Reducing the delay of phasor estimates under power system oscillations

Delay and computational complexity reduction on the phasor estimates calculated under power system oscillations is the main objective of this paper. Different approximations to the raised cosine (RC) filter lead to a reduction in delay and computational complexity of the phasor estimates. As for finite impulse response (FIR) filters, the minimum-phase implementation of the RC linear-phase FIR filter reduces by a half the delay of the phasor estimates, without introducing significant phase distortion and with shorter transients. This improvement in speed provides faster estimates for real-time monitoring and control applications. On the other hand, infinite impulse response (IIR) filters reduce the computational complexity of the estimates by a factor of ten, but without significant delay reduction, introducing a higher distortion, and with longer transient behavior. This solution could be useful for implementations in which computational complexity is a matter of serious concern. In this way, the paper provides a wide range of solutions for those who need more accurate, faster or simpler estimates.