Optimal operation of V2H and stationary storage batteries in a massive
PV penetrated consumer group
Takaya Sadatome,Yuzuru Ueda
Department of Electrical Engineering, Tokyo University of Science, Japan
3rd E-Mobility Power System Integration Symposium, Ireland Crowne Plaza Dublin Airport
October 14, 2019
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 1
Introduction|Recent trends in prosumers
The self-consumption of the power from residential PV by using EVs
Residential PV(Photovoltaic) • Duration of Feed-in tariff is ten years.
• The number of expired PV will increase.
Storage system • Prosumers may start shifting to
a self-consuming lifestyle.
EV(Electric Vehicle) • EV batteries are used as home power
supply (Vehicle-to-home (V2H)).
• EV’s environmental performance
depends on the power supply
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 2
System model Prosumer → 534 houses in a prosumer group
𝒅𝒅𝒕𝒕,𝒏𝒏 = 𝒍𝒍𝒕𝒕,𝒏𝒏 + 𝒔𝒔𝒕𝒕,𝒏𝒏 + 𝒆𝒆𝒕𝒕,𝒏𝒏 − 𝒑𝒑𝒕𝒕,𝒏𝒏 = 𝒈𝒈𝒕𝒕,𝒏𝒏 + 𝒐𝒐𝒕𝒕,𝒏𝒏 𝒕𝒕:time(time interval:10 min.), 𝒏𝒏:The number of houses and batteries(1~534)
SB
PV
EVLoad
Grid
𝒔𝒔𝒕𝒕,𝒏𝒏 𝒆𝒆𝒕𝒕,𝒏𝒏𝒍𝒍𝒕𝒕,𝒏𝒏
𝒑𝒑𝒕𝒕,𝒏𝒏
𝒈𝒈𝒕𝒕,𝒏𝒏
𝒅𝒅𝒕𝒕,𝒏𝒏
One Prosumer
other houses
𝒐𝒐𝒕𝒕,𝒏𝒏
Prosumer Group
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 3
Objective
• Propose the optimal battery operation to improve the self-consumption rate
in prosumer group
• Provide EV users convenience for driving
Peer-to-Peer transaction Prosumers (Group)
Electric Power
company
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 4
Battery operation outline
Single house operation
Group operation
Quick charge of EV
Use their own home appliance and batteries
Share surplus PV energy in group with others in the same group
Keep sufficient SOC of EV for driving …
…
…
Step1
Step2
Step3
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 5
Operation in each house
Prosumers consume PV power
1. by home appliance
2. by stationary battery or EV
Battery operation’s aim is the improvement of the self-consumption rate
0 2 4 6 8 10 12 14 16 18 20 22 24
time [h]
-4
-3
-2
-1
0
1
2
3
4
pow
er
[kW
]
before afterSingle house operation
Group operation
Quick charge of EV
Ensure EV user’s convenience
• SOC constraint of EV for
driving
Net demand get close to zero • Discharge during night
• Charge more PV energy
Two basic rules Step1
Step2
Step3
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 6
EV driving pattern SOC constraint (constraint time)
M T W T F S S
50km
Distance:150km (Sat.9am-Sun.9pm)
