Question 1

How many NMC strings would have to be placed in series to produce a bank voltage that exceeds 600 VDC?

Accepted Answer

The answer of How many NMC strings would have to...

Question 2

Technician A says that using multiple battery banks in parallel increases the electrical energy density. Technician B says that CEVs use multiple battery banks in series to increase the nominal operating voltage. Who is correct?

Accepted Answer

The answer of Technician A says that using multiple battery...

Question 3

Which of the following best describes the source of the energy recovered during regenerative braking in an electric powertrain?

Accepted Answer

Regenerative braking recovers energy by converting the vehicle's kinetic energy into electrical energy, which is then stored in the battery for future use. This process involves the traction motor, which acts as a generator during braking.

Question 4

Technician A says that that some CEVs are driven by a single, longitudinally-mounted (inline) traction motor directly coupled to drive wheels. Technician B says that a CEV drive axle can use a pair of in-axle traction motors coupled to reduction gearing in each wheel assembly. Who is correct?

Accepted Answer

The answer of Technician A says that that some CEVs...

Question 5

Technician A says that some CEVs use 6-phase AC traction motors. Technician B says that some CEVs use 9-phase AC traction motors Who is correct?

Accepted Answer

The answer of Technician A says that some CEVs use...

Question 6

What would be the advantage of using a 9-phase traction motor over a 3-phase motor in a CEV?

Accepted Answer

Using a 9-phase traction motor in a CEV (Commercial Electric Vehicle) offers several advantages over a 3-phase motor, including lower cable operating temperatures due to more efficient power distribution, the ability to use lower sectional area wiring because the power is divided across more phases, and increased power due to better utilization of the electromagnetic field. These benefits collectively contribute to improved performance and efficiency in electric vehicle applications.

Quiz 41: Electric Powertrains