Powertrain Components
Name two main components of an EV powertrain.
Battery pack and electric motor
What does BEV stand for?
Battery Electric Vehicle
What does kW measure in an EV?
Power
Give one advantage of EVs compared with conventional petrol or diesel vehicles.
They produce no tailpipe emissions during operation.
Which figure tells you how much energy an EV battery can store: kW or kWh?
kWh.
What is the function of the inverter in an EV?
It converts and controls electrical power between the battery and the electric motor
What is the main difference between a BEV and a HEV?
A BEV is powered entirely by electricity; a HEV combines an internal combustion engine with an electric motor and battery.
What is torque?
Rotational force produced by the motor.
Why might an EV be more efficient in urban driving than a conventional vehicle?
Regenerative braking can recover energy during frequent deceleration, and the electric motor can operate efficiently at low speeds.
A vehicle specification says Battery: 75 kWh; Motor: 150 kW. What do these two figures describe?
75 kWh is the battery's energy capacity; 150 kW is the motor's power rating
What is the function of the onboard charger (OBC)?
It converts AC electricity from an AC charging source into DC electricity for the battery.
Explain the difference between HEV and PHEV.
A HEV has a smaller battery that cannot normally be charged from an external power source. A PHEV has a larger battery that can be charged externally and can drive using electric power for a certain distance.
Explain SoC, SoH and regenerative braking.
SoC is State of Charge; SoH is State of Health; regenerative braking recovers kinetic energy during deceleration and stores it as electrical energy in the battery.
Why might an EV be more efficient in urban driving than a conventional vehicle?
Regenerative braking can recover energy during frequent deceleration, and the electric motor can operate efficiently at low speeds.
A technical sheet states: Range: 450 km / Battery: 75 kWh / DC charging: 150 kW / 0–100 km/h: 6.5 s. Which figure describes charging power?
150 kW
Explain the basic energy flow in a BEV from the battery to the wheels.
The battery supplies DC electrical energy to the inverter, which controls power to the electric motor. The motor converts electrical energy into mechanical energy, which is transferred to the wheels through the drivetrain.
A vehicle has a battery that can be externally charged, an internal combustion engine and an electric motor. Is it a BEV, HEV or PHEV? Explain.
PHEV, because it combines an internal combustion engine and electric motor with a battery that can be charged externally.
Explain the relationship between battery, inverter, electric motor and power management.
The battery stores electrical energy, the inverter controls electrical power to and from the motor, the motor converts electrical energy into mechanical power, and the power-management system controls how energy is distributed and used.
Compare two advantages and two limitations of EVs.
Advantages include high energy efficiency and reduced tailpipe emissions. Limitations can include charging time, charging infrastructure, range limitations and battery cost.
A specification sheet shows: Battery: 60 kWh; AC charging: 11 kW; DC charging: 100 kW; Range: 360 km. Which charging method is likely to be faster, and why?
DC charging, because the maximum charging power is 100 kW compared with 11 kW AC.
Explain the complete powertrain of a BEV using at least five components.
The high-voltage battery stores electrical energy. The inverter controls the electrical power supplied to the electric motor. The motor converts electrical energy into mechanical energy. The transmission/reduction gear transfers this torque to the wheels. The battery-management and power-management systems monitor and control the system.
Explain the main differences between BEV, HEV, PHEV and FCEV, including their energy source and how they are refuelled or charged.
A BEV uses a battery and is charged electrically. An HEV combines an internal combustion engine with a battery and normally cannot be externally charged. A PHEV combines both systems and can be externally charged. An FCEV uses hydrogen in a fuel cell to generate electricity for an electric motor and is refuelled with hydrogen.
Use battery pack, inverter, motor, torque, regenerative braking, SoC and power management in one technically accurate explanation of how an EV operates.
“The battery pack supplies electrical energy to the inverter, which controls power to the motor. The motor produces torque to drive the wheels. During deceleration, regenerative braking can recover energy and return it to the battery. Power management controls energy flow according to vehicle demand and battery SoC.”
Your partner says: “EVs are always better than petrol cars.” Give a balanced technical response with at least two advantages and two limitations.
“EVs can offer high efficiency, lower operating emissions and regenerative braking. However, charging infrastructure, charging time, range and battery production remain important considerations. The advantages and limitations depend on the vehicle and its use.”
Interpret this specification sheet: Battery: 82 kWh / Motor: 220 kW / Maximum DC charging: 175 kW / Range: 510 km / Torque: 450 Nm / 0–100 km/h: 5.2 s. Which figure represents energy capacity, motor power, maximum charging power, range and torque, respectively?
Energy capacity = 82 kWh; motor power = 220 kW; maximum charging power = 175 kW; range = 510 km; torque = 450 Nm.