1,720,977 research outputs found
Integrating model predictive control and deep learning for the management of an EV charging station
Get PDFExplicit model predictive control (EMPC) maps offline the control laws as a set of regions as a function of bounded uncertain parameters using multi-parametric programming. Then, in online mode, it seeks the best solution within these areas. Unfortunately, the offline solution can be computationally demanding because the number of regions can grow exponentially. Thus, this paper presents the application of a deep neural network (DNN) to learn the EMPC's regions for a photovoltaic-based charging station. The main uncertain parameters in this study are the forecast error of photovoltaic power production and the battery's state of charge. Additionally, the connection or disconnection of an electric vehicle is considered a disruption. The final controller creates the regions at the start of each prediction time or when a disruption occurs, only using the previously created DNN. The obtained solution is validated using data from an e-vehicle charging station installed at the University of Trieste, Italy
Real time Energy Management System of a photovoltaic based e-vehicle charging station using Explicit Model Predictive Control accounting for uncertainties
Get PDFThis paper proposes an Explicit Model Predictive Control (eMPC) for the energy management of an e-vehicle charging station fueled by a photovoltaic plant (PV), a battery energy storage system (BESS), and the electrical grid. The method computes offline an explicit solution of the MPC, which is stored and then used for real time control. Multiparametric programming is used to calculate the explicit solution by mapping the MPC laws as a function of uncertain parameters. In this paper, the uncertainties introduced into the multiparametric programming are the photovoltaic power production, the electricity price, the battery's state of charge, and the electric vehicle power consumption. Moreover, the environmental impact of the charging station operation is considered through the CO2 emissions level. The explicit solution is computed for a specific range of uncertain parameters. Then, during the real-time control, their current values are measured to evaluate the control laws saved beforehand. The proposed approach, consisting of an offline MPC-based determination of the control laws followed by their online use, reduces the computational burden without affecting the MPC performance. Numerical simulations and experimental results confirm the eMPC's performance for the proposed application
A Review of the Optimization and Control Techniques in the Presence of Uncertainties for the Energy Management of Microgrids
Get PDFThis paper reviews the current techniques used in energy management systems to optimize energy schedules into microgrids, accounting for uncertainties for various time frames (day-ahead and real-time operations). The current uncertainties affecting applications, including residential, commercial, virtual power plants, electric mobility, and multi-carrier microgrids, are the main subjects of this article. We outline the most recent modeling approaches to describe the uncertainties associated with various microgrid applications, such as prediction errors, load consumption, degradation, and state of health. The modeling approaches discussed in this article are probabilistic, possibilistic, information gap theory, and deterministic. Then, the paper presents and compares the current optimization techniques, considering the uncertainties in their problem formulations, such as stochastic, robust, fuzzy optimization, information gap theory, model predictive control, multiparametric programming, and machine learning techniques. The optimization techniques depend on the model used, the data available, the specific application, the real-time platform, and the optimization time. We hope to guide researchers to identify the best optimization technique for energy scheduling, considering the specific uncertainty and application. Finally, the most challenging issues to enhance microgrid operations, despite uncertainties by considering new trends, are discussed
Dynamic modelling and control of a PV generator for large scale applications
No full textAs large scale photovoltaic power plants are increasing their capacity, the new grid codes are requiring that these power plants have similar performance as conventional power plants do. Because of this, it is essential to study the performance of these power plants under different solar irradiance, temperature and electrical characteristics. As the basic unit of these type of power plants are the PV generators, the present study explains in detail the model of a PV generator: PV array, the DC bus, the PV inverter, the filter and the transformer. The control method for active and reactive power is also explained and considers the variation of ambient conditions plus the capability curves of PV generators. Finally, some simulations are developed to validate the model
Effect of Variable Solar Irradiance on the Reactive Power Response of Photovoltaic Generators
