A SMF (single-mode optical fiber) multi-point synchronous triggering system is proposed in this paper. This system uses the partial discharge sensors embedded in basin insulators mounted on the GIS cavity to obtain a stable trigger signal. Triggering system transmits the optical trigger signal through the single-mode optical fiber. Therefore, this system is able to transmit the trigger signal using the communication optical fiber cable installed in the power plants without the need to lay fibers manually. Through theoretical and experimental analysis, the inherent time difference between each triggering channel is determined. The fast transient overvoltage generated by the breaker operation in 500 kV GIS at a pumped storage power station is measured by this system. The analysis of the measurement results shows that the system can reliably trigger the oscilloscope to record the fast transient waveform. The propagation time of the fast transient overvoltage wave between two measurement points obtained by the synchronous trigger device is basically consistent with the theoretical analysis.

Fast transient overvoltage, pumped storage power plants, synchronous trigger, GIS, single-mode fiber