Electromagnetic ring network ring opening method for multi-DC infeed receiving-end grid

Abstract

The invention discloses an electromagnetic ring network ring opening method for a multi-DC infeed receiving-end power grid. According to community structure characteristics of a complex network, a low-voltage grade power grid in an electromagnetic ring network is divided into a plurality of sections, and an electromagnetic ring network ring opening scheme is formed according to the dividing sequence of the plurality of sections. Based on the definition of a multi-infeed short circuit ratio, weighted infeed short circuit ratio indexes are constructed, effects of the electromagnetic ring network on a multi-DC infeed system are evaluated quantitatively, and a preferred electromagnetic ring network ring opening scheme is selected from the schemes satisfying security checks. The embodiment analysis shows that the method can be used for providing theoretical basis for the formation of the electromagnetic ring network ring opening scheme and effectively reflecting the impacts of the ring opening scheme on the voltage support capability of the multi-DC infeed system.

Description

technical field [0001] The invention relates to a method in the field of power system analysis, in particular to an electromagnetic ring network open-loop method for multi-direct current feeding into a receiving-end power grid. Background technique [0002] Multiple DC centralized feed-in is an important feature of my country's receiving power grid in the future, such as the Yangtze River Delta, Pearl River Delta, Shandong Peninsula and other regions will have multiple DC centralized feed-in. After research, it is found that the biggest risk faced by the multi-DC feed-in receiving end grid is the problem of voltage stability. During the AC system fault, short-term commutation failures occur on multiple DC circuits near the fault point. After the fault on the AC side is cleared, the multiple DC circuits are in the process of simultaneous recovery, which needs to absorb a large amount of reactive power from the AC system. If multiple DC restorations fail and blockage occurs s...

AI Technical Summary

Problems solved by technology

[0008] For multi-DC infeed-receiving-end power grids, the open loop of the electromagnetic ring network reduces the short-circuit capacity of the DC commutation bus on the one hand, and on the other hand lengthens the electrical distance between multiple DC circuits, which may increase the short-circuit ratio of multiple infeeds. Large, it may also reduce it, it is necessary to quantitatively evaluate the impact of the open loop of the electromagnetic ring network on the multi-DC feeding system

However, none of the existing electromagnetic ring network open-loop methods consider the impact of the open-loop scheme on the voltage support capability of the multi-DC feed-in system, so it is not suitable for the situation where multiple DC feed-in to the receiving end grid

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