Effect of Transformer's Distributed Capacitance on Charging Time of Series Resonant Constant Current Charging Power Supply

Series resonant constant current charging topology is used for charging capacitive power equipment due to its constant current charging characteristics and strong short-circuit protection capability. However, the parasitic parameters of the transformer in the topology will significantly affect the high-frequency current charging characteristics of the power supply, leading to difficulty in precise voltage and current control. Accordingly, this paper analyzes the influence of parasitic parameters on the output characteristics of traditional series resonant converters. Circuit models with equivalent and without parasitic parameters are built on the PSIM platform, and the relationship between transformer-distributed capacitance and charging time is deduced based on simulation results. The results can guide the design of high-frequency series resonant constant current charging power supplies.