Neutral Point Balanced Hybrid Modulation Strategy Based on Virtual Space Vector
Aiming at the neutral point voltage imbalance of diode clamped three-level inverter(NPC),the causes and ef-fects of neutral point potential imbalance are analyzed firstly.Secondly,the neutral point potential control method based on re-dundant small vector can not suppress the neutral point potential fluctuation caused by medium vector in the region of high modulation ratio.A neutral point potential hybrid modulation strategy based on virtual space vector is proposed.In this method,the charge conservation method is used in the low modulation ratio range,the virtual space vector modulation is introduced in the high modulation ratio range,and the fuzzy controller is used to adjust the coefficient of the virtual small vector,so that it has the ability of closed-loop feedback control,and can effectively suppress the offset of the neutral point potential.
NPC three-level invertervirtual space vector modulationneutral point voltage balancefuzzy control
万方数据
维普
