China's first 110kV eco-friendly rapid-switching fault current limiter has been connected to the grid and is now in operation

On April 14, in Jinchang city, Gansu province, as soon as the command was given, an artificially simulated single-phase instantaneous grounding short-circuit arc was instantly triggered at the 1.4-kilometer mark of the Shuang'er Line of the 330kV Dongdatan Substation belonging to State Grid Jinchang Power Supply Company.

Just 6.8 milliseconds later, the rapid switch on the medium-voltage side of Main Transformer No 2 actuated precisely and successfully engaged the current-limiting reactor, marking the triumphant conclusion of the first manually initiated grounding short-circuit test in Gansu province to validate the performance of rapid switches! This test serves as a pivotal technical support for the security protection of new power systems. Meanwhile, the nation's first 110kV eco-friendly rapid-switching fault current limiter has been commissioned at the 330kV Dongdatan Substation of State Grid Jinchang Power Supply Company.

It is reported that the 110kV eco-friendly rapid-switching fault current limiter installed this time marks the debut of NARI-RELAYS' latest equipment designed to restrict short-circuit currents on 110kV busbars. This device comprises a 50 kA rapid circuit breaker and a 12-ohm current-limiting reactor. Boasting the core technical strengths of "swift response and precise control," the entire system leverages dual protection devices, optical fiber communication control circuits, and electromagnetic repulsion mechanisms. These advantages enable the rapid engagement of the current-limiting reactor within milliseconds, effectively capping the fault current within a safe threshold, ensuring the safe disconnection of ordinary switches, and significantly enhancing the safe and stable operation of the power grid.

To comprehensively verify the reliability and safety of a novel current-limiting device under extreme operating conditions, and to tackle the formidable challenge posed by the combination of gaps in locally available artificial short-circuit testing technology and grid operation risks, Gansu Provincial Company took a bold and innovative approach, systematically conducting a 110kV artificial grounding short-circuit test for the first time.

For this test, a "three-in-one" collaborative mechanism was established, led by the Equipment Management Department of the provincial company, which formed a special working group. This group conducted joint, multi-disciplinary site inspections, precisely calculated short-circuit current parameters, reviewed and approved project proposals, procured specialized test equipment and protective devices, and visited peer units in Ningxia for on-site learning and benchmarking. State Grid Jinchang Power Supply Company implemented a wall chart strategy for various stages of the project, including civil construction, electrical installation, equipment commissioning, safety verification, and equipment startup. By comparing standards and benchmarks, they considered system safety from multiple dimensions, including each startup step and setting value, to provide comprehensive support for the project. Simultaneously, an emergency reserve mechanism was established to efficiently allocate specialized test equipment and rapid defect elimination materials. Gansu Electric Power Research Institute assembled an expert team to oversee and verify the entire technical process.

The commissioning and grid integration of the 110kV eco-friendly rapid-switching fault current limiter has addressed the challenge of excessive short circuits in the development of new power systems, decreasing the likelihood of system instability. This holds immense significance for the establishment of safe, efficient, and low-carbon new power systems. It will enhance regional power supply capabilities, supporting the growth of Jinchuan Group Co Ltd, a Fortune Global 500 company located in Gansu province, with high-quality electricity, and actively contributing the "Jinchang experience" to the advancement of new power system construction.