Electric Vehicles Final Study Guide

True

A H bridge changes the current direction in motor stator windings in motors used in some electric vehicles. (T/F?)

Lithium

A chemical element that appears in the name of the battery technology used in most new battery electric vehicles is . . .

False

A controller for a modern brushless DC motor for an electric car does not need to have information about the angular position of the permanent magnet rotor. (T/F?)

True

A controller for a modern induction motor for an electric car does not need to have information about the angular position of the rotor. (T/F?)

True

A disadvantage of a DC motor with brushes and mechanical commutator (switch) is that the brushes wear out and need to be replaced. (T/F?)

False

A modern three phase induction motor with a controller for an electric car cannot produce torque at zero speed. (T/F?)

False

A new battery technology used in electric vehicles to power the vehicle electric drive motor is lead acid. (T/F?)

False

A three phase H bridge cannot be used in the power electronics for an electric motor in an electric vehicle. (T/F?)

High voltage of 3.6V, high energy density, high power density, fast charge possible, no memory effect, long cycle life, lower self discharge

Advantages of Li-ion batteries

True

Battery Management Systems (BMS) for lead acid batteries are simpler than BMS for lithium ion batteries (T/F?)

Higher cost, stricter design requirements, need for protective circuitry

Disadvantages of Li-ion batteries

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?)

False

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?)

Insulated Gate Bipolar Transistors (IGBT)

High power solid state switching devices for use in electric vehicle power electronic are . . .

False

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?)

False

Important disadvantages of Li Ion batteries compared to Ni Metal Hydride batteries are lower energy density in wh/kg and lower power density in watts/kg. (T/F?)

Specific Energy, Cost, Life Span, Specific Power, Safety, Performance

Important parameters to consider when choosing a battery chemistry to use in an electric vehicle battery are the following . . .

True

In an electric car, regenerative braking occurs when the electric motor controller produces a higher voltage on the battery terminals than the open circuit voltage of the battery. (T/F?)

False

It is not possible to have regenerative braking in an electric car that use an induction motor. (T/F?)

True

Li Ion batteries do not have a memory effect if not discharged completely for each discharge cycle. (T/F?)

True

Modern three phase brushless Dc motors (synchronous AC motors) have strong permanent magnets in the rotors (T/F?)

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?)

False

Modern three phase induction motors have strong permanent magnets in the rotators. (T/F?)

False

Most hybrid gasoline electric vehicles use lead acid batteries to power the vehicle electric drive motor. (T/F?)

False

Most modern electric cars use three phase variable reluctance motors. (T/F?)

False

Most modern electric motors do not need a controller (electronics) to limit the maximum current at zero speed. (T/F?)

True

Most modern gasoline/electric hybrid cars use brushless DC motors. (T/F?)

False

Most modern gasoline/electric hybrid cars use induction motors. (T/F?)

False

Power electronic for modern battery electric vehicles have efficiencies less than 80%. (T/F?)

False

Solid state switches and inductors in a DC regulator cannot step up the voltage from a battery (T/F?)

True

Some modern plug in battery electric cars use induction motors. (T/F?)

True

Some of the electric vehicle on the market today use different Lithium based chemistry. (T/F?)

False

The Nissan Leaf has the largest battery in any electric vehicle being sold today. (T/F?)

False

The Tesla Model S has the smallest battery of any electric vehicle being sold today. (T/F?)

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?)

cylindrical, prismatic, and pouch

The cell formats (cell shapes) discussed in class were . . .

True

The description of a battery as being a Lithium Polymer battery has more than one meaning. (T/F?)

False

The oldest battery technology used in electric vehicles to power the vehicle drive motor is lithium ion. (T/F?)

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?)

False

The rotor of the three phase brushless DC motor does not have to turn a the same angular velocity as the angular velocity of the magnetic field around the stator coils. (T/F?)

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?)

True

The stators of modern three phase brushless DC motors and modern induction motors can be very similar. (T/F?)

True

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?)

E = BLV

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.

F = BIL

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.

A, B, D

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 E) Lead acid batteries will likely replace Li Ion batteries in future high performance electric cars