Regenerative medium-voltage AC drive based on a multicell arrangement with reduced energy storage requirements

• Published in: IEEE transactions on industrial electronics (1982) Vol. 52; no. 1; pp. 171 - 180
• Main Authors: Perez, M.A., Espinoza, J.R., Rodriguez, J.R., Lezana, P.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.02.2005; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: A C motors; AC motors; Active control; Capacitors; Circuit topology; Diodes; Electrolytic cells; Energy storage; Energy storage reduction; Harmonics; Medium voltage; Motors; multilevel converter; Power quality; Power system harmonics; Reactive power; Rectifiers; Regenerative; regenerative cell; Strategy; Topology
• ISSN: 0278-0046; 1557-9948
• DOI: 10.1109/TIE.2004.841095

Multicell power circuit topologies have proved to be an effective alternative to medium-voltage ac drives. The main advantage is the improved power quality at both the ac system and the motor sides. However, several drawbacks are present in these configurations, such as a lack of sustained regenerative operating mode, uncontrolled input reactive power, and a large second current harmonic that is injected by the load into the dc link of each cell, which leads to a bulky electrolytic capacitor. This paper proposes to replace the input diode-based front-end rectifier with an active front-end rectifier in all cells of the topology and a novel control strategy in order to overcome the aforementioned drawbacks. In fact, the active front-end rectifier allows the topology to regenerate and the control strategy handles the reactive input power and reduces the large second current harmonic from the dc-link capacitor, thus reducing its size. These features are achieved without any penalties in the quality of both the ac input current and the motor voltage waveforms. Experimental results confirm the theoretical considerations.