Economic evaluation of dynamic thermal rating under variable loading conditions for the flexibility of power systems with wind power plants

Generally, the design of the transmission elements is made by considering the worst weather and load conditions in the power system. When the temperature of the cables and overhead lines is low, these can have a capacity of loading more. This situation causes the lines to design based on static rating calculation to be used inefficiently. Therefore, operational flexibility of power system can be achieved by using dynamic rating methods in overhead lines and underground cables, while the variable weather conditions and loading conditions are considered. Unlike the studies in the literature, the thermal analysis of the cable can be made by considering the changing loading and weather conditions. In the analysis, the wind power plants is discussed for variable loading conditions. As a result of this assumption, it is found that the variable loading has a very important effect on the dynamic line rating, such as weather conditions. The economic consequences of variable load conditions on cable sizing are analyzed using the net present value method by considering the dynamic rating calculations. In the analysis, it is revealed that if the dynamic rating of the cable is used, it will be suitable for short-Term investments. In this study, thermal analysis of underground cables is based on numerical method by using Fluent program, while overhead lines are based on analytical method by using the ETAP program.