Current limiting device and method, direct-current power grid protection device and direct-current power grid system

Abstract

The invention relates to a current limiting device and method, a direct-current power grid protection device and a direct-current power grid system. The current limiting device comprises an electronicswitch, a current limiting branch and a control branch, wherein the input end of the electronic switch is connected with one end, far away from a direct-current power grid, of a direct-current circuit breaker, the output end of the electronic switch is connected with a converter, the current limiting branch is connected with the electronic switch in parallel and used for limiting short-circuit current, and the control branch is connected with the electronic switch and is used for controlling the electronic switch to be turned off from on when the short-circuit fault of the direct-current power grid is detected, so that the short-circuit current flows through the current limiting branch. According to the current limiting device provided by the invention, by limiting the short-circuit current, the converter locking before the short-circuit current cutoff of the direct-current circuit breaker can be avoided, so that the reliable and continuous operation of a direct-current power grid system can be ensured.

Description

technical field [0001] The present application relates to the technical field of power grids, in particular to a current limiting device and method, a DC power grid protection device and a DC power grid system. Background technique [0002] The DC grid system has been vigorously promoted because of its high-quality power and reliable power supply performance. However, in practical applications, it is the basic principle of fault ride-through to selectively and quickly remove the DC bipolar short-circuit fault without affecting the normal and continuous operation of the DC grid system. Require. Compared with the AC system, the DC grid system has lower damping, and once a fault occurs, the short-circuit current rises very quickly. [0003] In order to ensure the continuous and reliable operation of the DC grid during faults, DC circuit breakers are generally used in traditional technologies to selectively cut off the short-circuit current. However, once a bipolar short-circu...

AI Technical Summary

Problems solved by technology

However, once a bipolar short-circuit fault occurs on the DC grid side, the DC short-circuit current rises very fast, and the DC circuit breaker cannot cut off the short-circuit current in time, which will cause the converter in the DC grid system to be blocked, resulting in a short-term outage of the DC grid

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