Study On The Unified Power-flow Controller In Nanjing Power Network

Unified Power Flow Controller(UPFC)is the representative of the latest generation of Flexible AC Transmission Systems(FACTS).UPFC set several FACTS device control measures,its application marks the FACTS technology development of new heights.UPFC device has the function of quick and flexible control of active and reactive power,voltage,impedance and flow angle of grid.It can carry out real-time power flow control for AC transmission system.This paper combines the UPFC demonstration project to be put into operation in Nanjing,Jiangsu Province in 2016,and is refined and sublimated from the early stage of grid planning and engineering design.First of all,the analysis of Nanjing 220 kV Westen ring network transmission bottleneck problems and reasons,combined with the actual project proposed multi-solution,through technical and economic comparison,recommended UPFC program to enhance power supply capacity.By further analyzing the technical principle and basic control mode of UPFC device,it is proved that UPFC has effective power flow regulation and control function,which can solve the bottleneck problem of Nanjing West ring network and demonstrate the necessity and feasibility of the first UPFC project in China.The steady-state mathematical model of unified power flow controller is established by user-defined interface(UD)using the Power Syatem Analysis Software Package(PSASP)which developed by China EPRI.Based on the calculation and analysis of the transmission grid with UPFC steady state model,based on the results of the power flow calculation,considering the demand of the 220 kV Westen ring network in Nanjing,the reasonable selection of UPFC Rated capacity,laying the foundation for the practical application of the project.