Neutral-point (NP) voltage coordinate control model in two-stage three-level DC-AC converters is originally proposed. NP current of DC-AC converters is directly used as the power allocation coefficient of DC-DC converters to compensate NP AC fluctuation. Besides, the decoupled PI control is used to overcome NP DC bias. With the balanced and non-fluctuated NP voltage, AC waveform quality is improved. The coordinate control is experimentally validated in a three-level T-type inverter connected with a three-level boost (TLB) converter.
