| 1. |
- Sonderby, Ida E., et al.
(författare)
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Dose response of the 16p11.2 distal copy number variant on intracranial volume and basal ganglia
- 2020
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Ingår i: Molecular Psychiatry. - : Nature Publishing Group. - 1359-4184 .- 1476-5578. ; 25:3, s. 584-602
-
Tidskriftsartikel (refereegranskat)abstract
- Carriers of large recurrent copy number variants (CNVs) have a higher risk of developing neurodevelopmental disorders. The 16p11.2 distal CNV predisposes carriers to e.g., autism spectrum disorder and schizophrenia. We compared subcortical brain volumes of 12 16p11.2 distal deletion and 12 duplication carriers to 6882 non-carriers from the large-scale brain Magnetic Resonance Imaging collaboration, ENIGMA-CNV. After stringent CNV calling procedures, and standardized FreeSurfer image analysis, we found negative dose-response associations with copy number on intracranial volume and on regional caudate, pallidum and putamen volumes (β = −0.71 to −1.37; P < 0.0005). In an independent sample, consistent results were obtained, with significant effects in the pallidum (β = −0.95, P = 0.0042). The two data sets combined showed significant negative dose-response for the accumbens, caudate, pallidum, putamen and ICV (P = 0.0032, 8.9 × 10−6, 1.7 × 10−9, 3.5 × 10−12 and 1.0 × 10−4, respectively). Full scale IQ was lower in both deletion and duplication carriers compared to non-carriers. This is the first brain MRI study of the impact of the 16p11.2 distal CNV, and we demonstrate a specific effect on subcortical brain structures, suggesting a neuropathological pattern underlying the neurodevelopmental syndromes.
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| 2. |
- Antoniadou-Plytaria, Kyriaki, 1989, et al.
(författare)
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Chalmers Campus as a Testbed for Intelligent Grids and Local Energy Systems
- 2019
-
Ingår i: IEEE International Conference on Smart Energy Systems and Technologies (SEST). - 9781728111568
-
Konferensbidrag (refereegranskat)abstract
- This paper presents an overview of a testbed for intelligent distribution grids, local energy systems, and energy flexible buildings, which is being developed at the campus of Chalmers University of Technology in Gothenburg, Sweden. It describes the test sites, the functionalities, and the planned demonstration activities within the scope of on-going research projects. The proposed demonstrations include a local energy market platform, energy management solutions for microgrids and smart buildings, as well as voltage control in distribution grids. The paper aims to show how the physical energy supply systems of the university are being adapted to integrate the communication and control set-ups that provide the technical requirements for smart grid interoperability. As an example, the on-site implementation of remote battery control is presented, where initial results show the feasibility and potential benefits of the external control. Finally, challenges and lessons learned during the development of the testbed are highlighted.
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| 3. |
- Antoniadou-Plytaria, Kyriaki, 1989, et al.
(författare)
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Market-based Energy Management Model of a Building Microgrid Considering Battery Degradation
- 2021
-
Ingår i: IEEE Transactions on Smart Grid. - 1949-3053 .- 1949-3061. ; 12:2, s. 1794-1804
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a model for energy management system of a building microgrid coupled with a battery energy storage. The model can be used to dispatch the battery as a flexible energy resource using a market-based setting. The battery is modeled considering battery degradation and real-life operation characteristics derived from measurements at a residential building. The performance of the model was evaluated first with simulations and integrated afterwards to an energy management system, which was demonstrated at a real residential building (HSB Living Lab) equipped with photovoltaic and battery storage systems. The simulation results showed that the building owner, and subsequently the residents, could benefit from the proposed model in reduced annual cost up to 3.1% under the considered pricing scheme. The demonstration results showed that dispatch under the measurement-based model could decrease the undelivered energy over the daily requested amount from the battery from 13.3% to 3.7%. Thus, the proposed model, which couples the measurement-based dispatch with battery degradation, can lead to a more accurate estimation of the building operation cost and an improved overall performance of battery as a flexible resource in building microgrids.
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| 4. |
- Antoniadou-Plytaria, Kyriaki, 1989, et al.
(författare)
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Scenario-based Stochastic Optimization for Energy and Flexibility Dispatch of a Microgrid
- 2022
-
Ingår i: IEEE Transactions on Smart Grid. - 1949-3053 .- 1949-3061. ; 13:5, s. 3328-3341
-
Tidskriftsartikel (refereegranskat)abstract
- Energy storage is one of the most important components of microgrids with non-dispatchable generators and can offer both energy and flexibility services when the microgrid operates in grid-connected mode. This paper proposes a scenario-based stochastic optimization model that can be used to determine the energy and flexibility dispatch of a residential microgrid with solar and stationary battery systems. The objective of the model is to minimize the expected energy and peak power cost as well as the battery aging cost, while maximizing the expected revenue from flexibility. The formulated stochastic optimization problem is solved in rolling horizon with the uncertainty model being dynamically updated to consider the most recent forecast profiles for solar power and electricity demand. The benefits of the proposed approach were demonstrated by simulating the daily operation of a real building. The results showed that the estimated flexibility was successfully dispatched yielding an economic value of at least 7% of the operation cost of the building microgrid. The model can be used by flexibility providers to assess their flexibility and design a bidding strategy as well as by system operators to design incentives for flexibility providers.
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| 5. |
- Fotouhi, Ali, 1983, et al.
(författare)
-
Two-stage demand-side management in energy flexible residential buildings
- 2024
-
Ingår i: JOURNAL OF ENGINEERING-JOE. - 2051-3305. ; 2024:4
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, an optimisation model is developed for two-stage energy management of a residential building to minimise energy cost under monthly power-based tariffs for peak demand and time-variable electricity prices. The expected peak demand is determined in the first stage, and then the energy management system minimizes energy costs during the second stage. The second stage's optimisation problem is solved in a rolling time window, facilitating real-time operation of flexible energy sources in the building. This includes optimal charging and discharging of the battery energy system, electric vehicle battery charging, heating system operation, and determining the optimal start times for washing machines and dishwashers, all close to real-time. The proposed approach enables users to predict and manage peak demand in daily operation, staying below the predetermined value through a close to real-time energy management system. The effectiveness of this two-stage approach in demand-side management for residential buildings is demonstrated through a realistic case study. In this study, an optimisation model is developed for two-stage energy management of a residential building to minimise energy cost under monthly power-based tariffs for peak demand and time variable electricity prices. The expected peak demand is determined in the first stage, and then the energy management system minimises the energy cost in the second stage. The optimisation problem of the second stage is solved in a rolling time window for the real time operation of the flexible energy sources in the building. image
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| 6. |
- Fotouhi Ghazvini, Mohammad Ali, 1983, et al.
(författare)
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A Centralized Building Energy Management System for Residential Energy Hubs
- 2019
-
Ingår i: SEST 2019 - 2nd International Conference on Smart Energy Systems and Technologies.
