A New Passive Islanding Detection Solution Based on Accumulated Phase Angle Drift

Abstract

The existing passive methods for islanding detection are mainly based on the detection of voltage and frequency deviation after islanding, using protections such as voltage vector shift (VVS) and rate of change of frequency (ROCOF). Although there are reported issues with these passive methods such as inherent non-detection zones and nuisance trips, utilities prefer the passive methods due to the low cost and simplicity of deployment. In this paper, one composite passive islanding detection method is presented. It tracks the voltage phase angle, the system frequency, and ROCOF every power cycle. If three phase voltage vectors shift in the same direction and the rotated angle values are balanced, the calculation of the accumulated phase angle drift (PAD) will be initiated. This calculation continues until the ROCOF measurement is below the ROCOF setting threshold. If the accumulated phase angle drift reaches the set angle threshold, the condition for islanding is claimed. The performance of this composite method is verified under different scenarios based on Matlab Simscape multidomain physical systems and practical waveforms recorded from sites. Although there are still non-detection zones, this composite PAD solution has better sensitivity than existing VVS and ROCOF methods and is stable under external system faults.

A Market Assessment of Distributed Battery Energy Storage to Facilitate Higher Renewable Penetration in an Isolated Power System

“…However, in terms of network build out avoidance and local peak supply constraints there is an argument for smaller and more distributed battery connections. This study is limited in that the impact of vector shift in the voltage waveform during rapid changes in system conditions on the ROCOF has not been considered [49]. Vector shift can impact the ROCOF calculation and is dependent on the location.…”

Islanding Detection of Synchronous Distributed Generator Based on the Active and Reactive Power Control Loops

“…The pattern illustrates dynamic behavior of the DG in islanding and non-islanding situation. Some other passive islanding detection solutions are [10][11][12][13][14], and vector surge relay [15]. The main drawbacks of these methods are large none-detection zone (NDZ), low ability discrimination between islanding and non-islanding situation, and the problem of determining the threshold values.…”