| Abstract |
This paper discusses the design of a high power, synchronously rectified, bi-directional, boost dc-dc converter that acts to interface the lead-acid traction batteries and supercapacitor peak power buffers of an electric vehicle drive-train. The paper presents the dc-dc converter design methodology, and thermal power loss analysis, employed to evaluate the selected dc-dc converter topology, and determine the minimum number of paralleled MOSFET devices required for each switching cluster. Furthermore, a coupled thermal and electrical model is used to analyse the behaviour of the parallel path currents within a synchronously rectified switching cluster. Using this model it is possible to investigate the effects of on-state device parameter variations on the current sharing between paralleled, synchronously rectified MOSFET devices, and hence optimise the number of paralleled devices, to ensure correct operation with non-uniform current sharing between device diodes. |
