Probabilistic determination of the operational flexibility of active distribution networks with high penetration of full-converter interfaced renewable distributed generation units

In this paper a method to estimate the flexibility of an active distribution network (ADN) with full-power converter interfaced distributed generation (DG) units based on intermittent renewable energy sources (RES) is presented. The proposed method can be used to assess the capability of an ADN to reliably provide ancillary services from a given moment for a short period of time considering the probabilistic availability of intermittent RES and the operating limits of DG units, converter interfaces and the distribution grid.