Correlation Techniques Applied to Power System Transfer Function Determination

Abstract

In electrical power systems, particularly those operating near the stability limit, it would be desirable to determine a mathematical description of the system elements without disturbing the system by test signals. This thesis presents a method of achieving this result by applying correlation techniques to fluctuations of electrical variables which occur during normal operation. The necessary correlation theory is presented along with practical considerations necessary to implement the process on a digital computer. The magnitudes of the fluctuations are small, thus requiring special measuring equipment. The design of such equipment is discussed, and tests on the adopted correlation process and the equipment are included. Tests, using these correlation techniques to determine the frequency response function, were successfully applied to systems simulated on an analog computer. Similar tests on actual power system components were not successful. This failure is believed to be caused by the limited computation equipment which was used to interpret the data, rather than the overall method.