Development of real time stability monitoring system for power system operation

This paper presents an on-line real time stability monitoring scheme. The proposed stability monitoring system is set up by using a personal computer (PC) with AD conversion interface. To investigate the accuracy of the monitored results, experimental studies has been performed on an analog simulator. A four-machine infinite-bus system was utilized for the tests on the analog simulator. The test system has two modes of oscillations: high frequency local modes beyond 1 Hz related to individual unit, and a low frequency global mode from 0.3 to 0.4 Hz. The damping and the frequency of these two typical modes are identified accurately by using the proposed on-line monitoring system.