A study of the application of fast valving and braking resistor for an intelligent SPS

There are some kinds of remedial action schemes that deal with sudden disturbance situations in a transmission network. Generator tripping with an SPS (Special Protection System) is one of the remedial action schemes, and it is a powerful and effective method of solving transient stability problems. When an extra-high-voltage transmission line that is transferring a large amount of power is tripped, generators designated by a SPS are tripped to prevent over-speeding of the generators. However, the tripping of generators can cause difficulties in the power system operation, and if large amounts of power are tripped, load shedding can occur. Therefore, it is desirable that a minimum number of generators is tripped in required stable conditions. For this purpose, an intelligent SPS is currently being developed to reduce the number of generator tripping events. In this paper, an application method involving fast valving and a braking resistor are analyzed as suitable action schemes for a SPS.