Using participation factors to improve the consistency and accuracy of Prony analysis for voltage stability monitoring applications

Steadily increasing demand for electricity has led to today´s electric power networks often being stressed to their stability limits. Improved methods of stability monitoring are needed to manage this increased stress. Modal analysis could provide a relatively lightweight assessment of the stability of the system but some method is needed to accurately determine the modal content of the power system. Prony analysis has been suggested as a means to determine a power system´s modal content directly from signals within the system. However, Prony analysis has proved to be difficult to implement due to the complexities in its parameter selection. This work addresses that difficulty by numerically exploring a novel role for modal participation factors as a way to select which signals to monitor and analyze with Prony analysis. The results show that using participation factors in this way can greatly improve the accuracy of the estimates generated by Prony analysis. The resulting accurate estimates can be used to provide critical early warning of impending voltage instability in the system.