Transmission line fault probability evaluation method taking regard of indeterminate instability position

Abstract

The invention discloses a transmission line fault probability accurate evaluation method. Aiming at the condition that during the fault probability evaluation process, the instability position is indeterminate, the instability region of the fault is dynamically evaluated, the distribution of the instability region in different scenes can be obtained, and therefore the fault probability evaluation result is relatively accurate. Compared with a conventional bisection method, a conventional sectioning method and the like, the transmission line fault probability accurate evaluation method is advantaged in that the problem that after a rocking curve is obtained through numerical simulation, the evaluation of the system stability degree or the analysis of the system stabilizing mechanism is difficult is avoided, and the instability portion and the instability proportion of the line can be worked out accurately aiming at various working conditions. Through the result, the system instability probability can be worked out more accurately, and the possibility of that the difference between the calculating result when the line operates in special working conditions and the actual result is relatively large is reduced.

Description

technical field [0001] The invention relates to a method for calculating the failure probability of a transmission line, in particular to a method for evaluating the failure probability of a transmission line considering the uncertain location of instability. Background technique [0002] In recent years, with the continuous development and expansion of the power industry, the scale of the power system has continued to increase, and the scale of the interconnected grid has also become larger and larger. Once a major power outage occurs, it will cause very serious consequences and losses in a long time and in a wide range. For example, the big power outage in Brazil in 2009 caused half of Brazil's land area to fall into a power outage, causing huge losses and harm. In this case, system reliability risk assessment is of great significance to ensure the safe operation of the system. [0003] Since the power system in actual operation is deeply affected by the environment, nat...

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Problems solved by technology

For the above method, when the system stability is not monotonous or abnormal with the change of the fault location, or when the fault causes multiple instability domains on the line, the calculation results may have a large deviation; at the same time, when the system operation considers the external Disasters, such as lightning strikes, the uneven distribution of minefields caused by the uncertainty of their occurrence may aggravate the deviation of calculation results, resulting in unsatisfactory final evaluation results

Moreover, the above method obtains the rocking curve through numerical simulation, and it is difficult to evaluate the degree of system stability and analyze the mechanism of system stability.

[0005] It can be seen from the above that the existing methods for calculating the probability of system instability still have certain defects in the determination and evaluation of the proportion of line instability and the system stability margin.

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