Study Of The Optimal Allocation Of SVC Device

Flexible AC Transmission System（FACTS）technology is a revolutionaryinnovation for the traditional power grid.With the gradual deepening and promotionof the FACTS technology theory and engineering application, the ability that FACTSdevices could improve the level of power transmission lines and power systemstability can be reflected gradually. In the practical power system operation, the activepower can be consumed and large amounts of reactive power could be absorbed.Therefore, it’s significant to compensate the reactive power for the improvement ofthe power system operation stability. As one of the shunt FACTS devices, SVC canquickly adjust reactive power of the system and maintain voltage stability of thenodes to greatly improve the voltage stability of the power system. So the applicationof SVC in power system may be wide.However, considering the economy and technicality of the SVC deviceinstallation, it is impossible and not necessary to install overmuch SVC in thepractical electric network. And it is supposed to optimize the allocation of SVCdevice basing on network architecture, mode of operation and the weak link ofdifferent power systems, so as to determine the best location to install in the electricalsystem. Linearization method can be adopted mainly for traditional placementmethod of SVC, but it can ignore the strongly nonlinear phenomena effect which thesystem may be showed in a dangerous operation mode. Therefore the adoption ofconventional linear method may lead to inaccurate or even erroneous results. UsingNormal Form theory, the high-order analytical solution of the system can be obtained,which covers more nonlinear information of the systems.The paper woule make the research for the SVC location method based onNormal Form theory. Firstly, the auxiliary dynamic flow equations that are alsodifferential equations would be constructed basing on the power flow equations andvoltage oscillation curve analytical solution of all load node using normal form theory can be derived when subjectes to a little interference in a dangerous operation mode;Then the optimal location of SVC will be determined by solving nonlinearparticipation factors, second-order participation factors and other indicators relyingon the obtained first-order and second-order correlation coefficient; Finally, in orderto evaluate the correctness of the best location of SVC, the time-domain simulationcould be conducted by PSAT toolbox to analyse the raised extent of the systemvoltage stability after the placement of SVC. The effectiveness of the proposedmethod in the paper can be verified by the IEEE14-node and39-node system.