Voltage Regulation Effect Analysis And Improvement Strategy Of AVC System In Guangzhou Nansha Power Grid

With the rapid development of high voltage level,large capacity and cross-region power grid,we have higher standards and stricter requirements on voltage quality,to ensure the safety,quality and economic operation of power grid.Before the Automatic Voltage Control(AVC)system was put into operation,the voltage quality of power grid in Guangzhou Nansha District was not high enough,which was affected by seasonal changes,fluctuations by large peak and valley load and uneven distribution.In order to improve the voltage quality of power grid in Nansha District and to reduce the network loss from the main network,evaluating the voltage regulation effect of AVC system and puting forward the improvement regulation strategy is urgent to conduct in-depth research.This paper briefly describes the basic theory of voltage and reactive power control of power system,the basic principle and control strategy of substation AVC system.Based on the actual power grid parameters,adopt the method of simulation calculation on 220 kV Huqiao substation affiliate,the representative web site in Nansha power grid,monitor the actual load data for 24 hours a day,contrast the change of 10 kV busbar voltage of every substation and network loss before and after AVC control strategy actions taken,and analyze the impact of AVC system controls on voltage quality and operational economy in Nansha power grid.Through simulation,the effects of AVC system regulation strategy on reducing voltage offset,reducing voltage fluctuation,controlling the 10 kV busbar voltage within the qualified range and reducing network loss can be quantitatively evaluated.While verifying the effect of AVC system regulation on the voltage quality of Nansha power grid,combining with the actual operation of Guangzhou power grid AVC system,we also find some defects and deficiencies in the regulation of AVC system,such as the deficiency of the nine-zone diagram strategy,the problem of capacitor configuration and switching,and the low comprehensive automatic level of some substations.In view of these problems,the corresponding improvement strategies,such as adopting seventeen-zone diagram control strategy,carrying out substation comprehensive automation transformation,optimizing AVC system strategy in different ways,and connecting 500 kV substations to AVC system,all of which have achieved certain results.