Security Region-Based Economic Dispatch of Distribution Grids with Multiple Virtual Power Plants

As virtual power plants (VPPs) integrate a high penetration of renewable distributed generations, the intermittent and uncertain outputs make the power flow-coupling relationship between virtual power plants and the distribution grid complex. Without the guidance mechanism for energy resource coordination, the return of the power market might be less, and the problem of power flow violation might occur. Therefore, coordinated plans are required for the entire grid. Solving the existing nonlinear coordinated model takes a long time, so this paper establishes a linear coordination method based on the static security region (SSR). First, based on the grid topology, a generation method is proposed for hyperplane expressions of the distribution grid SSR. Second, based on the SSR, this paper established an optimization model to minimize the overall operating cost of the distribution grid with multiple VPPs. Third, based on the Karush-Kuhn-Tucker (KKT) conditions, the amount and price of electricity transacted are scheduled, and a coordinated strategy is derived for the distribution grid and VPPs. A modified IEEE-33 node grid with three VPPs is used for the simulation, and the results indicate that the proposed method significantly accelerates the calculation speed by orders of magnitude.