System-Level Magnetic Interference Modeling in Electrified Monorail System for Track-Side Safety Design

This article 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 2-D 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 four 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.