Voltage sag characteristic quantity random evaluation method based on scene construction

Abstract

The invention relates to the technical field of power distribution network operation management, and discloses a voltage sag characteristic quantity random evaluation method based on scene construction, and the method comprises the following steps: 1, generating a basic scene set through employing an optimal quantile method based on a power distribution network grid structure according to relay protection segmentation parameters; 2, reducing the basic scene set into a few typical scene sets by applying a K-medoids clustering method; and step 3, according to a short-circuit calculation principle, in combination with historical monitoring data of the short-circuit fault of the power distribution network, performing voltage sag characteristic quantity evaluation at the sensitive load point. According to the method, a K-medoids clustering method is applied, a method for reducing a basic scene set into a few typical scenes is adopted. The difficulty of a large number of repeated tests of methods such as short-circuit calculation or simulation tests is avoided, the number of groups needing to be calculated is greatly reduced in a preprocessing mode, most similarity calculation is avoided, the calculation difficulty and time are reduced, and the applicability of the method in a large-range power distribution network is improved.

Description

Technical field [0001] The invention relates to the technical field of distribution network operation management, in particular to a method for randomly evaluating voltage sag characteristic quantities based on scene construction. Background technique [0002] With the rapid development of modern optoelectronics, semiconductor chips, precision machining and other cutting-edge manufacturing industries, users' sensitivity to voltage sags has increased significantly, resulting in huge economic losses. In order to improve the quality of power supply and reduce the economic loss caused by voltage sag failure, it is critical and necessary to evaluate the characteristics of voltage sag at each node of the distribution network and carry out targeted management. However, considering that the voltage sag is a random accident, the frequency of occurrence is low, and the monitoring system is imperfect, it is difficult to actually measure it. Most of the existing methods are based on short-c...

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Problems solved by technology

[0003] (1) The evaluation of distribution network voltage sag characteristic quantities by means of short-circuit calculations, simulation tests, etc., has a large amount of calculation and poor convergence, and its application in the evaluation of large-area distribution network voltage sag characteristic quantities is limited

[0004] (2) The random evaluation method of scene construction has not been applied to the evaluation and calculation of voltage sag characteristic quantities

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