Selectivity problem in adaptive overcurrent protection for microgrid with inverter-based distributed generators (IBDG): Theoretical investigation and HIL verification
Document Type
Article
Publication Date
8-1-2022
Abstract
The advancements in smart grid technologies had brought forth the prospect of self-healing distribution grid through intentional islanding, aided by the steadily rising penetration of inverter-based distributed generations (IBDGs). Adaptive protection is the key enabler for this resilient grid architecture. For cost-effectiveness, overcurrent relays (OCRs) with adaptive features had been proposed, often with the sensitivity problem due to low short-circuit current magnitude from the IBDG taken into consideration and largely addressed. However, apart from this widely discussed sensitivity problem, there is an underlying issue on selectivity of the OCR which is frequently disregarded when designing an adaptive overcurrent protection scheme for IBDG dominated microgrid. This selectivity problem is mainly caused by the current diversion to load during fault, which is often disregarded when performing OCR grading for a conventional grid. In this paper, this selectivity problem of the OCR is discussed in depth through a comparative study of conventional grid and a modern IBDG dominated grid. The coordination time interval margin violations problems are demonstrated through theoretical calculations and real-time hardware-in-the-loop experiments. This research aims to provide better insights into the selectivity problem as a step towards achieving a cost-effective yet reliable overcurrent-based adaptive protection for IBDG dominated microgrid.
Keywords
Relays, Optical character recognition software, Microgrids, Inverters, Sensitivity, Voltage control, Topology, Adaptive protection, Distributed generation, Inverters, Islanding, Microgrids, Power distribution networks, Power system faults, Power system protection, Self-healing microgrid, Smart grids
Divisions
umpedac
Funders
Ministry of Higher Education, Malaysia through the Fundamental Research Grant Scheme (FRGS) [FRGS/1/2020/TK0/UM/02/28],Higher Institution Centre of Excellence (HICoE) Program Research under Grant UMPEDAC - 2020 (MOHE HICOE - UMPEDAC)
Publication Title
IEEE Transactions on Power Delivery
Volume
37
Issue
4
Publisher
IEEE-Inst Electrical Electronics Engineers Inc
Publisher Location
445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA