AbstractâThis paper analyzes the impact of the charge of EVs. (Electrical Vehicles) on a power grid. In order to simulate the behavior of the EV charging on the ...
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European Association for the Development of Renewable Energies, Environment and Power Quality (EA4EPQ)
International Conference on Renewable Energies and Power Quality (ICREPQ’10) Granada (Spain), 23rd to 25th March, 2010
Preparation of full paper for the International Conference on Renewableof Energies Deterministic and Probabilistic Assessment the and Power Quality Impact of the Electrical Vehicles on the Power Grid A. Author1, B. Author2 and C. Author1 1 E. Valsera-Naranjo1 , A. Sumper1,2 afila-Robles1 , A. Sudri`a-Andreu1,2 1 , P. Lloret-Gallego , R. Villaf´ Department of Electrical Engineering 1 Centre d’Innovaci´ o Tecnol`ogica en E.T.S.I.I., Vigo University Convertidors Est`atics Campus i Accionaments(CITCEA-UPC), Departament d’Enginyeria El`ectrica, of Lagoas – Marcosende, 36310 Vigo (Spain) Universitat Polit` e cnica de Catalunya. Phone/Fax number:+0034 986 812685, e-mail: A.Author@uvigo.es, C.Author@uvigo.es EU d’Enginyeria T`ecnica Industrial de Barcelona, 2 European Association for the Development of Renewable Environment and Power Quality (EA4EPQ) Comte d’Urgell, 187; 08036 Barcelona,Energies, Spain. http://www.citcea.upc.edu 2 IREC CataloniaMailing address Institute for Energy Research Phone, fax, e-mail Josep Pla, B2, Pl. Baixa. 08019 Barcelona, Spain http://www.irec.cat eduard.valsera@citcea.upc.edu, sumper@citcea.upc.edu, A. Language lloret@citcea.upc.edu, roberto.villafafila@citcea.upc.edu, sudria@citcea.upc.edu Abstract. The abstract in placed in the left-hand column and starts at about 11 cm from de top of the page. It should give concise information on the aims, the methods, the results and the conclusions of the paper. Its length should not exceed 200 words. Abstract—This paper analyzes the impact of the charge of EVs (Electrical Vehicles) on a power grid. In order to simulate the behavior of the EV charging on the grid a model of its battery Key words has been found (EV’s charging curve). As the way of the EV is charged from the grid affects critically to the voltage levels Please the main keylines words your text to 5)are and to thewrite saturation of the two of modalities of (3 charge presented: separatednot-controlled by commas. charge and controlled charge. Finally, the simulations have been performed from two points of view: deterministic analysis and probabilistic analysis.
1. Introduction
Authors of acceptedI. abstracts will be requested to submit I NTRODUCTION a full paper for inclusion in the International Conference TheRenewable recent awareness about fuels and the environment on Energies andfossil Power Quality CDRom and hasalso arisen more sustainable alternatives regarding means an extended abstract of one sheet. The full papers are of transport. Consequently, hybrid vehicles and pure electrical due January 20, 2010. vehicle have become the main alternatives for green transportation. new trend hassent caused market or activation and it The full This papers have to be as a pdf-file a word file is (.doc) expected thatofhybrid and electrical will constitute to one the following e-mail vehicles addresses: theicrepq@icrepq.com, majority in private icrepq@uvigo.es transport. or: Moreover, one kind of hybrid vehicles, the plug-in electric donsion@uvigo.es vehicles (PHEV), will not only charge their batteries, but Pleasewill carefully to PHEV also beread ableandto follow inject these power instructions to the network ensure a uniform quality vehicles and appearance when required, as the electrical (EV) do. of Thisall fact contributions. suggests that EV penetration will affect current power system performance. Then, it is necessary to study some scenarios explain the nature of the previous work, in of Clearly penetration of such vehicles intoproblem, the electrical network purpose and contribution of the paper. order to maintain security and quality of power supply within standard limits. 2. Page Layout On one hand, in order to analyze the impact of EVs integration into the power grid, aspects related to storage Papers should notbatteries) exceed and six the double column A4 of technologies (namely charging process (21x29.7cm) pages including figures, tables and such storage devices have to be studied. In order to analyze diagrams. On the last page try to balance both columns.