-
Konferensbidrag (refereegranskat)abstract
- This paper proposes a framework for energy management in modern smart buildings under the context of integrated energy systems. The added value of this work is using the rolling time window framework for decision-making, along with the inclusion of the peak load tariffs. The rolling time window is used to send updated control commands near to real-time. A Swedish multi-family residential building is used in the case study. The results of the case study verify the effectiveness and the validity of the proposed model. The results show that by integrating the electricity and the district heating network with a 11 kW heat pump, the total energy cost reduces around 27%.
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| 7. |
- Fotouhi Ghazvini, Mohammad Ali, 1983, et al.
(författare)
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A Close-to-Real-time Energy Management System for Smart Residential Buildings
- 2019
-
Ingår i: 2019 IEEE Milan PowerTech, PowerTech 2019. ; 2019, s. 1-6
-
Konferensbidrag (refereegranskat)abstract
- This paper proposes a close to real-time energy management system for multi-family residential buildings. The aim of the model is to optimally manage the controllable energy sources in a rolling time window to reduce the total energy cost of the building, considering the time variable electricity prices. A mixed-integer linear programming model is developed to control the washing machines, dishwashers and the energy storage system in a smart building. The performance of the model is evaluated through simulating the operation of an energy management system during one day using the measurement data from a real building located within Chalmers University of Technology campus. The results show that the proposed model can help reduce the building's energy cost by 9% and reduce the peak demand 18.78% using the resource flexibilities in the building, without causing discomfort for the tenants.
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| 8. |
- Fotouhi Ghazvini, Mohammad Ali, 1983, et al.
(författare)
-
A rolling horizon approach for the optimal real-time dispatch of energy sources in smart residential buildings
- 2019
-
Konferensbidrag (refereegranskat)abstract
- This paper develops a close-to-real-time energy management system for a smart multi-family residential building with PV production and energy storage systems. The model aims to control the operation of controllable residential appliances to minimize the total energy procurement cost while ensuring the users’ satisfaction. A mixed-integer linear programming model is developed to solve the optimization problem in a rolling time window. The results of the case study verify the effectiveness and validity of the proposed model. Implementing the proposed approach in a residential building reduces the peak demand by 24.5% and the total energy procurement cost by 4.3%.
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| 9. |
- Mirzaei Alavijeh, Nima, 1993, et al.
(författare)
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Key Drivers and Future Scenarios of Local Energy and Flexibility Markets
- 2021
-
Ingår i: 2021 IEEE Madrid PowerTech, PowerTech 2021 - Conference Proceedings.
-
Konferensbidrag (refereegranskat)abstract
- This paper explores the key drivers of local energy and flexibility markets, develops a set of plausible future scenarios for these markets, and analyzes the scenarios' impact. The results can provide insight to policymakers, researchers, system operators, and aggregators in a better design and more successful implementation of local markets. This study is based on the well-established scenario planning technique of "intuitive logics"and it is conducted by means of qualitative methods, surveys, and cross-impact analysis. Results explore and rank the impact and uncertainty of 20 key factors and trends which can affect the future of local energy and flexibility markets. The results show that factors related to the availability of active and smart end-users, and regulatory incentives are the most impactful and uncertain ones in the future of local markets. Four future scenarios are introduced based on these factors and their impacts are discussed.
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| 10. |
- Srivastava, Ankur, 1989, et al.
(författare)
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A Review on Challenges and Solutions in Microgrid Protection
- 2021
-
Ingår i: 2021 IEEE Madrid PowerTech, PowerTech 2021 - Conference Proceedings.
-
Konferensbidrag (refereegranskat)abstract
- Protection of microgrid has become challenging due to the hosting of various actors such as distributed generation, energy storage systems, information and communication technologies, etc. The main protection challenges in the microgrid are the bi-directional power flow, protection blinding, sympathetic tripping, change in short-circuit level due to different modes of operation, and limited fault current contribution by converter-interfaced sources. This paper presents a comprehensive review of the available microgrid protection schemes which are based on traditional protection principles and emerging techniques such as machine learning, data-mining, wavelet transform, etc. A categorical assessment of the reviewed protection schemes is also presented. The key findings of the paper suggest that the time-domain and communication-assisted protection schemes could be suitable solutions to address the identified protection challenges in the microgrid.
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| 11. |
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| 12. |
- Agathokleous, Christos, 1993, et al.
(författare)
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Stochastic Operation Scheduling Model for a Swedish Prosumer with PV and BESS in Nordic Day-Ahead Electricity Market
- 2019
-
Ingår i: 2019 IEEE Milan PowerTech, PowerTech 2019.
-
Konferensbidrag (refereegranskat)abstract
- In this paper, an optimal stochastic operation scheduling model is proposed for a prosumer owning photovoltaic (PV) facility coupled with a Battery Energy Storage System (BESS). The objective of the model is to maximize the prosumer’s expected profits. A two-stage stochastic mixed-integer nonlinear optimization (SMINLP) approach is used to cope with the parameters’ uncertainties. Artificial Neural Networks (ANN) are used to forecast the markets’ prices and the standard scenario reduction algorithms are applied to handle the computational tractability of the problem. The model is applied to a case study using data from the Nordic electricity markets and historical PV production data from the Chalmers University of Technology campus, considering a scaled up 5MWp power capacity. The results show that the proposed approach could increase the revenue for the prosumer by up to 11.6% as compared to the case without any strategy. Furthermore, the sensitivity analysis of BESS’s size on the expected profit shows that increasing BESS size could lead to an increase in the net profits.
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| 13. |
- Alvarez Quispe, Erik Fransisco, et al.
(författare)
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Values and Impacts of Incorporating Local Flexibility Services in Transmission Expansion Planning
- 2022
-
Ingår i: Electric Power Systems Research. - : Elsevier BV. - 0378-7796. ; 212
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a cost-based TSO-DSO coordination model to quantify the value of local flexibility services and analyze its impact on the transmission grid expansion and the system operation. Flexibility is provided to the DC power flow transmission grid model by microgrids within the integrated AC power flow distribution grid model. The model's objective is to minimize the overall cost of transmission investments and procured flexibility and is achieved using a bilevel optimization approach where the power exchanges on all connected grid interfaces are controlled. Case studies using a combined test system of the IEEE RTS-96 transmission network interfacing multiple 33-bus distribution grids were performed to validate the model and assess the values and impacts of local flexibility on the transmission system expansion. The results showed that the proposed model modified the investment plan and dispatch of flexibility resources reducing the investment and operation cost of the transmission system.
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| 14. |
- Antoniadou-Plytaria, Kyriaki, 1989, et al.
