Static equivalence method of external network in interconnected power grid

Abstract

Provided is a static equivalence method of an external network in an interconnected power grid. The static equivalence method comprises a static equivalence model which is established on a boundary and provided with a non-generator node; two sensitivity equations before and after equivalence are equaled; and a virtual generator voltage, an equivalence injection current, an equivalence branch to ground and the like are deduced after static equivalence of the external network. In the aforementioned computation processes, the boundary of the static equivalence model is additionally provided with the equivalence branch to ground of the non-generator node of the boundary. A maximum safety error and a relative error of a line inactive injection power and an active injection power of an internal network are both improved, and a node maximum voltage amplitude relative error in the internal network is also improved so that higher static equivalence accuracy of the external network is obtained, and static safety analysis on the internal network can be better performed. When static safety analysis is performed on the internal network, a more accurate current value is also obtained.

Description

technical field [0001] The invention relates to a method for estimating external network parameters in an interconnected power grid, in particular to a method for performing static equivalent values ​​on external networks in an interconnected power grid. Background technique [0002] Each power supply unit (bureau, station) uses a computer to conduct real-time static security analysis of the power network managed by it to realize online control, which is an important link to ensure the safe operation of the power network. With the development of the electric power industry, a huge interconnected power grid has been formed. Therefore, for the control center of each power supply unit, there is a difference between the internal network that can be controlled and managed and the external network that is not controllable and does not need to be managed. , that is, the internal network and external network are included in the interconnected grid. And because the external network ...

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Problems solved by technology

However, due to reasons such as that there is no equivalent branch to the ground in the equivalent branch set in the static equivalent model of the external network in this prior art, the effect after performing the static equivalent value of the external network on the actual power grid ( Corresponding to the IEEE14 node standard test system for testing), still not good enough

Specifically, the maximum relative error between the voltage amplitude of the boundary nodes and the node voltage amplitude in the internal network and the voltage amplitude of the boundary nodes is still relatively large, and the maximum safe error and relative error of the active injected power and reactive injected power in the internal network are also are still larger

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