This paper presents the design of a medium-powerrating isolated power supply for ultra-fast tracking converters and MOS-gate driver circuits in medium and high voltage applications. The key feature of the design is its very low circuit input-to-output parasitic capacitance, which maximizes its noise immunity from noise due to fast changes in voltage. The converter is a voltage-controlled current source, utilizing a transformer with extremely low inter-winding parasitic capacitance, which is achieved by separating the windings by a significant distance. Experimental measurements show that an overall circuit input-to-output parasitic capacitance of 10 pF in a 300 W prototype can be achieved. The circuit input-to-output capacitance per watt is therefore 30 times lower than that of existing approaches. A mathematical model of the inter-winding capacitance of the proposed transformer, circuit analysis, and experimental results are provided to prove the feasibility of the converter.
I E E E Transactions on Power Electronics, 2015, Vol 30, Issue 6, p. 3319-3333
Current transformers; Parasitic capacitance; Switching converters; Stacking; Dc-dc power converters