Research On Reactive Disturbance Of GIC And Its Monitoring Method In EHV Power Grid

The essence of power grid blackout accident caused by magnetic induction current(GIC) is that transformer dc bias magnetic saturation results in-the increasing of reactive loss and decreasing of transmission line voltage,and then the decreasing of reactive compensation device (SVC) and capacitor reactive power support ability. A chain reaction in the grid voltage collapse, causing a blackout accidents.In the study of the influence of GIC to power grids’operation, traditional theory is to build grid GIC reactive disturbance monitoring and early warning system,and then evaluate the reactive disturbance level. The key to the evaluation of the GIC accurate power grid is set up of the reactive power perturbation model. Taking Qo and△U as the evaluation index of the reactive power disturbance. A EHV high voltage power system reactive power disturbance levle evaluation model. Reactive power disturbance level to evaluate the application of this model to the EHV power grid. The main reserch contents are as following:Firstly,this paper expounded the mechanism of GIC reactive disturbance on power grid,and explained basic definitions and related caculation parameters of reactive power disturbance, and applied J-A theoretical model to the simulation analysis of transformer GIC reactive disturbance level. Secondly, considering the influence factors on GIC reactive disturbance level, the paper realized the equivalent of transformer and transmission line, and established the evaluation model of power grid GIC reactive disturbance level, and applied this model to2015EHV grid planning.The assessment results illustrated the feasibility of the model. Finally, on the basis of the proposed model, the paper established the GIC reactive disturbance monitoring and early warning platform, and proposed the usual monitoring and early warning method, which did favor for the assessment and preventing the risk caused by GIC reactive disturbance.