Evaluation of Carrier-Based PWM Methods for Multi-level Inverters

Carrier-based methods have been used widely for switching of multilevel inverters due to their simplicity, flexibility and reduced computational requirements compared to space vector modulation (SVM). Several multi-carrier modulation methods with miscellaneous properties have been already known. The paper also proposes another three new multi-carrier techniques being more efficient for high-power inverter applications. While evaluating and comparing these new methods with all basic methods, such as PS, PD, POD and APOD through measures like THD, WTHD, WTHDO, switching losses and DC bus utilization, the paper shows their advantages for applications of diode-clamped and cascade multi-level topologies by simulation results. The validity of obtained results is approved by experimental results.