A brushed DC motor with a motor constant of 0.85 is used as

traction motor of an electric vehicle. If the motor has the following

specifications at the rated condition (in

forward motoring mode)

• Armature current: 50 A 

• Armature resistance: 20 mΩ
• Back EMF: 150 V
• No load torque of 4 Nm.

a. Determine the rated torque and speed of the motor. 

b. Determine the efficiency of the motor.

A series HEV that uses

Atkinson cycle engine has a combined efficiency of 79% from the generator to the

wheel. When the vehicle was tested on a chassis dynamometer, the vehicle road

load energy was found to be 3 MJ. Determine the engine efficiency and the amount of fuel (liter) consumed

during this test, if

• The fuel is gasoline with specific energy of

  42.6 kJ/g and density of 0.75 kg/L.

• When the engine operates at its optimum operating

  condition with BSFC of 220 g/kWh, it generates output power of 20 kW.

a. Determine the maximum resistive force experienced by the vehicle when it travels at a speed of 100 km/h with a tailwind of 3 m/s

b. Determine the required tractive  force for it to travel with a constant acceleration of 3.8 m/s² from 0 to its top speed of 160 km/h on a flat ground without any headwind or tailwind. 

A battery electric vehicle is tested on a simple drive cycle at a constant velocity of 10 m/s for a duration of 5 minutes and at a constant speed of 15 m/s for another 5 minutes. 

The vehicle road load power is described as follow: 

P_R=180v+3.6v²+0.3v³

and the efficiencies are as follow: 

• Battery to wheel efficiency (
  Image failed to load: \eta
  \eta _B-W) is 85% 
• Grid efficiency ( \eta Grid) is 34%
• Charging efficiency from the plug to battery ( \eta C) is 86% 

a. Determine the total energy consumption of the vehicle (From grid to wheel) 

b. Determine the vehicle fuel economy in Wh/km (From battery to wheel)

The powertrain of a hybrid electric vehicle or battery electric vehicle most likely look like below image(s): 

Based on the exterior features of the vehicle, which of the following is/are most likely an electric vehicle?

The followings is/are true if the motor operates in forward generating mode:

Which of the following is the main characteristics of Parallel HEV?

The main requirements of a traction motor in electric vehicle are: 

The vehicle road load coefficients derived from the coast down test correlates to: