Enhancing distribution system resilience using micro-phasor measurement units to address unintentional islands following faults

Abstract

This paper proposes a novel approach to assess network conditions, enabling timely decisions to be made regarding protective actions or control adjustments for distributed generators (DGs) instead of immediate disconnection upon detecting an unplanned islanding event. By facilitating swift decision-making, this strategy aims to minimize outage durations, enhance system reliability, and improve customer satisfaction levels. The first step in the proposed approach involves the implementation of a passive islanding detection method based on continuous monitoring of voltage and current phasors at DG buses equipped by micro-phasor measurement units (μPMUs). Subsequently, a faulted line detection algorithm is applied to identify if the fault lies within the isolated area. If the fault determined to be within the separated region, the DG disconnects from the grid, providing power solely to its local load. In contrast, if the fault is located outside the isolated area or if islanding occurs due to reasons other than faults, the DGs control strategies are adjusted to support the islanded conditions effectively. The performance of the proposed procedure is thoroughly analyzed through the integration of MATLAB and DIgSILENT simulation environments. The IEEE 33-bus and IEEE 69-bus test systems with both synchronous-based and inverter-based DGs are used for the assessment.