Research On Dynamic Line Rating:Climatology And Impact On Reserve Sizing

In response to the challenges of climate change,environmental pollution,and the depletion of traditional fossil fuels,to meet the higher requirements of social and economic development for energy,all countries have paid increasing attention to the development of sustainable new energy sources.However,with the increasing popularity of renewable energy applications,the uncertainty of renewable energy sources and the prediction errors have brought difficulties to the operation and scheduling of power systems.In recent years,the power flow has changed more and more frequently,higher capacity is needed during the peak period of power demand,and the rapid economic development also need higher requirements for economical and reliable operation of the power grid.There is an ideal method to solve this problem which is simply upgrading all the transmission line,but the cost is high above the benefits,and construction hampered by a lack of environmental policies and land resource constraints.With the increasing penetration of intermittent energy resources,the determination and design of the Dynamic Line Rating(DLR)for the overhead line have been developed and installed in the past years.The DLR technology of transmission lines provides a feasible alternative for improving the transmission capacity of the line,deeply excavating the actual transmission potential of the power network,and does not need to build additional lines to improve the flexibility of power system operation.As the technique is not mature,improvement and evaluation of the details are required for ensuring the security and stability of the power grid with higher benefits after its application.Especially the economic benefits determination of DLR is a multilateral case which is difficult to evaluate,and the research thesis focusing on this topic is quite rare.Under this background,this thesis proposed a DLR for transmission lines based on historical meteorological information to improve the transmission capacity and the operational flexibility of the system,and applied this technology to the European Internet for simulation verification,considering the technical and economic aspects.Firstly,this thesis summarized the research status of DLR at home and abroad,and discussed the technical difficulties of its application,and pointed out that with the development of technology,it is expected to overcome these problems.Subsequently,the thesis proposed an alternative method for selecting transmission lines for overhead lines.Based on the worse weather conditions,the DLR was relatively conservative.A simulation of the simplified model of the European interconnected power grid was carried out and applied to the interconnection transmission lines of Germany,France,Belgium,Spain and Portugal.The impact of the application of this technology on the European power grid was discussed.The results show that the application of DLR can increase the flexibility of power system operation,thereby greatly reducing load loss and increasing the intermittent renewable energy grid connection rate.In order to analyze the economic aspect of the DLR,this thesis proposes a method for determining the size of the reserve capacity based on the DLR methodology.The required reserve after the application of this technology is roughly calculated.The economic aspects were discussed based on simulation results of the electricity price and reserve capacity.The research shows that the proposed technology will not increase reserve capacity requirements,and its economic benefits are considerable.The development prospects of the DLR are prosperous.