English (check carefully for correct grammar and spelling)
B. Margins the impact of EV on the power grid, load flow calculations in a standard network performed following. doand that, Set the urban top and bottomare margins to 2 cm, and theToleft different penetrations of EV network are considered. right margins to 1.7 cm. into The the spacing between the two should be 1.25 are cm shown and commented lately. Thecolumns results of simulations On the other hand, an European standard which defines the Justification: Fullby EVs is needed. Until a new type of 1) connector to be used 2) Headers and Footers: None standard gets develop, it is proposed to use a SCHUKO (CEE 3) Page Numbering: None 7/4) connector type for currents up to 16A. In addition, to slow charging, the output values of the charging station should be C. 16Type Sizes up to A per plug, 230 V ± 10%, and 50 Hz ± 1% [1]. Manuscripts must be typed with a proportional serif E LECTRICAL V EHICLE typeface such II. as Time New Roman. The type sizes to be used for the different parts in the paper are shown in a In order to analyze the impact of the EVs into the grid, Table I. model of its charging curve is needed. From all the existing Table I. - Type Sizes
models of EV, the charging curve chosen is from the Mitsubishi I-MIEV [2]. This vehicle has an autonomy of 160 km SIZE APPEARANCE and Title its batteries are made of Li-ion (50Ah 16kWh 330V) 14 pt Bold centred [2]; Fig.1Author shows the charging curve of 11 theptEV when its capacity at Centred 20%.Abstract The battery is charging at full9 power during 2 hours and pt thenMain decreases its charging power exponentially since the hour text 10 pt 4; atPrimary this time it is considered that the battery is completely heading 12 pt Bold, left charged. Secondary headings 10 pt Italic, flush left The way headings of how EVs are charged theindented grid has a Tertiary 10 pt from Italic, critical influence on its impact on the voltage levels Tables 9 pt Centred and on the saturation of the lines. Considering this fact, two modalities Table and figure captions 9 pt Centred of charge are presented: not-controlled charge and controlled References 9 pt charge. In the not-controlled charge EVs start the charge as theyD.park. In Spacing the controlled charge, EVs only can charge during Line a determined period of time of the day (low-load period). In both modalities charge, the number EVs between charging Singled spaced, ofwith a double line of space paragraphs. Allow an extra half space above a line
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is defined establishing different scenarios of EV penetration over the vehicles acceding to the city (Fig.2). The curve of the movement of the vehicles has been obtained from an estimation of the curve of Barcelona [3] and has been shifted two hours earlier in order have a better representation of the Denmark’s vehicle movement (in this estimation, population has also been considered).
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During the charging process of the EV, will be charging simultaneously EV with different states of charge. Therefore, a model is needed to take this fact into account in the steadystate simulations. Eq.1 models the superposition of the demand caused by the EV in different charging states, where R is penetration of EV, Pev is the maximum power which a car can charge, i is the counter associated to the actual hour, j is the counter associated to the previous hour, ∆vak,k−1 is the increase of EV between the hour i and the hour j and Cevk is the charging state of the EV (Fig.1).
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In order to study the most critical situation the Winter(week) case has been chosen from all the possible situations of electrical demand because it has the highest demand in every hour (Fig.5). Therefore, the wind power generation curve is from this period. Fig.6 depicts a representative daily generation for the three wind power generation units. 14 Winter (week) Summer (week) Winter (weekend) ( ) 12
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Applying this model to the vehicle movement curve, the demand curves for the both charging modalities can be obtained (Fig.3)
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III. P OWER G RID 0
The scenario of the simulations is a part of the Danish sample grid (Fig.4) [4]. This grid, of 400 MW of short-circuit power, has 3 wind turbine generation units of 630 kW at busbars B013, B015 and B017. In addition, there are three combined cycle units of 3 MW each one at the busbar B005, but for purposes of the study has remained disconnected. Loads are at the busbars B005, B010, B011 and B012. Due to simplify the interpretation of the simulations and the results, EVs have been separated from the other consumptions.
