Topology and control of a family of non-isolated three-port DC-DC converters with a bidirectional cell

A family of integrated non-isolated three-port DC-DC converters (NI-TPCs) interfacing a renewable source, a storage battery and a load is proposed for stand-alone renewable power system application. The NI-TPCs proposed are generated by introducing a bidirectional cell to the basic DC-DC converters. With the NI-TPC proposed, single stage conversion between any two of the three ports is achieved. A multi-carrier based PWM scheme is proposed and applied to the NI-TPC based upon analysis of the power relations among the three ports. Power management strategy with four regulators achieving maximum power point tracking (MPPT) control of input source, charging control of battery and voltage control of load is proposed for a stand-alone renewable power system. The converters operate in every operation mode and switch between different modes freely and seamlessly. Experimental results with a prototype are given to verify the topology, operation and control of the proposed NI-TPC.