Probability Load-flow calculation applying Method of Cumulants

V diplomskem delu smo se osredotočili na delovanje elektroenergetskega sistema (EES) in opisali ter med seboj primerjali dve verjetnostni metodi za izračun oziroma napoved napetostnih razmer in pretokov moči v elektroenergetskih sistemih. Analize z verjetnostnimi pristopi bodo zaradi množice stanj in stohastične narave tako imenovanih obnovljivih virov v prihodnje predvidoma pridobivale na veljavi. Opisali smo metodo Monte Carlo in metodo kumulant ter obe preizkusili na testnem omrežju z vključenim SSSC. Z obema metodama smo izračunali verjetnostne napetostne razmere in verjetnostne pretoke delovne ter jalove moči. Izračune smo izvedli za enopolni in trifazni testni sistem. Rezultate izračunov smo podali v obliki tabel in grafov. Ugotovili smo, da so odstopanja med obema metodama prisotna, vendar niso prevelika. Zato se lahko za manjše sisteme brez in z vključeno regulacijsko napravo uporabi metoda kumulant, ki je v primerjavi z metodo Monte Carlo manj točna, a bistveno hitrejša.In diploma we focused on the operation of the electric-power system. Two probabilistic methods for the calculation and prediction of voltage conditions and power flows in electric-power systems have been described and compared. Analysis with probabilistic approaches will probably gain influence in the future, due to multiplicity of conditions and stochastic nature of the so-called renewable energy sources. We described the Monte Carlo method and the method of cumulants and tested both on the test system with the SSSC switched on. With both methods we calculated the probability voltage conditions and probability load-flows of active and reactive power. We made calculations for single-phase and three-phase test system. The results were presented in tables and graphs. For smaller systems with or without regulator, method of cumulants can be used. In comparison with the Monte Carlo method, this method is less accurate but significantly faster