Fast automatic contingency analysis and ranking technique for power system security assessment

One of the essential aspects of modern power system security assessment is the consideration of any contingencies arise due to planned or unplanned line outages leading to system overloads or abnormal system voltages. Several techniques have been developed in the past few years to address this problem but computation time has been identified as the constraint making the process inefficient. This paper presents a new algorithm for automatic contingency analysis and ranking caused by line outage in a power transmission system. All steps in the algorithms including the load flow analysis; removal and reinsertion of line and overall ranking process were accommodated in one complete programme making it a complete and effective solution for contingency analysis and ranking. A pre-developed line-based voltage stability index is used as a tool in determining the severity of the contingencies. Results from experiments showed that this technique is much faster than the existing technique while reducing human error constraint.