In the light of the demand for regenerative braking energy feedback system for subway and subway,a modular series-parallel energy-fed topology with fast fuses is adopted.This topology reduces the cost of the device,solves the problem of insufficient IGBT current,and improves the reliability of the device.In this paper,the influence of the modulated wave signal and the carrier signal on the circulation are quantitatively analyzed.The internal current control strategy and the carrier synchronization technique are used to suppress the circulation of the parallel module.The test results show that the direct parallel connection of AC and DC side can be realized through the regenerative braking energy feedback device based on multi module series parallel connection and the current deviation of the parallel inverter is less than 1%,the DC voltage deviation of the series inverter is less than 1%.