A1:Long-distance weekend leisure
82.5% (Sat.12am-9am)
M T W T F S S
150km
Distance:50km (Sat.10am-Sun.8pm)
41% (Sat.7am-10am)
A2:Short-distance weekend leisure
Distance:50km (Mon. Wed. Fri. Sun. 10am-5pm)
41% (7am-10am) B1:Active use
M T W T F S S
50km
Distance:5km (Mon. Wed. Fri. Sun. 1pm-5pm)
22.5% (12pm-1pm) B2:Suburban use
M T W T F S S 5km
Distance:50km (Weekdays 7am-7pm)
C1:Long-distance commuting
41% (4am-7am) M T W T F S S
50km
Distance:15km (Weekdays 8am-6pm)
C2:Short-distance commuting
26.5% (7am-8am) M T W T F S S
15km
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 7
EV constraint calculation SOC constraint (constraint time)
M T W T F S S
50km
Distance:150km (Sat.9am-Sun.9pm)
A1:Long-distance weekend leisure
82.5% (Sat.12am-9am)
M T W T F S S
150km
Distance:50km (Sat.10am-Sun.8pm)
41% (Sat.7am-10am)
A2:Short-distance weekend leisure
Distance:50km (Mon. Wed. Fri. Sun. 10am-5pm)
41% (7am-10am) B1:Active use
M T W T F S S
50km
Distance:5km (Mon. Wed. Fri. Sun. 1pm-5pm)
22.5% (12pm-1pm) B2:Suburban use
M T W T F S S 5km
Distance:50km (Weekdays 7am-7pm)
C1:Long-distance commuting
41% (4am-7am) M T W T F S S
50km
Distance:15km (Weekdays 8am-6pm)
C2:Short-distance commuting
26.5% (7am-8am) M T W T F S S
15km
electric consumption of EV
Constraint value
Constraint time
SOC constraint = lower limit SOC of EV
+𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 𝑝𝑝𝑝𝑝𝑝𝑝𝐸𝐸𝐸𝐸 𝐸𝐸𝐸𝐸𝑟𝑟𝑟𝑟𝐸𝐸𝐸𝐸𝐸𝐸𝑟𝑟 𝑓𝑓𝑝𝑝𝐸𝐸 𝑟𝑟𝐸𝐸𝐸𝐸𝑑𝑑𝐸𝐸𝑑𝑑𝑑𝑑 ÷ 𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 𝐸𝐸𝑝𝑝𝑑𝑑𝑐𝑐𝑟𝑟𝑐𝑐𝑝𝑝𝐸𝐸𝐸𝐸𝑝𝑝𝑑𝑑 𝑝𝑝𝑓𝑓 𝐸𝐸𝐸𝐸
𝐶𝐶𝐶𝐶𝑝𝑝𝐶𝐶𝐸𝐸𝐸𝐸𝐸𝐸𝐶𝐶 𝑝𝑝𝑓𝑓 𝐸𝐸𝐸𝐸 𝑏𝑏𝐶𝐶𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐶𝐶
Required energy for driving ÷ electric consumption of EV
Capacity of EV battery +
𝐶𝐶𝑝𝑝𝑑𝑑𝑐𝑐𝐸𝐸𝐸𝐸𝐶𝐶𝐸𝐸𝑑𝑑𝐸𝐸 𝐸𝐸𝐸𝐸𝑐𝑐𝐸𝐸 =𝑆𝑆𝑆𝑆𝐶𝐶 𝐸𝐸𝑝𝑝𝑑𝑑𝑐𝑐𝐸𝐸𝐸𝐸𝐶𝐶𝐸𝐸𝑑𝑑𝐸𝐸 − 𝑆𝑆𝑆𝑆𝐶𝐶 𝑓𝑓𝑑𝑑𝑟𝑟𝑑𝑑𝑝𝑝𝑓𝑓 𝐸𝐸𝐸𝐸
𝑀𝑀𝐶𝐶𝑀𝑀 𝑝𝑝𝑟𝑟𝐸𝐸𝑝𝑝𝑟𝑟𝐸𝐸 𝑝𝑝𝑓𝑓 𝐸𝐸𝐸𝐸 𝐸𝐸𝑑𝑑𝑑𝑑𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 Constraint time =
SOC Constraint - SOC of EV
Max output of EV inverter
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 8
Operation of two batteries
SOC Constraint of EV battery for driving (DC) → One more SOC case
EV battery had four cases
(SOC Constraint)
Stationary battery had three cases
𝐷𝐷𝐶𝐶 𝐷𝐷𝐶𝐶
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 9
Operation of two batteries
12 combinations of two batteries operation.
One charge / discharge pattern was assigned to each case.
five kinds of patterns were prepared for each of charge operation and discharge operation.
