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Design of Powered Rail Vehicles and Locomotives
Published in Simon Iwnicki, Maksym Spiryagin, Colin Cole, Tim McSweeney, Handbook of Railway Vehicle Dynamics, 2019
Maksym Spiryagin, Qing Wu, Peter Wolfs, Valentyn Spiryagin
Eddy currents are produced within any metal object that has relative motion with a nearby magnetic field. These currents dissipate energy within the metallic object. Conservation of energy requires that these losses be reflected in the mechanical system as retarding forces. As an eddy current brake uses a non-contact braking method, mechanical wear is avoided. In railway applications, two configurations are used. These are linear railhead brake systems or disc brake systems. Both are widely deployed in high-speed trains.
E
Published in Philip A. Laplante, Comprehensive Dictionary of Electrical Engineering, 2018
echo width analog telephony to cancel echoes from signals that traverse the entire round-trip connection, and in full-duplex voiceband modems, where the echo is due to leakage through the near-end hybrid. echo width in a 2-D scattering problem, the width needed to capture the exact amount of incident power, that when the scattering body is replaced by a cylinder, and the cylinder radiates the captured power, the amount of power received at a specified point is the same as that received if the scattering body is not replaced. Echo width is the 2-D analog of radar cross section in 3-D. The units of echo width are meters. Eckert, John Presper (1919-1995) Born: Bryn Mawr, Pennsylvania Best known as one of the designers of ENIAC (Electronic Numerical Integrator And Calculator), an early computer. Like many computer pioneers during World War II, Eckert was looking for more efficient ways of calculating trajectory tables for artillery and ranging systems for radar. Eckert graduated from the University of Pennsylvania and remained there to work with John Mauchly. Eckert and Mauchly later formed a company and continued to develop and refine their machine. Eckert eventually sold the company to what would become the Sperry Rand Corporation. Here he produced UNIVAC I (Universal Automatic Computer), one of the first commercially successful computers. The chief improvement of this machine over its predecessors was in its use of a stored memory. ECL ecliptic See emitter-coupled logic. plane of earth's orbit around the sun. edge coupled microstrip lines the microstrip lines that have the same ground plane and are on the same dielectric substrate and are parallel to each other. The coupling is mainly due to the fringing fields at the edges of the lines. edge detection the location of edges in an image by computer. See Canny operator, gradient buying power from one or more of the other systems in the interconnection group. ectopic beat a heart beat that originates from other than the normal site. eddy current a circulating current in magnetic materials that is produced as a result of timevarying flux passing through a metallic magnetic material. eddy current brake a braking device in which energy is dissipated as heat by generating eddy currents. eddy current drive a magnetic drive coupled by eddy currents induced in an electrically conducting member by a rotating permanent magnet, resulting in a torque that is linearly proportional to the slip speed. eddy current loss the energy wasted in sustaining undesirable eddy currents in an electrical conductor. EDFA See erbium doped fiber amplifier.
Speed-based multiobjective optimisation of a cage-secondary permanent magnet linear eddy current brake
Published in International Journal of Systems Science, 2023
Wen Chen, Baoquan Kou, Mengyao Wang, Xv Niu
Eddy Current Brake is a braking equipment that utilises eddy current effect, which can convert the kinetic energy of the braking unit to the eddy currents in the conductor plate to achieve the purpose of braking. Unlike the conventional adhesion braking, the eddy current is non-contact braking. Therefore, the eddy current brake has the advantages of high reliability, low noise and long service life. With those features, the eddy current brake is considered as a suitable braking device for the braking of transmission system, the rail transit system and so on Gulec et al. (2019), J. Tian et al. (2020), Lubin and Rezzoug (2015), Jin et al. (2022), Mohammadi et al. (2014), Gulec et al. (2021) and Kou et al. (2014). The background of this research is high-speed rail transit braking. In order to increase the reliability of the braking system and avoid the risk of power failure, permanent magnets (PMs) are mostly used in the primary of high-speed braking (Shin et al., 2018). Moreover, as linear high-speed braking requires the long track, it will increase the cost of the manufacture. Therefore, increasing the braking force in all speed ranges to shorten the braking distance and reduce the manufacturing cost are the critical studies of the high-speed rail transit braking system.