Method for current differential protection of direct current electric transmission line

• Main Authors: JIAO ZAIBIN, SUONANJIAR, GAO SHUPING, SONG GUOBING
• Format: Patent
• Language: Chinese; English
• Published: 01.06.2011
• Subjects: CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION

The invention discloses a method for current differential protection of a direct current electric transmission line, which comprises the following steps: according to a distributed parameter model of the electric transmission line, using mode transformation in a time domain to transform sampling values of direct current and direct current voltage into a modulus; then using the mode voltage and thecurrent of two ends from two ends of a line respectively to calculate mode current of certain point of the line at each moment; and using the mode current to directly construct a current differentialprotection criterion, or synthesizing electrode current through electrode mode inverse transformation, and then constructing the current differential protection criterion according to the electrode current. The method can improve the sensitivity and the reliability of direct current line protection, has good controllability and high security, has a complete setting theory, overcomes the defects of the conventional traveli