Probability load flow calculation method considering admitting ability of power grid

Abstract

The invention discloses a probability load flow calculation method considering the admitting ability of a power grid. The method comprises the following steps that 1, a cumulative distribution function of a new energy power generation power variable is built according to the admitting ability of the power grid to new energy power generation power, wherein the cumulative distribution function is described in the form of a piecewise function; 2, the sampling frequency between all sections of the new energy power generation variable is calculated according to the cumulative distribution function F(pk) of the built new energy power generation power variable based on the proportional distribution principle, then a Latin hypercube sampling method is utilized for sampling all the sections of the new energy power generation power variable, and a sample matrix of the new energy power generation power variable is built; 3, the sample matrix of the new energy power generation power variable is adopted as an input variable for probability load flow calculation, a disperse result of an output variable is obtained, an empirical distribution function is utilized for fitting, and a probability distribution function of the output variable is obtained. The application range of the Latin hypercube sampling method is widened, and calculating precision is guaranteed.

Description

technical field [0001] The invention relates to a method for calculating the probability power flow taking into account the acceptance capacity of the power grid. Background technique [0002] As large-scale new energy power generation is connected to the grid, the randomness and volatility of new energy power generation lead to more and more obvious node voltage or branch power flow limit violations during the operation of the power system, which reduces the safety of power system operation. Therefore, it is necessary to qualitatively and quantitatively analyze the impact of new energy generation access on the power system. In the aspect of testing the planning scheme or operation of the power system including new energy power generation, the traditional power flow calculation method can no longer reflect the system operation under the change of operation mode, and it is replaced by the probabilistic power flow calculation method that can reflect the probability characteris...

AI Technical Summary

Problems solved by technology

In fact, limited by the capacity of the power grid and the channel transmission power of the grid tie line, the power generated by new energy cannot be completely accepted by the power grid, resulting in the probability distribution of the variable of power generated by new energy is no longer a conventional distribution, but a piecewise function Irregular distributions described in the form

[0004] Among the probabilistic power flow calculation methods, the calculation accuracy of the Monte Carlo simulation method based on random sampling is the highest, and it is often used as a standard to test the effectiveness of other methods. However, the Monte Carlo simulation method requires thousands of operations to obtain high-precision results. Tens of thousands of deterministic power flow calculations lead to quite long calculation time. In order to improve the calculation speed, the Monte Carlo simulation method is improved by replacing random sampling with Latin hypercube sampling method. Latin hypercube sampling method is a stratified sampling method , can greatly reduce the number of samples and improve the calculation speed, but the traditional Latin hypercube sampling method is very efficient for the scenario where the power variable of new energy generation is conventionally distributed, and for the case of irregular distribution limited by the capacity of the power grid hard to handle

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