Method, system and storage medium for monitoring ultra-low frequency oscillation strong negative damping unit

Abstract

The invention discloses a method, a system and a storage medium for monitoring an ultra-low frequency oscillation strong negative damping unit. The method includes: monitoring the electromagnetic power deviation and the system frequency deviation of the generator set during the ultra-low frequency oscillation process of the system; Power deviation and system frequency deviation, calculate the electromagnetic power torque vector of the generator set; calculate the inertial torque vector of the generator set during the ultra-low frequency oscillation process of the system; calculate the generator set according to the electromagnetic power torque vector of the generator set and the inertial torque vector of the generator set The mechanical power torque vector of the generator set; the strong negative damping unit in the generator set is identified according to the mechanical power torque vector of the generator set, and the primary frequency regulation of the strong negative damping unit is blocked. The invention can quickly identify the strong negative damping unit by using the mechanical power torque vector obtained through monitoring and calculation, and effectively suppresses the ultra-low frequency oscillation of the system by blocking the primary frequency adjustment of the strong negative damping unit, and can be widely used in the field of power system operation and control.

Description

technical field [0001] The invention relates to the field of power system operation and control, in particular to a method, a system and a storage medium for monitoring ultra-low frequency oscillation strong negative damping units. Background technique [0002] In recent years, the phenomenon of ultra-low frequency oscillations in practical power grids has attracted extensive attention from industry and academia. Internationally, ultra-low-frequency oscillations with an oscillation frequency of about 0.05 Hz occurred successively in 1960 in the American Northwest Power Grid, in 2006 in the Turkish Power Grid, and in 2011 in the Columbia Power Grid. Similar abnormal frequency fluctuations were also observed in China during the 2012 Jinsu DC island test and the 2016 Yunnan power grid asynchronous test. At the same time, the simulation analysis conclusions of the literature point out that there is a risk of frequency oscillation after the asynchronous interconnection between t...

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Problems solved by technology

At the same time, the simulation analysis conclusions of the literature pointed out that there is a risk of frequency oscillation after the asynchronous interconnection between the Southwest Power Grid and the Central China Power Grid through the Yu-E flexible DC back

[0003] This type of ultra-low frequency oscillation generally occurs in hydropower systems with a high proportion. This is due to the water hammer effect in the power adjustment process of the hydropower unit, which causes the initial power change to be opposite to the change in the guide vane opening, resulting in a large phase lag. Very low frequency oscillation phenomenon

Related research based on the damping torque method shows that this type of ultra-low frequency oscillation is caused by the instability of the primary frequency modulation due to the negative damping torque of the mechanical power of the hydroelectric unit

In actual operation, the existing monitoring system can only monitor the electromagnetic power and frequency of the unit, but cannot monitor the mechanical power of the unit, resulting in the operator being unable to locate the unit with strong negative damping (that is, the negative damping is large and greater than a certain threshold). Quickly Quiet Ultra Low Frequency Oscillations

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