Zero-Crossing Detection Algorithm Based on Narrowband Filtering

To deal with the simultaneous jump of phase, frequency and amplitude in the transient process of signals and improve the accuracy of zero-crossing detection, this paper proposes a fast zero-crossing detection algorithm for this complex condition. The algorithm initially normalizes the electrical quantity before it passes through the narrow-band filter. Then the algorithm is used to calculate the zero-crossing time and eliminate the zero offset and jitter. Finally, the phase information of positive and negative zero crossing points is obtained. Simulation results show that the algorithm improves the tracking accuracy based on higher response speed and has strong robustness in a complex grid environment. It is simple to implement, which can meet the requirements of capacitors and other equipment switching control.