Prediction Approach of Negative Rail Potentials and Stray Currents in Medium-Low-Speed Maglev

Abstract

The problem of negative rail potentials (NRPs) appears in the line of the medium-low-speed (MLS) maglev. It is vital to forecast the NRP and the corresponding stray currents (SCs) in order to prevent safety hazards. This article proposes the prediction methods of NRP and SC for the first time for the MLS maglev. On the basis of developing a two-layer rail–earth circuit, a simplified prediction approach based on the analytical formula derivation is proposed to obtain the behaviors of NRP and SC under different steady running scenarios. Afterward, in order to accurately reveal the influence of vehicle-grid parameters, the ac component and the energy dispersal path of the maglev system are detailed, and the precise vehicle-grid model is developed to consummate the prediction approach using MATLAB. Under the premise of verifying the scheme effectiveness using the captured data in the on-site of the Chinese Xinzhu MLS maglev line, the scheme application studies are provided to investigate the behaviors of NRP and SC while considering the ac effect and the varying velocity of load current and rail–earth conductivity.