A protection device and protection method for DC distribution network

Abstract

The embodiment of the invention discloses a protection device for a direct-current distribution network and a protection method thereof, wherein the direct-current distribution network comprises an inverter and a multi-stage power distribution device; the protection device for the direct-current distribution network comprises a current limiting module, wherein the input end of the inverter is electrically connected with a power supply end of the direct-current distribution network; the input end of the current limiting module is electrically connected with the output end of the inverter; the incoming end of the first-stage power distribution device is electrically connected with the output end of the current limiting module; the current limiting module is used to limit the output current of the current limiting module to be a second preset current when the output current of the current limiting module is greater than a first preset current and to control the input end and the output end of the current limiting module in a current direct-connection state when it is monitored that the output current of the current limiting module is smaller than a third preset current. The technicalscheme provided by the embodiment of the invention can improve the reliability of power supply of the direct-current distribution network and avoid the situation that one part breaks down and the whole network is paralyzed.

Description

technical field [0001] The invention relates to the technical field of power systems, in particular to a protection device and a protection method for a DC distribution network. Background technique [0002] The DC distribution network has better performance than the AC distribution network in terms of transmission capacity, controllability, improvement of power supply quality, reduction of line loss, isolation of AC and DC faults, and flexible and convenient access to renewable energy. Power quality, reducing the use of power electronic converters, reducing power loss and operating costs, coordinating the contradiction between large power grids and distributed power, and giving full play to the value and benefits of distributed energy. [0003] However, the DC distribution network has the characteristics of short electrical distance and weak fault damping. When a fault occurs, the fault current rises rapidly and is much larger than the normal load current. It has the chara...

AI Technical Summary

Problems solved by technology

[0003] However, the DC distribution network has the characteristics of short electrical distance and weak fault damping.

When a fault occurs, the fault current rises rapidly and is much larger than the normal load current. It has the characteristics of one fault and the whole network feels it, resulting in the paralysis of the whole network and the failure to handle the fault.

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