An isolated dc-dc boost converter using two cascade control loops

This paper presents an isolated dc-dc converter designed to operate as a primary stage of an on-board dc-ac power supply for diesel-electric engines, The dc-ac power supply must provide a sinusoidal waveform of 127V rms front 72V dc bus of the engine, The de-de push-pull current-fed converter has been used to obtain an isolated 200V de output voltage from the available 72V de Teas engine, This converter operates as a boost converter with constant frequency and duty cycle greater than 50%, Two control loops operating in cascade mode were used, A fast inner current loop regulates the boost inductor current, Whereas an external. control loop keeps a constant output voltage, The experimental results ha-se been obtained for a 300W laboratory prototype operating at 50kHz, The converter efficiency was 93% at full load, and the output voltage regulation was less than 1% for 10% to 100% load changes.