Method for calculating probabilistic power flow of hybrid power grid with consideration of correlation high-dimensional random variables

Abstract

The invention discloses a method for calculating a probabilistic power flow of a hybrid power grid with consideration of correlation high-dimensional random variables. The method comprises: determining a probability distribution type and a parameter according to historical data of random variables in a hybrid power grid and calculating a correlation matrix RX between the random variables; transforming the random variables conforming to random distribution to a standard Gaussian distribution domain and calculating a correlation matrix RZ between the standard Gaussian distribution based on the correlation matrix RX between the random variables; according to the correlation matrix RZ, calculating a covariance matrix PZZ between the standard Gaussian distribution; determining a proportional expansion coefficient alpha in disposal of the random variables conforming the standard Gaussian distribution by an STUT algorithm; selecting a sample point Z in the standard Gaussian distribution domain; carrying out inverse transform on the sample point Z to a multidimensional arbitrary distribution domain; carrying out hybrid power grid deterministic power flow calculation group by group by using2n+1 groups of sample points in the multidimensional arbitrary distribution domain as input amounts; and acquiring a calculation result of the probabilistic power flow analysis of the hybrid power grid. Therefore, a problem of high-dimensional random variables with relevant correlations in the actual AC-DC hybrid power grid probabilistic power flow analysis is solved; the weak link during the actual AC-DC hybrid power grid running process is discovered timely; and the reliability and safety of the grid running are improved.

Description

technical field [0001] The embodiments of the present invention relate to the technical field of grid connection of new energy sources, and in particular, to a method for calculating the probabilistic power flow of a hybrid grid considering high-dimensional random variables with correlation. Background technique [0002] The Voltage Source Converter based High Voltage Direct Current (VSC-HVDC) system based on the voltage source converter will be widely used in the grid connection of new energy bases, the interconnection of asynchronous grids and the strengthening of regional transmission grids. A large number of probabilistic uncertainty sources will emerge in the future AC / VSC-MTDC hybrid grid. At the same time, there is often a certain degree of correlation between these sources of uncertainty. Then, the probabilistic power flow calculation of AC / VSC-MTDC hybrid grid can be defined as a high-dimensional probabilistic power flow analysis problem with correlation. [0003]...

AI Technical Summary

Problems solved by technology

However, when the TUT algorithm deals with high-dimensional uncertainty analysis problems, its sample points will have a "sample point discrete effect" with the increase of the dimension of the random variable, which will eventually lead to a decrease in the accuracy of the probabilistic power flow analysis

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