1,720,996 research outputs found
A Review of Primary and Secondary Control for Islanded No-Inertia Microgrids
No full textMicrogrid (MG) control represents an impactful and important topic in current academic and industry research related to power systems. MG operations can be distinguished in grid-connected and islanded operations. Among these two, islanded operation is for sure the more challenging since the MG control need to cope with voltage and frequency regulation that is usually not a problem for grid connected ones. Achieving these goals become even more complex if no-inertia MGs are considered i.e. MG where no synchronous generation is directly connected to the grid. This paper proposes a detailed review of state-of-the-art architecture for the hierarchical control of islanded, no-inertia MGs in order to highlight its characteristics and limitation with the aim of providing a suitable background for further developments of control approaches for this kind of applications
Electric Vehicle Fleet Management for a Prosumer Building with Renewable Generation
No full textThe integration of renewable energy systems in buildings leads to a reduction in energy bills for end users and a reduction in the carbon footprint of such buildings, usually referred to as prosumers. In addition, the installation of charging points for the electric vehicles of people working or living in these buildings can further improve the energy efficiency of the whole system if innovative technologies, such as vehicle-to-building (V2B) technologies, are implemented. The aim of this paper is to present an Energy Management System (EMS) based on mathematical programming that has been developed to optimally manage a prosumer building equipped with photovoltaics, a micro wind turbine and several charging points for electric vehicles. Capabilities curves of renewable power plant inverters are modelled within the EMS, as well as the possibility to apply power curtailment and V2B. The use of V2B technology reduces the amount of electricity purchased from the public grid, while the use of smart inverters for the power plants allows zero reactive power to be drawn from the grid. Levelized cost of electricity (LCOE) is used to quantify curtailment costs, while penalties on reactive power absorption from the distribution network are evaluated in accordance with the current regulatory framework. Specifically, the model is applied to a prosumer building owned by the postal service in a large city in Italy. The paper reports the main results of the study and proposes a sensitivity analysis on the number of charging stations and vehicles, as well as on the consideration of different typical days characterized by different load and generation profiles. This paper also investigates how errors in forecasting energy production from renewable sources impact the optimal operation of the whole system
Energy Management System for the Optimal Operation of a Grid-Connected Building with Renewables and an Electric Delivery Vehicle
No full textThe paper proposes a Mixed-Integer Linear Programming (MILP) optimization model used to define an Energy Management System (EMS) to daily operate two Renewable Energy Source (RES) power plants and an Electric Vehicle (EV) charging station installed in a building. The analysed case study refers to a building located in a small town on an island in the South of Italy. The building hosts the post office and the EV is a van used to transport mail. The building is connected to the external distribution grid, allowing active and reactive power exchanges. Different scenarios have been evaluated, considering the installation of photovoltaic (PV) modules, small wind turbines (WTs) and enabling vehicle-to-building (V2B) application. The analysis aims to highlight the role of RES power plants to limit reactive power absorption from the distribution grid and the contribution of the electric vehicle to mitigate RES curtailment
Simplified Conditions for the Evaluation of Droop-Controlled Microgrids Stability
No full textThe control logic of a Microgrid (MG) represents one of the most important topic in power system engineering research. The most common and well-known control logic is represented by the droop one, that allows each MG source to share the power request and to participate to the frequency and voltage controls. In order to reach this goal, the stability of this control logic is fundamental and it is important to understand if a determined working point can be reached. In this paper a new stability condition, based on a mathematical framework and with some simplifying assumptions is presented. The proposed approach has the advantage of being a fast calculation that can predict the reachability of a particular working point that reflects a particular load request without using numerical algorithm or software simulators. The proposed methodology is finally validated with two simulations realized on PSCAD-EMTDC
Energy Efficient Channel Coding based on Position Awareness and Radio Link Budget Estimation
No full textOptimal Operation of an Industrial Microgrid within a Renewable Energy Community: A Case Study of a Greentech Company
No full textThe integration of renewable energy sources in the European power system is one of the main goals set by the European Union. In order to ease this integration, in recent years, Renewable Energy Communities (RECs) have been introduced that aim to increase the exploitation of renewable energy at the local level. This paper presents an Energy Management System (EMS) for an industrial microgrid owned and operated by a greentech company located in the north of Italy. The company is a member of an REC. The microgrid is made of interconnected busbars, integrating photovoltaic power plants, a fleet of electric vehicles, including company cars and delivery trucks supporting Vehicle-to-Grid (V2G), dedicated charging stations, and a centralized battery energy storage system. The industrial site includes two warehouses, an office building, and a connection to the external medium-voltage network. The EMS is designed to optimize the operation of the microgrid and minimize the operating costs related to the sale and purchase of energy from the external network. Furthermore, as the company is a member of an REC, the EMS must try to follow a desired power exchange profile with the grid, suggested by the REC manager, with the purpose of maximizing the energy that is shared within the community and incentivized. The results demonstrate that, when minimizing only costs, local self-consumption is favored, leading to a Self-Sufficiency Rate (SSR) of 65.37%. On the other hand, when only the adherence to the REC manager’s desired power exchange profile is considered in the objective function, the SSR decreases to 56.43%, net operating costs increase, and the energy shared within the REC is maximized
Energy Management System for the Operation of an Electric Vehicle Charging Hub Fed by Solar and Wind Energy Sources
No full textPower Systems Modelling and Digital Twins for Real Time Simulations
No full textThe Digital Twin (DT) has become a pivotal technology for representing, simulating, optimizing and visualizing the physical world, serving as a catalyst for digital transformation and sustainable development. This paper explores the integration of DTs in power systems, focusing on Real-Time Simulation (RTS) using Speedgoat, a widely employed real-time simulator. RTS solutions play a crucial role in modelling and simulating DTs and their services. This paper presents different strategies for RTSs of power system DTs on Speedgoat, specifically tested on a plant with Reactive Power Compensation (RPC) system and three Converter Units (CUs). The proposed approaches, developed in Simulink® Real-TimeTM, are discussed and demonstrated, with potential for generalization to more complex DTs. The close relationship between RTSs and DTs underscores their vital role in ensuring secure and reliable operations in future power grids
Electrokinesiographic Study of Oropharyngeal Swallowing in Neurogenic Dysphagia
No full textElectrokinesiographic study of swallowing (EKSS) can be useful for the assessment of patients with suspected or overt neurogenic dysphagia. EKSS consists of multichannel recording of the electromyographic (EMG) activity of the suprahyoid/submental muscle complex (SHEMG), the EMG activity of the cricopharyngeal muscle (CPEMG), and the laryngopharyngeal mechanogram (LPM). The LPM is an expression of the mechanical changes that the laryngopharyngeal structures undergo during the pharyngeal phase of swallowing. This method allows detailed evaluation of the magnitude, duration and temporal relations of the different events that characterize oropharyngeal swallowing, and thus in-depth exploration both of physiological deglutition mechanisms and of pathophysiological features of swallowing in neurogenic dysphagia. Furthermore, EKSS can guide dysphagia treatment strategies, allowing identification of optimal solutions for single patients. For instance, CPEMG recording can identify incomplete or absent relaxation of the upper esophageal sphincter during the pharyngeal phase of swallowing, thus suggesting a therapeutic approach based on botulinum toxin injection into the cricopharyngeal muscle. More recently, the ‘shape’ of SHEMG and the reproducibility of both SHEMG and LPM over repeated swallowing acts have been implemented as novel electrokinesiographic parameters. These measures could be valuable for straightforward non-invasive investigation of dysphagia severity and response to dysphagia treatment in clinical practice
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