Applied Research On Automatic Voltage Control Of (AVC) Beijing Grid

Beijing power grid, which is in the centre of the Jingjintang power grid, is an important part and a load center of the North China Power Grid, and it is a typical receiving power system. Along with the enlarging of power-grid scale and the complex of power-grid structure, the existing voltage control mechanism can't meet the requirements for the safety, high quality and economic operation of the power grid. Beijing power grid AVC system can realize the automatic optimal control of reactive power and voltage from the angle of the whole system, it is of great significance to decrease the network loss, improve the voltage qualification rate, reduce the working intensity.This paper analyzes the characteristics about the control of the reactive voltage in Beijing grid, because of the dispatching jurisdiction, the control mode becomes complicated, therefore, the level 3 voltage control mode is proposed based on the "soft partition". The three-level control mode is analyzed according to overall structure drawing, and the thoughts of the decomposition-coordination, which contain three dimensions about the goal, time and space, are applied to understand the voltage control mode. The 220kV substations are the mainly control objects in the secondary substation control module, in which the control target, the control rule, the estimated control effect and the control equipment choice are analyzed detailedly. And the conclusion is: compared with the traditional substation control, the optimal control of 220kV substation orienting to kinds of control targets is coming true. That is to say, the voltage qulification rate of 10kV and 110kV must be first considered, especially the busbar voltage of 10kV. And then the busbar voltage of 220kV reach the target given by the AVC three-level optimization.This paper selects the Pinggu substation as representative of the load substation, and the Balizhuang substation of the ring net substation. In the AVC system, the open loop strategy validating of this two substations are analyzed by the method of artificially analysis; Take Taiyanggong substation and Caoqiao substation for example, the open loop strategy validating is analyzed by the method of power flow simulation calculation, which simulates the four power flow sections continuously. The problems of the AVC strategies are pointed out through the above analysis, and the modifications are put forward to ensure the system entering into the closed-loop conveniently and reliably. Meanwhile, through the analysis of the operational aspect in AVC system indicates that the quality of the voltage is comprehensively improved and the economic benefits of the system is enhanced.