Real-time phasor measurement for low frequency oscillation in power system

Low frequency oscillations often cause power system instability. The real-time phasor measurement technology provides a new monitoring and eliminating method. Several filtering algorithms for measuring the amplitude and frequency of power system oscillations are compared. Then the ability to measure the low frequency oscillation and the error under varying system frequency are discussed in the paper. Simulation results demonstrate that the raised cosine filter is of the highest accuracy and fastest speed. It can measure the oscillation parameters in two fundamental cycles accurately and has good performance in the real-time measurement of the low frequency oscillation from 2 Hz to 0.1 Hz. Its performance is also satisfying in oscillation measurement under varying system frequency.