Phasor and frequency measurements in power systems: Hardware strategy to improve accuracy in estimation algorithms

This paper discusses phasor and frequency estimation techniques with low computational cost for measurements in the power system. The objective of the paper is to investigate the use of hardware to improve accuracy in measurements while maintaining the low computational cost. The phasor estimation algorithms are usually based on Discrete Fourier Transform (DFT) while the frequency is obtained by angle derivation. The hardware strategy consists in controlling the sampling rate to minimize the DFT spectral leakage. The control is performed from estimated frequency, ensuring accuracy even with changes in the electrical system frequency. The strategy proposed is implemented in an embedded system, where synthesized signal tests were evaluated. As a result, it is obtained a drastic reduction in estimation errors without requiring more processing power.