An Active Frequency Response Event Control Strategy

Abstract

The invention discloses an active frequency response event control strategy. The active frequency response event control strategy comprises: in an offline state, clustering all possible operation states of a power system according to selected frequency stability related state quantity to form several typical scenes, analyzing the typical scenes to determine an active frequency response control strategy of each scene to form a control decision table, determining the active frequency response event control strategy: dividing frequency fluctuation and evolution process of a power grid into two stages, namely, a frequency decline phase and a frequency recovery stage; and performing frequency control on the power grid by adopting an active frequency response event control mode in the frequencydecline phase and adopting a passive frequency response parameter feedback control mode in the frequency recovery stage. The control strategy provided by the invention can effectively intercept frequency decline in the frequency decline phase so as to avoid low-frequency load reduction of the system, and makes the system restore the stability in the frequency recovery stage as soon as possible toavoid frequency oscillation of the system in an active control process.

Description

technical field [0001] The invention relates to the technical field of electric power systems, in particular to an active frequency response event control strategy. Background technique [0002] At present, a variety of factors lead to a severe situation in the frequency stability of the future power grid, and the ever-increasing means of frequency response on the load side of the source network need to be better coordinated to give full play to the control performance and improve the frequency stability level. [0003] The essence of frequency stability is the active power balance on the time scale of seconds to minutes after the disturbance, and its development process and stability depend on the power balance at the two ends of the "offensive and defensive". "Attack" corresponds to the amount of unbalanced power, and "defense" corresponds to the three main factors of frequency value before failure, system inertia and frequency response capability. On the "offensive" side...

AI Technical Summary

Problems solved by technology

On the "offensive" side, the transmission power of UHV AC and DC transmission lines is increasing day by day, clean and efficient giant thermal power and nuclear power units are gradually replacing polluting and inefficient small thermal power units, and the number of power imbalances caused by single component failures has increased significantly; Poor environment, coupled with the rapid accumulation of pollution on DC lines, leads to a high failure rate of DC unipolar blocking of UHV transmission lines

On the "defense" side, on the one hand, the renewable energy whose capacity proportion is constantly increasing occupies the power generation space of conventional thermal power units, resulting in a reduction in the number of conventional units connected to the grid, resulting in a continuous decline in system inertia and frequency response capabilities; further, system inertia And the reduction of frequency response ability makes the overall increase of frequency deviation under normal operation state, leading to a sharp increase in the probability of the frequency being at a low level before the failure

[0004] In order to ensure the operation safety and quality of the entire power grid, the frequency response is set as a free cross-regional mutual support function, which is an essential transmission auxiliary service for all power generation units. Its control mode is decentralized and autonomous control based on local frequency differences. Although the system The frequency response capability is the synthesis of the frequency response capabilities of all generator sets, but the asynchronous frequency response among the generator sets will reduce the overall effect of the frequency response

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