A New Fast Filtering Algorithm Based on Multiple Digital Sampling Rate Conversion

Abstract

When the Optical Current Transformer (OCT) with different sampling frequencies is applied to differential protection, the output data of OCT of each branch of the differential protection are required to be converted to a uniform sampling frequency. The filtering algorithm is inevitably applied in the progress of frequency conversion. In the essay, a new Zero Phase Maxflat filtering algorithm, the prototype of which is IIR digital filter, achieving zero phase maxflat pass band amplitude characteristics and zero-phase filtering. The algorithm is with high accuracy and achieves a rapid filter with lower order along with the shorter filter time and fast protection action. In the end, simulation is used to verify the feasibility and effectiveness of the algorithm.