Recording-data-based protection safety margin assessment method

Abstract

The invention relates to a recording-data-based protection safety margin assessment method. A fault occurs at a power grid, wave recording is started and recording data are recorded, an electrical quantity value is calculated in a faulty mode by using the recording data based on a protection principle, and substitution of a protection operation criterion is carried out to calculate a protection setting value; a safety margin of current protection, a safety margin of low-voltage protection, and a safety margin of distance protection are respectively calculated; and a fault type is determined based on recording data at the two sides of the faulty line and a fault point position and a transition resistance are calculated, system equivalent impedances and equivalent potentials of the two sides of the faulty line are calculated, correlation branch coefficients of the electrical quantities of the two sides of the faulty line are calculated, and a fault with the same features is simulated. With the method, wave recording can be started automatically when the fault occurs at the power grid; the electrical quantity value can be calculated in a faulty mode by using the recording data based on the protection principle; and the protection operation criterion is substituted, thereby verifying the adaptability of the protection setting value.

Description

technical field [0001] The invention relates to a technology in the field of power system protection, in particular to a protection safety margin evaluation method based on wave recording data. Background technique [0002] The relay protection device is the guarantee for the safe operation of the power system. Most of the large-scale power outages that have occurred at home and abroad are directly or indirectly related to the incorrect action of the relay protection device. Therefore, reasonable arrangement of the relay protection setting value is an important condition to ensure the safe operation of the power grid. At present, the setting value of the relay protection device is set according to the maximum and minimum operating modes of the system in the offline state, and remains unchanged during the system operation or only switches between individual typical modes. With the expansion of the power grid, there are more and more combinations of operation modes, and the ...

AI Technical Summary

Problems solved by technology

However, the defect and deficiency of this technology is that the protection setting value adopts the offline setting method and adopts the offline protection setting value setting, and its effectiveness is greatly affected by the model and parameter accuracy of each component in the power grid. In addition, the core of the technology The idea is that when the protection input is greater than the protection setting value, the corresponding action will be generated after a certain delay

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