Simulation model of a three-port bi-directional series resonant DC-DC converter to determine component specifications

Multi-port converters are used in applications where multiple energy sources such as fuel cells, PV array, batteries supply the load. In this paper component design of a threeport series resonant converter is discussed. The series resonant tank parameters such as the peak tank current and voltage which are needed to design the tank capacitor and inductor are calculated by simulating the nonlinear state space model of the converter. Since the converter operates at different modes based on power flow between sources and load, simulation is repeated at different operating points to determine the worst case ratings of the components. Other specifications of the converter such as the transformer VA rating, switch currents, input and output filter design are estimated from simulation. Softswitching is possible due to the resonant nature of the converter and the range of softswitching based on load and power flow variations are calculated using the simulationmodel. Simulation is performed for a prototype converter and the results are tabulated.