Unit output optimizing method for improving transient stability margin of receiving end power grid

Abstract

The invention discloses a unit output optimizing method for improving transient stability margin of a receiving end power grid. According to the method, for the receiving end power grid with a known running state, the transient stability margin of each generator and the sensitivity of transient stability margin to the active output of the unit are calculated, the generator transient stability constraint is used as a constraint condition, a mathematical model of unit output optimization is proposed, and the optimal scheme of each generator output is obtained. According to the method, various operation constraint conditions in the output process of the optimization unit are comprehensively considered, and the output limit value, the limit value of the branch power and the limit value of thevoltage amplitude of a node are considered, so that the adaptability of various operation modes of the system is high, engineering practical operation is easy, and the transient stability characteristic of the generator can be ensured to meet the expected condition by optimizing the unit output.

Description

technical field [0001] The invention belongs to the technical field of power systems, and in particular relates to a unit output optimization method for improving the transient stability margin of a receiving-end power grid. Background technique [0002] The safety and reliability of the power system is the primary goal of the power grid operation, and the analysis and control of the transient stability of the power system has always been one of the research focuses in the industry. my country has a vast territory and uneven energy distribution. Under the background of grid interconnection, local disturbances may cause large-scale transient stability problems. At the same time, due to its many advantages, DC transmission technology has been widely used in grid interconnection and long-distance large-capacity transmission. The grid structure of the AC / DC hybrid receiving end grid is becoming more and more complex, and the probability of system failure is rising; the transien...

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Problems solved by technology

[0006] In addition, the staff of my country's electric power system put forward the "three lines of defense" against failures. For the possible transient security and stability problems of the power grid, control measures such as machine cutting, load shedding, or decoupling are implemented according to the control strategy to maintain the transient state of the system. Stable; but the "three lines of defense" is difficult to operate, and some loads and generators need to be lost when necessary

[0007] Flexible DC transmission technology is also widely used in power grids to adjust the transient stability characteristics of the system, but flexible DC technology requires a huge investment and may bring new stability problems

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