Method and system for cascading failure risk assessment of high proportion wind power grid-connected

Abstract

The invention discloses a cascading fault risk assessment method and a cascading fault risk assessment system for high-proportion wind power grid connection. The cascading fault risk assessment methodand the cascading fault risk assessment system comprise the following steps: establishing a wind power prediction error model according to the wind power prediction error historical data to obtain the wind power output distribution; Select the initial fault set; When a fault occurs in the initial fault set, the fault chain search is started: whether the power system is disconnected or not is judged; if the fault is disconnected, the island balance is carried out and the current fault chain search is stopped; If the power system is not disconnected, the stochastic power flow calculation is carried out. If the non-convergence probability of the power flow calculation result is greater than the set value, the load shedding control is carried out. According to the accident chain set generatedabove, the power system loss risk index and line importance index are calculated. The technical proposal provided by the invention fully considers the influence of wind power uncertainty in the evolution process of the accident chain, has more comprehensive risk assessment to the system, and is suitable for the background of high-proportion wind power grid connection.

Description

technical field [0001] The invention relates to the technical field of electrical control, in particular to a cascading failure risk assessment method and system for a high proportion of wind power grid-connected. Background technique [0002] Cascading failures in power systems are a process in which initial disturbances cause other related components to fail one after another and continue to develop. It is the main cause of many major blackouts worldwide in recent years. Although wind power forecasting methods are being continuously improved, there are still 20% to 30% forecasting errors. In the context of a high proportion of renewable energy connected to the grid, the high penetration rate of wind power makes the impact of this uncertainty on the power side of the system more significant, increasing system risk. Therefore, an in-depth study of the system cascading failure risk of wind power grid-connected is of great significance for improving the prevention and control...

AI Technical Summary

Problems solved by technology

[0004] The problems of the above research methods are: the complex system theory describes the physical process of cascading failures and reveals the self-organized critical characteristics of the power grid; the complex network theory is often used to analyze system vulnerability, but it cannot fully reflect the actual dynamic characteristics of the power grid; the fault chain The model combines the actual physical process to simulate cascading failures, which can not only quantitatively analyze cascading failures, but also effectively control the amount of calculation

[0005] The current cascading failure model for wind power grid-connected takes the actual output of wind power as a definite quantity when generating the cascading failure path. The impact of wind power prediction error cannot be ignored, and cascading failure assessment under this wind power processing method cannot fully reflect the system risk

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