Open AccessStudy on pre‐charging process and pre‐insertion resistors selection of VSC‐HVDC system with different MMC topologies
Author(s) -
Lu Yuxin,
Huang Ying,
Zhao Xiaobin,
Xu Dizhen,
Guo Long,
Qin Kang
Publication year - 2019
Publication title -
the journal of engineering
Language(s) - English
Resource type - Journals
ISSN - 2051-3305
DOI - 10.1049/joe.2018.8713
Subject(s) - resistor , network topology , selection (genetic algorithm) , process (computing) , electrical engineering , computer science , materials science , topology (electrical circuits) , engineering , computer network , voltage , artificial intelligence , operating system
Here, the uncontrolled rectification pre‐charging characteristics of the VSC‐HVDC system with different modular multilevel converter (MMC) topologies such as full‐bridge, half‐bridge, and hybrid topologies are proposed based on theoretical analysis and PSCAD/EMTDC simulations. Different MMC topologies have a great impact on the selection of pre‐insertion resistors. The surge energy of pre‐insertion resistors is the lowest with the full‐bridge sub‐module (FBSM) MMC, while much higher with the half‐bridge sub‐module (HBSM) MMC. In order to prevent start‐up failure caused by extremely non‐uniform voltage between FBSM and HBSM of hybrid MMC, the FBSM should be turned to half‐bridge state by valve control system as soon as possible so as to carry out the second charge, and then balance the sub‐modules voltage by bypass certain high‐voltage sub‐modules. The half‐controlled charging process has a great influence on the absorbed energy of the pre‐insertion resistors of hybrid MMC. The research results can be used to guide the selection of VSC‐HVDC pre‐insertion resistors and start‐up strategy making.