(författare)
-
Effect of Short-term and High-resolution Load Forecasting Errors on Microgrid Operation Costs
- 2022
-
Ingår i: IEEE PES Innovative Smart Grid Technologies Conference Europe. - 9781665480321 ; 2022-October
-
Konferensbidrag (refereegranskat)abstract
- The aim of this paper is to evaluate the effect of the load forecasting errors to the operation costs of a grid-connected microgrid. To this end, a microgrid energy scheduling optimization model was tested with deterministic and stochastic formulations under two solution approaches i.e., day-ahead and rolling horizon optimization. In total, twelve simulation test cases were designed receiving as input the forecasts provided by one of the three implemented machine learning models: linear regression, artificial neural network with backpropagation, and long short-term memory. Simulation results of the weekly operation of a real residential building (HSB Living Lab) showed no significant differences among the costs of the test cases for a daily mean absolute percentage forecast error of about 12%. These results suggest that operators of similar microgrid systems could use simplifying approaches, such as day-ahead deterministic optimization, and forecasts of similar, non-negligible accuracy without substantially affecting the microgrid's total cost as compared to the ideal case of perfect forecast. Improving the accuracy would mainly reduce the microgrid's peak power cost as shown by its 20.2% increase in comparison to the ideal case.
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| 15. |
- Antoniadou-Plytaria, Kyriaki, 1989, et al.
(författare)
-
Energy Scheduling Strategies for Grid-connected Microgrids: A Case Study on Chalmers Campus
- 2019
-
Ingår i: Proceedings of 2019 IEEE PES Innovative Smart Grid Technologies Europe, ISGT-Europe 2019.
-
Konferensbidrag (refereegranskat)abstract
- This paper focuses on the optimal energy management of grid-connected microgrids with battery energy storage systems. The microgrid energy management and the optimal power flow of the distribution network are formulated as mixed-integer linear optimization problems to evaluate microgrid energy scheduling strategies including cost minimization, maximum use of own resources, and minimum energy exchange with the upstream network. The real distribution network of Chalmers University of Technology campus is used as a case study. The study results show that economic optimization yields an annual microgrid cost reduction of 4%. Alternatively, if the microgrid minimizes the energy exchange, virtual islanding operation (zero energy exchange) for 3211 hours can be achieved within a year. The results also present the effects on the operation and cost of the distribution system and highlight a trade-off between microgrid cost minimization and battery lifetime.
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| 16. |
- Babaei, Saman, et al.
(författare)
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Effects of Plug-in Electric Vehicles on Distribution Systems: The Real Case of Gothenburg
- 2010
-
Ingår i: IEEE PES Conference on Innovative Smart Grid Technologies Europe, Gothenburg, Sweden, October 10-13, 2010. - 9781424485109
-
Konferensbidrag (refereegranskat)abstract
- The electric power system is changing and, especially, the electrical distribution system will meet new features. One of the large changes is a transformation of the transportation sector with the use of electricity, with introduction of electrical vehicles and Plug-in Electric Vehicles (PEVs). This will pose new challenges and opportunities for the electric distribution companies. This paper analyzes the effects of PEVs charging on the local 400 V and 10 kV electric distribution systems in the city of Gothenburg, Sweden, using steady-state power flow analysis. Two different areas representing residential area and commercial area have been simulated for the worst-case scenario, which is simultaneous charging of all the vehicles during the peak load period. The number of PEVs used has been estimated based on the load level at each customer location. The study results have shown that overloading of lines would occur when simultaneous charging of the vehicles during the peak load period. There would, however, be no problem with the voltage drop at the customer’s location during PEVs charging. An iterative method is proposed to estimate the maximum number of possible vehicles charging in the distribution system without resulting in any line overloaded. This method is also applied when one of the feeders is on outage to ensure the N-1 reliability criterion.
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| 17. |
- Bertling, Lina, 1973, et al.
(författare)
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Integration of plug in hybrid electric vehicles and electric vehicles - Experience from Sweden
- 2010
-
Ingår i: Power and Energy Society General Meeting, 2010 IEEE. - 9781424483570
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Integration of plug in hybrid electric vehicles and electric vehicles (PHEVs and EVs) includes a wide area of topics like grid effects, different charging concepts, charger designs, harmonics from the charger etc. This short paper gives an introduction to ongoing work within this field in Sweden, and shows on research work within the topic at Chalmers University of Technology. ©2010 IEEE.
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| 18. |
- Bouloumpasis, Ioannis, 1987, et al.
(författare)
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Congestion Management using Local Flexibility Markets: Recent Development and Challenges
- 2019
-
Ingår i: Proceedings of 2019 IEEE PES Innovative Smart Grid Technologies Europe, ISGT-Europe 2019. ; 2019
-
Konferensbidrag (refereegranskat)abstract
- Increasing amount of renewable based distributed generation at distribution systems, leads to an increased need for active distribution network management dealing with local network congestion and voltage issues. Development of local flexibility markets aims to provide a market-based solution to these issues. This paper presents a comprehensive review of proposed approaches towards markets exploiting the flexibilities from the demand-side. Efforts have been made on presenting a systematic overview of market design, including e.g. framework, participation, bidding and clearing mechanisms, of local flexibility market proposals developed in recent years. The implementation and regulatory issues and challenges are also discussed. The paper also presents the conceptual framework of the local flexibility service market which is currently being developed within UNITED-GRID project. This proposal aims to provide a holistic approach on local service markets, so that Distribution System Operators (DSOs) are provided with a market-based instrument to manage their networks efficiently.
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| 19. |
- Bouloumpasis, Ioannis, 1987, et al.
(författare)
-
Local flexibility market framework for grid support services to distribution networks
- 2022
-
Ingår i: Electrical Engineering. - : Springer Science and Business Media LLC. - 1432-0487 .- 0948-7921. ; 104:2, s. 401-419
-
Tidskriftsartikel (refereegranskat)abstract
- The increasing volume of distributed resources and user-dependent loads in local networks has increased the concern for congestion and voltage management in distribution networks. To mitigate these issues, the implementation of local flexibility markets has been proposed to assist distribution system operators (DSOs) to manage their networks efficiently. This paper presents the framework of a local flexibility market, including the market participants and their roles. This framework aims to empower DSOs with a market-based instrument for the alleviation of congestion incidents by exploiting the flexibility of local resources. The proposed market aims to provide a tool for the holistic management of distribution networks by trading both reservation and activation of flexibility services, indifferent of the type and the timeline of the needed service. Three market modes are proposed, i.e., long-term, short-term and real-time market, and the interactions among those modes are shown. The operation of the market is explained in detail, including the identification of the needed services, the activation of the market as well as the proposed bidding, clearing and settlement mechanisms. The modelling of the long-term and real-time markets is also presented, along with some indicative simulation results for long-term and real-time services. Finally, the future developments as well as the major conclusions are discussed.
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| 20. |
- Göransson, Lisa, 1982, et al.
(författare)
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Elbilar och förnyelsebar elproduktion
- 2014
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Ingår i: Perspektiv på eldrivna fordon 2014. - 9789198097443 ; , s. 20-21
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 21. |
- Göransson, Martin, 1991, et al.
