A Phase Shift Control Strategy for the DCX to Realize a Wide Voltage Range by a Variable Mode Transformer

A phase shift control strategy for the variable mode DC/DC transformer (DCX) to realize a wide voltage range is proposed. The DCX is realized by the series resonant converter (SRC), which employs a variable mode transformer. Different from a regular full bridge SRC-DCX, the circuit topology is realized by some certain numbers of the half bridge (HB) SRC modules. By continuously changing the phase shift angles between the HB SRC modules, the effective turns ratio of the variable mode transformer can vary. As a result, the voltage conversion ratio of the DCX can be adjusted by the phase shift angle even if the frequency is fixed. The gain model of the proposed DCX is derived and the voltage conversion model is verified by the experimental results.