A Fast Screening Method for n-k Fault Sets in Power System

Abstract

The invention discloses a method for screening an N-k fault set of a power system rapidly. In the prior art, only safety margin, for eliminating all N-1 faults and the part of N-2 faults, of the system is guaranteed based on existing static safety and stability checking; however, with consideration of economy and practical calculation difficulty, potential risks that can not be checked still need to be studied. According to the method provided by the invention, on the basis of definition of a large initial element fault screening scale, a fault set including a key element is found out rapidly by using a system major fault triggering situation as a standard, so that a searching range in the set narrows down further; and the operation is carried out until an N-k fault set meeting the requirement is localized finally. According to the method provided by the invention, unnecessary sampling can be avoided to the great extent. Further precise screening is carried out on the high-capacity screening sample obtained by preliminary screening, so that the calculation complexity is lower than that of the Monte-Carlo-algorithm-based global random screening method obviously and the calculation efficiency is improved. Besides, traversal sampling is avoided to reducing the calculation load.

Description

technical field [0001] The invention relates to the field of fault analysis of power systems, in particular to a fast screening method for N-k fault sets of power systems. Background technique [0002] In power system stability analysis, the screening and determination of expected faults is a very important link. However, with the continuous expansion of the power grid structure and the continuous enhancement of the power grid's ability to resist risks, the fault sets that can cause severe power outages in the actual large-scale power grid are often composed of multiple (assumed to be k, k is usually greater than or equal to 2) component failure components. If we want to verify all N-k faults, we will face the problem of combinatorial explosion in the actual large-scale power grid. It is obviously unrealistic to perform ergodic random sampling verification on this computing scale. [0003] Screening expected fault sets is a preventive measure in power system safety analysis...

AI Technical Summary

Problems solved by technology

[0005] The existing static safety and stability verification only guarantees the safety margin of the system when dealing with all N-1 and some N-2 faults. Due to economic considerations and the difficulty of actual calculation, the potential risk of failure to verify still to be studied

In fact, although multiple faults are an important cause of serious system failures and need to be focused on research, due to the large scale of the system, it is difficult to fully realize the fault set screening of multiple faults

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