On February 28th, the Unified Power Flow Controller(UPFC) for 220kV Nanjing Western-Ring grid witnessed the successful clearing of earthing short-circuit current during the test. The test was conducted to examine the mechanical performance, control and protection functions of the UPFC solution provided by NR Electric. A manual earth fault was performed to Phase B, in which the UPFC was quickly bypassed it within 2ms. After the switch was reclosed, the UPFC immediately restarted to drive the line power flow to pre-fault condition. During the test, each component operated normally and all protection devices operated appropriately.
The UPFC was put into service in 220kV Nanjing Western-Ring grid in December 2015. Since its operation, it realizes flexible control of power flow, and consequently improves the power supply capability and reliability in the Nanjing city grid. This test shows NR Electric’s UPFC can sustain the current impulse caused by a short-circuit fault. The high reliability and well ride-through performance make it suitable for all kinds of city grids.