Zero-Crossing Detection Frequency Estimator Method Combined with a Kalman Filter for Non-ideal Power Grid

This paper proposes a Zero-Crossing Detection Frequency Estimator Method combined with a Kalman Filter for Non-ideal Power Grid. The Kalman filter generates the in-phase and in-quadrature signals from the voltage grid. Due to the adaptive feature of the Kalman figure, the in-phase and in-quadrature signals are free of noise and harmonics and it guarantees an accurate frequency estimation for a long range of grid frequency. With both clean signals in-phase and in-quadrature, the frequency estimator computes the arc tangent of the relationship between them. The result is a ramp signal varying from -pi to +pi. Such a signal is used to estimate the frequency. Considering zero-crossing detection, the frequency estimator counts the number of samples within a fundamental period. Experimental results show the efficacy of the proposed method. The frequency estimator was implemented C2000 Delfino MCU F28379D LaunchPad development kit.