A high-efficiency leakage current suppression method for a three-stage and four-stage hybrid current source flexible power flow transfer device

The current source type flexible power transfer device, which uses a hybrid modulation of three-segment and four-segment methods, solves the common-mode leakage current problem and achieves efficient suppression without increasing hardware or with a slight increase in switching frequency, thereby improving system safety and reliability.

CN122159694APending Publication Date: 2026-06-05TIANJIN UNIV
View PDF 0 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
TIANJIN UNIV
Filing Date
2026-03-17
Publication Date
2026-06-05

AI Technical Summary

Technical Problem

Existing current source type back-to-back flexible power transfer devices have common mode leakage current problems in medium and high voltage applications. Existing suppression methods increase hardware costs or reduce efficiency, making it difficult to meet the comprehensive requirements of engineering applications.

Method used

The current source type flexible power transfer device, which adopts a hybrid modulation of three-segment and four-segment methods, selects the combination with the minimum sum of the average common-mode voltage and the effective vector cubic components through zero vector optimization and time splitting, thereby achieving efficient suppression of common-mode voltage and avoiding the need to increase hardware or only slightly increase the switching frequency.

Benefits of technology

It significantly reduces common-mode voltage and leakage current, improves system safety and operational reliability, and meets the safe operation requirements of medium and high voltage power distribution networks.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN122159694A_ABST
    Figure CN122159694A_ABST
Patent Text Reader

Abstract

The application provides a leakage current suppression method of a variable switching frequency adaptive flexible power flow transfer device, and belongs to the technical field of flexible power distribution network interconnection. The method first adopts three-stage modulation on the rectification side and the inversion side, compares and analyzes the average common-mode voltage and the leakage current under nine zero vector combinations, and optimally selects a configuration scheme to reduce the leakage current. If the leakage current is still out of limit, the zero vector action time is further split into two sections on the side where the output current modulation is small and the zero vector action time is long, so that the average common-mode voltage is further reduced. Compared with the traditional three-stage traversal method, the method can further suppress the common-mode leakage current under the premise of only slightly increasing the switching frequency, and overcomes the leakage current problem caused by the complexity of the common-mode voltage of the current source.
Need to check novelty before this filing date? Find Prior Art