Multi-voltage-grade electric network reliability evaluation method based on transmission node capacity model

Abstract

The invention discloses a multi-voltage-grade electric network reliability evaluation method based on a transmission node capacity model. The method comprises the following steps: confirming a boundary transmission node of an electric network with different voltage grades; confirming a capacity model of the electric network and the boundary transmission node, namely a maximum load capacity model of the electric network and the boundary transmission node or probability and frequency distribution characteristics of the maximum load capacity of the electric network and the boundary transmission node; combining the maximum load capacity model of the electric network and the boundary transmission node with a corresponding load model of the electric network and the boundary transmission node, and realizing reliability evaluation of the electric network and the boundary transmission node; calculating a capacity model of a superior power transmission network and a boundary transmission node of the superior power transmission network in reliability analysis of a power distribution network, and realizing reliability analysis calculation of the multi-voltage-grade electric network. The method not only realizes reliability analysis calculation of a multi-voltage-grade system but also can intuitively reflect effective (available) transmission capacity (load capacity) and related characteristics of the corresponding electric network (system), and improves the level of a power system reliability analysis technology.

Description

technical field [0001] The invention belongs to the technical field of power system reliability analysis, and in particular relates to a multi-voltage level power grid reliability evaluation method based on a transmission node capacity model. Background technique [0002] Power system reliability assessment can generally be divided into three levels, namely the reliability assessment of power generation system, the reliability assessment of power generation and transmission combined system and the reliability assessment of power generation, transmission and distribution system. The combined power generation and transmission system, also known as the Bulk Electricity System (BES), is mainly responsible for the power generation and transmission tasks of the power system. Due to the high complexity and large amount of calculation of the reliability evaluation of the power generation, transmission and distribution system, the existing power system reliability analysis method mai...

AI Technical Summary

Problems solved by technology

However, in the existing reliability analysis methods, whether it is analytical method or simulation method, it is difficult to directly reflect the power supply capacity of the large power grid. When the load model of the large power grid or the specific load reduction (switching) strategy of the distribution network itself changes, It is necessary to re-analyze and calculate. When the system scale is large, the calculation cost is very high. By establishing the transmission node capacity model of the upper-level voltage level system as the equivalent power supply model of the lower-level voltage level system, it is not only helpful to realize multi-voltage coordination Efficient reliability analysis and calculation of the hierarchical system, and can intuitively reflect the effective (available) transmission capacity (load capacity) and related characteristics of the corresponding power grid (system), providing an effective and intuitive reference for the planning and operation of the power system

At present, there are methods that propose to use the maximum load capacity (Maximum Loadability, ML) and its probability distribution of the large power grid and its connection point with the lower-level power system (main distribution system) as the capacity of the large power grid or its connection point with the power distribution system. model, and use the power grid capacity model and load model to perform convolution to evaluate the reliability of the large power grid and its connection points. ML can reflect the power supply capacity of the large power grid more intuitively, but this method only involves the probability distribution of ML and does not Only the calculation method of power shortage probability and power shortage reliability index is discussed, but the frequency-related distribution and reliability index calculation method are not given. In the analysis and calculation, the load reduction strategy of the large power grid and the load transfer between nodes are ignored. The impact of power supply on the maximum load capacity of the large power grid, and there is no overall analysis of the large power grid and power distribution system, which has great limitations

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