Method and device for recovering direct-current short-circuit failure of hybrid modular multilevel converter

A modular multi-level, fault recovery technology, applied in the direction of emergency treatment AC circuit layout, power transmission AC network, etc., can solve the problems of inability to synchronously increase DC voltage, abnormal communication between stations, etc., to achieve stable recovery, no inrush current Effect

Active Publication Date: 2017-07-14
XUJI GRP +4
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0007] The purpose of the present invention is to provide a DC short-circuit fault recovery method and device for a hybrid modular multilevel converter, which is used to solve the short-circuit fault recovery

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  • Method and device for recovering direct-current short-circuit failure of hybrid modular multilevel converter
  • Method and device for recovering direct-current short-circuit failure of hybrid modular multilevel converter
  • Method and device for recovering direct-current short-circuit failure of hybrid modular multilevel converter

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Embodiment Construction

[0034] The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

[0035] An embodiment of a DC short-circuit fault recovery method for a hybrid modular multilevel converter of the present invention:

[0036] Such as figure 1 The double-terminal or multi-terminal flexible DC transmission system composed of half-bridge and full-bridge sub-module hybrid modular multilevel converters shown in the figure, the number of full-bridge and half-bridge sub-modules in the system are N and M respectively, where N≥ 2. M≥2; figure 1 middle: u sm is the sub-module voltage, U dc is a DC voltage, HBSM (half-bridge sub-module) is a half-bridge sub-module, and FBSM (full-bridge sub-module) is a full-bridge sub-module. When a DC bipolar short-circuit fault is detected, the full-bridge sub-module can output a negative voltage. By using this feature, the system can more flexibly control the system DC voltage U while maintain...

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Abstract

The invention relates to a method and device for recovering the direct-current short-circuit failure of a hybrid modular multilevel converter. The convertor station control mode needing to be recovered is divided into a master station mode and a slave station mode; when one convertor station is selected as the master station, other convertor stations are used as the slave stations; and, when the master station gradually rises direct-current voltage to a rated value, the slave stations track the direct-current voltage of the master station through the difference between a direct-current feedback value and a direct-current reference value, so that synchronous rising of the direct-current voltage is realized. By means of the method and device for recovering the direct-current short-circuit failure of the hybrid modular multilevel converter disclosed by the invention, inter-station communication is not needed in the whole recovery process; cooperation of a circuit breaker is not needed; the convertor stations can recover the direct-current voltage rapidly and stably after the direct-current short-circuit failure is ended, and can recover the direct-current voltage to the normal operation state before the direct-current failure according to a pre-set process and detection of the own electrical quantity; impact current does not exist in the recovery process; and the grid-connected state can be continuously kept.

Description

technical field [0001] The invention belongs to the technical field of direct current transmission, and in particular relates to a method and a device for recovering a direct current short-circuit fault of a hybrid modular multilevel converter. Background technique [0002] At present, with the development of fully-controlled power electronic devices and the application of power electronic technology in power systems, the flexible DC transmission technology based on voltage source converters has been paid more and more attention. Modular multilevel converter (MMC) is one of the voltage source converters used in flexible DC transmission systems. It is composed of multiple sub-modules connected in a certain way. By controlling the IGBT groups of each sub-module The input and cut-off states make the AC voltage output by the converter close to a sine wave, realizing efficient energy transmission. [0003] In traditional modular multilevel converters, half-bridge sub-modules are...

Claims

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Application Information

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IPC IPC(8): H02J3/36
CPCH02J3/001H02J3/36Y02E60/60
Inventor 李道洋吴金龙王先为刘欣和张浩行登江孙树敏李广磊
Owner XUJI GRP
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