Determination of criteria to find the quality of an electrical connection

A contact system is a nonredundant technical structure of electric railways that should provide uninterrupted power supply for railway vehicles. The failure of one part can lead to failure of the contact system. About 20% of damage to contact systems is due to inadmissibly high temperature at part of an overheated catenary. In this paper, normative indices are analyzed to determine the state of the terminal under operating conditions. The existing methods of thermal control are unable to determine the current heat state of an electric bolted connection with required accuracy. Heating control of electrical connections is suggested. To determine the state of the electrical connection, the factor of defectiveness due to heating is selected. As a result, criteria for determining the state of an electrical connection are obtained, which allows a methodology to be developed for monitoring the quality of an electrical connection.