Quantum Mode Series Resonant Converter Utilized as Active Voltage Regulator of a Split DC Bus Capacitor

Abstract

Certain modern power electronics systems require active regulation of the split DC bus capacitor voltages. The series resonant converter is suitable to be utilized as an active voltage regulator, due to its ability to operate with soft switching, and hence, with high efficiency. In discontinuous conduction mode, the series resonant converter operates with a constant unity voltage gain, thus achieving balancing of the DC link. However, discontinuous conduction mode does not provide means for achieving a different voltage distribution, which is important in many scenarios. On the other hand, by operating in quantum mode (i.e. type 2 discontinuous conduction mode), the voltages across DC bus capacitor can be regulated. Therefore, the modeling of the quantum mode series resonant converter connected across split DC bus is presented in this paper. The steady-state operation as well as transient behavior are discussed and experimentally verified on a laboratory prototype.