Contingency analysis of power system by using voltage and active power performance index

Now a days power system protection is an important task for an operating engineer, which can be done by doing online security assessment. Contingency analysis is one of the best methods to forecast the condition of power system if any unwanted event occured in the power system. To do contingency analysis first the operator has to know the parameters like voltage, power and voltage angle at each and every bus by doing load flow analysis on the system. Newton Raphson method is the best load flow method as it gives accurate results in less time. In this paper all line outage contingencies in a standard 6 bus and 5 bus power system has been done in MATLAB environment. For each line outage contingency, load flow analysis has been done on the system and the active power and voltage performance indices have been calculated. These two performance indices will give the idea about the change in active power flow through the lines and voltages at the buses for a particular line outage. Summation of these two indices will give the performance index value through which ranking of severity will be given to the lines. And from the load flow results comparison has been done between low rank and high rank line outage contingencies. This contingency analysis helps the operational engineer to know which line outage is dangerous to the system and what prior action is to be taken to minimize the effect of that particular line outage.