A ZCS Isolated Full Bridge Boost Converter with Multiple Inputs
A modular based, zero current switched (ZCS) isolated full bridge boost converter with multiple inputs is presented. By connecting a simple auxiliary circuit, between the full bridge input and the input choke, in each module, the transformer leakage inductance and output capacitance of the switching devices are used to create a quasi resonant path for facilitating ZCS of all full bridge switching devices. The operation of the auxiliary circuit integrates into the FB circuit and each auxiliary circuit operates independently among the modules. Thus, the operation of the multiple input structure will not be affected by the newly added auxiliary circuits, but, at the same time, all switches become zero current switched. A 290 W prototype with two input voltages of 5 V and 12 V has been tested and built. Theoretical predictions are verified with the experimental measurement results. The effectiveness of the proposed auxiliary circuit on improving the conversion efficiency is studied.
2007 IEEE Power Electronics Specialists Conference