Modeling and Modulation of NNPC Four-Level Inverter for Solar Photovoltaic Power Plant

Table 5

Mechanism of capacitor voltage balancing.

Level	ΔVCi	Phase current ia	Redundancy state
2	ΔVC1< 0	<0	2B
		≥0	2A
	ΔVC1 ≥ 0	<0	2A
		≥0	2B
1	ΔVC2< 0	<0	1B
		≥0	1A
	ΔVC2 ≥ 0	<0	1A
		≥0	1B