Assessment On Influence Of Voltage Control On The Coltage Quality And Voltage Stability Of Foshan Grid

With the increasingly high demand to voltage quality, how to improve voltage qualityhas become the objectives of electric power company. Due to the uneven distribution ofregional load, peak and valley load fluctuations and other factors, the voltage quality ofFoshan grid is not well enough. In order to improve the voltage quality and the voltagestability of Foshan Power Grid, the task of analyzing the effect of reactive power controlstrategy to the voltage quality of grid and voltage stability, and looking for a method of furtherimproving the voltage quality and stability is very important.This article compares the reactive power optimization technical differences at home andabroad, analyses the fundamental theory of the power system reactive power control and thesubstation reactive power control and the nine zone control chart of VQC, uses the powerflow calculation method to simulate and analyze the two typical area of Foshan grid one dayof24hours of real time data. It contrasts the changes of10kV bus voltage and high voltageside of transformer reactive power before and after adopting VQC control strategy, and thenanalyses the influence for voltage quality and the economic of Foshan after using reactivepower control strategy. Using the continuous power flow method, it simulates the high andlow load of two selected area, analyses the PV curve, in order to understand the change ofload margin before and after the control strategy of VQC, and derive the effect to the powersystem static stability.Through the simulation and analysis, it proves that using VQC control strategy caneffectively control the voltage of low voltage side bus to regular range, reduce the voltagedeviation, decrease the voltage fluctuation, extend the time of regular voltage. At the sametime by continuous power flow analysis, it obtains that the VQC control strategy caneffectively increase the load margin, make the load voltage drop slowly, and improve thevoltage level. It proves that the VQC control can improve the voltage quality and voltagestability of Foshan Power Grid effectively, and it can improve the economy of power gridoperation. Lastly, according to the simulation results, some suggestions about the VQCcontrol strategy of Foshan Power Grid is given.