A Framework of Intelligent Sampling Rate Conversion Algorithm for ECT Digital Power Plant

In the application of electronic current transformer (ECT), it is required to convert different sampling rates to the same rate, when the differential protection device is connected with the various ECTs of different sampling rates. In this paper, the sampling rate conversion algorithm based on decimation and interpolation is studied, which can realize the adaptive sampling rate conversion by a rational factor of L/M and provide an intelligent implementation structure for the algorithm - the time-varying filter structure with improved high-efficiency calculating ability. It can be shown from the examples that when converting the high sampling rate to low one, the algorithm not only has the sampling rate conversion function, but also has the ability to filter the high frequency element in it and then reduce the differential current.