A third line of defense configuration method for adaptive isolated grid scale

Abstract

The invention discloses a third defense line configuration method adaptive to the scale to an isolated power grid, and belongs to the technical field of electric power system automation. A high-frequency generator tripping scheme adopts two-stage configuration, the first stage is used for inhibiting a frequency rise of the whole network, and the second stage is used for preventing overspeed protection action of a unit, and sets a second stage action constant value on the basis of an overspeed protection action constant value of the unit; and a configuration scheme of the first stage of high-frequency generator tripping and low-frequency low-voltage load shedding includes a quick action area and a compensation area, and according to an installing characteristic and a load characteristic of the isolated power grid, a principle of maximizing an action constant value range of the last round of the quick action area and the first round of the compensation area is used to arrange action constant values of other rounds. The third defense line configuration method adaptive to the scale of the isolated power grid can give full play to regulating characteristics of the unit and load in the isolated power grid, and can effectively avoid the problem of overcontrol caused by multi-round successive action due to a too small round range in a traditional configuration method.

Description

technical field [0001] The invention belongs to the technical field of electric power system automation, and in particular the invention relates to a third line of defense configuration method for self-adaptive isolation grid scale. Background technique [0002] In order to prevent the stability of the power grid from being damaged after extremely serious faults, or even large-scale power outages, the power system widely adopts low-frequency and low-voltage load shedding, out-of-step splitting, and high-frequency cut-off to form the third line of defense. For a long time, the maximum frequency offset or voltage offset that may occur in the system has been generally determined based on off-line simulation analysis and calculation at home and abroad, and the low-frequency and low-voltage load shedding scheme and high-frequency cut-off scheme have been determined by round-by-wheel tuning. The document "Discussion on Several Issues in the Formulation of China's Low Frequency Loa...

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Problems solved by technology

Compared with complex large power grids, this kind of power grid covers a small area, the grid structure is weak, and the installed capacity and load level of the power grid are very limited. Once a fault occurs, power shocks such as power supply or load loss are likely to cause rapid voltage and / or frequency instability; Moreover, affected by product market environment factors, the installed capacity and load level of such isolated power grids change rapidly. The conventional method of setting the action plan of the third line of defense round by round may easily lead to multiple rounds of successive rapid actions resulting in over-control, or even low-frequency The alternating actions of low-voltage load shedding and high-frequency machine cut-off cause the power grid to stop completely; moreover, conventional methods cannot reflect the impact of the development and change of the installed capacity of the power grid on the safety and stability of frequency and voltage

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