Моделирование температурного режима, мониторинг и прогнозирование перегрева болтовых контактных соединений токоведущих шин

Abstract

The widely used infrared imaging control of bolted connections in live rectangular buses is performed without direct access to the object being diagnosed. This gives only an approximate idea of the contact state, whereas the contact layer condition remains poorly known. The high thermal conductivity of the live bus material makes the thermal field pattern near the contact connection rather soft, which significantly adds complexity to the diagnostics. Therefore, it is important to develop diagnostics of contact connections by dynamic methods based on analyzing the thermal effect of rectangular test or quasi-rectangular operational current pulses in the busbars of electrical installations. By analyzing the temperature field dynamics in the flat contact zone it becomes possible to establish a functional relationship between the contact zone temperature and the bus free surface temperature, and also the relationship between the temperature recorded on the bus surface and the transition resistance, which is the contact quality characteristic. It has been shown, by simulating the contact surface temperature control in the dynamic monitoring mode, that it is possible to determine the rectangular bus bolted connection overheating protection response time. It is proposed to use the obtained dependence as a conversion function for an intelligent electrical contact temperature sensor.