A risk based contingency analysis method incorporating load and generation characteristics

This paper presents an efficient and realistic contingency analysis method. The contingencies are ranked based on their risk index value which incorporates both the probability and the severity of the contingency. Severity for each contingency is computed based on load loss, equipment overloads, voltage magnitude violation at nodes and system frequency deviation from the nominal value. The proposed method considers line/transformer outages as well as generator outage contingencies. A modified Fast Decoupled Power Flow method which considers frequency and voltage dependent characteristic of loads, generator regulation characteristics and sensitivity based transformer tap adjustments is used to evaluate the contingencies. The power flow method is suitable for any AC/DC power system and can carry out contingency analysis even if the system gets islanded.