Method for determining unit action coefficient based on subsynchronous oscillation analysis

Abstract

A method for determining a unit action coefficient based on subsynchronous oscillation analysis is used for a multi-direct-current sending end system, and comprises the steps that the conversion current bus voltage of the direct current K corresponding to the maximum value in action coefficients of all direct currents on an ith generating set is reduced by 1%; the change rates of the voltages of other direct current conversion current buses are obtained, and multi-direct-current interaction factors are determined according to the change rates; the equivalent capacity for the multiple direct currents to be equivalent to one direct current K is determined according to the direct current interaction factors; the comprehensive action coefficient of all the direct currents on the ith generating set is worked out through the obtained equivalent capacity. The interaction factors of the multiple direct currents are used for enabling the multiple direct currents to be equivalent to be one direct current, then the comprehensive action coefficient of the multiple direct currents on the generating set is obtained with the single-loop direct current unit action coefficient method, the reliability is high, and the level of analyzing subsynchronous oscillation risks of the multi-direct-current system is increased.

Description

technical field [0001] The invention belongs to the technical field of generator set failure analysis, in particular to a method for determining the unit action coefficient based on subsynchronous oscillation analysis. Background technique [0002] In a power grid with DC transmission, subsynchronous oscillation may occur when the distance between the thermal power unit and the DC rectifier station is relatively close. As for its mechanism, the electrical industry generally believes that due to the rapid control of DC transmission, it may make the shaft of the unit The subsynchronous frequency oscillation with complementary subsynchronous torsional vibration frequency is a negative damping feature in the power grid, so it may cause the subsynchronous torsional vibration of the unit shafting to appear unstable. For the subsynchronous oscillation problem caused by DC transmission, the current main analysis methods include the unit action coefficient method, which is a quantita...

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Problems solved by technology

[0004] One of the purposes of the present invention is to provide a method for determining the unit action coefficient based on subsynchronous oscillation analysis, so as to solve the problem in the prior art that the risk of subsynchronous oscillation cannot be detected or the reliability of the detection result is low in the multi-circuit DC transmission scheme The problem

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