A novel dynamic frequency estimation algorithm in power system

Frequency of voltage signals in power system is a key parameter to reflect the operational state of the whole system. Therefore, a new algorithm is needed to attain a more accurate frequency estimation in both steady state and dynamic conditions, for high level application such as wide area control that let the power system operate in a healthy manner. A dynamic modulation signal model is proposed via Taylor expansion to approximate dynamic voltage signals. The Taylor expansionpsilas derivatives, expressed by consecutive phasors, are to characterize the dynamic behaviour and then be used to revise the phasorspsila estimations of the modulation signal. Revised phasors can be employed to calculate the frequency of the signal based on phasor based frequency measurement technique. Finally the frequency estimation at the report time can be acquired accurately by modifying the frequency using the frequency derivative. Theoretic analysis and simulation allow us to conclude that performance of the algorithm proposed in this paper is much better than traditional phasor-based frequency measurement techniques in dynamic conditions.