WHAT IS HAPPENING IN THE SYSTEM?

Transcription

1 VIEW ON THE GRID Nordic EV Sumit, Session Will the Grid Collapse? February 2, 2018 Oslo, Norway Dr. Jonas Persson Vattenfall AB, R&D, Dep. Power Technology, Stockholm, Sweden

2 PROGRAM What is happening in the system? What are the solutions to avoid a collapse? A new clever load which can help the grid Measurement campaigns Conclusions and Challenges 2

3 WHAT IS HAPPENING IN THE SYSTEM? Everything seems to happen right now! Electric cars are coming. A boom in economy, webuilda lotofhouses and appartments. New business coes to the Nordic countries. Challenges in the grid. 3

4 WHAT ARE THE SOLUTIONS TO AVOID PROBLEMS? Flexibility (cars, new loads, heating systems, and other old loads should act flexible). More distributed production such as photo voltaics. Energy storage at all voltage levels, the lower voltage level the more use we can have of them (Voltage control, etc). Here we have however regulatory issues. Digitalization (Communication and forecasting). Newtechnology where batteries is one example, new components will appear, for sure! More and stronger networks. 4

5 A NEW WAYTO FUELYOURCAR Charge at home Charge during leisure time Charge at work Charge at the road Charginghappensat new places Charging happens at many different sites At homeand at workit can be enoughwith kw (one-phase, A) Destination charging11-22 kw (three-phase, A) Fast charging> 50 kw 5

6 A NEW CLEVERLOAD New characters of this new load They are relatively large loads connected to weak and strong points in the power system. Equipped with power electronics which produce harmonics. But, they are equipped with communication possibilities which make them possible to control; when the vehicle should be charged/not charged. The most clever load ever connected to the grid? Less cars in the future? 6

7 THE POWER SYSTEM IS UNDERGOING A CHANGE Today: From Production to Consumer Constant Production Tomorrow: Multi-directional flow Volatile Production Transmission grid Solar ecar Distribution grid CHP Wind Households Industry Customer Storage 7

8 MEASUREMENTS * Two different measurement campaigns on two different cases; Charge of seventeen electric cars within one three-phase group in an office garage (one-phase, 16 A each, 35 kw peak). Fast charge of electric plug-in hybrid bus #73 in Stockholm (three-phase, 100 kw peak). * Paper Measurement of Harmonics and Sags in Grid Voltages when Charging Electric Vehicles, 1 st E-mobility Power System Integration Symposium, Berlin, Germany, October 23,

9 MEASUREMENT IN AN OFFICE GARAGE IN STOCKHOLM Charge of 17 electric cars within one three-phase group in an office garage in Stockholm Each car has one-phase charging with 16 A each (230 V) All 17 cars distributed on one threephase group A 35 kw peak distributed on all phases once 9

10 CHARGE OF SEVENTEEN ELECTRIC CARS WITHIN ONE THREE-PHASE GROUP IN AN OFFICE GARAGE, AUGUST 23, Current (10-min) 0 00:10:00 01:50:00 03:30:00 05:10:00 06:50:00 08:30:00 10:10:00 11:50:00 13:30:00 15:10:00 16:50:00 18:30:00 20:10:00 21:50:00 23:30:00 L1 (A) L2 (A) L3 (A) 09:10 07:30

11 CHARGE OF SEVENTEEN ELECTRIC CARS WITHIN ONE THREE-PHASE GROUP IN AN OFFICE GARAGE, AUGUST 23, Voltage (10-min) :10:00 01:50:00 03:30:00 05:10:00 06:50:00 08:30:00 10:10:00 11:50:00 13:30:00 15:10:00 16:50:00 18:30:00 20:10:00 21:50:00 23:30:00 09:10 07:30 L1-N (V) L2-N (V) L3-N (V)

