Permutation Entropy Thresholding: A Non-Linear Signal Processing Method for Islanding Detection

ABSTRACT

A novel passive method based on Permutation Entropy (PE) is proposed for fast, efficient, and differential detection of islanding from other disturbance events in power system. The extremely remarkable attributes of PE such as efficient and fast detection of change in dynamics as well as computational and conceptual simplicity can be appropriately utilized to devise a thresholding system that can differentiate the change in dynamics of islanding event from the non-islanding ones with negligible Non-Detection Zone (NDZ). As NDZ is the most critical issue of existing passive islanding detection methods, which overshadows its beneficial characteristics, this new approach can prove to be a suitable alternative with an added benefit of faster detection. The method is evaluated with grid connected single as well as multi-DG systems and its robustness against effects of load quality factors, active and reactive power mismatches is investigated. Results show that this method can detect the islanding disturbance and differentiate it from other disturbances within half a cycle. The performance of the proposed method is evaluated with photovoltaic (PV) sources and also validated on IEEE 14 bus model. Results indicate the suitability of the PE method for the common DG source of PV for a wide range of power mismatches including the worst cases and also its robustness against false tripping during DG switching. The results verify the credibility and advantage of the proposed PE thresholding method and its suitability for adopting into existing networks for passive islanding detection.

KEYWORDS:

• Distributed generation
• Islanding
• Microgrids
• Permutation entropy
• Photovoltaic systems
• Power system protection

Acknowledgement

One of the authors, (BMK) would like to thank Dr. J. Bhatt, Director, STIC, CUSAT for the extensive support and encouragement provided for doing the research work.

Additional information

Notes on contributors

Sindhura Rose Thomas

Sindhura Rose Thomas is a research scholar in Electrical and Electronics Engineering Department, School of Engineering, Cochin University of Science and Technology, Kerala, India. She is also working as an assistant professor in Muthoot Institute of Technology and Science, Kerala, India. Her research interests are dynamics of non-linear systems, non-linear signal processing techniques, and its application to power systems. Email: [email protected]

Bindu M. Krishna

Bindu M Krishna has obtained MSc (Physics) from St Paul's College, Mahatma Gandhi University, PhD from International School of Photonics, Cochin University of Science and Technology. She is currently working as a research scientist at the Sophisticated Test and Instrumentation Centre, Cochin University of Science and Technology. Area of specialization: nonlinear dynamics & secure communication.

Usha Nair

Usha Nair is a graduate and post graduate in electrical engineering. She has completed her PhD from Cochin University of Science and Technology and worked as an associate professor in the Department of Electrical and Electronics Engineering for 20 years and retired in the year 2019. She is presently working as adjunct faculty in the same department. Her areas of interest are nonlinear dynamical analysis, control system design, time series analysis and renewable energy. Email: [email protected]