Insulated Modular Auxiliary Power Source Concept with Multiple Outputs

Abstract

This paper presents an insulated auxiliary power source with multiple outputs based on a two-stage structure, where the first-stage operates as a controlled current source and the second-stage as an active rectifier. The second-stage is replicated for each load, where the output voltage is independently controlled by a hysteresis band controller integrated to the auxiliary power source's circuit. Insulation between the multiple stages is achieved by a medium-frequency transformer for each output. The main aim of this auxiliary power supply is to feed modular multilevel converters in laboratory applications that run at the lower range of medium-voltage dc. Theoretical analysis of the auxiliary power supply is presented and verified experimentally for the converter's two main modes of operation.

Passive Voltage Balancing In Modular Multilevel Converter During Precharge: Analysis And Design

“…"Manuscript received 07/23/2020; first revision 10/31/2020; accepted for publication 12/10/2020, by recommendation of Editor Demercil de Souza Oliveira Jr. http://dx.doi.org/10.18618/REP.2020. 4.0042" The APSs can be fed either externally by a high-voltage isolated source or by their own SM capacitor [8], [9]. The cost and complexity of the APS is high when externally fed, since its insulation has to withstand medium/high voltages.…”