Adaptive Frequency Estimation Method for ROCOF Islanding Detection Relay
Department of Electrical and Computer Engineering
Rate-of-change-of-frequency (ROCOF) is one of the most popular local islanding detection methods due to its simplicity and low cost. However, the method suffers from significant non-detection zone (NDZ) and experiences security issues due to non-islanding events. In this article, an enhancement of the ROCOF relay, improving frequency estimation is proposed and compared to standard methods. Results are obtained through real-time hardware-in-the-loop (RT-HIL) simulations using an IEC61850 compliant STM32F746NG microprocessor acting as a ROCOF relay. Feasibility of the method has been proven experimentally. As demonstrated, it has an ability to significantly mitigate a number of nuisance trippings for non-islanding events. For the CIGRE medium voltage benchmark distribution network, the proposed method provided full security at the setting of 0.5 Hz/s for adjacent feeder faults, whereas the standard methods happened to fail even at the setting of 1 Hz/s. Additionally, as shown, an improvement of the relay security can lead to reduction of NDZ.
IEEE Transactions on Power Delivery
Adaptive Frequency Estimation Method for ROCOF Islanding Detection Relay.
IEEE Transactions on Power Delivery,
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/2668