Analysis of 3-level inverter scheme with DC-link voltage balancing using LS-PWM & SVM techniques

Multilevel converters in FACTS and distributed generation system are very promising area for academic researchers and industry interest. Here two different modulation schemes of 3-level Neutral point clamped inverter are proposed and presented. The inherent neutral point potential unbalance issues and balancing methods for LS-PWM and SVM techniques are analyzed in detail. Total Harmonic Distortion in output voltage and current is used as the performance indicator for the inverter. It can be concluded that LS-PWM has higher harmonic distortions and high losses when compared to SVM. SVM technique also is excellent in DC bus voltage balancing. The experimental results for a 1.5kW prototype validate the simulation and theoretical results.