Transient energy-based combined fault detector and faulted phase selector for distribution networks with distributed generators

摘要

Selective phase tripping during unbalanced short-circuit fault helps in improving the reliability of the smart distribution systems. Selective phase tripping demands correct identification of faulted phase(s). The existing practices fail to identify the faulted phase(s) correctly in smart grids that include inverter-interfaced distributed generators (DGs), such as wind and solar photovoltaic (PV) DGs. This paper presents a fault-detection and faulted-phase(s)-identification scheme for smart distribution systems installed with both synchronous and PV distributed generators. In this work, the transient energies derived from the superimposed components of the measured voltage and current signals at both ends of a feeder are utilized for accomplishing the fault-detection and faulted-phase(s)-identification task. The performance of the proposed method is evaluated for numerous fault and nonfault cases generated on three different test systems through power system computer aided design/EMTDC at different system operating modes and topologies. Fast response time (less than one cycle), low computational burden, and relatively high accuracy compared to the existing methods justify the efficacy of the proposed approach.