Reliability analysis of industrial power systems taking into account voltage sags

A reliability analysis method that combines a Monte Carlo simulation with an electrical network is presented. The method considers short circuits followed by an intervention of the protection instead of just the removal of a component. The correct and incorrect behavior of the protection can be modeled in detail. The method is suitable for industrial power systems with sensitive loads. The method can be used to compare the reliability of the supply for different design alternatives, to quantify the gain that can be obtained by increasing the voltage solidity of a plant, and to choose a maintenance policy. The author presents an overview of the power system model used and discusses the interruption criterion, the protection model, and the aging of components. For an example network the influence of voltage solidity and maintenance is discussed