An Improvement Algorithm for Online Identification of Thevenin Equivalent Parameters

Abstract

With the development of the power system, the operating state of the power system is becoming increasingly complex. The assumption of traditional Thevenin equivalent parameters tracking algorithm limited its effectiveness in fast-changing complex system, for which it cannot be applied to the system when the power grid suffers disturbances in the equivalent side. To solve the above problems, an improvement of the traditional Thevenin equivalent parameters tracking algorithm is proposed in this paper. Based on Taylor equation, the direct identification of Thevenin equivalent parameters is replaced by the solution of increment, which eliminates the influence of disturbance location on Thevenin equivalent parameters calculation. The Thevenin equivalent parameters of the system can be calculated only by using the local phasor measurements at adjacent times. The effectiveness of the proposed algorithm is verified by DIgSILENT / PowerFactory 15.0 and IEEE 39 bus standard test system.