Online estimation of signal parameters in the presence of harmonic and noise distortion

An algorithm based on the concept of Kalman filtering is proposed in this paper for the estimation of signal attributes, like amplitude, frequency and phase angle. This technique can be used in protection relays, digital AVRs, DSTATCOMs, FACTS and other power electronics applications. Furthermore this algorithm is particularly suitable for the integration of distributed generation sources to power grids when fast and accurate detection of small variations of signal attributes are needed. Practical considerations such as the effect of noise, higher order harmonics, and computational issues of the algorithm are considered and tested in the paper. Several computer simulations are presented to highlight the usefulness of the proposed approach. Simulation results show that the technique can simultaneously estimate the signal attributes, even if it is highly distorted due to the presence of non-linear loads and noise.