scholarly journals Modeling Vehicles to Grid as a Source of Distributed Frequency Regulation in Isolated Grids with Significant RES Penetration

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 720 ◽  
Author(s):  
Neofytos Neofytou ◽  
Konstantinos Blazakis ◽  
Yiannis Katsigiannis ◽  
Georgios Stavrakakis
Keyword(s):  
Power Systems ◽  
Electric Vehicles ◽  
Renewable Energy Sources ◽  
Rapid Development ◽  
Frequency Regulation ◽  
Charging Station ◽  
Battery Capacity ◽  
Regulation Services ◽  
Primary Frequency ◽  
The Impact

The rapid development of technology used in electric vehicles, and in particular their penetration in electricity networks, is a major challenge for the area of electric power systems. The utilization of battery capacity of the interconnected vehicles can bring significant benefits to the network via the Vehicle to Grid (V2G) operation. The V2G operation is a process that can provide primary frequency regulation services in the electric network by exploiting the total capacity of a fleet of electric vehicles. In this paper, the impact of the plug-in hybrid electric vehicles (PHEVs) in the primary frequency regulation is studied and the effects PHEVs cause in non-interconnected isolated power systems with significant renewable energy sources (RES) penetration. Also it is taken into consideration the requirements of users for charging their vehicles. The V2G operation can be performed either with fluctuations in charging power of vehicles, or by charging or discharging the battery. So an electric vehicle user can participate in V2G operation either during the loading of the vehicle to the charging station, or by connecting the vehicle in the charging station without any further demands to charge its battery. In this paper, the response of PHEVs with respect to the frequency fluctuations of the network is modeled and simulated. Additionally, by using the PowerWorld Simulator software, simulations of the isolated power system of Cyprus Island, including the current RES penetration are performed in order to demonstrate the effectiveness of V2G operation in its primary frequency regulation.

scholarly journals A Model Predictive Control for the Dynamical Forecast of Operating Reserves in Frequency Regulation Services

Forecasting ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 228-241
Author(s):  
Pavlos Nikolaidis ◽  
Harris Partaourides
Keyword(s):  
Power Systems ◽  
Real Time ◽  
Renewable Energy Sources ◽  
Great Accuracy ◽  
Frequency Regulation ◽  
Feed Forward Neural Network ◽  
Reserve Requirements ◽  
Model Control ◽  
Regulation Services ◽  
System Frequency

The intermittent and uncontrollable power output from the ever-increasing renewable energy sources, require large amounts of operating reserves to retain the system frequency within its nominal range. Based on day-ahead load forecasts, many research works have proposed conventional and stochastic approaches to define their optimum margins for reliability enhancement at reasonable production cost. In this work, we aim at delivering real-time load forecasting to lower the operating-reserve requirements based on intra-hour weather update predictors. Based on critical predictors and their historical data, we train an artificial model that is able to forecast the load ahead with great accuracy. This is a feed-forward neural network with two hidden layers, which performs real-time forecasts with the aid of a predictive model control developed to update the recommendations intra-hourly and, assessing their impact and its significance on the output target, it corrects the imposed deviations. Performing daily simulations for an annual time-horizon, we observe that significant improvements exist in terms of decreased operating reserve requirements to regulate the violated frequency. In fact, these improvements can exceed 80% during specific months of winter when compared with robust formulations in isolated power systems.

scholarly journals Electric Vehicles and Biofuels Synergies in the Brazilian Energy System

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4423 ◽  
Author(s):  
Géremi Gilson Dranka ◽  
Paula Ferreira
Keyword(s):  
Power Systems ◽  
Co2 Emissions ◽  
Electric Vehicles ◽  
Large Scale ◽  
Renewable Energy Sources ◽  
Energy System ◽  
Electricity Production ◽  
Transport Sector ◽  
Transportation Sector ◽  
The Impact

Shaping a secure and sustainable energy future may require a set of transformations in the global energy sector. Although several studies have recognized the importance of Electric Vehicles (EVs) for power systems, no large-scale studies have been performed to assess the impact of this technology in energy systems combining a diverse set of renewable energies for electricity production and biofuels in the transportation sector such as the case of Brazil. This research makes several noteworthy contributions to the current literature, including not only the evaluation of the main impacts of EVs’ penetration in a renewable electricity system but also a Life-Cycle Assessment (LCA) that estimates the overall level of CO2 emissions resulted from the EVs integration. Findings of this study indicated a clear positive effect of increasing the share of EVs on reducing the overall level of CO2 emissions. This is, however, highly dependent on the share of Renewable Energy Sources (RES) in the power system and the use of biofuels in the transport sector but also on the credits resulting from the battery recycling materials credit and battery reuse credit. Our conclusions underline the importance of such studies in providing support for the governmental discussions regarding potential synergies in the use of bioresources between transport and electricity sectors.