EV battery had four cases
(SOC Constraint)
Stationary battery had three cases
𝐷𝐷𝐶𝐶 𝐷𝐷𝐶𝐶
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 10
Operation of two batteries
Charge operation
Discharge operation
「ES」 ・・・ EV battery → Stationary battery
𝐷𝐷𝐶𝐶 𝐷𝐷𝐶𝐶
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 11
Operation of two batteries
𝐷𝐷𝐶𝐶 𝐷𝐷𝐶𝐶
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 12
Operation of two batteries
𝐷𝐷𝐶𝐶 𝐷𝐷𝐶𝐶
• Stationary battery has no power • Saving EV power → EV is discharged until DC Discharge
Ⅰ and Ⅱ:EV is preferentially charged for SOC Constraint of EV for driving(DC)
Ⅲ and Ⅳ : Stationary is first charged
Ⅳ:EV is full → Only stationary is charged
Charge
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 13
Operation in prosumer group
𝑐𝑐𝑃𝑃𝑡𝑡 = �𝑐𝑐𝑝𝑝𝑡𝑡,𝑛𝑛
𝑁𝑁
𝑛𝑛=1
Surplus power
𝑐𝑐𝐿𝐿𝑡𝑡 = �𝑐𝑐𝐸𝐸𝑡𝑡,𝑛𝑛
𝑁𝑁
𝑛𝑛=1
Shortage power
𝑐𝑐𝐷𝐷𝑡𝑡 = 𝑐𝑐𝐿𝐿𝑡𝑡 − 𝑐𝑐𝑃𝑃𝑡𝑡 Net demand
Total amount in prosumer group Group operation
Single house operation
Quick charge of EV
𝒔𝒔𝒑𝒑𝒕𝒕,𝟏𝟏
𝒔𝒔𝒍𝒍𝒕𝒕,𝟒𝟒
𝒔𝒔𝒍𝒍𝒕𝒕,𝟑𝟑
𝒔𝒔𝒑𝒑𝒕𝒕,𝟐𝟐
Sharing surplus PV power in prosumer group
Step1
Step2
Step3
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 14
Operation in prosumer group
the ratio of shortage in each house and shortage in consumer group
𝒔𝒔𝑷𝑷𝒕𝒕 × 𝒔𝒔𝒍𝒍𝒕𝒕,𝒏𝒏𝒔𝒔𝑳𝑳𝒕𝒕
proportional distribution
Distributed power consumed by 1. each electrical load. 2. each EV batteries.
𝒔𝒔𝒑𝒑𝒕𝒕,𝟏𝟏
𝒔𝒔𝒍𝒍𝒕𝒕,𝟒𝟒
𝒔𝒔𝒍𝒍𝒕𝒕,𝟑𝟑
𝒔𝒔𝒑𝒑𝒕𝒕,𝟐𝟐
Step1
Step2
Step3
Group operation
Single house operation
Quick charge of EV
Sharing surplus PV power in prosumer group
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 15
Operation in prosumer group
Quick charge
• If EV battery does not reach SOC Constraint of EV battery for
driving, this step is executed.
• Get the SOC of EV up to more than SOC Constraint of EV
battery for driving.
