EV Technology & Future Trends Flashcards
7 cards from real CAE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 EV Technology & Future Trends flashcards as text
Bi-directional onboard chargers (OBCs) supporting V2H (Vehicle-to-Home) differ from standard OBCs in that they must:
Answer: Output AC power synchronized to home load requirements without grid synchronization (island mode)
V2H in island mode requires the OBC to generate stable AC voltage and frequency autonomously to power home loads when the grid is unavailable, a fundamentally different operation from grid-tied charging.
What is the significance of the C-rate in lithium-ion battery specifications?
Answer: The charge or discharge current relative to the cell's rated capacity
A 1C rate discharges a cell in one hour; 2C in 30 minutes; the C-rate normalizes current to capacity so cells of different sizes can be compared on power delivery terms.
Inductive wireless charging for EVs loses efficiency compared to conductive charging primarily due to:
Answer: Air gap and coil misalignment increasing leakage flux and reducing coupling coefficient
The physical air gap between primary (ground) and secondary (vehicle) coils reduces the magnetic coupling coefficient, causing significant flux leakage and efficiency losses compared to direct contact charging.
In EV motor control, Maximum Torque Per Ampere (MTPA) control strategy is used to:
Answer: Operate the motor at the optimal current angle to produce required torque with minimum current magnitude
MTPA determines the d-q axis current split that delivers commanded torque at the lowest possible stator current, minimizing copper losses and inverter current stress.
The Ragone plot is used in EV energy storage comparison to show the trade-off between:
Answer: Specific energy (Wh/kg) vs. specific power (W/kg)
The Ragone plot maps energy density against power density, visually showing that batteries offer high energy but moderate power while ultracapacitors offer high power but low energy.
Which emerging EV powertrain concept uses hydrogen as an onboard energy carrier but drives wheels with an electric motor, avoiding a combustion process?
Answer: Fuel cell electric vehicle (FCEV)
FCEVs electrochemically convert hydrogen and oxygen to electricity in a fuel cell stack, producing only water vapor as a byproduct, with an electric motor providing final propulsion.
Automakers are targeting battery pack energy densities above 400 Wh/L at the pack level primarily by pursuing which technology combination?
Answer: Higher nickel NMC cathodes paired with silicon-dominant anodes in cell-to-pack designs
High-Ni NMC or NCA cathodes maximize cathode capacity while silicon anodes offer ~10x the lithium storage of graphite; CTP packaging then removes module overhead to reach 400+ Wh/L pack-level targets.