12 CHARGE OF SEVENTEEN ELECTRIC CARS WITHIN ONE THREE-PHASE GROUP IN AN OFFICE GARAGE, AUGUST 23, ,5 3 2,5 2 1,5 1 0,5 Voltage THD (%)(10-min) 0 00:10:00 01:50:00 03:30:00 05:10:00 06:50:00 08:30:00 10:10:00 11:50:00 13:30:00 15:10:00 16:50:00 18:30:00 20:10:00 21:50:00 23:30:00 09:10 07:30 L1 THD (%) L2 THD (%) L3 THD (%)

13 THE POWERISSUEIS NATIONAL, REGIONAL AND LOCAL Winter Summer Sweden had in year 2005 a power need as described in the Figure If 25% of all electric cars (2016: cars) needs to be charged as in the Office garage, then they will peak with 2.4 GW at 9: MW corresponds to one (1) degree in outdoor temperature (2.4 GW = 6 degrees) Available over-capacity needed in our networks 13

14 REGIONAL NETWORKCANBE INFLUENCED MOREANALYSISNEEDED New evening-peak Existing evening-peak An increased demand of 2.5 % (1 MW in this example) Load-shift the charging ofthe carto after7 PM Local incentive can havea bigimpact! 14

15 DEMANDIN ENERGY The demand in energy during a year with the same assumptions as above will for of electric cars in Sweden where only half of them are used during one day and charged twice will be 10 TWh annually. 10 TWhis a rough idea of what energy that will be needed in the future power system for electric vehicles in Sweden. Follows scenarios from other sources. The energy demand in Sweden was 140 TWhin year 2016.

16 LOCALLYTHEREIS A NEEDOFLOAD-SHIFT TARIFFS CANCREATEINCENTIVE Cloth dryer 2000 W Floor heating 1000 W (10 sqm) Oven 1500 W TV 140 W Load-shifthas beentestedin Smart Grid Gotland with good result Local load-shift is always integrated in our chargingstations todayand thesestations will be more advanced 16

17 CONTROL OFLOADS Flexibility is the key for the future. Cars as well as other loads should act flexible. Energy storage at many voltage levels. Soft control but also hard control should be possible to do, such as traffic lights, but, you should be able to choose for your significant loads. Such a control can help the grid, i.e., locally, regional, or national.

18 MEASUREMENT FAST CHARGING OF BUS 73 IN STOCKHOLM Fast chargingof100 kw at Ropstenand Karolinska Institutet Demands 6 minutes of charging time The loadingsequencestarts automaticallywhenthe driver has parkedand puton the parkingbrake Electro-Magnetic Field(EMF) The charging station has been procured and installed by Vattenfall. Vattenfallis also operating the stations during the project period incl. First Line Service. Fast charging at end stations 18

19 ZEEUS PLUG-IN ELECTRIC HYBRID BUSES AT LINE 73 VOLTAGE THD (%) VS CHARGING Charging station power down 15 min. (off)10:00-10:15 Current in ampere (one phase) during Bus charging, Current raise to 100 A during charge sequence (6 min) but due to use of same scale as Voltage THD only the lower value has been showed in the graph Voltage THD in % of nominal voltage. The value do not follow the charge sequence described above. This shows that the THD value origins from all other loads in the area. Max THD is 8%. Studymadeby Jonas Wetterström at Vattenfall R&D, Power Technology. 19

20 CONCLUSIONS AND DISTRIBUTION CHALLENGES Possible challenges Analyse bottlenecks(kw-mw), how to use available capacity Analyse differences in strong/weak networks Unsymmetries, currents in return conductors, harmonics in return conductors Voltage drops, methods for fast analysis, might be problems in weak grids Harmonics, might be problems in weak grids. Electro-Magnetic Fields(EMF)/Environment Flexibility is the key for the future! Cars as well as other loads should act flexible. Energy storage at different voltage levels. Soft control but also hard control should be possible to do, such as traffic lights, but, you should be able to choose for your significant loads. Such a control can help the grid, i.e., locally, regional, or national. The energy demand will be some 10 TWhannually in Sweden. 20

21 Thank you! Jonas Persson, Vattenfall AB, R&D