Reducing the delay of phasor estimates under power system oscillations

The delay and computational complexity of phasor estimates under power oscillations are minimized in this paper. Different approximations to the raised-cosine (RC) filter lead to a reduction in the delay and computational complexity of the phasor estimates without significant distortion. The minimum-phase implementation of the linear-phase RC filter reduces the delay of the phasor estimates by about half, with a shorter impulse response and without the introduction of significant phase distortion. This improvement in speed provides faster phasor estimates for real-time monitoring and control applications in power systems. On the other hand, infinite-impulse-response filters reduce the computational complexity of the estimates by a factor of ten but without significant delay reduction and with a longer transient behavior and the introduction of a higher distortion. However, this solution could be useful for implementations in which the concern about computational complexity prevails over the concern about delay and distortion.