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| 2. |
- Ahlgren, Erik, 1962, et al.
(författare)
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Produktionsrelaterade systemstudier
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I denna rapport, Produktionsrelaterade systemstudier – flexibla el- och värmesystem, har kortfattat ett antal områden som kan tänkas få betydelse för utvecklingen av de svenska el- och värmeförsörjningssystemen analyserats. Målet har varit att ge en bakgrundsbeskrivning av ett antal tekniska och teknisk-ekonomiska områden som kommer att påverkas av och/eller påverka framtida el- och värmeförsörjning. Författarna har utgått från de övergripande frågorna, såsom försörjningstrygghet i en avreglerad marknad och energisektorns miljöpåverkan speciellt med avseende på klimatpåverkan. Systemgränsen runt el- och värmesektorn har avsiktligt dragits mycket brett så att också bebyggelse- och industrisektorerna är inkluderade, eftersom dessa är de klart dominerande sektorerna både med avseende på elanvändning och med total energianvändning. Avsikten med detta har varit att peka på den stora betydelse som ändrade energiefterfrågemönster inom bebyggelsesektorn och än annan syn på industrisektorn, inte bara som energianvändare utan också delvis som energileverantör, kan få för det framtida el- och värmeförsörjningssystemet. Studien behandlar produktionsrelaterade elsystemfrågor, men med ett perspektiv av interaktion mellan tillgång och efterfrågan. Ett stort antal tillförseltekniker och –system har kort berörts. Vissa av dessa dominerar systemet idag, andra kan tänkas få en inte oväsentlig betydelse i framtida system. Genomgående trycks på behovet av en integrerad analys där hänsyn tas till samspel mellan tillförsel och användning, mellan teknik och ekonomi, mellan kort och lång sikt, mellan el och värme och även transporter, för att uppnå en högre verkningsgrad och därmed minskad miljöbelastning. Verkningsgraden har betraktats utgående från ett systemperspektiv snarare än från ett anläggnings-perspektiv. Slutsatsen av analysen är att det fortfarande finns ett antal markanta kunskapsluckor, och att dessa framför allt finns på systemnivå i samspelet, eller det möjliga samspelet, mellan ovan nämnda områden; tillförsel och användning; el, värme och transporter; samt betydelsen för försörjningssystemet av förväntade ändringar med tiden av såväl el- och värmeefterfrågan, som av tillgängliga tekniska lösningar.
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| 3. |
- Altintas, Atilla, 1979, et al.
(författare)
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Forecasting of Day-Ahead Wind Speed/electric Power by Using a Hybrid Machine Learning Algorithm
- 2023
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Ingår i: Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering. - 1867-8211 .- 1867-822X. ; 502 LNICST, s. 3-11
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Konferensbidrag (refereegranskat)abstract
- The amount of energy that has to be delivered for the following day is currently predicted by power system operators using day-ahead load forecasts. With the use of this forecast, generation resources can be committed a day in advance, some of them may require several hours’ notice to be ready to produce power the following day. In order to determine how much wind power will be available for each hour of the following day, power systems with large penetrations of wind generation rely on day-ahead predictions. The main objective of this study is to improve the day-ahead forecasting of wind power by improving the forecasting method using machine learning. A hybrid approach, which combines a mode decomposition method, Empirical Mode Decomposition (EMD), with Support Vector Regression (SVR), is used. The results suggest that using Support Vector Regression together with the hybrid method, which includes the Empirical Mode Decomposition to predictions can improve the accuracy of predictions. Higher accuracy forecasting of wind power is expected to improve the planning of dispatchable energy generation and pricing for the day-ahead power market.
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| 5. |
- Antoniadou-Plytaria, Kyriaki, 1989, et al.
(författare)
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Chalmers Campus as a Testbed for Intelligent Grids and Local Energy Systems
- 2019
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Ingår i: IEEE International Conference on Smart Energy Systems and Technologies (SEST). - 9781728111568
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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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| 6. |
- Antoniadou-Plytaria, Kyriaki, 1989, et al.
(författare)
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Effect of Short-term and High-resolution Load Forecasting Errors on Microgrid Operation Costs
- 2022
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Ingår i: IEEE PES Innovative Smart Grid Technologies Conference Europe. - 9781665480321 ; 2022-October
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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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| 7. |
- Antoniadou-Plytaria, Kyriaki, 1989, et al.
(författare)
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Energy Scheduling Strategies for Grid-connected Microgrids: A Case Study on Chalmers Campus
- 2019
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Ingår i: Proceedings of 2019 IEEE PES Innovative Smart Grid Technologies Europe, ISGT-Europe 2019.
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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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| 8. |
- Antoniadou-Plytaria, Kyriaki, 1989, et al.
(författare)
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Market-based Energy Management Model of a Building Microgrid Considering Battery Degradation
- 2021
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Ingår i: IEEE Transactions on Smart Grid. - 1949-3053 .- 1949-3061. ; 12:2, s. 1794-1804
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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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| 9. |
- Antoniadou-Plytaria, Kyriaki, 1989, et al.
(författare)
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Scenario-based Stochastic Optimization for Energy and Flexibility Dispatch of a Microgrid
- 2022
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Ingår i: IEEE Transactions on Smart Grid. - 1949-3053 .- 1949-3061. ; 13:5, s. 3328-3341
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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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| 10. |
- Babaei, Saman, et al.
(författare)
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Effects of PHEVs in power distribution systems: reviews and analyses
- 2010
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Ingår i: CIRED Workshop on Sustainable Distribution Asset Management and Financing, 7-8 June 2010, Lyon, France.
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Konferensbidrag (refereegranskat)abstract
- This paper deals with the analysis of the impacts of plug-in hybrid electric vehicles (PHEVs) on the power system, with focus on the low voltage power distribution system. First a review of the technical challenges in the power system due to the mass introduction of PHEVs in the transportation sector is given. Then the paper shows on an analysis of the overloading effects of PHEVs on the distribution system with normal charging and quick charging of PHEVs for an IEEE 13-node distribution test system using power flow analysis. The results of the study show that introduction of PHEVs in the transportation sector will lead to overloading of distribution system and cause voltage problems at the end-users. The paper also analyzes the effects of PHEVs in the transmission system, using the Nordic 32-bus test system. The study results showed that the overloading problem is not prominent. However, one interesting and important result is that PHEVs may lead to overvoltages in some buses in the transmission system which requires the voltage control measures. PHEVs would also lead to increased number of network violations in the contingency analysis.
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