Recursive and non-recursive algorithms for power system real time phasor estimations

This work presents some of the computational algorithms used for phasor estimations in Electrical Power Systems. The IEEE C37.118.1 standard establishes the phasor estimation structure and performance, but does not define the algorithm itself to be used. Considering this, various methods can be adopted provided that the standard precision is met. Some estimation algorithms presented in the literature were compared in this paper, and their behavior was evaluated for some test cases. The methods: Discrete Fourier Transform, Recursive Discrete Fourier Transform, Least Squares, Recursive Least Squares, Discrete Wavelet Transform and Recursive Wavelet Transform were tested using synthetic signals, evaluating the Total Vector Error, response and delay times, as well as overshoot. The algorithms were also embedded in hardware and evaluated by simulated signals, using the outputs of a Real Time Digital Simulator.