Electric Vehicles

Question 1

What are the three types of electric vehicles?

Answer 1

1) hybrid (HEV)
2) Plug-in Hybrid (PHEV)
3) Battery (BEV)

Question 2

What are the advantages of an EV?

Answer 2

- Local availability of energy source
o Stimulating local economy
o Decrease dependence external countries
- Fewer GHG emissions 
o Total emissions factor = well to tank + tank to wheel

Question 3

EV infrastructure: charging on LV-network. How does it work? What are the charging limits?

Answer 3

• AC grid versus DC battery
• Most cars have onboard AC/DC converter
• Limits AC-charging power because of:
  1) Grid capacity
  1. 1) 3 phase * 32A * 230V = 22 kW (public)
  1. 2) 1 phase * 16A * 230V = 3.7 kW (home power plug)
  2) Car convertor
  2. 1) PHEV 3.7 kW, BEV 7 to 22 kW

Question 4

What impact has EV charging on the power grids?

Answer 4

• Average Dutch household demand: 2790 kWh/year
• BEV electricity demand: 13000 km/year * 0.2 kWh/km = 2600 kWh/year
• Can the current LV-grid handle this increase?

Question 5

What is the difference between uncontrolled and controlled charging?

Answer 5

• Lower the evening peak, while increasing the mid-day and night load.
• This can reduce the total system costs (electricity production and infrastructure)

Question 6

What do you need to know for EV demand flexibility?

Answer 6

• Parking duration
• Charging duration
  o Energy needed [kWh]
  o Maximum charging power [kW]

Question 7

What are the three key points of EV’s?

Answer 7

• EVs have much potential to save emissions. (But dependent on electricity generation mix)
• Uncontrolled EV demand is expected to violate LV-network capacity limits
• There are possibilities to shift charging demand (smart charging) and use EVs provide grid services (e.g. V2G)