Active neutral-point-clamped (ANPC) three-level converter for high-power applications with optimized PWM strategy

This paper introduces a three-level solution for high-power applications, and compares the differences between the three-level topology neutral-point diode clamp (NPC1) and the active neutral-point clamp (ANPC). It then summarizes three ways to optimize the PWM control method by taking advantage of the ANPC's new features. Several PWM algorithms are analyzed in simulation, and compared with regard to commutation loop, power losses, and efficiency. It is very important to balance the resulting losses of the switches by an optimized switching scheme, as this limits the output capability when the maximum junction temperature is reached. From the comparison result, the optimal PWM algorithm can be selected to improve system performance based on the working conditions.