Power grid reliability evaluation method based on maximum entropy principle and cross entropy important sampling

Abstract

The invention discloses a power grid reliability evaluation method based on a maximum entropy principle and cross entropy important sampling. According to the method, the maximum entropy principle is introduced, an optimization model with the maximum information entropy of an important sampling probability density function under the condition that a prior information constraint condition is met is established, an optimization model with the minimum cross entropy of the important sampling probability density function is coupled, and a multi-target planning model for continuous random variable important sampling distribution estimation is constructed; and multiple inferior solutions of the problem,namely a general expression of an important sampling probability density function is obtained through an optimization theory. The continuous random variable important sampling probability density function established by the method is completely based on each moment constraint condition of prior information, and the distribution form of the important sampling probability density function does not need to be assumed, so that the method is more flexible and universal. The problem that an existing probability evaluation technology is poor in real-time performance is hopefully solved, and therefore the accuracy and rationality of electric power operation checking are remarkably improved.

Description

technical field [0001] The invention belongs to the field of power system reliability evaluation, in particular to a power grid reliability evaluation method based on the principle of maximum entropy and cross-entropy important sampling. Background technique [0002] With the large-scale grid integration of renewable energy generation represented by solar energy and wind energy, the uncertain factors in the operation of the power system are becoming more and more complex. Once the hidden risks cause system outage, it will cause huge economic losses to the grid company and seriously affect the society. Production and life, disturbing the normal order of society. Therefore, reliability analysis in the planning, operation and maintenance of power system is of great significance to meet the needs of users for high-quality and reliable electric energy and ensure the stability of social production and life. Power system reliability assessment is based on the probabilistic and qua...

AI Technical Summary

Problems solved by technology

However, the probability density functions of continuous random variables (such as load, wind speed, or light intensity, etc.) in power systems have various forms, and it is too restrictive to directly assume that the important sampling probability density functions obey normal distribution or lognormal distribution.

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