A protection configuration method for a typical multi-terminal flexible DC power distribution system

Abstract

The invention discloses a protection configuration method for a typical multi-terminal flexible direct current power distribution system. The typical multi-terminal flexible direct current power distribution system is divided into an alternating current system protection region, a main converter protection region, a direct current line protection region and an access converter protection region; and a protection scheme is configured for each protection sub-region by combining the operating requirements of the direct current power distribution system and the factors of fault and electrical characteristics and the like on the basis of division of the protection regions. The scheme can comprise different protection algorithms, which can protect the safety of equipment in the region, and simultaneously can be used as backup protections of other regions. Configuration of protection devices is to determine the installation positions and the number of the protection devices, employing simplicity, convenience and reliability as principles. According to the method, the fault position in the direct current power distribution system can be quickly and reliably judged; fault removal and isolation are achieved; stable operation of the multi-terminal flexible direct current power distribution system can be ensured; and the protection configuration method has certain guiding significance in follow-up study of the protection system.

Description

technical field [0001] The invention belongs to the technical field of power system relay protection and safety control, and in particular relates to a protection configuration method of a typical multi-terminal flexible DC power distribution system based on a ModularMulti-level Converter and a modular multi-level converter. Background technique [0002] With the complexity of urban load and the rapid increase of distributed power access rate, the traditional AC distribution network is facing more and more difficulties in satisfying power supply reliability, power quality, and transmission capacity. The use of MMC technology in urban power grids with intensive electricity consumption can use its rapid controllability to solve the problems of power supply difficulties, high operating costs and difficult power flow control in urban power supply, and maintain the safe, reliable and economical operation of urban power grids. The development of DC power distribution system can al...

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Problems solved by technology

[0005] The protection strategy of multi-terminal flexible DC power distribution system has been studied at home and abroad, but there is no engineering application in China. However, domestic multi-terminal flexible DC transmission projects have many engineering applications, such as Zhoushan multi-terminal flexible DC transmission project, Nanao multi-terminal flexible DC transmission project, Shanghai Nanhui flexible DC transmission demonstration project, Ge-Nan flexible DC transmission project, San-Chang flexible DC transmission project, etc.

Although the protection strategy of the flexible DC transmission system is relatively mature, and there are many similarities between the protection strategies of the flexible DC transmission system and the power distribution system, the unique electrical characteristics of the flexible DC power There are many and complex lines, high power quality requirements, and fast power flow reversal, all of which require us to study configuration strategies for these characteristics of protection

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