Charging operation by SOC Constraint of EV battery for driving
Step1
Step2
Step3
Single house operation
Quick charge of EV
Group operation
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 16
Evaluation|Self-consumption
Self-consumption rate:𝑺𝑺𝑺𝑺
𝑃𝑃:Total PV generation per year
𝐺𝐺:Total power from prosumer to the distributed grid
𝑑𝑑:Number of house
𝑆𝑆𝑅𝑅 =𝑃𝑃𝑎𝑎 − 𝐺𝐺𝑎𝑎
𝑃𝑃𝑎𝑎× 100 𝑆𝑆𝑅𝑅𝑛𝑛 =
𝑃𝑃𝑛𝑛𝑎𝑎 − 𝐺𝐺𝑛𝑛𝑎𝑎
𝑃𝑃𝑛𝑛𝑎𝑎× 100
In the prosumer group In each house
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 17
Evaluation|EV driving by PV
EV environmental performance:𝑬𝑬𝑷𝑷
𝐸𝐸𝑛𝑛𝑟𝑟𝑟𝑟𝑛𝑛:The total EV’s electric consumption during driving
𝐸𝐸𝑛𝑛𝐺𝐺:The total EV’s purchased power for driving
𝑑𝑑:Number of house
𝐸𝐸𝑃𝑃𝑛𝑛 =𝐸𝐸𝑛𝑛𝑟𝑟𝑟𝑟𝑛𝑛 − 𝐸𝐸𝑛𝑛𝐺𝐺
𝐸𝐸𝑛𝑛𝑟𝑟𝑟𝑟𝑛𝑛× 100
• The ratio of PV energy and the purchased power from the grid.
• Larger this value is, better environment performance of EV is.
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 18
Evaluation|Self-consumption
CO2 emissions:𝑪𝑪𝑬𝑬
𝐶𝐶𝑆𝑆2𝑐𝑐: CO2 emissions, 𝑃𝑃:Electric energy, 𝐷𝐷 :Driving distance
Content coefficient
Case Value
Generation PV power [g-CO2/kWh] 32.5
Thermal power [g-CO2/kWh] 690
Driving EV (running by the PV power) [g-CO2/kWh] Equal to PV power
EV (running by the thermal power) [g-CO2/kWh] Equal to thermal power Gasoline Vehicle (GV) [g-CO2/km] 101
• The electric consumption of EVs is 6 km/kWh (0.67 kWh/km).
𝐶𝐶𝐸𝐸 = 𝐶𝐶𝑆𝑆2𝑐𝑐 × 𝑃𝑃 𝐶𝐶𝐸𝐸 = 𝐶𝐶𝑆𝑆2𝑐𝑐 × 𝐷𝐷
Electricity Vehicle
→ →
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 19
Evaluation|Cost
Content Unit price [JPY/kWh]
PV power generated from residential PV 𝐶𝐶𝑃𝑃 14 The power from the other prosumers 𝐶𝐶𝑂𝑂𝑟𝑟 23
The power sent to the other prosumers 𝐶𝐶𝑂𝑂𝑠𝑠 14
The power from the distributed grid 𝐶𝐶𝐺𝐺𝑟𝑟 26
The power sent to the distributed grid 𝐶𝐶𝐺𝐺𝑠𝑠 11
Power procurement cost:𝑪𝑪
𝐶𝐶 = 𝐶𝐶𝑃𝑃 ∙ 𝑃𝑃𝑛𝑛𝑎𝑎 + 𝐶𝐶𝑂𝑂𝑟𝑟 ∙ 𝑆𝑆𝑟𝑟𝑛𝑛𝑎𝑎 − 𝐶𝐶𝑂𝑂𝑠𝑠 ∙ 𝑆𝑆𝑠𝑠𝑛𝑛
𝑎𝑎 + 𝐶𝐶𝐺𝐺𝑟𝑟 ∙ 𝐺𝐺𝑟𝑟𝑛𝑛𝑎𝑎 − 𝐶𝐶𝐺𝐺𝑠𝑠 ∙ 𝐺𝐺𝑠𝑠𝑛𝑛
𝑎𝑎
• The fuel consumption of GVs is 23km/L.
• Gasoline cost is 139 JPY/L.
