Fault detection and isolation method for multi-branch low-voltage direct current distribution system

Abstract

The invention discloses a fault detection and isolation method applicable to a multi-branch low-voltage direct-current power distribution system, and belongs to the safety detection technical field of a direct-current power distribution system. According to the method, single-branch sub modules are flexibly configured according to nodes and branches of the direct-current system; the multi-branch low-voltage direct-current power distribution system protection is formed comprehensively; fault recognition is realized by detecting the inductive current and the capacitor voltage characteristics in each branch sub module; and fault isolation is carried out by controllable electronic switches in the branch sub modules. According to the method, a direct-current circuit breaker is not required, so that the cost is relatively low; the fault detection and isolation method is applicable to the multi-branch and single-loop, single-pole and dual-pole direct-current power distribution system; the fault detection and isolation method is simple in method, high in protection action speed, and relatively high in transitional resistance tolerance; and meanwhile, only the fault branches are isolated, so that the power failure range is not enlarged.

Description

technical field [0001] The invention belongs to the technical field of safety detection of DC power distribution systems, and in particular relates to a fault detection and isolation method suitable for multi-branch low-voltage DC power distribution systems. Background technique [0002] With the development of power electronics technology and control technology, HVDC transmission technology is more and more widely used in long-distance and large-capacity power transmission due to its good controllability and economy. In the field of medium and low-voltage distribution networks, DC power supply systems have also attracted widespread attention and are used in industrial parks, rail transit traction power supply systems, aircraft and ship power supply systems, etc. Compared with the AC power distribution system, the DC power distribution technology has the following advantages: 1) The DC power distribution network can save line investment, and also has the advantages of high p...

AI Technical Summary

Problems solved by technology

Due to the large amount of equipment in the flexible DC power distribution system, the operation mode is changeable, and the fault characteristics are affected by factors such as system topology, fault type and fault location, showing complex polymorphic characteristics, which brings great challenges to the design and cooperation of the protection system. difficulty

Especially in the multi-branch power distribution system, because the relevant fault detection methods are not very mature, coupled with the technology and configuration costs of DC circuit breakers, the DC power distribution protection system still lacks relevant standards and operating experience, and is not yet very mature. Cost-effective relay protection technology and equipment to deal with various faults in the DC power distribution system

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