Here we deal with the protection and control principles of high voltage stations. HV Bus Differential Protection is studied along with restrictions due to CT saturation and mismatch and its solution, “Restraint Differential Protection”.

Starting with system faults and how they affect switchyard configuration and elements simple “Differential Protection” is examined along with the mal-operation due to CT saturation and mismatch.

High-voltage circuit breakers are examined as to the various types (oil, vacuum, air blast, SF6), their controls (closing/tripping/anti-pumping) Reclosure Synchrocheck relay CUH 90 – VG, as well as breakers failure protection, is part of this module along with a quick look at dynamic monitoring equipment. Transfer and remote tripping along with the need to provide immunity from ground rise potential and open-circuit situations.