Title:
CURRENT DIFFERENTIAL PROTECTION METHOD FOR SELF-ADAPTIVE HALF-WAVELENGTH LINE BASED ON TIME-DIFFERENCE METHOD
Document Type and Number:
WIPO Patent Application WO/2017/128631
Kind Code:
A1
Abstract:
A current differential protection method for a self-adaptive half-wavelength line based on a time-difference method. Since an electrical distance of half-wavelength power transmission is long, after a fault occurs, there is an obvious time difference between the actuation times for protecting starting elements at two sides of a line. According to the principles of wave propagation, the position of a fault point can be determined by means of a difference between the actuation times for protecting the starting elements at the two sides of the line. By means of taking the fault point as a differential point, a current value at the differential point can be obtained according to a long line equation by means of the voltage and current at protection-mounted positions at the two sides of the line, and a differential current is then calculated. Since the sensitivity of current differential protection criterion, when a fault occurs at different points of the line, is different, self-adaptively changing a braking coefficient and a threshold value of current differential protection according to the different positions of the differential points. Based on the current differential protection criterion composed of the current at the differential point and the self-adaptively changed braking coefficient and threshold value, it can be ensured that current differential protection has sensitivity across the entire line.
Inventors:
LIANG XUMING (CN)
GUO YARONG (CN)
LIU HUANZHANG (CN)
LI XIAO (CN)
ZHOU ZEXIN (CN)
DU DINGXIANG (CN)
WANG DELIN (CN)
LI JING (CN)
LI HUIXIN (CN)
LI ZHONGQING (CN)
GUO YARONG (CN)
LIU HUANZHANG (CN)
LI XIAO (CN)
ZHOU ZEXIN (CN)
DU DINGXIANG (CN)
WANG DELIN (CN)
LI JING (CN)
LI HUIXIN (CN)
LI ZHONGQING (CN)
Application Number:
PCT/CN2016/089672
Publication Date:
August 03, 2017
Filing Date:
July 11, 2016
Export Citation:
Assignee:
CHINA ELECTRIC POWER RES INST (CN)
STATE GRID CORP CHINA (CN)
CENTRAL CHINA BRANCH OF STATE GRID CORP OF CHINA (CN)
STATE GRID CORP CHINA (CN)
CENTRAL CHINA BRANCH OF STATE GRID CORP OF CHINA (CN)
International Classes:
H02H7/26
Foreign References:
| CN105576623A | 2016-05-11 | |||
| JPH06289067A | 1994-10-18 | |||
| CN1858954A | 2006-11-08 | |||
| CN102868150A | 2013-01-09 | |||
| CN102856890A | 2013-01-02 | |||
| CN102324722A | 2012-01-18 |
Attorney, Agent or Firm:
CHINA PAT INTELLECTUAL PROPERTY OFFICE (CN)
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