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 20
Used data
PV generation (Time interval : 10 min) building 534 houses in Tokyo
time August 1, 2016 〜 July 31, 2017 Electrical Load (Time interval : 10 min)
building 534 houses in Tokyo time August 1, 2016 〜 July 31, 2017
Data of the system
Specification of batteries EV Stationary battery
40 kWh Capacity 5 kWh 3 kW Output of Inverter 3 kW 90 % Efficiency 90 %
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 21
Case study
Case Content
Operation Vehicle 1 As a group EV (V2H) 2 Each house EV (V2H) 3 Each house GV
• Share PV energy in prosumer group (Case 1)
• If prosumer has EV, prosumers use V2H system (Case 1&2)
• All prosumers have stationary battery
• Don’t consider transmission loss
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 22
Result | Net demand
12/09 12/10 12/11
Date
-4
-3
-2
-1
0
1
2
3
4
5
6
Pow
er
[kW
]Case 0:Net demand Case 1:Group ope. (EV)
Case 2:Individual ope. (EV) Case 3:Individual ope. (GV)
12/09 12/10 12/11
date
20
30
40
50
60
70
80
SO
C[%
]
Group(EV) Individual(EV)
Driving
Date
Driving Constraint
(EV)
The driving pattern “A-1” Constraint time (EV battery) : Fri.12am-Sat.9am SOC Constraint (EV battery) : 82.5%
Driving time : Sat.9am-Sun.9pm Driving distance : 150km
• 1st day:Sharing PV energy in group operation • 2nd day:EV was charged by power from grid
Peak power
EV was charged by more PV energy
(Fri.) (Fri.) (Fri.)
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 23
Result | Net demand
• The self-consumption rates were over 90% in more than half of prosumers when prosumers were operated as a group.
• The median value was 91.7% in case 1 and improved by 3.9% than that of case 2.
12
3
30 40 50 60 70 80 90
100
SCR [%]SCR [%]
30 40 50 60 70 80 90 100
1
2
3
Case
Case
Case
80 82 84 86 88 90 92 94 96 98
100PV charge rate of EV [%]PV charge rate of EV [%]
100 80 90 92 94 96 98 82 84 86 88
1
2 Case
Case
Case1:Group operation (EV) Case2:Individual operation (EV) Case3:Individual operation (GV)
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 24
Result | Net demand
Case Self-consumption rate [%]
EV environmental performance [%]
CO2 emissions [t-CO2]
Electricity Cost [million JPY]
Vehicle Cost [thousands JPY/month]
1 93.2 91.7 1101 2.74 9.87 2 81.0 87.8 1281 2.68 10.1 3 59.8 - 3005 7.06 235
• The self-consumption rates was improved by 1.15 times.
• EV was charged by the more PV energy in the case of group operation than the individual operation.
• CO2 emissions decreased.
• Electricity Cost increased slightly, but total electricity cost decreased.
Case1:Group operation (EV) Case2:Individual operation (EV) Case3:Individual operation (GV)
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 25
Conclusion
Acknowledgment A part of this study was supported by CREST JST (issue number: JPMJCR15K1). We would like to thank everyone who supported this study.
• Proposed battery operation method to improve the self-consumption rate in group. • SOC Constraint (EV battery) contributed to EV user convenience. • Operating prosumers as a group
Case Self-consumption rate [%]
EV driving performance [%]
CO2 emissions [t-CO2]
Electricity Cost [million JPY]
Vehicle Cost [thousands JPY/month]
1 93.2 91.7 1101 2.74 9.87 2 81.0 87.8 1281 2.68 10.1 3 59.8 - 3005 7.06 235
Table. Result Summary
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 26
Reference [1] Takaya Sadatome, Yuzuru Ueda, “Examination of improvement effect of self-consumption rate by introducing V2H system”, Grand Renewable Energy 2018 Proceedings.,
[2] National road and street traffic situation survey, “FY2015 National road and street traffic situation survey / General traffic survey / summary table”, [Online]. Available: http://www.mlit.go.jp/road/census/h27/ (in Japanese)
[3] New Energy and Industrial Technology Development Organization, ”NEDO PV-Powered Vehicle Strategy Committee Interim Report”, January 2018. [Online]. Available: https://www.nedo.go.jp/content/100885778.pdf.
