A protection scheme for microgrid with multiple distributed generations using superimposed reactive energy. (November 2017)

• Record Type: Journal Article
• Authors: Bukhari, Syed Basit Ali; Saeed Uz Zaman, Muhammad; Haider, Raza; Oh, Yun-Sik; Kim, Chul-Hwan
• Is Part Of: International journal of electrical power & energy systems. Volume 92(2017)
• Page Start: 156
• Page End: 166
• Publication Date: 2017-11
• Subjects: Microgrid protection scheme -- Superimposed reactive energy -- Fault detection -- Fault location -- High-impedance fault; Electrical engineering -- Periodicals; Electric power systems -- Periodicals; Électrotechnique -- Périodiques; Réseaux électriques (Énergie) -- Périodiques; Electric power systems; Electrical engineering; Periodicals; 621.3
• DOI: 10.1016/j.ijepes.2017.05.003
• Languages: English
• ISSNs: 0142-0615

Abstract

Highlights: A new strategy is proposed for protection of microgrids against solid and high impedance faults. Sequence components of superimposed current are used to detect fault incidents in microgrids. Superimposed reactive energy is used for fault location and classification in microgrids. The paper outlines the structure and key components of the proposed protection relay. Abstract: With the growing integration of distributed generation, distribution networks have evolved toward the concept of microgrids. Microgrids can be operated in either the grid-connected mode to achieve peak shaving and power loss reduction or the islanded mode to increase the reliability and continuity of supply. These two modes of operation cause a challenge in microgrid protection, because the magnitude of fault current decreases significantly during the transition of a microgrid from the grid-connected mode to the islanded mode. This paper proposes a protection scheme for the microgrid based on superimposed reactive energy. The proposed scheme uses the Hilbert transform to calculate the superimposed reactive energy (SRE). The sequence components of superimposed current are adopted to detect fault incidents in the microgrid. The faulty phase and section are recognised by using the directional characteristics of SRE along with a threshold value. Moreover, a relay structure, which enables the proposed protection scheme, is designed. The significant feature of the proposed protection scheme is that it has the ability to protect the looped and radial microgrids against solid and high-impedance faults. To verify the efficacy of the proposed approach, extensive simulations have been carried out using the MATLAB/SIMULINK software package. The results show that the proposed scheme successfully identifies and isolates various types of fault in a microgrid and performs well with different fault resistances and fault locations.