Cascading fault search and weak link analysis method based on operational reliability model

Abstract

The invention relates to a cascading failure search and weak link analysis method based on an operation reliability model. The method comprises steps: initial failure is generated randomly; a DC power flow is calculated, whether a load threshold-crossing line exists in a power system is judged, if yes, a next step is carried out, or otherwise, the operation is stopped; an initial failure set is generated, and through the operation reliability model, the threshold-crossing line outage probability is calculated; the power system state probability is calculated; if the power state probability is larger than a set threshold and the failure scale is smaller than a set threshold, the power state is added to an alternative failure set, and if no state meeting the condition exists, search is stopped; the initial failure set is taken as an alternative failure set, the current alternative failure set is emptied, and the above steps are repeated. Through searching a cascading failure event in different initial failure and analyzing a system weak link, a corresponding system reform scheme is provided, happening of the cascading failure is prevented, a subsequent event is found during an event development process, and further evolution of the cascading event can be prevented.

Description

technical field [0001] The invention relates to a method in the field of risk analysis of cascading faults in electric power systems, in particular to a method for searching for cascading faults and analyzing weak links based on an operation reliability model. Background technique [0002] At present, the power grid has entered a period of rapid development of cross-regional interconnection and ultra-high voltage and ultra-high voltage AC-DC hybrid transmission. The complexity of the power grid has increased sharply, and the risk of cascading failures leading to large-scale blackouts has gradually increased. The occurrence of cascading failures in the power system is often due to the redistribution of the power flow after the system is initially disturbed, so that some normally working components in the system are out of operation due to overload or serious deviation from the rated working conditions, which further causes the change of the power flow in the system, and then ...

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Problems solved by technology

Among them, the method based on complex network theory analyzes the mechanism of the occurrence, development and propagation of cascading faults from the perspective of graph theory, and can analyze the vulnerability of the power grid under static conditions. Dynamic operation; the cascading failure assessment method based on complex theory focuses on the macroscopic characteristics of cascading failures, adopts a simplified power grid model, and analyzes the weak links of the system and the risk of cascading failures of the power grid through statistical data, which is mainly used to guide power grid planning; mode search method The cascading faults of the power grid are simulated by establishing models and algorithms that conform to the actual physical process of the power grid. However, as the system scale increases, the amount of calculation will increase exponentially, and the time-consuming will increase greatly.

At the same time, in other studies, the event correlation in the development of cascading failures is ignored, which may underestimate the spread of cascading failures and their impact

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