A Method for Correcting Frequency and RoCoF Estimates of Power System Signals with Phase Steps

A Method for Correcting Frequency Estimates for Synthetic Inertia Control

“…In that work, the residual of the Kalman filter is used as the inverse reliability metric and a frequency corrector stage was proposed. This paper continues the research in [10] on the use of a frequency correction algorithm to obtain better frequency estimates for distorted signals. In particular, the main contributions of this work are:…”

“…Since then a series of developments have allowed it to be used in nonlinear systems. This paper uses the Extended Kalman Filter (EKF) used in [10]- [12] for frequency estimation. Due to space limitations other techniques like the Unscented Kalman Filter (UKF) were evaluated but not included here.…”

“…In addition to those, other estimation algorithms based on Kalman filters [10]- [12], H ∞ filters [13], [14], nonlinear least squares [15], and adaptive notch filters (ANF) have been proposed [16]- [18].…”

“…The frequency estimate can then be corrected when it is deemed not reliable. This idea was advanced in [10] with a Kalman filter based frequency estimation approach. In that work, the residual of the Kalman filter is used as the inverse reliability metric and a frequency corrector stage was proposed.…”

“…Their performance was also validated under noise conditions. • Extending the frequency corrector algorithm in [10] by introducing a ramp limit to the frequency corrector. The ramp limit smooths the transition from a corrected value of frequency to a value that is deemed correct.…”