AE-APU4 Hybrid & Battery Electric Vehicles (BEV) Lecture Review

Comprehensive practice flashcards covering hybrid drive systems, electric motor types, battery management, efficiency metrics, and vehicle safety protocols based on lecture notes.

What is the etymological origin of the word 'hybrid' in the context of vehicles?

It comes from Latin and means 'close mixing of dissimilar things,' referring to a vehicle powered by at least $2$ different power sources and containing $2$ energy storage systems.

According to EU agreements, what was the average CO2 emission requirement for cars in 2020 and the projected limit for 2025?

The requirement for $2020$ was $95\,g\,CO_2/km$, and the limit for $2025$ is set at $70\,g\,CO_2/km$.

Distinguish between 'Tank-To-Wheel' and 'Source-To-Wheel' (Well-To-Wheel) efficiency.

Tank-To-Wheel refers to losses occurring from the vehicle's fuel tank to the driven wheels, while Source-To-Wheel considers the entire chain from energy production/generation to the wheels.

What is the 'H' quantification ratio used to classify hybrid types?

$H$ is the ratio of the power of the electrical machine to the total installed power. Micro-hybrids have $H \approx 0.05$, Mild-hybrids $H \approx 0.10$, and Full-hybrids $H > 0.25$.

What is 'KERS' and where is it commonly used?

KERS stands for Kinetic Energy Recovery System, a flywheel accumulator system used in Formula $1$ to convert braking energy into kinetic energy for later acceleration.

How does a Serial Hybrid Drive (S-HEV) operate?

An internal combustion engine is coupled to a generator to provide electrical energy. There is no mechanical connection to the wheels; propulsion is provided entirely by an electric motor.

Explain the difference between a P1 and a P2 Parallel Hybrid configuration.

In P1, the electric machine is mounted directly on the crankshaft; in P2, a coupling is placed between the combustion engine and the electric machine, allowing pure electric driving without 'drag torque' from the engine.

What is a 'Power Split Hybrid' (SP-HEV) and which vehicle is a famous example?

It combines serial and parallel principles using a planetary gear system at its heart; a prominent example is the Toyota Prius.

Define 'Boosting' in hybrid driving.

An operating condition during acceleration where the power outputs of the combustion engine and the electric motor are both positive and add together to provide high dynamics.

What are the components of a 'Range Extender' (REEV) unit?

A module usually consisting of an internal combustion engine and an electrical generator, used only to generate electricity to charge the battery and increase driving range.

What is the primary difference between Synchronous and Asynchronous (Induction) electric machines?

In synchronous machines, the rotor follows the magnetic field frequency exactly ($n = n_1$). In asynchronous machines, the rotor rotates slower than the field, a difference known as 'slip' ($n < n_1$).

What is 'Field Weakening' in an electric motor?

The process of reducing magnetic field strength once maximum voltage is reached to maintain the voltage, which results in a decrease in torque but allows for higher speeds at constant power.

What does 'SOH' stand for and what does it describe?

State of Health; it describes the current condition of a battery compared to a new battery, often referred to as the 'aging rate'.

In high-voltage vehicle safety, what is the 'Pilot Line'?

A safety loop that monitors the integrity of the HV system; if a plug is disconnected or a component is opened, the Pilot Line is interrupted, and the BMS disconnects the HV battery via relays.

Define 'BZE' (Batterie-Zustand-Erkennung) and its three key parameters.

It is the battery condition determination system, identifying State of Charge (SoC), State of Function (SoF), and State of Health (SoH).

What is 'Galvanic Coupling' in the context of EMC?

A form of interference where two different circuits share a common return line (body ground), causing the current of one to generate a signal voltage in the other.

Describe 'Equipotential Bonding' (common ground) in EV safety.

The practice of connecting all conductive housings of HV components to a common ground to prevent high contact voltages in the event of an insulation fault or short circuit.

What are 'IGBT' transistors and where are they used?

Insulated Gate Bipolar Transistors; they are power switches used in inverters to convert DC battery voltage into AC for the electric machine, typically rated for $600\,V$.

Compare the cycle life of HEV batteries vs. BEV batteries.

HEV batteries typically undergo $300,000$ to $400,000$ shallow cycles ($5\text{--}10\%$ discharge), while BEV batteries undergo approximately $3,500$ deep cycles ($90\%$ discharge).

What is 'PEMFC' and why is it preferred for vehicles?

Proton Exchange Membrane Fuel Cell; it is preferred because of its low operating temperature ($80\,^{\circ}C$), high power density ($1000\,W/kg$), and flexible behavior during load changes.

How does 'Regenerative Braking' save fuel?

By using the electric motor as a generator during deceleration to convert kinetic energy into electrical energy, which is stored in the battery for future drive use ($2\text{--}10\%$ fuel savings).

What is the purpose of a DC/DC Converter in an EV?

It converts high voltage (HV) from the traction battery into low voltage ($12\,V$) to supply the standard on-board electrical network and charge the auxiliary battery.

In charging technology, what are the CP and PP pins?

CP is Communication Pilot (active communication between car and station); PP is Proximity Pilot (detects if the plug is inserted and signals drive-away protection).

What is an 'Axial Flux Machine'?

A synchronous machine where the magnetic field runs axially rather than radially, resulting in a very narrow construction suitable for hub motors.

What voltage levels are considered dangerous for humans in DC and AC systems?

DC voltage from $60\,V$ and AC voltage from $25\,V$ are considered dangerous to fatal.