# Glossary of Abbreviations



## mattW (Sep 14, 2007)

A list of commonly used abbreviations to do with electric cars in alphabetical order. If you are asking 'what does that stand for?' then this is the place to be:

*AC -* Alternating Current: The standard type of electricity in homes and the most effective way of powering an EV. In AC circuit the voltage swings between positive and negative meaning current flows in both directions (hence 'alternating').


*AGM *- Absorbed Glass Mat: a style of construction of lead-acid batteries, in which the electrolyte is absorbed by a mat of glass fibres.


*BEMF* - Back ElectroMotive Force: A voltage that occurs in electric motors where there is relative motion between the armature of the motor and the external magnetic field. One practical application is to use this phenomenon to indirectly measure motor speed and position. Can be detected using a number of methods. Shunts on each windings power, current sensing transformers, and hall effect sensors.


*BEV - *Battery Electric Vehicle- See EV below, An electric vehicle whose energy source is exclusively stored in batteries, rather than as fuel for a fuel cell or engine.


*DC* - Direct Current: A form of electricity where current only flows in one direction. This is the form of electricity produced by batteries and the most common system used in EV conversions.


*DOD* - Depth of Discharge: A measure of how much energy has been withdrawn from a battery. It is expressed as a percentage of the total battery capacity. For example - if you use 25ah of a 100ah battery, that is running the battery to 25% DOD.


*EV *- Electric Vehicle: usually referring to registered passenger vehicles but can refer to any vehicle that is powered exclusively by an electric drive train.


*FCV-* Fuel Cell Vehicle: A vehicle powered by a fuel cell, which uses a chemical reaction to produce electricity directly from the oxidation reaction of the fuel, rather than through combustion. The fuel is usually hydrogen, but can be alcohol or natural gas. This is essentially an electric vehicle but using a fuel as the source of energy rather than charge in a battery; a battery is still normally used between the fuel cell and motor, but energy is provided to the vehicle as fuel.


*FLA* - Flooded Lead Acid Battery: a lead-acid battery (see Pb-Acid) that uses a free liquid electrolyte, as opposed to one that uses gelled electrolyte (gel-cell) or a liquid electrolyte absorbed in a glass mat (AGM).


*ICE *- Internal Combustion Engine: the standard way to power a vehicle, this part is removed when converting to an electric car.


*LVC - *Low-Voltage-Cutoff*: *As the cells discharge, the cell voltage drops the cell can be damaged by taking the cell voltage to zero. Low Voltage Cutoff may be provided on each cell to shut down the power draw when the LVC is reached.


*PHEV *- Plug-in Hybrid Electric Vehicle: A hybrid electric vehicle with a substantial battery pack which is able to be charged by an external source other than its fossil fuel (i.e. plugged into household electricity). These vehicles often have the ability to travel is a 'pure electric mode' without using any conventional fuels.


*PWM* - Pulse Width Modulation: a technique for controlling voltage output in a motor controller, by turning output on in pulses at a constant frequency, with the duration (or "width") of the pulses varied to control output.


*LiFePO4* - Lithium Iron Phosphate battery chemistry.


*NiCd*, *NiCad* - Nickel Cadmium battery chemistry.


*NiMH* - Nickel-Metal Hydride battery chemistry.


*Li-poly, Li-Pol, LiPo* - Lithium Polymer battery chemistry.


*LiCoO2* - Lithium Cobalt Oxide battery Chemistry.


*Pb-Acid* - Lead-Acid battery chemistry.


*VRLA* - Valve Regulated Lead Acid: a style of lead-acid battery which does not have open vents, but instead has vents which are normally closed


_*BOL/EOL- *Beginning of life/End of life (Battery pack expectations)_
_More Information Needed..._


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## Sparweb (May 24, 2013)

Could the following be added? They seem to be used often enough:

VFD - Variable Frequency Drive

DTC - Direct Torque Control

FOC - Field Oriented Control

FPGA - Field Programmable Gate Array

PIC - Programmable Interface Controller

PID - Proportional Integral Differential (controller)

IGBT - Insulated Gate Bipolar Transistor

EMI - Electromagnetic Interference

(I could supply some definitions, but they'd just be copied from wikipedia. Perhaps someone more qualified could prepare some EV specific definitions, where applicable).

-edit-
while I'm at it:

BLDC - Brushless DC (motor) - a BLDC motor is usually designed with permanent magnets on the rotor, 3-phase windings on the outer stator, and operated with a suitable electronic motor drive.

ACIM - AC Induction (motor) - an induction motor is designed with a squirrel-care rotor and 1-phase or 3-phase windings on the outer stator, and operates directly from mains power because of electromagnetic induction of the field into the squirrel cage motor. They can be operated with a suitable electronic motor drive.

(anybody interested in carefully defining the differences between series-wound and shunt-wound DC motors?)


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## Mango Animal (Oct 1, 2021)

mattW said:


> *BEMF* - Back ElectroMotive Force


Produces electricity when the car is rolling if you have PM motors, even if the car is not on. This can destroy the power electronics.


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