| Abstract |
In the resonant dc-dc converter, the regulation of the output voltage for the changes of the input voltage and the load is performed by the control of the switching frequency. Consequently, it is often observed that the switching frequency in a voltage-resonant type dc-dc converter becomes extremely low when the input voltage decreases. This lowering of the switching frequency deteriorates the advantage of the high frequency in designing the circuit and sometimes causes the acoustic noise problem. In this paper, high power (5kW) buck-boost type voltage-resonant dc-dc converter with a single SI thyristor switch is proposed and analyzed, which operates in the discontinuous reactor current region. As a result, in this voltage-resonant dc-dc converter, the output voltage can be regulated sufficiently for the load change from no load to full load and for ±15% change of the input voltage. In this case, the change of the switching frequency can be restricted within ±10% and the switching frequency can be kept above 20kHz, the power conversion efficiency of 90% or more can be obtained. |
