Research On Optimal Allocation Of High Voltage Reactor With Considering The Randomness Of Large-scale Wind Farm

The high voltage reactor plays an important role in maintaining the grid voltage stability and improving the system reactive power distribution. The power grid in China shows the trends as grid scale expanding, interconnection strengthening and main voltage level in transmission network arising. All these changes in grid structure ask for the adaption of reactive power compensation devices. At the same time, the wind power generation in China is gradually showing the characteristics of large-scale centralized development and accessing grid through long high-voltage transmission. With the rapid growth of wind power, the voltage fluctuation caused by its randomness cannot be ignored. So the optimal allocation of high voltage reactor in such grid needs to consider the influence from wind power generation.This paper researched on the optimal allocation model of high voltage reactor in the power grid where large-scale wind farms accessed. The main work was organized as follows.Firstly, the index system was built up in analytic hierarchy process with three layers defined as objective layer, classification layer and index layer, considering the voltage index in main and the network loss index and reactive operating index as well. Each index has detailed definition and description.Secondly, the index weights were measured by combining subjective weight with objective weight. To be specific, the subjective weight is determined by the analytic hierarchy process with the judgment matrix constructed by the scale-extending method, and the objective weight is calculated by the entropy weight coefficient method.Thirdly, after summarizing the theory of stochastic programming, the expected value model was described in detail. Under considering the characteristics of large-scale wind power, this paper discretized the probability density function of active power of wind farm and proposed a calculation method based on the expected value model.Lastly, the optimal allocation model of high voltage reactor with considering the randomness of large-scale wind farm was build up basing on the above theory. And the theory was simulated within a real power grid. Simulation analysis shows that the best scheme can effectively improve the overall performance of power grid and also verify the sensitivity of the model itself.