[4] Ministry of the Environment, Ministry of Economy, Trade, and Industry, Japan, “Emission factor by electric power company (for the calculation of greenhouse gas emissions of specified emitters) -FY2016 results-”, 18. Dec. 2017. [Online]. Available: https://www.env.go.jp/press/files/jp/109569.pdf (in Japanese)
[5] New Energy and Industrial Technology Development Organization, ”Solar power development strategy (NEDO PV Challenges)”, September 2014.
[6] The website of the Tokyo Electric Power Company (TEPCO), Japan, “About consignment fee equivalent, etc.”, 18. Dec. 2017. [Online]. Available: http://www.tepco.co.jp/ep/private/plan2/chargelist06.html (in Japanese).
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 27
Reference [7] New Energy and Industrial Technology Development Organization, “Photovoltaic power generation roadmap for 2030”, 18. Dec. 2017. [Online]. Available: https://www.nedo.go.jp/content/100086787.pdf (in Japanese).
[8] The International Renewable Energy Agency, ”2017 renewable energy generation costs”, 2018. [Online]. Available: https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2018/Jan/IRENA_2017_Power_Costs_Summary_2018_JP_29052018.pdf?la=en&hash=BD0500DD2BE7C3779063E74F1248493D74AB98D6
[9] Eiki Arai, Yuzuru, Ueda, “Development of simple estimation model for aggregated residential load by using temperature data in multi-region,” 4th International Conference on Renewable Energy Research and Applications, #233, Italy, Nov. 22-25 (2015))
[10] S. Nishikawa and K. Kato “Demonstrative research on grid interconnection of clustered photovoltaic power generation systems” in Proc. 3rd WCPEC 2003, pp. 2652 2654.
Supplement
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 29
Near-future system
1. Effective use of PV energy by stationary battery and V2H
2. Peer-to-peer (P2P) electric power transactions
3. Prosumers are aggregated into prosumer’s group
Stationary battery
EV (V2H)
Aggregator
P2P
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 30
EV driving pattern
Pattern Type Driving time Driving
distance Constraint time
(EV battery) Driving constraint
(EV battery)
A. Weekend
A1:Long-distance weekend leisure
Sat.9am-Sun.9pm
150km Sat,12am-9am 82.5%
A2:Short-distance weekend leisure
Sat.10am-Sun.8pm
50km Sat,7am-10am 41%
B. Weekday/weekend (Mon., Wed., Fri., Sun.)
B1:Active use 10am-5pm 50km 7am-10am 41%
B2:Suburban use 1am-5pm 5km 12pm-1m 22.5%
C. Weekday
C1:Long-distance commuting
7am-7pm 50km 4am-7am 41%
C2:Short-distance commuting
8am-6pm 15km 7am-8am 26.5%
Table.1 EV driving pattern[1][2]
The difference in driving patterns provides the opportunity for the group's EVs to be charged with energy from residential PV.
