Abstract：DC/DC series-parallel combined systems, in which multiple standardized converter modules are connected in series or parallel at the output and input sides, can be classified into four possible architectures. Each architecture has its own specific application areas. This paper analyzes the inherent relationships between the input voltage/current sharing and the output voltage/current sharing of the four combined systems and finds out the control objects for each system. For the input-parallel combined systems, both input currents sharing control and output currents sharing control (input-parallel output-parallel) or output voltages sharing control (input-parallel output-series) can be adopted. For the input-series combined systems, only input voltages sharing control can be adopted. Based on the analysis, a general control strategy for series-parallel combined systems is proposed, which decouples the input/output variables sharing control loops and output voltage control. Furthermore, the control strategy can achieve modularization architectures for series-parallel combined systems without added controller to regulate input/output variables sharing. A prototype composed of three full-bridge converters is built to validate the effectiveness of the proposed control strategy.
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2009, Vol. 24 