(författare)
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Cost-benefit analysis of battery storage investment for microgrid of Chalmers university campus using OPF framework
- 2017
-
Ingår i: 2017 IEEE Manchester PowerTech, Powertech 2017; Manchester; United Kingdom; 18 June 2017 through 22 June 2017. - 9781509042371
-
Konferensbidrag (refereegranskat)abstract
- This paper presents a cost-benefit approach for evaluation of battery energy storage (BES) options to be installed in the electrical distribution grid of Chalmers University from the microgrid perspective. The evaluation is based on a multiperiod ac optimal power flow model applied for microgrid, which is referred to as the micro-OPF, with the objective function being the total grid operation cost. The model is developed for the real 12 kV grid of Chalmers. The micro-OPF is used as the calculation tool for the cost-benefit analysis where the benefit-to-cost ratios (BCR) of battery options in the grid in a year over the annualized cost of battery are evaluated for various options of battery sizes in the grid. The best location for the battery storage was however determined with the minimum loss criterion. The BCRs demonstrate the cost-effectiveness of the battery in microgrid operation. Battery options considered include both distributed option and a centralized option. It has been found that the best location of battery storage at Chalmers grid is at the point of connection to upstream grid of Gothenburg Energy distribution system for the centralized option. The study results show that the benefit gained from using battery storage increases with the size of battery, and the size with the highest BCR was found to be 2 MWh when considering the grid-connected mode of operation. The optimal size when the grid is in island mode is however dependent on island mode capability.
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| 22. |
- Hartvigsson, Elias, 1986, et al.
(författare)
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Local forecasts of electrc vehicles for grid planning purposes
- 2022
-
Ingår i: IET Conference Proceedings. - : Institution of Engineering and Technology. - 2732-4494. ; 2022:3, s. 878-882
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Tidskriftsartikel (refereegranskat)abstract
- Electrification of passenger vehicles is rapidly becoming the main alternative for decarbonizing transportation. The high power associated with charging of electric vehicles is likely to require actions from grid operators. Using machine learning and GIS analysis we produce forecasts of electric vehicles in very small cells, down to a few hundred meters for Norway. Using a baseline comparison, we find that a random forest model produces the overall lowest error, with a Mean Absolute Error of 14.0, and Mean Absolute Percentage Error of 33.9%. We find that both the existing vehicle fleet, and forecast shows that there is a large variation in electric vehicle adoption between cells. With knowledge where and when electric vehicles are adopted, grid operators can better plan their future investments related to electric vehicle charging, and thereby reduce investment costs.
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| 23. |
- Khezri, Rahmatollah, 1989, et al.
(författare)
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A Review on Implementation of Vehicle to Everything (V2X): Benefits, Barriers and Measures
- 2022
-
Ingår i: IEEE PES Innovative Smart Grid Technologies Conference Europe. ; 2022-October
-
Konferensbidrag (refereegranskat)abstract
- Increasing the number of electric vehicles (EVs) is necessary to support decarbonization of energy systems. Although high penetration of EVs brings new challenges to power systems as to provide sufficient energy and capacity for EVs charging, discharging of EVs would be a supportive option for electricity grid operators. Vehicle to everything (V2X) is the capability of EVs to support the grids through the vehicle to grid (V2G), vehicle to home (V2H), vehicle to load (V2L), vehicle to building (V2B) and vehicle to vehicle (V2V) technologies. The V2X technologies accelerate the electrification of the transport sector by creating added values for EVs. This paper provides a review of V2X implementation and the classification of the main benefits, barriers of V2X and possible measures to overcome. An overview of recent V2X demonstration projects worldwide has been presented along with their aims and scopes. Three groups of main benefits (i.e., social acceptance, market benefits, and economic benefits) are identified and discussed. Main barriers for V2X are categorized into four groups (i.e., technical, economic, regulatory, and social) and discussed. The paper also discussed possible measures to overcome the barriers to support successful implementation of V2X.
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| 24. |
- Khezri, Rahmatollah, 1989, et al.
(författare)
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Optimal EV Charge Scheduling Considering FCR Participation and Battery Degradation
- 2023
-
Ingår i: 2023 IEEE International Conference on Energy Technologies for Future Grids. - 2045-2322. - 9781665471640
-
Konferensbidrag (refereegranskat)abstract
- Emerging vehicle-to-grid (V2G) technology gives more flexibility to electric vehicles (EVs) for participating in ancillary service markets. This paper presents an optimal charge scheduling model for EVs by considering V2G, frequency containment reserve (FCR), and battery degradation, to investigate the profitability of FCR participation for an individual EV. The model considers the EV owners’ preferences for desired energy at the departure times while participating in FCR. The total scheduling cost of the EV is minimized through a mixed integer linear programming (MILP) problem. The outputs of the MILP model are the EV’s charge/discharge pattern and the amount of power for each scheduling horizon. It is found that FCR participation is quite profitable for EV owners.
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| 25. |
- Khezri, Rahmatollah, 1989, et al.
(författare)
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Optimal V2G Scheduling of an EV with Calendar and Cycle Aging of Battery: An MILP Approach
- 2024
-
Ingår i: IEEE Transactions on Transportation Electrification. - 2332-7782. ; In Press
-
Tidskriftsartikel (refereegranskat)abstract
- Since battery cost represents a substantial part of an electric vehicle’s (EV) total cost, the degradation of EV battery and how it is affected by being used in vehicle-to-grid (V2G) applications is a concern and the main argument against implementing V2G. Battery degradation is too complex in terms of non-linearity for practical optimization of V2G scheduling. This paper develops a mixed-integer linear programming (MILP) model to optimize the V2G scheduling of an EV, considering a detailed battery degradation model for calendar aging and cycle aging. In the developed model, calendar aging is affected by the state of charge, battery age, and temperature. The cycle aging is affected by temperature, C-rate, and the energy throughput of the battery. A case study is performed to minimize the annual operational cost of an EV with V2G capability for two different years of electricity cost and ambient temperature data. The results of the developed model are compared with four different cases: immediate charging, smart charging algorithms without V2G, V2G without degradation cost, and V2G with degradation cost as the objective function. It is shown that the developed V2G model achieves a slightly increased cycle aging due to usage in V2G. However, it reduces the overall scheduling cost of the EV by 48-88% compared to the immediate charging and by 10-73% compared to the smart charging. Furthermore, neglecting battery degradation in optimal V2G could lead to a 28% increase in scheduling cost.
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| 26. |
- Khezri, Rahmatollah, 1989, et al.
(författare)
-
Vehicle to Everything (V2X) - A Survey on Standards and Operational Strategies
- 2022
-
Ingår i: 2022 IEEE International Conference on Environment and Electrical Engineering and 2022 IEEE Industrial and Commercial Power Systems Europe, EEEIC / I and CPS Europe 2022.
-
Konferensbidrag (refereegranskat)abstract
- Number of plug-in electric vehicles (PEVs) is increasing significantly in the market. High number of PEVs in the grid, however, would bring major challenges to the electricity network to sufficiently supply the required charging for PEVs. Hence, making an interconnection between the transport and electricity systems is essential, and discharging of PEVs is a viable option to reduce the pressure on the network. To develop PEV discharging in a massive scale, the concept of vehicle to everything (V2X) has been emerged which includes the vehicle to home (V2H), vehicle to vehicle (V2V), vehicle to grid (V2G), vehicle to load (V2L), and vehicle to building (V2B) technologies. This paper presents a survey on the standards and operational strategies for further deployment of V2X. Hence, the existing standards are introduced and the need for new standards and regulatory frameworks to deploy the V2X technology is discussed. The charger types (i.e., onboard and offboard) are explained and compared in terms of benefits and existing challenges. The operational strategies for V2X are investigated and categorized. It is discussed how to develop a operation models for V2X application.