Application of Plug-In Electric Vehicles and Controllable Loads to Frequency Regulation

2012 ◽  
Vol 588-589 ◽  
pp. 1640-1643
Author(s):  
Shu Lei Deng ◽  
Bao Ping Liu ◽  
An Jun Li ◽  
Xiong Zhou ◽  
Yu Xiang Huang
Keyword(s):  
Renewable Energy ◽  
Feedback Control ◽  
Power Systems ◽  
Electric Vehicles ◽  
Renewable Energy Sources ◽  
Energy Sources ◽  
Frequency Regulation ◽  
Battery Charging ◽  
Vehicle To Grid ◽  
Simulation Results

High renewable energy penetration in power systems may bring a series of problems such as frequency fluctuations. Plug-in electric vehicles (PEVs) and controllable loads have been shifting into focus for this. A dynamic vehicle-to-grid (V2G) model with feedback control is proposed by considering the battery charging/discharging characteristics and the dynamic model of frequency regulation with PEVs and controllable loads for a single area is established. Simulation results demonstrate that the application of PEVs and controllable loads can relief the frequency refutation due to the randomness of renewable energy sources.

scholarly journals V2G Strategy for Primary Frequency Control of an Industrial Microgrid Considering the Charging Station Operator

Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 549 ◽  
Author(s):  
Sheeraz Iqbal ◽  
Ai Xin ◽  
Mishkat Ullah Jan ◽  
Salman Salman ◽  
Atta ul Munim Zaki ◽  
...  
Keyword(s):  
Electric Vehicles ◽  
Control Strategies ◽  
Frequency Control ◽  
State Of Charge ◽  
Frequency Regulation ◽  
Vehicle To Grid ◽  
Charging Station ◽  
Primary Frequency ◽  
Primary Frequency Control

Electric vehicles (EVs) have been receiving greater attention as a tool for frequency control due to their fast regulation capability. The proliferation of EVs for primary frequency regulation is hampered by the need to simultaneously maintain industrial microgrids dispatch and EV state of charge levels. The current research aims to examine the operative and dominating role of the charging station operator, along with a vehicle to grid strategy; where, indeterminate tasks are executed in the microgrid without the EVs charging/discharging statistics. The role of the charging station operator in regulation is the assignment of the job inside the primary frequency control capacity of electric vehicles. Real-time rectification of programmed vehicle to grid (V2G) power ensures electric vehicles’ state of charge at the desired levels. The proposed V2G strategy for primary frequency control is validated through the application of a two-area interconnected industrial micro-grid and another microgrids with renewable resources. Regulation specifications are communicated to electric vehicles and charging station operators through an electric vehicle aggregator in the proposed strategy. At the charging station operator, V2G power at the present time is utilized for frequency regulation capacity calculation. Subsequently, the V2G power is dispatched in light of the charging demand and the frequency regulation. Furthermore, V2G control strategies for distribution of regulation requirement to individual EVs are also developed. In summary, the article presents a novel primary frequency control through V2G strategy in an industrial microgrid, involving effective coordination of the charging station operator, EV aggregator, and EV operator.

scholarly journals Smart Control Strategies for Primary Frequency Regulation through Electric Vehicles: A Battery Degradation Perspective

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4586 ◽  
Author(s):  
Paolo Scarabaggio ◽  
Raffaele Carli ◽  
Graziana Cavone ◽  
Mariagrazia Dotoli
Keyword(s):  
Electric Vehicles ◽  
Operations Management ◽  
Control Strategies ◽  
Power Grid ◽  
Renewable Energy Sources ◽  
Ancillary Services ◽  
Operating Conditions ◽  
Frequency Regulation ◽  
Grid Model ◽  
Primary Frequency

