A New Adaptive Load-Shedding and Restoration Strategy for Autonomous Operation of Microgrids: A Real-Time Study

Abstract

A B S T R A C TIslanding operation is one of the main features of a MicroGrid (MG), which is realized regarding the presence of distributed energy resources (DERs). However, in order to deal with the control challenges, which an MG faces during island operation, particularly when the transition is associated with certain excessive load, an efficient control strategy is required. This paper introduces a Central Management Agent (CMA) which maintains the stability of the MG, once it is islanded, by controlling an Energy Storage System (ESS) and a Central Synchronous Generator (CSG). Further, this paper proposes a new adaptive load-shedding/restoration schemes that calculates the amount of power imbalance based on frequency measurements combined with the mean value of the frequency gradient. The primacy of the proposed scheme over existing schemes, like instantaneous frequency gradient-based load shedding scheme, is its robustness against frequency oscillations. Moreover, the proposed method acts compatible with the control routine of DERs and the intermittent nature of the PV plant. As another salient feature of this paper, a Hardware In the Loop (HIL) testbed for real-time simulation is developed under which the proposed scheme and related communication with CMA along with other components are evaluated. The obtained results show that the control strategy can confidently conserve the stability of the MG in islanded mode and meet smooth reconnection to the grid-connected mode.

A Disturbance Observer Based Fuzzy Feedforward Proportional Integral Load Frequency Control of Microgrids

“…In order to deal with the control challenges of islanded microgrids, an efficient control strategy is required. Toward this end, a Central Management Agent which maintains the stability of the microgrid by controlling an Energy Storage System and a Central Synchronous Generator is presented by Farzinfar et al [7].…”

A New Consensus-based Distributed Adaptive Control for Islanded Microgrids

“…Proper control of microgrid is a prerequisite for stable and economically efficient operation [4,5]. To maximize the use of resources and improve the effectiveness of DGs, a modern control approach is required to increase the microgrid reliability and to provide global stability for the system [6,7].…”