Title:
METHOD FOR IDENTIFYING SINGLE POLE GROUND FAULT IN VSC-DC POWER DISTRIBUTION NETWORK, AND SINGLE POLE GROUND FAULT PROTECTION METHOD FOR VSC-DC POWER DISTRIBUTION NETWORK
Document Type and Number:
WIPO Patent Application WO/2018/094862
Kind Code:
A1
Abstract:
Provided are a method for identifying a single pole ground fault in a VSC-DC power distribution network, and a single pole ground fault protection method for a VSC-DC power distribution network. The method comprises: acquiring voltages to ground (UP, UN) of positive and negative DC lines, acquiring a voltage change rate between the positive and negative DC lines; if an absolute value of the voltage change rate between the positive and negative DC lines is greater than a first comparison threshold (dUdcset), generating a pulse signal and stretching the pulse signal to a preset value (t1), and if an absolute value of a sum of the voltage to ground (UP) of the positive DC line and the voltage to ground (UN) of the negative DC line is greater than a second comparison threshold (Udcunbalset) for a duration exceeding a time threshold (t2), determining that a single pole ground fault has occurred. The method enables quick identification of a single pole ground fault. In the invention, a DC circuit breaker in which a DC line encountering a ground fault is located is skipped, thereby realizing quick isolation of a faulty line, and increasing reliability of power supply of a DC power distribution network.
Inventors:
ZHANG AILING (CN)
PENG ZHONG (CN)
LI SHAOHUA (CN)
LI TAI (CN)
JING XUEJI (CN)
ZHOU JINPING (CN)
SUN YUN (CN)
ZHAO JING (CN)
MA XIAOTING (CN)
HU YONGCHANG (CN)
SU JINGUO (CN)
LI YANMEI (CN)
PENG ZHONG (CN)
LI SHAOHUA (CN)
LI TAI (CN)
JING XUEJI (CN)
ZHOU JINPING (CN)
SUN YUN (CN)
ZHAO JING (CN)
MA XIAOTING (CN)
HU YONGCHANG (CN)
SU JINGUO (CN)
LI YANMEI (CN)
Application Number:
PCT/CN2017/070494
Publication Date:
May 31, 2018
Filing Date:
January 06, 2017
Export Citation:
Assignee:
XJ GROUP CORP (CN)
XJ ELECTRIC CO LTD (CN)
STATE GRID CORP CHINA (CN)
XJ ELECTRIC CO LTD (CN)
STATE GRID CORP CHINA (CN)
International Classes:
G01R31/02; H02H7/26
Domestic Patent References:
| WO2016156435A1 | 2016-10-06 |
Foreign References:
| CN102856881A | 2013-01-02 | |||
| CN104820157A | 2015-08-05 | |||
| CN105322536A | 2016-02-10 | |||
| CN105552947A | 2016-05-04 | |||
| US20130193766A1 | 2013-08-01 |
Other References:
SUN, GANG ET AL.: "Research on the Fault Location Method and Protection Configuration Strategy of MMC Based DC Distribution Grid", POWER SYSTEM PROTECTION AND CONTROL, vol. 43, no. 22, 16 November 2015 (2015-11-16), pages 127 - 133, ISSN: 1674-3415
Attorney, Agent or Firm:
CHINA PAT INTELLECTUAL PROPERTY OFFICE (CN)
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