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| 27. |
- Khezri, Rahmatollah, 1989, et al.
(författare)
-
Willingness to Participate in Vehicle-to-Everything (V2X) in Sweden, 2022—Using an Electric Vehicle’s Battery for More Than Transport
- 2024
-
Ingår i: Sustainability. - 2071-1050. ; 16:5
-
Tidskriftsartikel (refereegranskat)abstract
- Vehicle-to-everything (V2X) refers to the technology that enables electric vehicles (EVs) to push their battery energy back to the grid. The system’s V2X integration includes key functions like V2G, V2H, V2B, etc. This paper explores the preferences of Swedish EV drivers in contributing to V2X programs through an online questionnaire. Respondents were asked to answer questions in three contexts: (1) claims related to their EV charging, (2) V2G application by EV, and (3) V2H application by EV. The respondents were questioned about the importance of control, pricing, energy sustainability and climate issues, impact on the battery, the acceptability of V2X, range anxiety, financial compensation, as well as how and where they prefer to charge the EV. The results of the survey indicate that Swedish EV drivers are more interested in the V2H application than in V2G. Additionally, they express more concern about range anxiety than battery degradation due to the V2X application.
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| 28. |
- Mazidi, Mohammadreza, 1987, et al.
(författare)
-
A novel energy management system for optimal energy and flexibility scheduling of residential buildings: a case study in HSB Living Lab
- 2023
-
Ingår i: 2023 IEEE Asia Meeting on Environment and Electrical Engineering (EEE-AM). - 9798350381061
-
Konferensbidrag (refereegranskat)abstract
- The future distribution system needs more flexibility to handle the peak power demand arising from the electrification of heating and transportation. This paper proposes a novel energy management system (EMS) for residential buildings to optimize their electric and heat consumptions while offering flexibility in response to the requirements of the Distribution System Operator (DSO). The aim of the proposed EMS is to minimize the energy and peak power costs while simultaneously maximizing the revenue from offering flexibility. This is achieved through the optimal scheduling of battery energy storage charging and discharging as well as the efficient utilization of the heat pump. To cope with forecasting uncertainties, a rolling horizon-based algorithm with uncertainty modelling based on the chance constraint method is incorporated. The performance of the proposed EMS is investigated by simulating the daily operation of a real residential building. The case studies indicate that the scheduled flexibility can be successfully dispatched even in the presence of forecasting uncertainties, causing 6% reduction in the payment cost of the building.
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| 29. |
- Mazidi, Mohammadreza, 1987, et al.
(författare)
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Effects of Calendar and Cycle Ageing on Battery Scheduling for Optimal Energy Management: A Case Study of HSB Living Lab
- 2023
-
Ingår i: 2023 IEEE International Conference on Energy Technologies for Future Grids. - 9781665471640
-
Konferensbidrag (refereegranskat)abstract
- This paper deals with the optimal scheduling of a building microgrid coupled with solar photovoltaic and battery energy storage (BES) considering battery degradation. The aim is to minimize the operation cost of the microgrid which includes the cost of imported electricity from the grid, the degradation cost of the battery, the cost for the peak power drawn from the grid, and the revenue from selling electricity to the grid. The nonlinear models of calendar and cycle ageing are linearized to solve the optimal scheduling as a mixed-integer linear programming (MILP) problem. The developed model is examined for a real residential building microgrid (HSB Living Lab) in Gothenburg, Sweden. The results show that if the degradation of the BES is ignored, the operation cost of the microgrid will increase by 1,394 SEK per year, and the ageing cost of the BES will also rise by 42.27%.
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| 30. |
- Mazidi, Mohammadreza, 1987, et al.
(författare)
-
Real-time rolling-horizon energy management of public laundries: A case study in HSB living lab
- 2023
-
Ingår i: Energy Conversion and Management: X. - 2590-1745. ; 20
-
Tidskriftsartikel (refereegranskat)abstract
- Energy Management Systems (EMSs) play a vital role in managing energy consumption for both utilities and consumers. By using EMSs, utilities can influence on energy usage and ensure a more reliable and efficient grid operation, while consumers can make informed decisions about their energy consumption, leading to significant cost savings and reduced environmental impact. In this paper, a real-time rolling-horizon model is developed for managing energy consumption in public laundries aiming at minimizing energy costs, peak demand, and CO2 emission under the traditional Energy-Based Tariff (EBT) and the Power-Based Tariff (PBT). The developed model can not only reduce energy costs, peak demand, and CO2 emission by optimal task scheduling for washing machines and tumble dryers but also ensure users' preferences for a comfortable lifestyle. To demonstrate the effectiveness of the proposed EMS, several simulations were performed under different scenarios using real data and by a realistic case study in HSB living lab demonstration site. The simulation results reveal that implementing the proposed EMS can significantly decrease energy costs and peak demand in public laundries by 13.59% and 39.40%, respectively, when using the PBT tariff. However, the reduction in energy costs and peak demand is negligible when using the EBT tariff. Likewise, the results indicate that using the EMS and changing tariffs have a minimal impact on CO2 emissions reduction.
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| 31. |
- Mirzaei Alavijeh, Nima, 1993, et al.
(författare)
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A toolbox for comparing congestion management solutions for distribution networks
- 2023
-
Ingår i: 2023 IEEE Belgrade PowerTech, PowerTech 2023. - 9781665487788
-
Konferensbidrag (refereegranskat)abstract
- To address the emerging challenges in electricity distribution networks, various solutions have been proposed such as alternative tariff design, local flexibility markets (LFMs), bilateral contracts, and local energy markets (LEMs). However, choosing a suitable solution is not straightforward due to multi-dimensional complexity of the challenges which may vary under different circumstances. This paper proposes a toolbox for qualitative and quantitative comparison of the different solutions. The toolbox includes a multi-dimensional analytical framework and a flexible modeling and demonstration platform for conducting quantitative comparison studies. Four solutions i.e. LFM, LEM, cost-reflective tariffs, and bilateral contracts are compared qualitatively using the framework and a real demonstration example of an LFM design is presented utilizing the modeling platform. The toolbox can facilitate research on the local grid challenges and contribute to finding a suitable solution from a multi-dimensional perspective.
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| 32. |
- Mirzaei Alavijeh, Nima, 1993, et al.