Nowadays, due to the decreasing use of traditional generators in favor of renewable energy sources, power grids are facing a reduction of system inertia and primary frequency regulation capability. Such an issue is exacerbated by the continuously increasing number of electric vehicles (EVs), which results in enforcing novel approaches in the grid operations management. However, from being an issue, the increase of EVs may turn to be a solution to several power system challenges. In this context, a crucial role is played by the so-called vehicle-to-grid (V2G) mode of operation, which has the potential to provide ancillary services to the power grid, such as peak clipping, load shifting, and frequency regulation. More in detail, EVs have recently started to be effectively used for one of the most traditional frequency regulation approaches: the so-called frequency droop control (FDC). This is a primary frequency regulation, currently obtained by adjusting the active power of generators in the main grid. Because to the decommissioning of traditional power plants, EVs are thus recognized as particularly valuable solutions since they can respond to frequency deviation signals by charging or discharging their batteries. Against this background, we address frequency regulation of a power grid model including loads, traditional generators, and several EVs. The latter independently participate in the grid optimization process providing the grid with ancillary services, namely the FDC. We propose two novel control strategies for the optimal control of the batteries of EVs during the frequency regulation service. On the one hand, the control strategies ensure re-balancing the power and stabilizing the frequency of the main grid. On the other hand, the approaches are able to satisfy different types of needs of EVs during the charging process. Differently from the related literature, where the EVs perspective is generally oriented to achieve the optimal charge level, the proposed approaches aim at minimizing the degradation of battery devices. Finally, the proposed strategies are compared with other state-of-the-art V2G control approaches. The results of numerical experiments using a realistic power grid model show the effectiveness of the proposed strategies under the actual operating conditions.

scholarly journals Adaptive Robust Optimization-Based Optimal Operation of Microgrids Considering Uncertainties in Arrival and Departure Times of Electric Vehicles

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2646 ◽  
Author(s):  
Se-Hyeok Choi ◽  
Akhtar Hussain ◽  
Hak-Man Kim
Keyword(s):  
Robust Optimization ◽  
Electric Vehicles ◽  
Unit Commitment ◽  
Renewable Energy Sources ◽  
Market Price ◽  
Optimal Operation ◽  
Worst Case ◽  
Price Signals ◽  
Power Trading ◽  
The Impact

The optimal operation of microgrids is challenging due to the presence of various uncertain factors, i.e., renewable energy sources, loads, market price signals, and arrival and departure times of electric vehicles (EVs). In order to incorporate these uncertainties into the operation model of microgrids, an adaptive robust optimization-based operation method is proposed in this paper. In particular, the focus is on the uncertainties in arrival and departure times of EVs. The optimization problem is divided into inner and outer problems and is solved iteratively by introducing column and constraint cuts. The unit commitment status of dispatchable generators is determined in the outer problem. Then, the worst-case realizations of all the uncertain factors are determined in the inner problem. Based on the values of uncertain factors, the generation amount of dispatchable generators, the amount of power trading with the utility grid, and the charging/discharging amount of storage elements are determined. The performance of the proposed method is evaluated using three different cases, and sensitivity analysis is carried out by varying the number of EVs and the budget of uncertainty. The impact of the budget of uncertainty and number of EVs on the operation cost of the microgrid is also evaluated considering uncertainties in arrival and departure times of EVs.

scholarly journals Indices to Assess the Integration of Renewable Energy Resources on Transmission Systems

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Alexandros I. Nikolaidis ◽  
Francisco M. Gonzalez-Longatt ◽  
C. A. Charalambous
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Renewable Energy Sources ◽  
Ghg Emissions ◽  
Electrical Network ◽  
Transmission Network ◽  
Renewable Energy Resources ◽  
Continuous Increase ◽  
And Control ◽  
The Impact

The continuous increase on the penetration levels of Renewable Energy Sources (RESs) in power systems has led to radical changes on the design, operation, and control of the electrical network. This paper investigates the influence of these changes on the operation of a transmission network by developing a set of indices, spanning from power losses to GHG emissions reduction. These indices are attempting to quantify any impacts therefore providing a tool for assessing the RES penetration in transmission networks, mainly for isolated systems. These individual indices are assigned an analogous weight and are mingled to provide a single multiobjective index that performs a final evaluation. These indices are used to evaluate the impact of the integration of RES into the classic WSCC 3-machine, 9-bus transmission network.

