Comparative framework for AC-microgrid protection schemes: challenges, solutions, real applications, and future trends

Abstract

With the rapid development of electrical power systems in recent years, microgrids (MGs) have become increasingly prevalent. MGs improve network efficiency and reduce operating costs and emissions because of the integration of distributed renewable energy sources (RESs), energy storage, and source-load management systems. Despite these advances, the decentralized architecture of MGs impacts the functioning patterns of the entire system, including control strategy, energy management philosophy, and protection scheme. In this context, developing a convenient protection strategy for MGs is challenging because of various obstacles, such as the significant variance in short-circuit values under different operating modes, two-way power flow, asynchronous reclosing, protection blinding, sympathetic tripping, and loss of coordination. In light of these challenges, this paper reviews prior research on proposed protection schemes for AC-MGs to thoroughly evaluate network protection's potential issues. The paper also provides a comprehensive overview of the MG structure and the associated protection challenges, solutions, real applications, and future trends.

Stability-Constrained Settings of Directional Overcurrent Relays With Shifted User-Defined Characteristics for Distribution Networks With DERs

“…The CTI is the minimum time difference between the operation of backup and primary relays for any fault, with a recommended range of 0.2 to 0.5 seconds [5]. This constraint can be mathematically represented as shown in (3).…”

“…Although the contributions of MGs in terms of sustainability of supply, energy efficiency, and system reliability [2], they have been found to negatively affect existing protection systems due to the changes they bring to the short circuit levels. The changes depend on capacity, location, and operating mode and type of the DERs (inverter-based or synchronous-based) [3].…”

A Novel Fault Detection and Location Approach for DC Zonal Shipboard Microgrid Based on High-Frequency Impedance Estimation With IEC 61850 Communication Protocol

“…If both the detecting and received signals are equal to '1', the tripping signal will be '1'. If not, the tripping signal will be '0' as expressed by (17).…”

“…Moreover, the ships are exposed to various uncertainties, including; The fluctuation in photovoltaic (PV) output power due to ship movement, even with constant solar radiation [13], and uncertainties related to weather conditions like wave parameters (height and length) and wind characteristics (speed and direction) introduce variability in navigation resistance during the voyage. Thus, the ship's propulsion loads differ according to the various navigation uncertainties [14]- [17]. Such uncertainties affect the performance of the traditional protection schemes used in SPS.…”

The recent development of protection coordination schemes based on inverse of AC microgrid: A review

“…[39] The primary goal is to critically evaluate various AC microgrid protection approaches that have been suggested in the literature, with an emphasis on recent protection strategies that use innovative intelligent approaches. [40] This study covers earlier research on prospective AC-MG protection solutions in order to completely evaluate potential network protection issues.…”