Multi-port Bidirectional Energy Router for Urban Rail Transit and Its Key Technologies

Abstract

At present, urban rail transit power supply system can only realize unidirectional power supply, which cannot meet the development needs of green, intelligent and interconnected energy internet. A solution of AC/DC multi-port bidirectional energy router is proposed. It adopts high-frequency power electronic conversion technology, replaces the " isolation transformer + regenerative braking energy utilization equipment" structure in the traditional energy feedback system with an energy router, and connects the AC1180V port in parallel with the secondary side winding of the rectifier transformer, so as to realize the perfect integration with the existing urban rail unidirectional power supply system, and achieve the purpose of reducing weight and volume of the overall system and optimizing the structure of the power supply-energy feedback system. Through energy management system scheduling and two-direction smooth switching of the isolated DC-DC converter, flexible energy allocation among multiple power ports (AC400V/AC1180V/DC1800V/DC900V)is realized during train traction or braking. Key technologies such as high frequency topology parameter optimal design and magnetic saturation suppression of high-frequency transformer are adopted to realize soft switching of AC400V and AC1180V branches under all working conditions. Experimental results show that the solution can realize no static no-load loss, flexible and smooth switching between various working conditions; the temperature rise of each component is stable, the system can operate normally and stably, and its overall efficiency is more than 96%.

Keywords

• energy internet
• urban rail transit
• energy router
• soft switch
• multiple ports
• power electronic high frequency technology
• magnetic saturation suppression