General Electric Vehicle Terms EV - Electric Vehicle. BEV - Battery powered Electric Vehicle. Hybrid - A vehicle that runs on traditional liquid fuel and an electric motor. PHEV - Plug in Hybrid Electric Vehicle. Parallel Hybrid - A hybrid vehicle that can move from electric power, or mechanical power. Series Hybrid - A hybrid vehicle where mechanical power is converted to electrical power, which is then used to power an electric drive motor.
General Vehicle Terms ABS - Anti Lock Brakes SRS - Supplemental Restraint Systems aka Airbags PS - Power Assisted Steering. It makes the steering wheel easier to turn. PB - Power Assisted Brakes. It makes stopping the vehicle easier. AC - Air Conditioning system. Responsible for cooling the interior of the vehicle.
Battery Terms SOC - State of Charge. A percentage of how much capacity is left in the battery pack. DOD - Depth of Discharge. A percentage of how much energy has been discharged from the battery pack. Cycle Life - How many charge-discharge cycles a battery can provide. May depend on DOD. Deep Cycle - Refers to a battery that is designed to be discharged to a high DOD without an adverse effect on cycle life. Flooded PB or Flooded Lead Acid - Regular Lead Acid batteries containing water and electrolyte. VRLA - Valve Regulated Lead Acid. A sealed battery with valves that open to release excess internal pressure. AGM - Absorbed Glass Mat. Lead Acid batteries with the electrolyte suspended in a fiberglass mat. BMS - Battery Management System. Responsible for keeping all batteries in a pack at the same SOC. A simple BMS could be 1 regulator for each battery in a pack, that prevents the voltage or current from going above a setpoint during charging. A more complex BMS could communicate with the charger to set the charging voltage and current, and could also report the SOC of each cell, and the overall pack.
Basic Electrical Terms Current - A flow or movement of electrons. AC - Alternating Current. An electrical current where the direction and magnitude vary with time. DC - Direct Current. An electrical current where electrons move in 1 direction. Volt (V) - The measure of electric potential between 2 points. Amp or Ampere (A) - The measure of current moving through a conductor. Resistance - A measure of how much an object opposes electrical current. It is measured in Ohms (Ω) Watt (W) - A measure of power. In a DC system 1 W = 1 V x 1 A Watt hour (Wh) - A measure of energy. It is equal to Power x time. A 60 Watt light bulb turned on for 1 hour uses 60 Wh of energy. kiloWatt (kW) - 1000 Watts kiloWatt-hour (kWh) - 1000 Watt-hours Amp-hour (A h, A*h, Ah) - A measure of electric charge. The measure of a current flow for a time. 1 A of current for 1 hour = 1 Ah. 100 A of current for 2 hours = 200 Ah. Amp-hours are typically used to rate a battery's capacity. It is not a direct measure of energy stored in the battery, but can be used to estimate how long a battery will last under a given load. Magnetic Field - A field that extends in space, and exerts a magnetic force on moving electrical charges, or other magnetic fields. Magnetic Flux - A measure of the density and intensity of a magnetic field Series - Describes 2 or more electric devices hooked up in a row, from the positive end of 1 device, to the negative end of the next device. A common example is 10 12 volt batteries connected in series to create a 120 volt battery pack. Parallel - Describes 2 or more electric devices hooked up next to each other. Each negative end is tied together, and each positive end is tied together.
Electric Motor Terms Rotor and Stator refer to the mechanical construction of the motor. Rotor - The part of the motor that rotates. Stator - The part of the motor that is stationary.
Field and Armature refer to the electric components of the motor. Field - The main purpose of the Field component of a motor is to create a magnetic field for the Armature to interact with. The field can be made up of permanent magnets, or an electromagnetic coil. Armature - The mechanical power producing component of the motor. Electrical current flowing through the armature produces a magnetic field which interacts with the Field's magnetic field to produce torque and rotation. Commutator - The commutator periodically reverses the electrical current in the armature of the motor. It does so reverse the magnetic field generated by the armature, to continue interaction with the field, and continue rotation. Brush - Carbon contacts that connect the wiring to the rotating commutator inside the motor. Pigtails - Braided cables the connect to the brushes. Series Wound - A DC motor where the field coils and armature coils are wired up in series. Most common EV motors are a series wound motor, where the stator contains the field, and the rotor contains the armature. Out Runner - An inverted motor, where the field is the rotor, and is usually made out of permanent magnets, and the stator is the armature. Separately Excited (Sep-Ex) - A DC motor where the field coil and armature coils are separate, and receive current from 2 different sets of contacts on the controller. Shunt Wound - A DC motor where the field coil and armature coil are wired in parallel. Permanent Magnet (PM) - A DC motor where the field is produced my permanent magnets, and the armature is an electromagnetic coil similar to other types of DC motors. Brushless DC - A DC motor where the rotor contains permanent magnets, and the stator contains electromagetic coils. The commutator is eliminated and replaced with a more complex controller which switches the electrical current as needed to produce and continue motion AC Induction Motor (ACIM) - An AC motor where there is no electrical connection to the electromagnetic coils in the rotor. Instead an electric current is induced in the rotor, but the current in the stator. This induced current creates the magnetic field which interacts with the field generator in the stator. They require a complex controller similar to a Brushless DC motor.
EV System Terms Traction Motor - The main electric motor that drives the vehicle DC-DC converter - A device that outputs 14 volts dc to run the cars low voltage system. It replaces the alternator in a standard ICE vehicle. Precharge Resistor - A resistor wired in parallel to the main contactor to allow a limited current to flow to the motor controller. This current charges the capacitors in the controller to avoid a high surge current when operating the main contactor. Main Contactor - A device used to connect and disconnect the main battery pack from the motor controller.
Charger Terms CC - Constant Current. The battery charger outputs a steady current, usually until the battery voltage reaches a setpoint. CV - Constant Voltage. The battery charger outputs a steady voltage, and as the battery charges, the current drawn by the battery decreases. Float Charge - The charger holds the voltage to a steady value, to counteract battery self-discharge.