ASE L3 flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

High-voltage threshold definition

Alternating current above 30 V RMS or direct current above 60 V is classified as high voltage; circuits below these limits are not treated as shock-hazardous under normal dry conditions.

Class 0 insulating gloves

Class 0 rubber gloves are proof-tested at 5,000 V AC and rated for maximum use at 1,000 V AC or 1,500 V DC, with electrical retesting required every six months.

Let-go current threshold

About 10 to 15 milliamperes of 60 Hz current causes involuntary muscle contraction that prevents the person from releasing the conductor; 100 mA or more can cause ventricular fibrillation.

HVIL circuit function

The High Voltage Interlock Loop is a low-voltage series circuit routed through every HV connector; opening any connector breaks the loop and commands the battery contactors to open.

Isolation resistance requirement

ECE R100 requires at least 100 ohms per volt for DC high-voltage buses and 500 ohms per volt for AC buses, measured between live conductors and the chassis.

Lithium-ion cell voltages

Most automotive lithium-ion cells have a nominal voltage of 3.6 to 3.7 V, a full-charge voltage near 4.1 to 4.2 V, and a discharge cutoff around 3.0 V.

Coulomb counting state of charge

State of charge is estimated by integrating charge current over time; accuracy drifts from sensor error, so the estimate is periodically reset using open-circuit voltage.

Passive cell balancing

Passive balancing bleeds energy from the highest-voltage cells through resistors until all cells match, wasting the excess as heat but costing very little to implement.

Insulation monitoring device

An insulation monitoring device continuously measures resistance between the high-voltage bus and chassis; a value below the threshold sets a diagnostic code and may open the contactors.

Thermal runaway indicators

Cell self-heating without load, swelling, sweet or solvent odor, venting, and arc tracking on bus bars all indicate thermal runaway; evacuate the area and apply copious water.

Interior permanent magnet motor

An interior permanent magnet motor embeds magnets inside the rotor, producing reluctance torque plus magnetic torque, giving high efficiency and enabling field weakening at high speed.

Field weakening control

The inverter injects stator current that opposes rotor magnet flux, lowering back-EMF so the motor can spin above base speed without exceeding the available inverter voltage.

Inverter DC-link capacitor

The DC-link capacitor smooths bus voltage and supplies ripple current during PWM switching; it retains a lethal charge after shutdown and must be discharged before service.

Regenerative torque generation

When rotor speed drives back-EMF above the DC bus voltage, the inverter's anti-parallel diodes rectify the output and current flows back to the battery, producing braking torque.

Resolver rotor position sensing

A resolver outputs sine and cosine signals proportional to rotor angle, allowing the inverter to time phase currents correctly for maximum torque per ampere.

Silicon carbide inverter advantage

Silicon carbide MOSFETs switch faster and tolerate higher junction temperatures than IGBTs, cutting switching losses and allowing smaller cooling systems and higher efficiency.

Mechanical power formula

Power in watts equals torque in newton-meters multiplied by angular speed in radians per second; in horsepower, torque in pound-feet times rpm divided by 5252.

Hybrid state of charge window

Hybrid control keeps the pack roughly between 20 and 80 percent state of charge, a band that accepts regenerative charge and supplies peak assist without accelerated aging.

Equivalent consumption minimization strategy

This strategy converts electrical energy use into an equivalent fuel cost using a multiplier, then selects the torque split that minimizes total equivalent fuel over the trip.

CAN bus termination resistance

A healthy high-speed CAN network measures about 60 ohms between CAN-H and CAN-L because two 120-ohm terminating resistors at the bus ends appear in parallel.

Hybrid torque arbitration

The control module divides driver demand between engine and motors using efficiency maps, battery power limits, and drivability constraints, then transmits torque commands over the bus.

Precharge sequence timing

Contactor control closes the precharge contactor first, waits until DC-link voltage reaches about 95 percent of pack voltage, then closes the main positive contactor.

Regenerative braking limits

Regenerative torque is capped by battery charge power limit, state of charge, cell temperature, motor speed, and stability control intervention; friction brakes supply the remainder.

Brake blending handoff speed

Below roughly 5 to 10 km/h regenerative torque cannot be sustained, so the controller fades it out and phases in friction braking to hold pedal feel and stop the vehicle.

Regen during ABS activation

When anti-lock braking modulates, the controller rapidly reduces or cancels regenerative torque to avoid wheel-slip oscillation and to preserve anti-lock pressure control.

One-pedal driving calibration

Lifting the accelerator commands negative torque up to a calibrated maximum, so the vehicle decelerates and can stop, with friction brakes holding it at standstill.

Regenerative energy recovery efficiency

Round-trip regenerative recovery returns roughly 60 to 70 percent of kinetic energy to the pack; the losses come from motor, inverter, and battery internal resistance.

Electric HVAC compressor

Air-conditioning compressors in electric vehicles use a three-phase motor driven at 200 to 400 V with an integrated inverter; they operate only when high voltage is present.

Positive temperature coefficient heater

A PTC heater raises coolant or air temperature using high-voltage current; its resistance increases with temperature, giving self-limiting output and inherent over-temperature protection.

SAE J1772 control pilot

The EVSE encodes available current as the duty cycle of a 1 kHz pulse-width-modulated control pilot signal; the vehicle reads that duty cycle to set its charger current limit.

Onboard charger function

The onboard charger converts AC grid power into high-voltage DC, performs power factor correction, communicates with the supply equipment, and enforces isolation monitoring during charging.

DC fast charge standards

CCS, CHAdeMO, GB/T, and NACS deliver DC directly to the pack through dedicated pins; the off-board charger controls current while the vehicle manages contactors and isolation checks.