Hierarchical extra-high voltage direct current capacity and terminal location selection method and hierarchical extra-high voltage direct current capacity and terminal location selection system

Abstract

The invention relates to a hierarchical extra-high voltage direct current capacity and terminal location selection method and a hierarchical extra-high voltage direct current capacity and terminal location selection system. The method includes determining a start location for hierarchical extra-high voltage direct current connection into a 1000 kV power grid; selecting a start location for hierarchical extra-high voltage direct current connection into a 500 kV power grid; selecting hierarchical extra-high voltage direct current power transmission capacity; computing bus short-circuit capacity and an effective short-circuit ratio of a 500 kV transformer substation under the condition that hierarchical extra-high voltage direct current is not terminated; judging whether the effective short-circuit ratio meets requirements or not and forming a primary terminal location selection scheme set 1 of the hierarchical extra-high voltage direct current connection into the 500 kV power grid; judging whether an effective short-circuit ratio in the scheme set 1 meets requirements or not and forming a primary terminal location selection scheme set 2 of hierarchical extra-high voltage direct current connection into the 500 kV power grid; forming multiple alternative schemes of hierarchical extra-high voltage direct current connection into the 500 kV power grid according to the scheme set 2; screening reasonable schemes of extra-high voltage direct current connection into the 500 kV power grid; recommending a final hierarchical extra-high voltage direct current capacity and terminal location scheme. By the method, a hierarchical extra-high voltage direct current capacity and terminal location selection process is simplified and workload is reduced effectively.

Description

technical field [0001] The invention relates to the field of safety and stability analysis of power systems, in particular to a method and system for selecting UHV layered DC capacity and drop point. Background technique [0002] At present, my country's power grid has formed a North China-Central China AC interconnected power grid, and the East China Power Grid operates in isolation, and is connected to the North China-Central China Power Grid through a DC system. According to the plan, my country will build dozens of UHV DC projects in the next 10-20 years, and gradually form a UHV AC-DC hybrid power grid to supply power to the central and eastern load centers through UHV DC and AC systems. In order to alleviate the problems faced by the multi-infeed DC system, such as insufficient reactive power support capacity of the receiving end grid, and the dense sending system causing the short-circuit current to cross the line, UHV layered DC has become a new DC access mode. Comp...

AI Technical Summary

Problems solved by technology

On the whole, the current selection method for the UHV layered DC capacity and drop point is still too extensive, and the organization and system are relatively insufficient.

And with the rapid development of the power grid, the trend direction, short-circuit current level, safety and stability characteristics, etc. may all undergo major changes. It is difficult to adapt to the complex changes in the power grid in the near future when only relying on local experience to select the UHV layered DC capacity and location. and mid- to long-term comprehensive needs

Images