Three current hysteresis control strategy of four-leg three-level SVG

According to the topology of three-phase four-leg SVG, this paper presented a new control way of three level three current hysteresis basing on NPC. Which takes advantages of the third current hysteresis to judge the area of the reference voltage vector, and there is no need to use the inductance parameter L to calculate the reference voltage, therefore, in this way, there is no dependency on L, and the best switch state is selected after comparing the error current and the width of hysteresis. This paper also researches a kind of control way that takes full advantages of the space vector redundant state to balance the DC voltage, which doesn't need any control hardware. Experiments proved the way has good dynamic and static characteristics.