Design Considerations and Experimental Verification of a Rail Brake Armature Based on Linear Induction Motor Technology

Abstract

This paper describes the design considerations and experimental verification of an LIM rail brake armature. In order to generate power and maximize the braking force density despite the limited area between the armature and the rail and the limited space available for installation, we studied a design method that is suitable for designing an LIM rail brake armature; we considered adoption of a ring winding structure. To examine the validity of the proposed design method, we developed a prototype ring winding armature for the rail brakes and examined its electromagnetic characteristics in a dynamic test system with roller rigs. By repeating various tests, we confirmed that unnecessary magnetic field components, which were expected to be present under high speed running condition or when a ring winding armature was used, were not present. Further, the necessary magnetic field component and braking force attained the desired values. These studies have helped us to develop a basic design method that is suitable for designing the LIM rail brake armatures.

Development of a Rail Brake Derived from Linear Motor Technology

“…This means that the armature also plays the role of a braking resistor. The design method of the armature in accordance with this system is shown below [6].…”

A study on the transverse edge effect of an eddy current brake with a solid steel secondary

“…The proposed LIM rail brake [1–3] uses an armature of the LIM in place of the excitation pole of the conventional eddy current brakes and generates braking forces by dynamic braking operation, as shown in Fig. 1.…”

“…Because of these reasons, eddy current brakes have not yet been commercialized in Japan. Given this situation, we are aiming to solve the above‐mentioned problems by using linear induction motor (LIM) technology, and have been studying an LIM with the rail as a secondary conductor [1–3].…”

“…In an LIM or eddy current brake with a solid steel rail as a secondary conductor, it is important to note that the rail is narrow. While the influence of the longitudinal end effect peculiar to such a linear induction machine is not very significant [2,3], the transverse edge effect and the electromagnetic phenomena related to the finite width of the active zone and magnetic core greatly affect the performance of an LIM or eddy current brake. In some reports concerning two‐dimensional electromagnetic analysis of an eddy current brake, the transverse edge effect is taken into account by using some modifying coefficients [4].…”

“…On the other hand, in industrial development processes of those brakes, the three‐dimensional analyses of numerical field computation require many calculation models, many techniques, and much time for a design parameter survey. Therefore, a simplified analysis method with accuracy that is useful for predicting the approximate performance of such brakes is desired, which is convenient for predicting their performance in their early development stages [3].…”