SOME POSSIBILITIES OF MONITORING TRANSIENT THERMAL PROCESSES IN CONTACTS OF ELECTRICAL POWER SETUPS

The paper analyzes the possibilities of registering temperature on the contact surface of a bus bar connection is analyzed. The algorithm for determining the maximal value of temperature on contact surface is proposed. The method is based on dynamic measurement of external surface of contact pair by disconnecting the short-circuit current or by nonsynchronous motor starting. The requirements for the dynamic temperature sensor for typical events with a duration of 0.1–1 s are determined. The different ways of realization of the smart dynamic temperature sensor for high voltage electric power setups are discussed. Two types of designs of the sensor with a thermistor are considered. The sensor based on conductive signal transmission is badly applicable for high voltage setups because it has quite a thick insulation layer between the bus surface and the thermistor, therefore it has a reaction time about 10 s and is not suited for dynamic measurements. The optical channel for signal transmission allows to use thinner insulation layers that provide a 1 ms time reaction sensor. The sample of the sensor design with power supply from the busbar-induced voltage and industrial optical insulator is proposed.