An iterative DSP technique for tracking power system frequency and voltage phasors

This paper presents a DSP technique that provides correct and noise-free estimates of frequency and voltage phasors in about 20 ms and 16 ms respectively. The theoretical basis and testing of the technique are described in the paper. The technique requires modest computations and is suitable for near-nominal, nominal and off-nominal frequencies. The technique is general in form and can be designed to provide accurate estimates when signals include harmonic components. It is also suitable for use in synchronized phasor measurement units because frequency tracking is accomplished without changing the sampling rate.