Method and system for protecting subareas of direct-current (DC) power grids

• Main Authors: WEI CHUNXIA, WANG ZHIBING, YANG BO, LI YAN, CHI YONGNING, WU JING, XIE LIJUN, CAO YUANZHI, LIU CHAO, YAO LIANGZHONG
• Format: Patent
• Language: Chinese; English
• Published: 31.05.2017
• Subjects: CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION

The invention provides a method and a system for protecting subareas of direct-current (DC) power grids. The method comprises the steps of using DC protection units (RPUs) arranged on connecting lines of the DC power grids to collect fault protection information of a fault isolation device, and judging whether protection actions of the RPUs are started or not according to the fault protection information, so as to realize the subarea fault isolation among the DC power grids; using local measurement and protection units (LMPUs) arranged in the subareas of the DC power grids to judge whether protection actions of the LMPUs are started or not based on the fault protection information, so as to realize the fault isolation between the DC power grids and alternating current (AC) power grids. According to the method and the system, a layered and divisional DC power grid fault protection frame is adopted, and all LMPU systems are independent of one another, so that the coupling relationships between the LMPUs and bet