Power line traveling wave differential protection method, device, equipment and medium

Abstract

The invention provides a power line traveling wave differential protection method and device, equipment and a medium. The method comprises a step of collecting voltage and current at any end of a protected line in a sampling time window after starting protection, a step of calculating a current traveling wave, a step of obtaining a traveling wave differential current in a protection time window according to a current traveling wave difference of a phase difference transmission delay of two ends of a line and obtaining traveling wave braking current in the protection time window according to acurrent traveling wave sum of the phase difference transmission delay of the two ends of the line, a step of calculating transient high-frequency energy and transient low-frequency energy of the traveling wave differential current and transient low-frequency energy of the traveling wave braking current, a step of constructing line criterions (a first criterion C1, a second criterion C2, and a third criterion C3), and a step of determining whether to starting protection according to the criterions. According to the power line traveling wave differential protection method and device, the equipment and the medium, the requirements of a sampling rate and a communication rate are low without being affected by the limited frequency band of a capacitive voltage transformer commonly used in the high-voltage transmission line, the action speed is fast, and the sensitivity is enough in a high resistance ground fault under the premise of ensuring reliability.

Description

technical field [0001] The present invention relates to the field of relay protection of power systems, in particular to a traveling wave differential protection method for power lines, a traveling wave differential protection device for power lines, a computer device, and a computer-readable storage medium. Background technique [0002] The regional distribution of my country's energy resources is unbalanced, with the characteristics of energy and load inverter distribution, and the distance between the western energy base and the eastern load center is far away. Therefore, my country has proposed the "West-to-East Power Transmission" plan to develop long-distance and large-capacity ultra-high voltage power transmission lines to achieve optimal allocation of energy. UHV lines, as the aorta of the power grid to transmit energy, require fast, reliable, sensitive and selective relay protection to ensure the safe and stable operation of the entire system. [0003] Current diffe...

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Problems solved by technology

Due to the vigorous development of ultra-high voltage transmission lines in my country, there have been more studies on traveling wave differential protection after the 21st century. However, the traveling wave differential protection currently applied to the field only uses the power frequency component of the electrical quantity and needs to be filtered by low frequency. , the action speed is slow, affected by the saturation of the current transformer, and may refuse to operate when the high-resistance ground fault occurs; while the traveling wave differential protection using high-frequency information in the theoretical research has a fast action speed and is not affected by the saturation of the current transformer. However, it is not practical due to the capacitive voltage transformer on site and the existing communication conditions.

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