Closed-loop Control Design for a Three-level Three-phase Neutral-point-clamped Inverter Using the Optimized Nearest-three Virtual-space-vector Modulation
Publication date: 2007-06-21
Published in: IEEE Power Electronics Specialists Conference 2006, Jeju (South Korea) - PESC 2006
ref. DOI: 10.1109/PESC.2006.1711953

Local members

Joan Rocabert

PhD. Senior Researcher

External members

Busquets-Monge, S. , Ortega, J.D. , Bordonau, J. , Beristain, J.A.



This paper presents a closed-loop control scheme for the three-level three-phase neutral-point-clamped DC-AC converter using the optimized nearest-three virtual-space-vector pulsewidthmodulation, a modulation that produces a low output voltage distortion with a significant reduction of the DC-link capacitance. A specific loop modifying the modulating waveforms is introduced to rapidly control possible perturbations in the neutral-point voltage balance. The remaining part of the control is analogous to the control for a two-level converter with an appropriate interfacing to the selected modulation, including an online estimation of the load displacement angle at no extra cost. The closed-loop control is designed for the case of a renewable energy source connected to the AC mains and its performance is analyzed through simulation and experiments