Sensitivity analysis and its applications in power system improvements

The propose of this paper is to study the application of optimal power flow sensitivity for power system improvements. The optimal capacitor placement for injecting reactive power into a power system yields the highest system power factor, decrease in total generation cost and total system losses. The optimal power flow is used to compute the optimal system operating point at the lowest total generation cost under the normal steady state condition. After that, the sensitivity analysis is applied to evaluate the change of total generation cost with respect to the change of reactive power at any bus to determine the optimal location of the capacitor banks. The method of optimal power flow sensitivity is simple but powerful. This method greatly reduces the computational work of computing optimal power flow for several different systems in which capacitors are to be installed. The sensitivity technique is applied to 5-bus and 9-bus test systems. The results show that the technique gives the same answers as the simple technique in which more calculations are needed.