System-level Magnetic Interference Modeling in Electrified Monorail System for Track-side Safety Design

Abstract

This paper presents a modeling technique to characterize the system-wide magnetic interference that impacts track-side safety in the early design of a DC electrified monorail system. A simulation algorithm based on the 2D finite-difference method is implemented to accommodate Poisson’s equation for cross-component magnetic coupling between nearby power lines and system infrastructure. This also takes into account the interaction with the train-track electrification through the movement performance and power flow simulations. This computational scheme estimates the track-side area exposed to strong magnetic fields, thus revealing the impermissible area in accordance with EN 50121-4 and EN 45502-2-1. The earthing arrangement of metallic walkways and cable trays in the middle of the guideway is also examined to prevent electrocution with respect to EN 50122-1 criteria. Numerical results indicate that, for the operation under steady-state AC-line faults, an additional 15% and 12.39% of high-risk areas shall be accounted for in the space utilization management of equipment and persons, respectively. It can also be seen that the mitigation measure of allowing up to 4 guideway-beam spans per earthing point is reasonable to reduce the risk of electric shock hazard. The outlined numerical scheme could provide proper guidance for early confidence prior to system installation.