Coupling Effect of Reflux Safety Parameters in Main Line and Depot of Multitrain DC Traction Power Systems

Abstract

Currently, exorbitant reflux safety parameters (RSPs), including stray current (SC) and rail potential (RP), evidently exist in multitrain dc traction power systems, which has brought a serious disaster for the system. RSP of the main line and depot both exceeds the standard limits and has a correlation at the same time. In this article, the coupling effect of RSP in the main line and depot is studied to clarify the abnormal rise of RSP in multitrain subway systems. The coupling simulation model of the system with main line and depot is proposed during the dynamic operation of multitrain, based on which the calculation method of RSP in the main line and depot is established. Dynamic distribution of RSP in different cases is simulated, and field tests are carried out based on the second power supply zone in Hefei Metro Line 2. Results show that the coupling effect of the RSP can be effectively evaluated by the proposed model. The RSPs of the main line and depot are obviously affected by each other and can be effectively restrained by improving the unilateral connecting device (UCD).