The impact of global trends on the electric vehicle market in Russia: Challenges, opportunities and directions of development

2021 ◽  
Vol 17 (5) ◽  
pp. 913-939
Author(s):  
Tat'yana S. REMIZOVA ◽  
Dmitrii B. KOSHELEV
Keyword(s):  
Electric Vehicle ◽  
Electric Vehicles ◽  
Carbon Footprint ◽  
Renewable Energy Sources ◽  
Economic Security ◽  
Vehicle Development ◽  
Global Trends ◽  
Electric Cars ◽  
Positive Effects ◽  
The Impact

Subject. The article reviews various transport electrification scenarios, which would help reduce the CO2 emissions and environmental threats. The environmental and economic security can also be affected if the State insufficiently understands the importance of electric vehicle development, their popularization. It is also crucial to encourage the consumption, develop the infrastructure, innovative projects, which reshape the power engineering structure. Objectives. We determine how global trends influence the production and integration of electric vehicles in Russia. We also evaluate the environmental and cost effectiveness of morot vehicle electrification, opportunities and trajectories for the electric vehicle development nationwide. Methods. The study involves methods used to summarize regulatory, empirical and theoretical data, and general and partial scientific methods and techniques, such as abstraction, analysis, analogy, etc. Results. The article shows the extent of electric transport development worldwide, and focuses on environmental issues and opportunities to reduce the carbon footprint by using electric vehicles and renewable energy sources. We point out opportunities, threats, prospects and disadvantages of the electric vehicle use in Russia. The article indicates how the use of electric cars can be developed in Russia, considering changes in the production structure and the generation of positive effects as much as possible. Conclusions. Currently, Russia evidently lags behind the global production and use of electric cars, without having a priority of the carbon footprint reduction. The strategy for the car segment advancement is underdeveloped. Suggested herein, the ideas for the electric car segment development are aimed to encourage the consumption, production, advancement of infrastructure and innovative projects, and ensure the environmental security of the country.

scholarly journals Impact of Primary Frequency Control of Offshore HVDC Grids on Interarea Modes of Power Systems

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3879 ◽  
Author(s):  
Ali Bidadfar ◽  
Oscar Saborío-Romano ◽  
Vladislav Akhmatov ◽  
Nicolaos A. Cutululis ◽  
Poul E. Sørensen
Keyword(s):  
Power Systems ◽  
Frequency Control ◽  
Wind Farms ◽  
Offshore Wind ◽  
Offshore Wind Farms ◽  
Dc Voltage ◽  
Simultaneous Use ◽  
Primary Frequency ◽  
Primary Frequency Control ◽  
The Impact

Offshore high-voltage DC (HVDC) grids are developing as a technically reliable and economical solution to transfer more offshore wind power to onshore power systems. It is also foreseen that the offshore HVDC grids pave the way for offshore wind participation in power systems’ balancing process through frequency support. The primary frequency control mechanism in an HVDC grid can be either centralized using communication links between HVDC terminals or decentralized by the simultaneous use of DC voltage and frequency droop controls. This paper investigates the impact of both types of primary frequency control of offshore HVDC grids on onshore power system dynamics. Parametric presentation of power systems’ electro-mechanical dynamics and HVDC controls is developed to analytically prove that the primary frequency control can improve the damping of interarea modes of onshore power systems. The key findings of the paper include showing that the simultaneous use of frequency and DC voltage droop controls on onshore converters results in an autonomous share of damping torque between onshore power systems even without any participation of offshore wind farms in the frequency control. It is also found that the resulting damping from the frequency control of offshore HVDC is not always reliable as it can be nullified by the power limits of HVDC converters or wind farms. Therefore, using power oscillation damping control in parallel with frequency control is suggested. The analytical findings are verified by simulations on a three-terminal offshore HVDC grid.

scholarly journals Analysis of the Sensitivity of Extended Kalman Filter-Based Inertia Estimation Method to the Assumed Time of Disturbance

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 483 ◽  
Author(s):  
Davide del Giudice ◽  
Samuele Grillo
Keyword(s):  
Kalman Filter ◽  
Extended Kalman Filter ◽  
Situational Awareness ◽  
Renewable Energy Sources ◽  
Estimation Method ◽  
Electric Power System ◽  
Estimation Methods ◽  
Frequency Regulation ◽  
Time Required ◽  
Primary Frequency

The frequency behavior of an electric power system right after a power imbalance is determined by its inertia constant. The current shift in generation mix towards renewable energy sources is leading to a smaller and more variable inertia, thereby compromising the frequency stability of modern grids. Therefore, real-time inertia estimation methods would be beneficial for grid operators, as their situational awareness would be enhanced. This paper focuses on an inertia estimation method specifically tailored for synchronous generators, based on the extended Kalman filter (EKF). Such a method should be started at the time of disturbance, which must be estimated accurately, otherwise additional errors could be introduced in the inertia estimation process. In this paper, the sensitivity of the EKF-based inertia estimation method to the assumed time of disturbance is analyzed. It is shown that such sensitivity is influenced by the initially assumed inertia constant, the use time of the filter and by the time required for primary frequency regulation to be activated.

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