A new numerical distributed busbar protection

The paper describes a new numerical protection for busbar. The proposed protection employs a protection technique based on polarities of transient current waves for identification of the faults internal and external to the busbar. In the technique, the polarities of transient currents can be extracted reliably using a wavelet transform modulus maximum. To improve the reliability of the distributed busbar protection system, message exchange based on "protection signal bus" is presented and applied for the implementation of distributed bus protection. Using this method the comparison and exchange of polarity information among the protection units can be completed reliably.