A new control strategy for neutral-point-clamped active rectifiers

A new control strategy has been developed for interfacing a neutral-point-clamped active rectifier with the mains. In particular, a method, based on the modulation of the input currents amplitudes, is proposed to compensate the dc-link capacitors voltages fluctuations. The proposed strategy gives good results in all the operating conditions, but it appears to be very useful especially in no-load or low-load operations, where other methods fail. Analytical, simulation, and experimental results, derived from a reduced-scale prototype, are presented and confirm the validity of the proposed approach.