Impacts of renewable and alternative energy sources on operation and stability of electrical network

This paper deals with the evaluation of renewable and alternative energy sources network interconnection and their impacts on the operation and stability of electrical network. The article shows the dependence of the voltage level magnitude in the point of common connection on the power factor of the renewable energy sources generator. The following part analyses, how the short-term power variation of the power plants (wind and photovoltaic) regarding the weather changes cause the voltage variations according to the generator operational mode. These variations negatively influence the distribution network operation and the power quality. The dynamic variations were simulated by the NEPLAN software. In conclusion the feasibility of the plant interconnection is evaluated respecting other important factors (flicker, ripple control signal damping, harmonic voltages content, protective relays function)