GSR017: Treatment of Switch Faults in Operational Timescales

Under the current version of the NETS SQSS, switch faults are secured for new generation connections but only with respect to limiting the loss of power infeed to the infrequent infeed loss risk. Switch faults can potentially cause wider system issues such as instability, system splits, cascade tripping and voltage collapse depending on the substation at which they occur, the network running arrangement and the demand and generation level at the time of fault. A review of the current SQSS will determine the need case for securing against the above challenges in the event of switch faults in operational timescales.