is nothing but the combination of two classical topologies that are Neutral Point Clamped(NPC) and Flying Capacitor(FC). As this Hybrid inverter involves Capacitor in its configuration therefore, their is an issue of Capacitor Voltage Balancing(CVB). Hence the necessary condition arises that is to maintain Vdc/3 voltage across Flying capacitors inorder to obtain perfect four level output[8]. Hence the performance of Nested Neutral Point Clamped Multilevel Inverter is observed in MATLAB Simulink by using simple pulse triggering without Capacitor Voltage Balance control and its simulation is also done with capacitor voltage balancing control, further its performance is also analysed by implementing it with level-shift Sinusoidal Pulse Width Modulation technique(Phase-Disposition) with capacitor voltage balancing control technique in MATLAB simulink.