Electromechanical transient method based relay protection fixed value online check method

Abstract

The invention discloses an electromechanical transient method based relay protection fixed value online check method. The method comprises the following steps of (1) obtaining real-time measurement data of a power grid from an EMS, and establishing a power grid network algebraic model; (2) obtaining zero-sequence parameters and a protection fixed value of the power grid from a relay protection setting software database; (3) combining with a self electromechanical transient model parameter database, and solving a simultaneous algebraic equation and nonlinear equation through an electromechanical transient simulation method to obtain dynamic process data of each state variable of the system in a fault process and after the fault disappears respectively; and (4) performing check on the protection fixed value according to the dynamic process information of each state variable obtained in the step (3). According to the method, the accuracy of the short-circuit calculation result can be improved; online check and real-time early warning for the relay protection fixed value can be realized; and the automatic degree of the protection fixed value operation is improved.

Description

technical field [0001] The invention belongs to the field of power system relay protection, in particular to a method for checking the setting value of a relay protection device. Background technique [0002] In recent years, with the rapid development of the power grid, a large number of power grid infrastructure, power transmission, and power grid transformation projects have been put into operation, and the calculation of the setting value of the relay protection can no longer meet the requirements of its production cycle. In the process of putting into production of infrastructure and technical transformation projects, the methods of bus stop, line stop and power grid disconnection are becoming more and more complicated, the abnormal operation of the power grid has increased significantly, and the time has been extended. The task of tuning calculations presents a formidable challenge. [0003] At present, the short-circuit current calculation in engineering practice gen...

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Problems solved by technology

However, the above-mentioned patent method uses the static network impedance equivalent method for fault calculation, does not consider the detailed transient model of the power system, and does not consider the various regulating controllers ( Generator voltage regulator, governor, power system stabilizer, etc.), that is, only the instantaneous value of short-circuit current at the time of short-circuit fault is obtained, and the dynamic change process of short-circuit current that is more in line with the actual situation of the project is not obtained

[0012] The Chinese invention application number is 201010546967.1 patent application "on-line verification method of relay protection setting value based on dynamic short-circuit current", but it does not explain in detail how to use and calculate the real-time measurement data of the power grid

The commonly used short-circuit current calculation method in the prior art is a static method not based on the grid power flow. The short-circuit current has nothing to do with the active and reactive output of the generator before the fault, the operating voltage of the bus before the fault, and the load model. It is an algebraic equation, and what is obtained is the short-circuit current at the moment of short-circuit fault, and there is room for further improvement in accuracy and real-time performance

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