High-Speed Relay Equipment Protection

The paper addresses the problem of relay protection malfunction under the condition of saturated state of the current transformer magnetic core. The first part of the paper provides an overview on how this problem is solved in the related studies. The pros and cons of the existing approaches are highlighted and discussed. A method for reducing the influence of aperiodic components on the operation of digital relay protection is considered in detail. An algorithm for eliminating the aperiodic component in the current of the measuring element relay protection, caused by the saturation of current transformer cores, is shown and described as a simple step-by-procedure, providing the opportunity of its real-time applications. The authors focus the discussion and concluding remarks of the paper on the major advantages and the promising application spheres of the proposed approach. All the calculations provided in the case study section are based on real metering data.