Development of efficient models of Magnetic Braking Systems of railway vehicles

Abstract

In modern railway vehicles, the use of Magnetic Braking Systems is continuously increasing, because they are characterized by high braking performances and low energy consumptions. Hence, the study and the accurate modelling of Magnetic Braking Systems is a very important issue, because they significantly affect the dynamics of vehicle and electrical supply circuit. Usually, the performances of Magnetic Braking Systems are evaluated on test-rigs in order to reduce times and costs of testing phases. For this reason, the authors focus on the development of a complete 3D model of Magnetic Brake System test-rig (built in COMSOL), including all the electromagnetic, circuital and mechanical parts. These parts are often studied separately in the literature; however, a combined analysis is crucial to correctly describe the behaviour of the whole system. The proposed model is highly modular (to describe different Magnetic Brake System test-rig layouts characterized by a different number of magnetic polar expansions) and aims at obtaining a compromise between accuracy and numerical efficiency. Subsequently, a second simplified lumped parameter model derived from the complete one and built in MATLAB is developed, to further reduce the computational load without decreasing the results accuracy. In this work, both the models have been developed and validated in collaboration Ferrovie dello Stato and compared with other simplified models present in the literature.

Increasing mine train mass by means of improved efficiency of service braking

“…3b). Braking force on a wheel is growing during 2 s up to maximum value 11 F equal to 4450 N; wheel lock-up results in sharp decrease in the braking force down to the value of 1640 N (Fig. 3d).…”

“…While using a magnetic rail device, a share of the magnetic attraction force of a braking unit is transmitted onto the locomotive axes; due to that, rail reaction under a wheel increases. Within section I, additional wheel load does not result in changes in braking force 11 F ; the effect is demonstrated in the increased stability of the locomotive underframe in the rail gage. Within section II, law of changes in braking force will be determined by the product of wheel load by the friction coefficient of wheel slip along the rail; however, in this case, rail reaction under a wheel will be higher by the additional load value -consequently, friction force of a wheel along the rail will be higher as well.…”

“…Ideas to equip mine cars with brakes have not been developed further as well. At the same time, rail magnetic brakes have been used successfully on rolling stock of rail transport for more than 100 years; those brakes develop additional braking effort, independent from traditional brakes, at the expense of brake unit and rail friction [11,12]. Operational practice has proved high efficiency of their application for emergency braking and as the parking brake; however, attempts to use rail magnetic brakes for service braking were not successful.…”

A SVM framework for fault detection of the braking system in a high speed train

“…In Kang (2007), a hardware-in-the-loop system is built to simulate the dynamics of a braking system of a HST. A modelling framework of magnetic braking systems is proposed in Galardi et al (2015) to test efficiency.…”

Improved Sustainability of Railway Systems: The Tesys Rail Project

“…Safety and operational issues (such as the distinction between service and emergency braking) also influence the complex interactions between different braking systems. In a previous work [2] the authors have focused on the detailed simulation of each sub-system, with a particular attention to some components such as the pneumatic [8] and electro-pneumatic [9] brake plant or the magnetic track brake [10], to which some specific studies have been dedicated. which controls the application of traction, coasting (no longitudinal effort applied) and braking (service or emergency braking according to the speed error and to the value of the safety state of the train).…”