New technique for frequency and amplitude estimation of power system signals

This paper describes the design, analysis and computational aspects of a technique for the measurement of power system voltage, current and frequency. This technique can be used in a digital AVR for the state estimation of turbine-generator terminal quantities or in a digital relay for protection of a power system. This technique provides fast and accurate estimation of power system frequency, and is used in a Kalman-filtering algorithm to estimate power system voltage and current signals. Practical considerations such as the effect of power system harmonics, noise, frequency changes, mechanical and electrical load changes are taken into account during implementation of this technique. Several computer simulation tests are presented to highlight the usefulness of the technique. Simulation results show that the technique can simultaneously estimate the amplitude and frequency of a sinusoidal signal, even in the case that the signal is distorted by harmonics or noise or encounters frequency changes.