A full-bridge three-level single phase inverter with stressless commutation cell and special PWM technique

This paper presents a full-bridge three-level single phase inverter which contains two switches operating in high frequency and two switches working in low frequency. In order to reduce the commutation losses each high frequency switch uses a stressless commutation cell, requiring a special pulse width modulation technique when a three level inverter is desired. To justify this special PWM technique, a comparative analysis among some PWM techniques is carried out. Furthermore the operating principles, relevant equations and test results are presented. The obtained results validate the proposed inverter.