Study On The Short-Circuit Current Limiting Measures In Xinjiang Zhundong 220kV Power Grid

The Xinjiang power grid is located in the far west of China, it is the origin of ’One Belt and One Road’and the beginning of the World’s Energy Internet to the west development. Xinjiang Power Grid will develop the ultra-high voltage (UHV) power grid relies on the energy strengths such as the coal, wind energy and optical energy during the 13th Five Year Plan. Two UHV DC transmission projects, Zhongdong Wucaiwan-Wannan and Zhongdong-Sanhua, will be built which their voltage level is ±1100kV. In addition, build an UHV DC transmission project, Kashgar-Pakistan, which the voltage level is ±800kV. At the same time, strengthen the construction of the distribution network which the voltage level is less than 750kV、220kV. The short circuit current is growing up with the increasing of the scale and capability of Xinjiang Power grid with the increasing of the number of generator units and the construction of power grid is stronger and stronger.The earliest area of the short circuit current exceeded in Xnjiang is Urumqi-Changji power grid and the problem is already regulated. However, the short-circuit current of Zhundong is rapid growth and second only to Urumqi-Changji Power grid with large projects of Zhongdong are constantly putting into production. The limitation of the operation mode will seriously affect the safety and stable operation of the power grid.According to researching the construction and the operation characteristics of Xinjiang Zhundong Power Grid, combine with the development plan of Zhundong 750kV power grid, research and forecast trend of the circuit current increasing, what is more, analysis the current limiting measures. The result shows that, recently, the busbar of power grid still need disconnect from the other and cut off the line to limit the short circuit current because the construction of Zhundong power grid is not completed, the 750kV/220kV power cannot run at the condition which is delimitation and subarea. So that, using delimitation and subarea to run the system is the best way to control the short circuit current when Zhnundong 750kV loop grid is completed. At the same time, some comprehensive measures such as using current limitation measure, busbar disconnected running are still needed in the system, especially for the nodes where the short circuit is higher than normal.In order to make sure that the current limiting effect is the best, and in view of the rationality, economy and feasibility, the paper present a comprehensive current limitation measure for the Zhundong power grid in 2016 and 2020:adjust the operation mode and add current limitation measure. The result shows that, this measure can not only satisfy the demand of the system running, but also control the short circuit current in the reasonable range.