Branch coefficient calculation method based on real-time data of power grid

Abstract

The invention discloses a branch coefficient calculation method based on a real-time data of a power grid. The method comprises the steps of: obtaining an online mode and real-time measurement data of the power grid from an EMS (energy management system); obtaining a real-time operation mode of the power grid by state estimation, or directly obtaining state estimation data from the EMS; obtaining a zero-sequence parameter of each power grid element from relay protection setting value setting software, and associating the zero-sequence parameter of the power grid into the online model data of the power grid through a name matching table; setting a fault position and a fault type; obtaining current vectors of a lower-level branch and an upper-level branch by short-circuit current calculation; and taking a mode value of the ratio of the current vector of the lower-level branch and the current vector of the upper-level branch, or taking the ratio of an amplitude of the current vector of the lower-level branch and the amplitude of the current vector of the upper-level branch, so as to obtain the branch coefficient based on the real-time data of the power grid. By adopting the method, the branch coefficient calculation method is simple in calculation process, and is suitable for setting and checking a protection setting value.

Description

technical field [0001] The invention belongs to the field of electric power system relay protection, and more specifically, the invention relates to a method for calculating branch coefficients required for setting and checking of electric power system relay protection fixed values. Background technique [0002] The selectivity of relay protection means that when the protection device operates, it disconnects the fault from the power system in the smallest possible interval, so as to ensure that the fault-free part of the system can still continue to operate safely. Selectivity includes two meanings: One is that the fault should only be removed by the protection device installed on the faulty component, and the other is that the protection device of the adjacent component should act as a backup protection for the faulty component. Therefore, there is a cooperative relationship between the upper and lower levels of protection. [0003] The introduction of the branch coeffici...

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Problems solved by technology

However, none of the current published literature involves the calculation method of the branch coefficient based on the real-time data of the power grid.

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