Analysis and Design of Series Voltage Compensator for Differential Power Processing

Differential power processing (DPP) has been proven effective in many applications. This article explores a series voltage compensator (SVC) architecture for voltage regulation of DPP systems. An SVC is connected in series between the input dc bus and the DPP system to compensate for the voltage difference. It only processes a fraction of the overall power. The inclusion of an SVC changes the power flow of the DPP system and changes the loss distribution. We theoretically investigated the SVC power rating and the additional power conversion stress that SVC brings to the DPP converter. Accordingly, we identified the operation range where an SVC is more attractive than a conventional DPP pre-regulation converter that has to process the full power. Our analysis provides insights into system design and control strategy of SVC-DPP topologies. To validate the principles of SVC, a buck SVC is designed and applied to a ten-port DPP converter. The buck SVC can efficiently convert an input voltage ranging from 50 V to 65 V into a regulated 50 V for the DPP system. The size of the SVC is only 20% of the DPP converter, and the peak efficiency of the SVC-DPP system achieves 98.8%.