# A Novel Hybrid Approach Using SMS and ROCOF for Islanding Detection of Inverter-Based DGs

## TL;DR

This paper introduces a hybrid islanding detection method combining SMS and ROCOF techniques for inverter-based distributed generators, improving detection speed and reducing non-detection zones.

## Contribution

It presents a novel hybrid approach that integrates active and passive methods, enhancing detection accuracy and response time for inverter-based DGs.

## Key findings

- Effective detection under high-Q loads
- Operates accurately during load switching
- Does not interfere with normal system operation

## Abstract

This paper proposes a novel hybrid approach for islanding detection of inverter-based distributed generations (DG) based on combination of the Slip mode frequency-shift (SMS) as an active and rate of change of frequency (ROCOF) relay and over/under frequency relay as passive methods. This approach is utilized to force the DG to lose its stable operation and drift the frequency out of the allowed range of the frequency threshold. Performance of the proposed approach is evaluated under the IEEE 1547, UL 1741 and multiple-DG operation. The simulation results demonstrate the effectiveness of the proposed approach for detection of islanding, especially for loads with high quality factor. It operates accurately under the condition of load switching and does not interfere with the power system operation during normal condition. In other words, not only it holds the benefits of both SMS and ROCOF, but also it removes their drawbacks by having less non-detection zone and faster response.

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Source: https://tomesphere.com/paper/1702.03248