Design and Real-Time Implementation of a Centralized Microgrid Control System With Rule-Based Dispatch and Seamless Transition Function

Abstract

With reference to the newly released microgrid standards, design and real-time implementation of a centralized microgrid control system is presented in this article. In the grid-connected mode, the utility grid will provide the voltage and frequency reference at the point of connection. The assets within the microgrid will follow power command references provided by the control system. In the islanded mode, the energy storage system (ESS) can provide the voltage and frequency reference to all other generators. Based on the state-of-charge of the ESS, a rule-based dispatch is proposed, with priority given to diesel generator and then the storage in the middle state of charge range. To alleviate power fluctuations, meet smooth planned islanding requirement, and compensate for the feeder losses ignored in dispatch algorithm, a supplementary slackbus power control based on closed-loop feedback and first-order filter is proposed. The potential of the storage system in firming short-time power fluctuation and providing long-term load shifting capabilities is exploited. An emergency dispatch function for unplanned islanding considering the speed of response limitation of a diesel generator is also proposed. The proposed control strategy is implemented and tested on a controller hardware-in-the-loop test bench. It demonstrates the capability of the control system to reduce load shedding and renewable curtailment, and to implement power management at the point of interconnection. Index Terms-Controller hardware-in-the-loop (C-HIL) test, microgrid control system (MGCS), rule-based dispatch, slackbus power control, smooth transition, state of charge (SoC) management.

Synchronization of Low Voltage Grids Fed by Smart and Conventional Transformers

“…The need for PLL is overcome in [12] with the introduction of an integrated synchronization and control technique, which still requires the mains voltage measurements through a low-bandwidth communication link. The same occurs in [19], with the required signals that is transmitted to the centralized control system and then sent back to the switch and to the inverters primary controls. In [17] a fiber cable is installed between the switch and the converter acting as a master for the microgrid, while in [18] an Ethernet network ensures a fast communication.…”

Advanced Laboratory Testing Methods Using Real-Time Simulation and Hardware-in-the-Loop Techniques: A Survey of Smart Grid International Research Facility Network Activities

“…Since most MGs contain a limited number of assets, simple rule-based dispatch is sufficient for operation. The authors in [37] present the design and validation of a rule-based MGC. The controller topology is centralized in nature, i.e., all the measurements, instrumentation, and any requests from the utility (such as islanding) is communicated to the MGC which sends out the dispatch set-points and other control signals to all the assets.…”

“…1. Microgrid prototyping and validation: Testing AC, DC, and Hybrid MGs requires a wide variety of techniques and methodologies including: benchmarks and prototyping platforms [32][33][34][35], testing chains and procedures for centralized and decentralized controllers [36][37][38][39][40][41], and rapid control prototyping (RCP) for a quick development of new control strategies in a real hardware environments [42][43][44]. 2.…”

Energy Management Electronic Device for Islanded Microgrids Based on Renewable Energy Sources and Battery-based Energy Storage

“…These kinds of experimental platforms are defined as hardware-inthe-loop (HIL) and are commonly used an accepted for the validation of control and management strategies in a real hardware environment (IEEE, 2018). HIL allows a rapid prototyping and performance test of the electronic device by emulating the behavior under real conditions without complex lab setups (Montoya et al, 2020;Estrada, Vázquez, Vaquero, de Castro, and Arau, 2020;Sun et al, 2020).…”