Transient modeling of electromechanical relays

Abstract

Part 11: Plunger Type 50 Relays Jules Esztergalyos Bonneville Power AdministrationPortland, OR Abstruct -Electromechanical, plunger type 50 relay is modelled in EMTP/ATP using TACS. Mechanical magnetic, and electrical characteristics are represented in the form of simple mathematical models that can provide a useful tool for studying the dynamic responses of the Type 50 devices and incorporating them into a power system transient analysis. This paper is the second part of a summary report by Rensselaer Polytechnic Institute (RF'I) of work on relay modeling sponsored by the Bonneville Power Administration (BPA). Part I1 presents the Electro-Magnetic Transient Program/Alternative Transient Program (EMTP/ATP) model for plunger type 50 instantaneous overcurrent relays that compare with actual tests performed on the devices on a Power System Simulator (PSS) [l].

Electromechanical Modeling of a Contactor with AC Coil

“…However, some simulation details for the contactors are only described in specialized studies, for example, the nonlinear effect due to the limits for the armature displacement [6,7], the discontinuities in the armature path due to the changes in the springs and masses in motion [8,9], and the effects of the small air gaps between armature and core when the contactor is closed [9].…”

A command shaping approach to enhance the dynamic performance and longevity of contact switches

“…That is, a trade-off exists between the performance and device longevity using simple commands. The dilemma is usually solved by mechanical design optimization or by incorporation of feedback control through dynamic modeling [2][3][4][5]. In addition, selection of suitable contact materials can also improve the electrical contacts and the structural integrity [8,11].…”

“…Both electromagnetically (EM) and electrostatically (ES) actuated contact switches and relays have been widely used in macro scale mechatronics [1][2][3][4][5][6] and micro electromechanical systems (MEMS) [7][8][9][10][11][12][13] for various applications ranging from power delivery, signal transmission, and communications for decades. Because of their mechanical nature, switches generally have a limited lifetime and are prone to failure [14].…”