An Online Identification Method of Coherent Generator Group Based on Small Disturbance Analysis with Arnoldi

摘要

This paper presents an online method to identify the dominant generators in a coherent generator group with a certain oscillation mode. The dynamic stability analysis and online monitor is very important during either simulation research work or power system operation. Through implicitly restarted block Arnoldi method, power system dynamic stability is analyzed, the eigenvalues of power system dynamic equation and participation matrix of the eigenvalues are obtained in frequency field. The oscillation frequency, mechanical-electric related ratio, right vector and participation factor are also calculated, in which there is the identification feature information of each special mode about coherent generator groups. There are three steps to seek out the dominant generators of a coherent generator group. Firstly some electromechanical oscillation modes are selected through analyzing electromechanical circuit correlation ratio. Then, all generators are divided into two generator groups by the aggregation of right vector phase .Lastly, the dominant generators are picked out in a group through comparing the module of participation factor. This method succeeds in the dynamic security analysis and pre-warning system in North China Grid Company Limited. It clearly shows the relation between oscillation frequency and the generators in the power plant, and can help operator to find the valid control measures to prevent the low frequency oscillation accident.