Electric Motors Answers

1. Compare the motors in Figure 7 and Figure 10. The simple model motor has two poles. How many poles does the hybrid motor have?

The hybrid motor has 18 poles.

2. What are the advantages of electric power for the aircraft in Figure 3?

There are many, including lower fuel load, smaller and lighter engines, quiet running and lower cost.

3. For an electric car to have zero emissions of CO2, the battery needs to be charged from what kind of energy?

The electricity would have to come from a renewable source, such as solar, hydro or wind power.

Forces in a motor

Motor operation diagram

Figure 7: A simple two pole (one N and one S) DC motor.


Hybrid motor exploded view
(Courtesy of AVL.)

Figure 10: An exploded view of a typical hybrid drive motor (computer drawing and the real thing). The stator coils are tightly wound copper wire to create strong magnetic fields. 


Hybrid aircraft powertrain
(Courtesy of Siemens.)

Figure 3: Electric hybrid aircraft power. The electric motor provides high power for take off and short flights without fuel. A petrol engine drives a generator for backup power and longer range. Copper cables supply the high electric current to the motor.