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Electrical demand
In the deterministic and in the probabilistic analysis the voltage results presented are from two busbar. The first busbar is B005 and it has been chosen because L00 is always the load with the highest power. The second busbar chosen is B014 in order to have the behavior of a closer busbar to a wind power 2
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IV. D ETERMINISTIC A NALYSIS
Fig. 8. Voltage levels for the busbar B005 for the different penetrations of EV in the case of not-controlled charge for the deterministic analysis
In this section, the result from executing a deterministic analysis are shown. In this kind of analysis all loads are previously determined. The results from the two typologies of charge for the EV are presented for the different penetrations of EV.
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Fig. 9. Voltage levels for the busbar B005 for the different penetrations of EV in the case of controlled charge for the deterministic analysis
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Fig. 7. Voltage levels for the busbar B005 for the different penetrations of EV in the case of not-controlled charge for the deterministic analysis
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V. P ROBABILISTIC A NALYSIS
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From the compiled data during the week days of the winter season a mean and an standard deviation have been found for each hour of the day. In order to perform a probabilistic analysis 50 load flows for each hour have been executed generating random powers with the mean and the standard deviation founded previously.
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Fig. 10. Voltage levels for the busbar B005 for the different penetrations of EV in the case of controlled charge for the deterministic analysis
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Fig.11 and Fig.12 show mean voltage levels for the different penetrations of EV in the case of not-controlled charge. In both figures are the calculated mean voltage levels from the probabilistic analysis and the mean from the deterministic analysis. In order to have a most detailed view of the critical busbar, in this case B014, Fig.13 show the the range of voltage level that can be reached at this busbar.
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Fig. 13. Voltage levels for the busbar B005 for the different penetrations of EV in the case of not-controlled charge
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Fig. 11. Voltage levels for the busbar B005 for the different penetrations of EV in the case of not-controlled charge Voltage [pu u]
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Fig. 14. Voltage levels for the busbar B005 for the different penetrations of EV in the case of controlled charge
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Fig. 12. Voltage levels for the busbar B014 for the different penetrations of EV in the case of not-controlled charge
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VI. C ONCLUSION
Fig. 15. Voltage levels for the busbar B005 for the different penetrations of EV in the case of not-controlled charge
The objective of the paper is to analyze the impact of charging EVs from a Danish grid. Therefore, different penetrations of EV and charge modalities are proposed. In order to cover 4
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deterministic analysis and probabilistic analysis. On one hand, results from the simulations show that notcontrolled charge amplifies the demand of the line at the hours of the higher electrical demands. On the other hand, simulations show that with the controlled charge a high penetration of EVs can be charged without the need of investments in the power grid infrastructure.
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R EFERENCES
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[1] Valsera-Naranjo Sumper Lloret-Gallego Villaf´afila-Robles, Sudri`aAndreu. Electrical vehicles: state of art and issues for their connection to the network. Electrical Power Quality and Utilisation, 2009. 1 [2] http://www.mitsubishi-motors.com/special/ev/index.html. 1 [3] Dades B`asiques 2008 v.02. Ajuntament de Barcelona. Direcci´o de Serveis de Mobilitat., 2008. 2 [4] Roberto Villaf´afila-Robles. Probabilistic modeling in normal operation and the control of distribution systems with renewable source based DG units. PhD thesis, Universitat Polit`ecnica de Catalunya, 2009. 2
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Fig. 16. Voltage levels for the busbar B005 for the different penetrations of EV in the case of not-controlled charge
the maximum situations two analysis have been performed:
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