High speed numerical techniques for transmission line protection

The application of numerical processing techniques to the field of protection relays is well established. Numerical relays can be more flexible, cost effective and offer increased functionality compared with electromagnetic or static relays. However, due to restrictions in processing power and limitations of the algorithms used, previous numerical relays have not always met the protection performance that had been previously achieved by static relays. The design and selection of algorithms to produce a high speed distance relay are discussed, together with a summary of the implementation. The applications benefits and the additional features provided by such an implementation are also covered