The contradictions faced in practical engineering and design have proved the necessity and urgency of research on electrified railway dual-network interconnection converters. The major needs and engineering challenges in practical applications of dual-network interconnection converters are analyzed. According to the characteristics of the railway electric power supply and distribution network, a topological structure of an electrified railway dual-network interconnection converter with current limiting is proposed, its working principle and composition are analyzed in detail, and its variable impedance control strategy in voltage control mode and current limiting switching control mode is put forward. Moreover, the feasibility of the variable impedance control strategy is proved by a simulation model. In particular, an engineering prototype was used to prove that the voltage control mode of the converter has good practicability, and it can solve the difficulty in actual survey design, high cost, power quality degradation and other issues. Finally, the development potential of the interconnected converter in the future is prospected.

Dual-network interconnection converter  /  current limiting switching control  /  voltage control  /  variable impedance control  /  engineering prototype