Lightweight Topology and Control Strategy of DC Link in Traction Converter

In order to solve the problem that the weight of LC resonant circuit in DC link of the traction converter of high-speed train is too large, which causes the overall power density to decrease, an active power decoupling loop is introduced instead of LC resonant to suppress the secondary ripple of the bus voltage. In order to adapt to the rail transit application scenario with high power and low switching frequency, two-phase interleaved Buck chopper active power decoupling topology is selected as an alternative to LC resonant circuit. A power decoupling strategy based on repetitive control is proposed for the decoupling circuit, which reduces the weight of DC link, improves dynamic performance and improves stability. Finally, the feasibility of the proposed method is verified by simulation.