No full textNew grid requirements for large scale photovoltaic power plants (LS-PVPPs) demanding ancillary services make necessary the enhancement of photovoltaic (PV) generator's control. One of the challenges is the reactive power control despite the variable conditions. The aim of this paper is to present the response of reactive power considering the PV generator's capability curves and variable ambient conditions when maximum power point tracker (MPPT) is used for the active power control. For this purpose, a single PV generator of 0.6 MVA is simulated in DIgSILENT PowerFactory®. The results show that the active and reactive power varies with the ambient conditions
Dynamic study of a photovoltaic power plant interconnected with the grid
No full textThe drop of prices of photovoltaic technology has attracted investors to develop medium and large scale photovoltaic power plants (PVPPs). Because of the extent of land occupied by these PVPPs, the solar radiation along the plant is different. This situation causes several problems into the grid. Thus, the objective of this paper is to analyse the effect of a 6 MW PVPP at the point of common coupling considering different ambient conditions for each array. Three study cases are analysed considering temperatures of 10 °C, 30 °C and 40 ° C. In all the cases, the solar radiation is different in each array. The simulation and the results are conducted to understand the impact of ambient conditions in voltage, frequency and active power at the point of common coupling in a weak grid
Energy Resilience in Telecommunication Networks: A Comprehensive Review of Strategies and Challenges
Get PDFAs telecommunication networks become increasingly critical for societal functioning, ensuring their resilience in the face of energy disruptions is paramount. This review paper comprehensively analyzes strategies and challenges associated with achieving energy resilience in telecommunication networks. It explores various aspects, including policies, energy backup systems, renewable energy integration, and energy management techniques. This paper discusses how these strategies can be implemented to build resilience across three phases: preparedness (referring to the proactive measures taken in advance), response and relief, recovery and reconstruction. Additionally, it discusses the challenges associated with implementing energy resilience measures, taking into account policies, sustainability and environment, and climate change. By synthesizing existing research and identifying research gaps, this review paper aims to provide insights into the state-of-the-art practices and future directions for enhancing energy resilience in telecommunications, enabling robust and uninterrupted communication services
Evaluation of a State Observer for Frequency Estimation in a Grid Tied Photovoltaic Inverter
No full textAhstract-A phase locked loop (PLL) is commonly used to measure the electrical frequency deviations in PV grid tied inverters. However, this control is affected by sudden changes of power that usually happens with this type of power generation as the solar irradiance is intermittent. Thus, the aim of this paper is to estimate the frequency at the point of common coupling by using a state observer. The evaluation of the observer is developed in DIgSILENT PowerFactory under variable solar irradiance. The results show that the observer gives a more accurate frequency value than a PLL when quick changes of solar irradiance occur
The effect of ambient temperature on the yield of a 3 MWp PV plant installed in Ecuador
No full textThe integration of photovoltaic power plants in the distribution or transmission level is already a reality. Usually, the location chosen for these power plants consider high solar irradiance, but the temperature could be a drawback. Thus, the aim of this paper is to show the effect of solar irradiance and ambient temperature on the power generation of a photovoltaic power plant. For this, a real photovoltaic power plant is chosen in the Ecuadorian line in South America. The results show that the active power is reduced around 0.1 to 0.3 p.u when the ambient temperature is higher than 25 Celsius degrees although the solar irradiance is high
Review of advanced grid requirements for the integration of large scale photovoltaic power plants in the transmission system
No full textThe installation of large scale photovoltaic power plants connected at transmission level has increased during the last years. There are some challenges that these power plants have to overcome regarding the operation and control while dealing with the solar energy variability and uncertainty. Today, few countries are aware of the importance of this source of energy as part of the utility system and how it can affect the operability. Thus, this paper discusses about the trend of large scale photovoltaic power plants around the world and the importance of the development of grid codes for its integration. Then, the paper addresses a comparison of the grid codes of Germany, US, Puerto Rico, Romania, China and South Africa considering: fault ride through capability, frequency and voltage regulation, as well as active and reactive power support. In addition, a broad discussion about the challenges that the large scale photovoltaic power plants have to overcome is presented together with the compliance technology and future trend
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