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 31
EV constraint calculation SOC constraint (constraint time)
M T W T F S S
50km
Distance:150km (Sat.9am-Sun.9pm)
A1:Long-distance weekend leisure
82.5% (Sat.12am-9am)
M T W T F S S
150km
Distance:50km (Sat.10am-Sun.8pm)
41% (Sat.7am-10am)
A2:Short-distance weekend leisure
Distance:50km (Mon. Wed. Fri. Sun. 10am-5pm)
41% (7am-10am) B1:Active use
M T W T F S S
50km
Distance:5km (Mon. Wed. Fri. Sun. 1pm-5pm)
22.5% (12pm-1pm) B2:Suburban use
M T W T F S S 5km
Distance:50km (Weekdays 7am-7pm)
C1:Long-distance commuting
41% (4am-7am) M T W T F S S
50km
Distance:15km (Weekdays 8am-6pm)
C2:Short-distance commuting
26.5% (7am-8am) M T W T F S S
15km
electric consumption of EV
Constraint value
Constraint time
SOC constraint = lower limit SOC of EV
+𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 𝑝𝑝𝑝𝑝𝑝𝑝𝐸𝐸𝐸𝐸 𝐸𝐸𝐸𝐸𝑟𝑟𝑟𝑟𝐸𝐸𝐸𝐸𝐸𝐸𝑟𝑟 𝑓𝑓𝑝𝑝𝐸𝐸 𝑟𝑟𝐸𝐸𝐸𝐸𝑑𝑑𝐸𝐸𝑑𝑑𝑑𝑑 ÷ 𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 𝐸𝐸𝑝𝑝𝑑𝑑𝑐𝑐𝑟𝑟𝑐𝑐𝑝𝑝𝐸𝐸𝐸𝐸𝑝𝑝𝑑𝑑 𝑝𝑝𝑓𝑓 𝐸𝐸𝐸𝐸
𝐶𝐶𝐶𝐶𝑝𝑝𝐶𝐶𝐸𝐸𝐸𝐸𝐸𝐸𝐶𝐶 𝑝𝑝𝑓𝑓 𝐸𝐸𝐸𝐸 𝑏𝑏𝐶𝐶𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐶𝐶
Electric power required for driving ÷ electric consumption of EV
Capacity of EV battery +
𝐶𝐶𝑝𝑝𝑑𝑑𝑐𝑐𝐸𝐸𝐸𝐸𝐶𝐶𝐸𝐸𝑑𝑑𝐸𝐸 𝐸𝐸𝐸𝐸𝑐𝑐𝐸𝐸 =𝑆𝑆𝑆𝑆𝐶𝐶 𝐸𝐸𝑝𝑝𝑑𝑑𝑐𝑐𝐸𝐸𝐸𝐸𝐶𝐶𝐸𝐸𝑑𝑑𝐸𝐸 − 𝑆𝑆𝑆𝑆𝐶𝐶 𝑓𝑓𝑑𝑑𝑟𝑟𝑑𝑑𝑝𝑝𝑓𝑓 𝐸𝐸𝐸𝐸
𝑀𝑀𝐶𝐶𝑀𝑀 𝑝𝑝𝑟𝑟𝐸𝐸𝑝𝑝𝑟𝑟𝐸𝐸 𝑝𝑝𝑓𝑓 𝐸𝐸𝐸𝐸 𝐸𝐸𝑑𝑑𝑑𝑑𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 Constraint time =
SOC Constraint - SOC of EV
Max output of EV inverter
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 32
Constraint value
𝑆𝑆𝑆𝑆𝐶𝐶 𝐸𝐸𝑝𝑝𝑑𝑑𝑐𝑐𝐸𝐸𝐸𝐸𝐶𝐶𝐸𝐸𝑑𝑑𝐸𝐸 = 𝑆𝑆𝑆𝑆𝐶𝐶𝑚𝑚𝑚𝑚𝑛𝑛𝐸𝐸𝐸𝐸 +𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 𝑝𝑝𝑝𝑝𝑝𝑝𝐸𝐸𝐸𝐸 𝐸𝐸𝐸𝐸𝑟𝑟𝑟𝑟𝐸𝐸𝐸𝐸𝐸𝐸𝑟𝑟 𝑓𝑓𝑝𝑝𝐸𝐸 𝑟𝑟𝐸𝐸𝐸𝐸𝑑𝑑𝐸𝐸𝑑𝑑𝑑𝑑 ÷ 𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 𝐸𝐸𝑝𝑝𝑑𝑑𝑐𝑐𝑟𝑟𝑐𝑐𝑝𝑝𝐸𝐸𝐸𝐸𝑝𝑝𝑑𝑑 𝑝𝑝𝑓𝑓 𝐸𝐸𝐸𝐸
𝐶𝐶𝐶𝐶𝑝𝑝𝐶𝐶𝐸𝐸𝐸𝐸𝐸𝐸𝐶𝐶 𝑝𝑝𝑓𝑓 𝐸𝐸𝐸𝐸 𝑏𝑏𝐶𝐶𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐶𝐶
𝐶𝐶𝑝𝑝𝑑𝑑𝑐𝑐𝐸𝐸𝐸𝐸𝐶𝐶𝐸𝐸𝑑𝑑𝐸𝐸 𝐸𝐸𝐸𝐸𝑐𝑐𝐸𝐸 =𝑆𝑆𝑆𝑆𝐶𝐶 𝐸𝐸𝑝𝑝𝑑𝑑𝑐𝑐𝐸𝐸𝐸𝐸𝐶𝐶𝐸𝐸𝑑𝑑𝐸𝐸 − 𝑆𝑆𝑆𝑆𝐶𝐶 𝑝𝑝𝑓𝑓 𝐸𝐸𝐸𝐸𝑀𝑀𝐶𝐶𝑀𝑀 𝑝𝑝𝑟𝑟𝐸𝐸𝑝𝑝𝑟𝑟𝐸𝐸 𝑝𝑝𝑓𝑓 𝐸𝐸𝐸𝐸 𝐸𝐸𝑑𝑑𝑑𝑑𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸
Constraint time
EV constraint calculation
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 33
Step I Charge / Discharge pattern
Combination are 12(=3×4) patterns
A lower limit
B middle amount
C upper limit
Ⅰ lower limit
Ⅳ upper limit
Ⅱ below constraint before driving