(författare)
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Capacity limitation based local flexibility market for congestion management in distribution networks: Design and challenges
- 2024
-
Ingår i: International Journal of Electrical Power and Energy Systems. - 0142-0615. ; 156
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, five of the main design challenges of local flexibility markets (LFMs) for congestion management are identified and discussed based on desirable market properties from economics theory and literature review. The five main design challenges are low market liquidity, reliability, baselines, forecast errors at low aggregation levels, and the high cost of measurements. A comprehensive capacity-limitation based LFM design has been proposed to address the challenges and a simulation example is presented to illustrate the design. The proposed design facilitates market participants’ decision making by design elements that improve market liquidity, reliability and handling of forecast errors. Moreover, a new capacity limitation product is proposed that is not defined with respect to a baseline and does not require sub-meter measurements leading to lower costs and conflict-of-interest in delivery validation. Generic algorithms are also proposed for calculating utility and cost of the flexibility product. The proposed design and discussions can contribute to improving the inter-disciplinary area between engineering and economics while helping policy-makers and LFM stakeholders to further understand the problem from a multi-dimensional perspective.
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| 33. |
- Mirzaei Alavijeh, Nima, 1993, et al.
(författare)
-
Cost-Effectiveness of Carbon Emission Abatement Strategies for a Local Multi-Energy System - A Case Study of Chalmers University of Technology Campus
- 2020
-
Ingår i: Energies. - : MDPI AG. - 1996-1073 .- 1996-1073. ; 13:7
-
Tidskriftsartikel (refereegranskat)abstract
- This paper investigates the cost-effectiveness of operation strategies which can be used to abate CO2 emissions in a local multi-energy system. A case study is carried out using data from a real energy system that integrates district heating, district cooling, and electricity networks at Chalmers University of Technology. Operation strategies are developed using a mixed integer linear programming multi-objective optimization model with a short foresight rolling horizon and a year of data. The cost-effectiveness of different strategies is evaluated across different carbon prices. The results provide insights into developing abatement strategies for local multi-energy systems that could be used by utilities, building owners, and authorities. The optimized abatement strategies include: increased usage of biomass boilers, substitution of district heating and absorption chillers with heat pumps, and higher utilization of storage units. The results show that, by utilizing all the strategies, a 20.8% emission reduction can be achieved with a 2.2% cost increase for the campus area. The emission abatement cost of all strategies is 36.6–100.2 (€/tCO2 ), which is aligned with estimated carbon prices if the Paris agreement target is to be achieved. It is higher, however, than average European Emission Trading System prices and Sweden’s carbon tax in 2019.
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| 34. |
- Mirzaei Alavijeh, Nima, 1993, et al.
(författare)
-
Impact of Internal Energy Exchange Cost on Integrated Community Energy Systems
- 2019
-
Ingår i: iSPEC 2019 - 2019 IEEE Sustainable Power and Energy Conference: Grid Modernization for Energy Revolution, Proceedings. - 9781728149301 ; , s. 2138-2143
-
Konferensbidrag (refereegranskat)abstract
- Integration of more distributed renewable energy resources (RES) technologies in the past few years has led to reliability and stability issues in the energy systems due to the mismatch between the demand and the intermittent RES production. Integrated community energy systems (ICES) have been discussed as part of the solution for these challenges. In this paper, we have assessed the impact of the internal energy exchange (IEE) fee in ICESs with a model-based approach. The impact is considered for the performance of ICESs and the behaviour of different prosumers’ assets such as batteries, thermal energy storage, auxiliary heat pumps and demand response. A case study has been carried out on a district in Gothenburg, Sweden and the results show that the ICESs’ performance and the assets’ behaviour are highly affected by IEE fee and the ICES chooses different cost saving strategies at different IEE fees. For the case study, the community’s cost was reduced by 30%, and the electricity import and export by 45.6% and 97.2% respectively when low IEE fee were considered.
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| 35. |
- Mladenov, Valeri, et al.
(författare)
-
Peer to Peer technologies in energy network
- 2021
-
Ingår i: 2021 13TH ELECTRICAL ENGINEERING FACULTY CONFERENCE (BULEF). - 9781665441926
-
Konferensbidrag (refereegranskat)abstract
- Peer to peer trading can be a key element that will help in the transition to active management of electricity networks. This will increase network flexibility at optimal investment costs. Existing pilot projects with the expected results and clarification of the advantages and disadvantages are the subject of research in this article. Regulatory norms and the possibility of decentralized energy sources to provide an opportunity for transition to a low-carbon economy are considered.
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| 36. |
- Mohiti Ardakani, Maryam, 1989, et al.
(författare)
-
A Decentralized Transactive-Based Model for Reactive Power Ancillary Service Provision by Local Energy Communities
- 2023
-
Ingår i: 2023 IEEE Belgrade PowerTech, PowerTech 2023.
-
Konferensbidrag (refereegranskat)abstract
- Local Energy Communities (LECs) have been introduced to facilitate the high penetration of distributed energy resources into distribution systems (DSs), which can also be valuable sources of ancillary services for Distribution System Operators (DSOs). The aim of this paper is to investigate if and how LECs can contribute to the reactive power management of DSs. To this end, a transactive-based model is proposed to manage the reactive power of LECs in a decentralized way. In the proposed model, DSO sends transactive signals to LECs and incentivizes them to inject/absorb reactive power aiming at controlling the voltage profile of DS. Accordingly, the reactive power management and thus voltage control is performed without any direct interferences of the DSO in the resource scheduling of LECs. The proposed model is applied to the DS of Chalmers campus to demonstrate its performance in reactive power management and voltage control.
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| 37. |
- Mohiti Ardakani, Maryam, 1989, et al.
(författare)
-
A Risk-Averse Energy Management System for Optimal Heat and Power Scheduling in Local Energy Communities
- 2022
-
Ingår i: 2022 IEEE International Conference on Environment and Electrical Engineering and 2022 IEEE Industrial and Commercial Power Systems Europe, EEEIC / I and CPS Europe 2022.
-
Konferensbidrag (refereegranskat)abstract
- Local energy communities (LECs) facilitate energy distribution, supply, consumption, storage, and trading for the communities and their members. This paper proposes a risk-averse energy management system (EMS) for optimal heat and power scheduling in LECs. Three approaches namely high accuracy forecast models, advanced optimization models, and providing flexibility sources are followed to handle uncertainties of photovoltaic power and load. To this end, the load demand and photovoltaic power as uncertain variables are predicted using machine learning methods and the problem is modeled under uncertainties by information-gap decision theory (IGDT). This method doesn't require probability distribution functions of uncertain variables which makes it valuable in cases with high levels of uncertainties or lack of sufficient historical data. The advantage of flexibility in increasing robustness is studied by adjusting desired indoor and hot water temperatures. The effectiveness and efficiency of the proposed model are evaluated on the LEC at Chalmers University of Technology campus, Gothenburg, Sweden.
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| 38. |
- Mohiti Ardakani, Maryam, 1989, et al.
