A New Method Suitable for Real-Time Generator Coherency Determination

The aim of this paper is to illustrate that wide area generator speed measurements combined with Fourier analysis can be used to determine coherent generator groups. Studies are based on simulations in a 68-bus test system. Three test cases are investigated where the new method is compared to conventional methods based on the generator speed, modal analysis, and phasor angle measurement. The method introduced in this paper has proven to be an interesting alternative for generator coherency determination. It gives almost identical results to the offline methods based on the generator speed or modal analysis. Based on their trustworthiness the test cases indicate that the method reflects a more accurate coherency than the conventional online method based on phasor angle measurement. Moreover, compared with online applications using modal analysis the method supports real-time applications better according to its less extensive computational requirements.