Estimation of High-Frequency Oscillation's Magnitude and Frequency Based on Multi-Tone FIR Filter

Recently, several high-frequency oscillation (HFO) events have occurred, and have introduced a serious threat to power system stability. It is significant to estimate HFO magnitude and frequency in a fast and accurate way for HFO early warning and mitigation. This paper designs a novel finite impulse response (FIR) filter that is formed by several weighted window function-based FIR filters with different center frequencies, and is named the multi-tone FIR (MTFIR) filter. The frequency error introduced by the MTFIR filter is analyzed, and optimal MTFIR filter parameters are accordingly selected to achieve the smallest frequency error. Performance tests show that the proposed MTFIR filter estimator is more accurate than the conventional FIR filter, the interpolated discrete Fourier transform, and the P-class harmonic phasor estimator in HFO magnitude and frequency estimation. The response time of the proposed estimator is shorter than 20 ms, which meets the IEEE/IEC standard requirement on protection applications.