The Design Research Of UHV High-Capacity Current Limiting Reactor

With the development of power technology,the voltage level of transmission line is continuously improved.In the entire power line,many hub substations are forced to pull the switch due to short-circuit current being over the shutoff capacitance of the switch.In the power grid,adopting the current limiting reactance with high capacity is an effective means to limit short-circuit current,which can effectively limit short-circuit current so as to ensure the reliable operation of the power grid.Currently,installation of current limiting reactor is the most simple,economical and reliable measure to maintain the stable operation of power network.By the end of 2016,there will be no less than 20 500 kv substations which need to install this equipment in order to cope with the increasingly severe problem of short-circuit current being out of standard.A large number of projects of ultra-high voltage current limiting reactors will be implemented.Because of the large capacity and high-voltage level of the ultra high voltage current limiting reactor,the design of the product is difficult to some extent.In this paper,the problems existing in the design of large capacity ultra-high current limiting reactor are analyzed so at to provide the solutions.The research is mainly highlighted on the temperature design the ability to withstand short current and the design difficulty of insulation characteristics of the ultra-high current limiting reactor are analyzed and studied.The current limiting reactor and the feature of metal parts are analyzed and the calculation method is put forward for the temperature rise of the large capacity ultra-high current limiting reactor,whose accuracy is verified by the temperature rise of the product and the simulation software.The simulation calculation is used for the metal parts,whose structure is revised based on the calculation result.Finally the accuracy of the calculation is adjusted by the experiment.This paper introduces analysis of the structure of the ultra-high voltage dry and air current limiting reactor when the short circuit happens as well as when suffering electric power,wind load and earthquake load.The calculation is based on the living examples which illustrate the methods under the circumstance when reactor stands short circuit.This paper analyzes the problem of insulation of the ultra-high current limiting reactor including internal and external insulation of the reactor,protective measures of surface insulation,the insulating heat-tolerance calculation under the condition of overload and the selection of electrical clearance distance.This paper solves the design in terms of the temperature rise of the electric reactor and metal structure,providing the thoughts for the design in the temperature rise of this type of product,calculating the simulation coil in the aspect of electric power,illustrating the calculation method when the reactor stands the short circuit,studying the insulation problem and providing the designing solution.Finally the temperature rise of the current limiting reactor and the accuracy of electric power and insulation design are verified in light of simulation method,the experiment on temperature rise and thunder shock.Therefore the practical designing thoughts are provided aiming at solving the difficulties of this type of products.