Neutral-Point Potential Balance Control Strategy on Three-Level Active Power Filters

Table 1

Switching states of the three-level NPC converter (X = A, B, C).

SX1	SX2	SX3	SX4	Terminal voltage	Switching state
ON	ON	OFF	OFF	Udc	P
OFF	ON	ON	OFF	0	O
OFF	OFF	ON	ON	−Udc	N