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Electric Vehicles Final Exam Study Guide: Questions & Answers
Most modern gasoline/electric hybrid cars use brushless DC motors. (T/F?) (Ans- True The angular velocity of the rotor in an induction motor "slips" with respect to the angular velocity of the magnetic field around the stator coils. (T/F?) (Ans- True It is not possible to have regenerative braking in an electric car that use an induction motor. (T/F?) (Ans- False High power solid state switching devices for use in electric vehicle power electronic are... (Ans- Insulated Gate Bipolar Transistors (IGBT) Solid state switches and inductors in a DC regulator cannot step up the voltage from a battery (T/F?) (Ans- False
A H bridge changes the current direction in motor stator windings in motors used in some electric vehicles. (T/F?) (Ans- True Electronic switches in power electronics can control the shape of an AC current waveform that is applied to stator windings of an induction motor used in an electric vehicle. (T/F?) (Ans- True Electronic switches in power electronics cannot control the frequency of an AC current waveform that is applied to stator windings of an induction motor used in an electric vehicle. (T/F?) (Ans- False A three phase H bridge cannot be used in the power electronics for an electric motor in an electric vehicle. (T/F?) (Ans- False A chemical element that appears in the name of the battery technology used in most new battery electric vehicles is... (Ans- Lithium
Important parameters to consider when choosing a battery chemistry to use in an electric vehicle battery are the following... (Ans- Specific Energy, Cost, Life Span, Specific Power, Safety, Performance If a battery has a rating of 25 amps hours and is charged at 25 amps to full in one half hour, the charge rate is 1 C. (T/F?) (Ans- False The description of a battery as being a Lithium Polymer battery has more than one meaning. (T/F?) (Ans- True Some of the electric vehicle on the market today use different Lithium based chemistry. (T/F?) (Ans- True The Tesla Model S has the smallest battery of any electric vehicle being sold today. (T/F?) (Ans- False
The Nissan Leaf has the largest battery in any electric vehicle being sold today. (T/F?) (Ans- False The range of an electric car does not depend on the kWh capacity of the battery used to power the drive motor. (T/F?) (Ans- False The cell formats (cell shapes) discussed in class were... (Ans- cylindrical, prismatic, and pouch Battery Management Systems (BMS) for lead acid batteries are simpler than BMS for lithium ion batteries (T/F?) (Ans- True Which are the correct statements: A) Li Ion batteries have become less costly over several years B) There are still improvements being made in Li Ions batteries C) The cost of Li Ion batteries will not likely decrease below what it is today D) The cost of Li Ion batteries will likely decrease below what it is today
Most modern electric cars use three phase variable reluctance motors. (T/F?) (Ans- False Modern three phase brushless Dc motors (synchronous AC motors) have strong permanent magnets in the rotors (T/F?) (Ans- True Modern three phase induction motors have strong permanent magnets in the rotators. (T/F?) (Ans- False The stators of modern three phase brushless DC motors and modern induction motors can be very similar. (T/F?) (Ans- True Modern three phase induction motors have "squirrel cage" rotors that are made of a magnetic material (iron) and a good conductor (copper or aluminum). (T/F?) (Ans- True Most modern gasoline/electric hybrid cars use induction motors. (T/F?) (Ans- False
Some modern plug in battery electric cars use induction motors. (T/F?) (Ans- True A modern three phase induction motor with a controller for an electric car cannot produce torque at zero speed. (T/F?) (Ans- False What is the equation for the force, F, in Newtons on a wire of length L meters, running through a constant magnetic field of B Webbers/(square meter) with the wire carrying a current, I amps. (Ans- F = BIL What is the equation for the "back electromotive force (EMF)" denoted by E, generated in a wire of length L, moving at a velocity V perpendicular to a magnetic field of constant flux density B. (Ans- E = BLV The torque produced by a brush-commutator DC motor having a permanent magnet stator is proportional to the current I in the coil winding of the motor rotor (some other types of motors have a similar torque-current relationship). (T/F?) (Ans- True
The rotor of the three phase induction motor does not have to turn at the same angular velocity as the angular velocity of the magnetic field around the stator coils. (T/F?) (Ans- True
