Abstract:

In order to address the shortcomings such as the too narrow range of the AC input voltage and low stability of the DC charging modules in the current DC system of the substation,the overall design scheme of a new type of charging module with the wide input voltage range is proposed.Based on the comparative analysis of the charging module scheme based on the three-winding AC input and the charging module scheme based on the boost control,the charging module scheme based on the boost control is adopted.Taking the existing DC charging module as the basis,the parameters of the power conversion part are adjusted,and the auxiliary control and judgment units are added,and the prototype is developed.Through experimental verification,while maintaining the original electrical performance unchanged,when the grid fails and the voltage is low,the prototype can output a stable voltage normally (with the output power derated).

Key words: DC system, charging module, wide input voltage, topology design