(författare)
-
An IGDT-Based Energy Management System for Local Energy Communities Considering Phase-Change Thermal Energy Storage
- 2024
-
Ingår i: 2022 IEEE International Conference on Environment and Electrical Engineering and 2022 IEEE Industrial and Commercial Power Systems Europe, EEEIC / I and CPS Europe 2022. - 1939-9367 .- 0093-9994. ; 60:3, s. 4470-4481
-
Tidskriftsartikel (refereegranskat)abstract
- Local energy communities (LECs) facilitate energy distribution, supply, consumption, storage, and trading for the communities and their members. This paper proposes an energy management system (EMS) for optimal heat and power scheduling in LECs. A novel model for the phase-change thermal energy storage (TES) which is applicable in mixed integer linear problems (MILP), is introduced. Furthermore, a risk-averse and risk-seeker EMS is developed that incorporates the integration of TES to optimize electricity and heat scheduling in LECs. The developed EMS doesn't require probability distribution functions of predicted data which makes it valuable in cases with high levels of uncertainties or lack of sufficient historical data. To validate the performance of the proposed TES model, real time studies are conducted on an industrial TES provided by Azelio company. Likewise, the effectiveness and efficiency of the proposed EMS are evaluated on a real LEC at Chalmers University of Technology campus, Gothenburg, Sweden.
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| 39. |
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| 40. |
- Rahimi, S., et al.
(författare)
-
Using the advanced DMS functions to handle the impact of plug-in Electric vehicles on distribution networks
- 2014
-
Ingår i: 2014 IEEE International Electric Vehicle Conference, IEVC 2014. - 9781479960750
-
Konferensbidrag (refereegranskat)abstract
- Integration of Electric vehicles and their impact on power system have been a major topic within smart grid initiatives. It is proven that managing larger amount of loads in form of plug-in Electric vehicles (PEV) is a challenge for operation of low and medium voltage distribution network. The main objective of this paper is to discuss the usage of 'Integrated Volt/Var Optimization' function (which is one of main advanced distribution management system (DMS) functions) for handling the larger share of PEV load and reducing their impact on operation of Distribution System (DS). For this purpose, we propose a method for evaluating the impact of PEV charging on steady state operating condition of DS and identifying its possible capacity limitations in case of significant penetration of PEVs. We have applied a stochastic modeling for base EV load and have examined several different scenarios based on charging power and penetration level of PEVs to compare uncontrolled charging with base operation conditions. By presenting the results from our developed Volt/Var Optimization (VVO) engine, it is concluded that DMS functions can support handling of these new operating conditions for DSOs. A real distribution network in south western part of Sweden is used as test system for this study while a set of realistic load profile has been created based on real driving pattern (using the results of national survey from Swedish traffic authority) and actual base load for one year. In this work, the VVO function have been implemented in General Algebraic Modeling System (GAMS) by using a single mixed integer linear programming (MILP) model for the volt-var problem. The results of optimization are system loss and voltage profile along the network in comparison with 'base-case' solution.
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| 41. |
- Rossi, Joni, et al.
(författare)
-
Study of the European Regulatory Framework for Smart Grid Solutions in Future Distribution Systems
- 2020
-
Ingår i: CIRED - Open Access Proceedings Journal. - : Institution of Engineering and Technology (IET). - 2515-0855. ; 2020:1, s. 800-802
-
Konferensbidrag (refereegranskat)abstract
- Electric distribution systems in Europe are facing significant challenges due to climate change goals, changing market frameworks and technological innovations, which will significantly impact the role of the distribution system operators. The nature and scale of these challenges are strongly driven by the European vision and strategies on climate and energy. This study identifies which policies can become barriers for distribution grid innovation and the implementation of advanced smart grid solutions developed within the UNITED-GRID project. After an extensive review of new policy priority areas within the energy and climate framework and electricity market design, and subsequent discussions with three partner distribution system operators, five priority barriers are identified. The results show that ambitious decarbonisation targets and changing expectations on the distribution system operators’ role in the energy system would require more flexible and efficient network management. However, binding income frameworks, lacking incentives for innovation and regulatory uncertainties hinder modernisation in distribution systems. It can be concluded that these concerns increase the risks for distribution system operators and have to be considered by research projects and developers of smart grid solutions in order to implement and achieve market uptake of the developed solutions within the next 5–10 years.
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| 42. |
|
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| 43. |
- Sharma, Rohini, 1990, et al.
(författare)
-
FlexiGrid Tools for Real-Life Demonstrations of Local Energy System Concepts at Chalmers Campus Testbed
- 2023
-
Ingår i: 2023 IEEE Belgrade PowerTech. - 9781665487788
-
Konferensbidrag (refereegranskat)abstract
- The ongoing transition in the energy system is accompanied by various challenges such as congestion and voltage violations in electricity distribution networks. Suggested solutions to these challenges are, among others, local energy and flexibility markets, new tariff designs, and centralized control. Simulation and demonstration of such solutions often require a broad chain of tools that need to be automated. The aim of this paper is to present a simulation and demonstration platform integrating several of the required tool and their deployment at the Chalmers Campus test bed. The developed tools include PV and load forecasting, congestion forecasting, energy management system, model predictive control algorithms, and local energy and flexibility markets. The tools are integrated using a common and reusable platform called LESOOP for simulation and demonstration. Demonstration examples of PV and load forecasts, congestion forecasts, model predictive control, and energy management systems are presented and results are discussed. The paper contributes to a more successful transition of the energy system by sharing experiences and provides better understanding of the tool functionalities at the Chalmers campus test-bed. The identified gaps and gained knowledge from the real-life demonstrations at the test-bed can be valuable to projects and researchers aiming to develop a test-bed.
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| 44. |
- Srivastava, Ankur, 1989, et al.
(författare)
-
A Congestion Forecast Framework for Distribution Systems with High Penetration of PV and PEVs
- 2019
-
Ingår i: 2019 IEEE Milan PowerTech, PowerTech 2019.
-
Konferensbidrag (refereegranskat)abstract
- This paper presents a congestion forecast framework for electrical distribution systems with high penetration of solar photovoltaic and plug-in electric vehicles. The framework is based on probabilistic power flow to account for the uncertainties in photovoltaic production and load demand. The proposed framework has been implemented and tested using the data of the real distribution grid of Chalmers University of Technology campus. Cases studies have been carried out using the framework to analyse the impact of different local production levels and operating modes of solar photovoltaic inverter. The results have shown that cumulative probability for network congestion in branches and transformers would increase by 30% and 20% respectively, when the level of local PV generation, demand and PEVs demand to increase by 100%, 95% and 100% respectively. Also, results have shown that network congestion in branches and transformers is 4% and 8% respectively, more likely to occur in the constant-V mode as compared to constant-pf mode. These results can help distribution system operators to predict any upcoming congestion in their system and subsequently help them in taking suitable actions in order to mitigate congestion.
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| 45. |
- Srivastava, Ankur, 1989, et al.
