A Method of Dynamic Economic Dispatch of Power System Considering the Correlation of Multiple Wind Farms

Abstract

The invention relates to a method for electric power system dynamic economic dispatching with correlation of multiple wind power plants being considered. The method comprises the steps of putting forward a method for generating joint distribution of power output among the multiple wind power plants based on a Copula function, constructing a two-stage band compensation power grid dynamic economic dispatching model based on the distribution, introducing a compensation expected value into an objective function, and solving the compensation expected value by using integration so as to enable the compensation expected value to be converted into a numerical model from a stochastic model, that is, enabling two-stage band compensation dynamic economic dispatching to be converted into a numerical model from a stochastic programming model, thereby quantifying impact imposed on a power grid by a stochastic property of the wind power plants, and solving optimal unit output which satisfies the objective function and the minimum impact simultaneously. According to the invention, solving is carried out by adopting the two-stage band compensation dynamic economic dispatching model, and the solving accuracy of the model is improved.

Description

technical field [0001] The invention mainly relates to the technical field of dynamic economic dispatching of electric power systems, in particular to a method for dynamic economic dispatching of electric power systems considering the correlation of multiple wind farms. Background technique [0002] The economic dispatching problem of the power system refers to the determination of the optimal active power output scheme of each generating set put into operation under the precondition of satisfying the system power-charge balance and related operation constraints, so as to make the desired goal optimal, usually to optimize the economic efficiency. . If we consider the economic dispatch of the interaction between different time sections within a certain period, it is the dynamic economic dispatch of the power system. [0003] The power system economic dispatch problem is a large-scale, high-dimensional, multi-constraint programming problem, and its mathematical model is expre...

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Problems solved by technology

Among them, the method of forecasting wind field output transforms the mathematical model of power system dynamic economic dispatch including the random variable of wind field output into a deterministic model. Although the model is simple and the calculation is fast, it is greatly affected by prediction errors. The capacity needs to be increased; the calculation accuracy of this method depends on the selection of scenarios, and the calculation speed decreases as the number of scenarios increases. Slow and increased memory, difficult calculation, not suitable for large-scale power systems; when using statistical methods to find the probability model of wind field output distribution, it is mostly based on a single wind field distribution (normal distribution, etc.) to fit the probability model of wind field output distribution, and then A mathematical model of dynamic economic dispatch of power system in the statistical sense is obtained, but this method cannot fit the probability model of wind field output distribution well, and this method focuses on the study of the output law of a single wind field, ignoring the multi-wind field in the same region. The correlation between these factors may lead to the inability to satisfy the power balance constraints and line safety constraints, and the results obtained are inconsistent with the actual power system operation

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