| In recent years, application of battery & supercapacitor hybrid energy storage system in the electrical vehicle and distributed renewable energy system, has attracted wide attention. At present, for the purpose of making the hybrid energy storage application, main power supply and load interconnected, in most cases, multiple single-input DC/DC converters are used as the interface circuits. However, the integrated power converter having multiple interfacing ports (defined as multi-port DC/DC converter, or multi-input DC/DC converter) , could be used to replace the individual single-input DC/DC converters, achieving the effective link among the various renewable power generating units, energy storage elements and load by only one power electronic converter. It has become the hot research topic in recent years.To date limited research at home and abroad has been conducted on multi-port DC/DC converter, but almost all the circuit topologies proposed in those literatures have the following disadvantages: unidirectional power flow, no electric isolation, hard switching, numerous switching devices, low efficiency, complicated control structure, etc., which limit the applications. Aiming at the application problem of multi-port converter in the hybrid energy storage elements, this paper chooses the triple half bridge (THB) bi-directional DC/DC converter as the interfacing circuit of battery & supercapacitor hybrid energy storage system, based on the comprehensive comparison between the advantages and disadvantages of those multi-port converter topologies.According to the application of the triple half bridge (THB) bi-directional DC/DC converter in the fuel cell electrical vehicle energy management system, theoretical analysis of the operating principle, commutation process, steady state output characteristic, and soft switching conditions of this converter topology in the Boost and Buck operating mode, have been made in the paper, and the steady operation conditions and soft switching characteristic of the circuit in those two operating mode, are validated by the saber 2007 simulation software.This paper is also devoted to research the mathematical modeling and control system design of triple half bridge DC/DC converter. Simplified and order reduced state space average model and linear small signal model of the converter are built by introducing the switching function. Based on this small signal model, dual close loop control structure of the converter is constructed, and current inner loop & voltage outer loop control systems are designed and optimized through Bode diagram. Due to the mutual interference between two inputs of the current inner loop system, decoupling network is designed in this paper to achieve the independent control of two input inductor currents. Favorable dynamic performance and steady precision of designed converter control system are validated by simulation of Matlab/simulink software.At last, hardware circuit and digital control system of triple half bridge DC/DC converter are designed in this paper, and an experimental converter prototype of 2kW, which adopts TMS320LF2407A DSP as the control core, is built. Based on DSP software programming, digital phase shift modulation scheme is proposed. Experimental verification is carried out on this prototype, and the results have proved that the hardware circuit has favorable steady working performance in every mode, and power switches could realize ZVS, showing that the DSP based digital phase shift control method is fully feasible. The works above make way for deeply researching the battery & supercapacitor hybrid energy storage system and its application in the fuel cell electrical vehicle energy management system.
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