Performance Evaluation of a Multicell Topology Implemented With Single-Phase Nonregenerative Cells Under Unbalanced Supply Voltages

• Published in: IEEE transactions on industrial electronics (1982) Vol. 54; no. 6; pp. 2969 - 2978
• Main Authors: Baier, C.R., Guzman, J.I., Espinoza, J.R., Perez, M.A., Rodriguez, J.R.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.12.2007; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: AC generators; AC-AC power conversion; Circuit topology; Distortion; Electric potential; Feedforward control; Insulated gate bipolar transistors; insulated-gate bipolar transistor; Insulation; multicell single-phase topology; multilevel system; Multilevel systems; Performance evaluation; Power conversion; Power electronics; Rectifiers; Semiconductor diodes; Strategy; Topology; Unbalance; variable-speed drives; Voltage
• ISSN: 0278-0046; 1557-9948
• DOI: 10.1109/TIE.2007.903977

The analysis of a multicell topology that is implemented with single-phase nonregenerative cells under an unbalanced ac mains is presented. The study shows that the topology naturally compensates most of the voltage unbalance; for instance, for a 100% voltage unbalance in the ac mains, just 32% reaches the load. For critical applications, a feedforward control technique is proposed in order to compensate the remaining unbalance at the load side. The resulting topology, in combination with the proposed strategy, reduces near to zero the load fundamental voltage unbalance, while the input current unbalance and distortion are also improved. A theoretical analysis that is based on symmetrical components and the experimental results confirm the theoretical considerations.