摘要

With the increasing demand for electric energy, it has become an urgent problem to evaluate the potential transmission capacity of overhead conductors by dynamic thermal rating technology. The traditional dynamic thermal rating model is difficult to promote and implement due to difficulties in the accuracy of wind speed measurement and equipment installation and maintenance. Therefore, based on the principle of non-contact equivalent measurement, an equivalent hear transfer transient measurement model for dynamic thermal rating of overhead conductors is proposed, which can both fastly and accurately calculate the ampacity of overhead conductors and is easy to install and maintain for equipment, because it is independent of the conductor. Two data processing methods, numerical difference quotient derivation method and analytical derivation method, are proposed to solve the differential equations in the process of model establishment. Based on the finite element simulation of aluminum ball, the influences of different data processing methods on the calculation results of the equivalent heat transfer transient measurement model are analyzed. Finally, a breeze wind tunnel experiment platform is built to simulate the operation of the aluminum ball device, the experimental data are used to solve the model to determine the amount of transient data needed for model calculation, and the model calculation results are compared with IEEE Std 738?-2012 standard results to verify the accuracy of the model. The results show that when the equivalent heat dissipation transient measurement model is calculated by the analytical derivation method, the error of the model is less than 6% under the premise of ensuring the real-time performance, which meets the requirements of engineering applications, therefore, the transient measurement model of equivalent heat dissipation proposed in this paper can dynamically and accurately evaluate the current carrying capacity of overhead conductors in real time. ? 2022 Science Press.