Study on remaining life of the contact terminal of high-speed circuit breakers in subway vehicles
DANG Haitao
ZHAI Haojing
YANG Dazhang
XIANG Nan
AO Ni
Abstract：The high-speed circuit breaker is an important device to ensure the safety of train circuits,which controls the connection and disconnection of the circuit via opening or closing the moving and static contact terminal.It is an important basis to study the remaining life of the contact terminal for the operation and maintenance of circuit breakers.However,there is no systematic work being reported yet.Therefore,test scenarios were built that matched the operation and maintenance conditions of circuit breakers,and established a residual life model of circuit breakers based on test data.The contact terminal of high-speed circuit breakers in Chengdu Metro subway vehicles was taken as the research target,and then its evolution law of the remaining life in daily service conditions was studied by using a combination approach that comprises finite element simulation and test investigation,which was to study the variation rule of the thickness of the silver-plated layer thickness of the contact terminal with the number of uses.The numerical simulation results show that the stresses in moving and static contact terminals are less than the material fatigue limit,and the fatigue service life of both types of contact terminals is considered to be an infinite life level in the safety life assessment.Moreover,the test results show that the coating thickness of the moving contact terminal decreases with the increase of test cycles,yet the reducing thickness is mainly due to the wear caused by the grinding process such as bias grinding.Based on the linear prediction model,the remaining life of the moving contact terminal was evaluated,and the calculation results show that when the coating thickness of the moving contact terminal reduced from the initial 3.003 mm to the limit of 1.5 mm,the circuit breaker contact can be used for 19 313 cycles,corresponding to the natural year about 36.2,which is about 2.4 times of design service life.The predicted value has been verified by hypothesis testing,and the calculated result is within the predicted interval.The above research results are expected to provide relevant support for the development of maintenance intervals and maintenance strategies for contact terminals.
Keywords：Subway vehicleHigh-speed circuit breakerContact terminal wearNumerical simulationTest studyRemaining life
Publication Date：2025-12-15
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：10( 79-88 )