Ⅲ above constraint
before driving
The SOC level of the EV battery(4 cases)
The SOC level of the stationary battery(3 cases)
𝐷𝐷𝐶𝐶 𝐷𝐷𝐶𝐶 𝐷𝐷𝐶𝐶 𝐷𝐷𝐶𝐶
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 34
Charge case EV
Ⅰ Ⅱ Ⅲ Ⅳ
stationary A 1 1 4 3 B 1 1 4 3 C 2 2 2 5
Discharge case EV
Ⅰ Ⅱ Ⅲ Ⅳ
stationary A 10 10 7 7 B 8 8 9 9 C 8 8 9 9
12 combinations of two batteries operation.
One charge / discharge pattern was assigned to each case.
five kinds of patterns were prepared for each of charge operation and discharge operation.
Step II Charge / Discharge pattern
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 35
Method of using batteries are 5 combinations
Step III Charge / Discharge pattern
No use stationary battery is used
EV battery is used Both batteries is used (Stationary is prioritized)
Both batteries is used (EV is prioritized)
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 36
Charge or discharge Pattern Operation
Charge
1 EV battery → Stationary battery 2 EV battery 3 Stationary battery 4 Stationary battery → EV battery 5 No operation
discharge
6 EV battery → Stationary battery 7 EV battery 8 Stationary battery 9 Stationary battery → EV battery
10 No operation
Battery operation is above 10 kinds of operation
Step IV Charge / Discharge pattern
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 37
Step V Charge / Discharge pattern
Condition for charge and discharge patterns
Pattern EV battery Stationary battery
Charge
Dis charge
Photovoltaic Systems and Renewable Energy Integration TOKYO UNIVERSITY OF SCIENCE 2019/8/9 38
Result | Net demand
12/09 12/10 12/11
Date
-4
-3
-2
-1
0
1
2
3
4
5
6
Pow
er
[kW
]Case 0:Net demand Case 1:Group ope. (EV)
Case 2:Individual ope. (EV) Case 3:Individual ope. (GV)
12/09 12/10 12/11
date
20
30
40
50
60
70
80
SO
C[%
]
Group(EV) Individual(EV)
driving
Date
The driving pattern “A-1” Constraint time (EV battery) : Fri.12am-Sat.9am Driving constraint (EV battery) : 82.5%
Driving time : Sat.9am-Sun.9pm Driving distance : 150km
Surplus power
Case 1 Group operation
Case 2 Individual operation
Effective use of PV energy by group operation
• 1st day:Sharing PV energy in group operation • 2nd day:EV was charged by power from grid
Peak power
EV was charged by more PV energy