Search results for "MICROGRID"

Intelligent Energy Management System

2009

Energy management is nowadays a subject of great importance and complexity. It consists in choosing among a set of sources able to produce energy that will give energy to a set of loads by minimising losses and costs. The sources and loads are heterogeneous, distributed and the reaction of the system, the choice of sources, must be done in real-time to avoid power outage. The goal of this paper is to present a system able to self-regulate a heterogeneous set of power sources and loads organised as a coherent group of entities that is called micro-grid, in order to optimize several criteria such as: cost and efficiency. This system is based upon the Multi-Agent Systems paradigm. Each micro-g…

Short-circuit Calculations in Hybrid AC/DC Microgrids

2022

In this paper, the issues related to short-circuit calculations in hybrid AC/DC microgrids are discussed. The reference standard for short-current calculations in DC systems is the IEC 61660, which provides a mathematical formulation of the problem. The standard only includes radial DC grids and does not consider a more complex system, such as meshed DC systems or a hybrid AC/DC microgrid. This paper proposes a generalized approach that can be used independently of the characteristics of the hybrid system. The proposed approach is applied to two test microgrids and the results are compared with those obtained simulating the same grids with Neplan 360.

Dynamic Control of Static Converters for the Transition from Grid-on to Grid-off Operation of AC/DC Microgrids

2022

In this paper, specific control logics defined for generators, controllable loads and electric energy storage systems are illustrated in order to improve the reliability of AC/DC hybrid microgrids in their grid-off operation following failure events such as short-circuits, line breaks, sudden disconnections of generating units or loads, etc. After defining specific control schemes, these were modelled in a digital environment and finally tested with dynamic simulations. Finally, the paper highlights the role of virtual synchronous machine control for the self-healing capacity of islanded hybrid microgrids.

Assessing the Economic Benefit due to BESS Management in a Renewable Energy Community of a Small Island

2022

The paper presents a study carried out on the island of Pantelleria regarding the interaction among distributed energy resource and energy storage systems in renewable energy communities. EU, in the Clean Energy Package, defines the 'Jointly acting renewables self-consumers' (JARSCs) and the 'Renewable Energy Communities' (RECs) as innovative models to share energy from renewables facilities. Nevertheless, the behaviour of JARSCs and RECs is designed to maximize the final users' self-consumption without considering the impacts on the power grid operation. A comparison of various operational strategies of BESS and an investigation of their effect on the distribution network are key elements …

Frequency Dynamics in Fully Non-Synchronous Electrical Grids: A Case Study of an Existing Island

2022

The operation of a power system with 100% converter-interfaced generation poses several questions and challenges regarding various aspects of the design and the control of the system. Existing literature on the integration of renewable energy sources in isolated systems mainly focuses on energy aspects or steady-state issues, and only a few studies examine the dynamic issues of autonomous networks operated with fully non-synchronous generation. A lack of research can be found in particular in the determination of the required amount of grid-forming power, the selection of the number and rated power of the units which should implement the grid-forming controls, and the relative locations of …

A New Meta-Heuristic Multi-Objective Approach For Optimal Dispatch of Dispersed and Renewable Generating Units in Power Distribution Systems

2011

The application of stochastic methods in engineering research and optimization has been increasing over the past few decades. Ant Colony Optimization, in particular, has been attracting growing attention as a promising approach both in discrete and continuous domains. The present work proposes a multi-objective Ant Colony Optimization for continuous domains showing good convergence properties and uniform coverage of the non-dominated front. These properties have been proved both with mathematical test functions and with a complex real world problem. Besides the second part of the chapter presents the application of the new algorithm to the problem of optimal dispatch of dispersed power gene…

INVERTER-BASED DISTRIBUTED GENERATORS, MODELING AND CONTROL

In the last few years, electrical power generation is moving from a centralized generation towards distributed generation including on-site Renewable Energy Sources (RESs). In order to overcome RES related issues, as intermittent and fluctuating power, storage elements are included in the on-site generation system. The interaction between distributed generator (DG) units including RES, storage and front-end power converters should be carefully modeled in order to analyze the power system stability. An accurate modeling of DGs is required. In this thesis, a new modeling approach has been proposed for the inverter-based DGs based on the concept of electrostatic synchronous machines. Detailed …

Multi-objective long term optimal dispatch of distributed energy resources in micro-grids

2010

The amount of distributed generators in power distribution systems is evermore increasing, and the potential benefits and drawbacks are becoming clearer. The optimal management of Distributed Energy Resources (DER) in microgrids is essential to guarantee their best exploitation. Optimal operation allows to maximize their benefits, such as reduction of network energy losses, reduction of carbon emissions and to minimize the negative effects of a strong DER penetration, such as the increase of infrastructural investment and operational costs. Hence, DER management is a multi-objective problem in which many objectives of interest, often conflicting, need to be optimized simultaneously. In this…

A Comparison between RMS and EMT Grid-Forming Implementations in MATLAB/Simscape for Smart Grids Dynamics

2022

The article presents a comparison between phasor RMS and EMT models for grid-forming converters. The specific aspects related to the implementation in Simscape Electrical of MATLAB/Simulink are discussed for both RMS and EMT time-domains. The comparison between the different implementations is performed with the simulation of two widely studied grid-forming schemes, the virtual synchronous machine and the power-synchronization control. The simulation-based comparison examines transient phenomena with different characteristics and time scales, including frequency transients, phase jumps and short-circuit events. Specific indications regarding limitations and suitability of grid-forming model…

The possibility of applying combined heat and power microgrid model for industrial parks. A case study for Dong Nam industrial park in Vietnam

2023

Microgrid systems that combine cooling, heating and power (CHP) with distributed cogeneration units and renewable energy sources are a practical way to meet the growing need for energy, and industrial parks have enormous potential for the development of integrated electrical and thermal systems. This paper presents a microgrid CHP model and evaluates the possibility of developing the model in the Dong Nam industrial park in Ho Chi Minh City, Vietnam. HOMER software was used to evaluate the effectiveness of the model.