Informational Fundamentals of the Multiparameter Differential Protection of Busbar Generators against Single Line-to-Ground Faults

Abstract

The multiparameter differential protection of busbar generators against single line-to-ground faults (SLGF) is studied in accordance with information theory of protection. Such protection is based on the use of the individuality property of harmonic groups. Moreover, it controls many parameters of the higher harmonics of differential currents and is shown to have absolute selectivity. Given the properties of the harmonics of some groups, this perfection is achieved to maintain the aggregate information support of protection at a high level with SLGF in areas where the harmonics of other groups are insufficient. Depending on network parameters and modes, multiparameter differential protection does not require settings or adjustments. This advantage is provided by using relative characteristic values that are generated by the protection during operation. Such protection is sensitive due to a special active-adaptive recognition path, which can measure low-level harmonics against a background of the predominant component of the fundamental harmonic in the current.