Information Bases of Algorithms for Protecting a Generator Operating on Busbars from Single-Phase-to-Ground Faults.1 Part III. Investigation of the Information Bases of Algorithms Controlling Higher Current Harmonics

Resumo

The information bases of algorithms for protecting the stator of a generator operating on busbars from single-phase-to-ground faults (SPGFs) are investigated. The information bases of algorithms in which the effective values of the components of zero-sequence higher current harmonics and differential currents are studied. It is shown that higher harmonics in the current of the SPGFs of the generator stator are divided into three groups, the harmonics of each of which have the property of individuality, manifesting itself in the original character of dependence of their level on the location of the SPGFs. The information content of harmonics of one group enrich the information value of other harmonic groups, increasing protection sensitivity and selectivity. It follows from an analysis that the most promising direction of development of algorithms for protection against SPGFs is the use of components of higher current harmonics.