(författare)
-
A DSO Support Framework for Assessment of Future-Readiness of Distribution Systems: Technical, Market, and Policy Perspectives
- 2019
-
Ingår i: CIRED Conference Proceedings. - 2032-9644. - 9782960241501
-
Konferensbidrag (refereegranskat)abstract
- This paper presents the initial ideas for a framework to support the distribution system operators for assessing current status of network infrastructures, market/business models, and policies applicable to distribution systems, and thus identify future-readiness of their network. The assessment framework consists of two steps as the identification of the key indicators associated with this transition and assessing the current status by evaluation of these indicators based on inputs from distribution system operators. Case studies have been carried out for distribution system operators in three European countries, i.e., Göteborg Energi (Sweden), SOREA (France), and ENEXIS (The Netherlands). The key results have shown that presently the three distribution system operators have a small proportion of renewable power generation in their grids, but it is going to increase in the future. Hence, they need investments in flexibilities, generation and load forecasting, advanced network control, and protection strategies, etc. The results also suggest needs for development of novel business models for customers and changes in the policy and regulations. Finally, a comparative assessment of three distribution system operators is presented in the paper.
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| 46. |
- Srivastava, Ankur, 1989, et al.
(författare)
-
Decentralized Dynamic State Estimation of Transmission Lines Using Local Measurements
- 2023
-
Ingår i: IEEE Access. - 2169-3536 .- 2169-3536. ; 11, s. 78237-78250
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a novel decentralized dynamic state estimation (DSE) method for estimating the dynamic states of a transmission line in real-time. The proposed method utilizes the sampled measurements from the local end of a transmission line, and thereafter DSE is performed by employing an unscented Kalman filter. The advantage of the proposed method is that the remote end state variables of a transmission line can be estimated using only the local end variables and, hence, the need for communication infrastructure is eliminated. Furthermore, an exact nonlinear model of the transmission line is utilized for estimation and the DSE of one transmission line is independent of the other lines. These in turn result in reduced complexity, higher accuracy, and easier implementation of the decentralized estimator. The proposed method is applied to a case study with realistic transmission line parameters. The results from the case study affirm that the proposed method accurately estimates the state variables under different operating conditions. Furthermore, robust performance is achieved with different noise variances and types. The proposed DSE method is envisioned to have potential applications in transmission line monitoring, control, and protection.
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| 47. |
- Srivastava, Ankur, 1989, et al.
(författare)
-
Development of a DSO Support Tool for Congestion Forecast
- 2021
-
Ingår i: IET Generation, Transmission and Distribution. - : Institution of Engineering and Technology (IET). - 1751-8687 .- 1751-8695. ; 15:23, s. 3345-3359
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a novel DSO support tool with visualisation capability for forecasting network congestion in distribution systems with a high level of renewables. To incorporate the uncertainties in the distribution systems, the probabilistic power flow framework has been utilised. An advanced photovoltaic production forecast based on sky images and a load forecast using an artificial neural network is used as the input to the tool. In addition, advanced load models and operating modes of photovoltaic inverters have been incorporated into the tool. The tool has been applied in case studies to perform congestion forecasts for two real distribution systems to validate its usability and scalability. The results from case studies demonstrated that the tool performs satisfactorily for both small and large networks and is able to visualise the cumulative probabilities of nodes voltage deviation and network components (branches and transformers) congestion for a variety of forecast horizons as desired by the DSO. The results have also shown that explicit inclusion of load-voltage dependency models would improve the accuracy of the congestion forecast. For demonstrating the applicability of the tool, it has been integrated into an existing distribution management system via the IoT platform of a DMS vendor, Atos Worldgrid.
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| 48. |
- Srivastava, Ankur, 1989, et al.
(författare)
-
Dynamic State Estimation based Transmission Line Protection Scheme: Performance Evaluation with Different Fault Types and Conditions
- 2023
-
Ingår i: International Journal of Electrical Power and Energy Systems. - : Elsevier BV. - 0142-0615. ; 148
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents the experimental validation of a transmission line protection scheme based on dynamic state estimation for different fault types and conditions. The protection scheme utilizes real-time high-frequency sampled measurements from advanced sensors and evaluates the operating condition of the transmission line based on which a tripping signal is generated in case a fault occurs. The validation is performed using a physical scaled-down model of a power system, consisting of a transmission line, transformer, synchronous generator, and loads. The following faults are examined during the validation: unbalanced faults under different load conditions, high impedance fault, fault current fed from both ends, hidden failure, external fault, and load change conditions. The results show that the scheme performs as intended and thus proves its efficacy to detect various types of faults. The maximum fault detection time is calculated to be 42.5 milliseconds, while the maximum fault clearing time comes out to be 82.5 milliseconds, on par with currently employed protection methods. The obtained results demonstrate the ability of the scheme to detect different fault types under varying conditions and avoid potential issues with relay coordination
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| 49. |
- Srivastava, Ankur, 1989, et al.
(författare)
-
Transmission Line Protection Using Dynamic State Estimation and Advanced Sensors: Experimental Validation
- 2023
-
Ingår i: IEEE Transactions on Power Delivery. - 0885-8977 .- 1937-4208. ; 38:1, s. 162-176
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents the experimental validation of a protection scheme for a transmission line based on dynamic state estimation along with the practical application of advanced sensors in this protection scheme. The scheme performs dynamic state estimation with high-frequency measurements provided by the sensors, assesses the operating condition (i.e., health) of the transmission line in real-time, and thereby determines the tripping signal whenever a fault is detected. The validation was carried out in two steps, first with simulation studies for a three-phase fault and then with the experimental implementation using a physical scaled-down model of a power system consisting of transmission lines, transformers, and loads. The simulation and validation results have shown that the scheme performs adequately in both normal and fault conditions. In the fault case with the experimental setup, the scheme could correctly detect the fault and send the trip signal to the line’s circuit breakers with a total fault clearing time of approximately 65 milliseconds which is comparable to conventional protection methods. The average processing time for a measurement sample block is 12.5 milliseconds. The results demonstrate that this scheme and the sensors would work for transmission line protection which can avoid relay coordination and settings issues.
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| 50. |
- Steen, David, 1983, et al.
(författare)
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Assessment of Electric Vehicle Charging Scenarios Based on Demographical Data
- 2012
-
Ingår i: IEEE Transactions on Smart Grid. - 1949-3053 .- 1949-3061. ; 3:3, s. 1457-1468
-
Tidskriftsartikel (refereegranskat)abstract
- A massive introduction of Plug-in Electric Vehicles(PEVs) in the transportation sector would likely increase the total electricity consumption. Depending on how and when the PEVs are charged the effects on the power demand will vary. Previous studies have shown that uncontrolled charge of PEVs can cause problems for the electrical distribution system. This paper proposes an approach to control PEVs charging based on the charging behavior estimated from the demographical statistical data. In this approach, three different charge strategies are designed and the impacts of PEVs charging on the electrical distribution system are assess using standard load flow calculations. A case study using the proposed approach examines the real situation in Gothenburg, located on the west coast of Sweden. The results from the study show that the impacts on the electrical distribution system due to PEVs vary between different areas. By controlling the charging, the impacts can be reduced but the choice of control methods must be chosen carefully. Furthermore, the results indicate that a well-developed public charging infrastructure could reduce the stress on the residential electrical distribution systems since part of the charging can be done in commercial areas.
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