Safety and stability control system for AC outgoing line of converter station

Abstract

The application discloses a safety and stability control system of an AC outgoing line of a converter station, which comprises an AC station control and a unit control layer. The AC station control collects three-phase currents of each AC outgoing line in an AC bus of the converter station, judges whether the three-phase currents are greater than an overload setting value, and when the three-phase currents are greater than the overload setting value, determines whether there is any AC outgoing line of the AC bus whose three-phase current is less than a low-load setting value corresponding to the AC outgoing line. When there is an AC outgoing line whose three-phase current is less than the corresponding low-load setting value, it is judged whether the survival time of the three-phase current less than the low-load setting value and the three-phase current greater than the overload setting value is greater than a first threshold value, and when the survival time is greater than the first threshold value, an overload power limiting instruction is issued to the unit control layer. The unit control layer adjusts an upper limit value of DC power and a reference value of DC power of the converter station to reduce the three-phase current greater than the overload setting value. It can be seen that the application can maintain the stable operation of the flexible DC power transmission converter station.

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