A Calculation Method of AC System Contributed Short-Circuit Current During DC Fault in Multi-terminal AC-DC Hybrid Distribution Network

Abstract

The invention relates to a calculation method of short-circuit current contributed by an alternating-current system during the direct-current fault of a multi-end alternating current / direct current hybrid distribution network. The method includes the following steps that: 101, a post-direct-current inter-pole short-circuit fault equivalent circuit of the alternating current / direct current hybrid distribution network is provided according to the characteristics of fault current and contribution made by the alternating-current system to the fault current after an inter-pole short-circuit fault of a direct-current line occurs, wherein the equivalent circuit is composed of an alternating-current voltage source 301, an alternating-current system equivalent resistor 302, an alternating-current system equivalent inductor 303, a converter station direct-current side capacitor 206, direct-current line resistors 304 and 306, and direct-current line inductors 305 and 307; 102, an analytical expression of the short-circuit current contributed by the alternating-current system is derived according to the analysis of the step 101; and 103, the calculation method of the short-circuit current contributed by the alternating-current system during the direct-current fault of the multi-end alternating current / direct current hybrid distribution network is provided according to the analysis of the step 102, the steady-state average value, transient peak value time and transient peak value of the method are calculated.

Description

technical field [0001] The invention relates to a method for calculating the short-circuit current contributed by an AC system when a DC fault occurs in a multi-terminal AC-DC hybrid distribution network, and belongs to the technical field of the AC-DC hybrid distribution network. Background technique [0002] With the aggravation of global environmental pollution and energy crisis, the use of renewable energy such as wind energy and solar energy to replace traditional fossil energy for power generation has become a research hotspot around the world. The extensive grid-connection of renewable energy has put forward higher requirements for the control and protection technologies of the AC distribution network. The traditional AC distribution network has begun to face huge challenges in distributed power access, load diversification, and complex grid structures. challenge. The DC distribution network has certain advantages in absorbing distributed energy and reducing the numb...

AI Technical Summary

Problems solved by technology

[0004] In short, most of the existing researches focus on single-ended systems, and the proposed method is not suitable for multi-ended systems

And the existing research does not propose a practical calculation method for the contribution of the AC system to the short-circuit current

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