Research on Secondary Ripple Suppression of Single-phase Rectifier based on CRH3

The single-phase rectifier in traction drive system has the problem of secondary voltage ripple at the dc side, while the LC passive filter device used at present can effectively suppress the secondary voltage ripple at the dc side, but the required parameters are very large, which greatly reduce the power density of the converter. Therefore, this paper deeply analyzes the energy flow of traction drive system, deduces the voltage expression of the intermediate dc capacitance, analyzes the influence of the secondary ripple of dc voltage on the current at the rectifier network side according to the working characteristics of the rectifier, and finally researches the active secondary filtering method at the rectifier dc side.