The control region of hysteresis control for neutral-point voltage balancing of NPC three-level inverters

Neutral-Point voltage fluctuation is one of the most important issues of NPC three-level inverters. In this paper, two kinds of control region are proposed to evaluate the control effect of neutral-point voltage balancing schemes. Basing on hysteresis control strategy, the paper analyses the control region in SPWM and SVPWM respectively and finds their relationship, it also finds the relation between control effect and circuit parameters in different PWM method. The analyses are verified through simulation in MAT LAB.