A thermal model based dynamic rating system for overhead transmission lines

In the modern power system, the dynamic rating technology of transmission line has been drawing more and more attention in power system operation research. Developing dynamic rating system can raise short-term transmission capacity of transmission lines effectively and safely to satisfy the demands for power supply under emergency. The dynamic rating model based on thermal circuit is derived through the foundation of steady state model and transient state model of thermal circuit. The overhead transmission line temperature at any time is obtained through the first-order thermal circuit model. The field test data of dynamic rating system is analyzed. The effectiveness of the proposed model and dynamic rating system is verified by the simulation test and field test.