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.