Study on thermal model of dynamic temperature calculation of single-core cable based on Laplace calculation method

Abstract

In order to achieve the real-time calculation of cable core temperature, according to principles of heat transfer, proposed is the way of calculating cable core temperature based on the actual operating current and the cable surface temperature. This paper studies the dynamic response of cable core temperature based on the core temperature. Changes of actual running currents result in dynamic response of cable core temperature. In order to input the actual continuously changing real-time current into a real-time calculation model of cable core temperature, a set up of an equivalent Laplace thermal model of single-core cable according to cable core thermal circuit model has been developed using transform lumped parameter methods. This paper provides a reference and theoretical support for a real-time calculation model of the cables continuously changing current in operation. A step input current is applied and to achieve a continuously changing current as the input parameter for calculating the cable core real-time temperature. This is accomplished using the thermal circuit model which is able to calculate the core real-time temperature based on the above analysis. Finally, test and operating data can prove effectiveness and feasibility of cable core real-time temperature model which can calculate core temperature and cable temperature field by the actual cable surface temperature and the actual running real-time current.