Line differential protection method based on differential output of electronic current transformer

Abstract

The invention provides a line differential protection method based on differential output of an electronic current transformer, and belongs to the field of power system relay protection. The technical scheme is that an integration element in high-voltage side data processing of conventional line differential protection is removed, and differential signals output by the sensing head of a Rogowski coil are directly used to realize longitudinal differential protection of a high-tension transmission line, and complexity of a device is reduced, and data processing time is reduced. On the basis of ensuring reliability and speed, adverse effect caused by an extra integral circuit is prevented, the method adapts to differential output of the Rogowski coil. PSCAD / EMTDC simulation experiments show that the differential protection scheme based on the current differential signals is effective and feasible, line rapid differential protection can be realized by directly using the differential signals output by the electronic current transformer, the integration element is removed. The method adapts to requirements of interfaces of the electronic current transformer, and can be used for main protection of high-tension transmission lines.

Description

technical field [0001] The invention relates to a line differential protection method based on the differential output of an electronic current transformer, which belongs to the field of relay protection of electric power systems. Background technique [0002] With the development of the power industry, the required power transmission capacity continues to increase, and the operating voltage level is also getting higher and higher. Due to the inherent problems of iron core saturation, residual magnetism, and ferromagnetic resonance, traditional electromagnetic transformers are increasingly difficult to meet the growing needs of power systems. The application of electronic transformers will completely solve these problems. Electronic transformers have all the functions of traditional transformers, and have the benefits of not being affected by saturation and ferromagnetic resonance. They have good insulation performance, wide frequency bandwidth, large dynamic range, small si...

AI Technical Summary

Problems solved by technology

[0003] In recent years, electronic current transformers based on Rogowski coils have been gradually put into practical use, but since the output signal of the sensor head is the differential of the measured current, in order to restore the original signal, an additional integral module needs to be added, which will inevitably increase the high voltage side data processing time, resulting in a certain time delay and phase shift, thereby limiting the action speed of protection, reducing reliability, and increasing the energy supply burden on the high voltage side

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