Electric vehicles (EVs) are becoming more affordable, and numerous manufacturers are planning to significantly expand their offerings of them. Honda and GM, for instance, have already introduced multiple EV models with impressive consumer satisfaction ratings.
Battery electric vehicles (EVs) produce less greenhouse gases than cars with internal combustion engines, but still use energy sources which emit greenhouse gasses.
Battery
A battery is at the core of an electric motor vehicle and represents one of its most costly components, so manufacturers make every effort to cut costs during production. A key aspect of reducing production costs involves selecting optimal cell chemistry: this includes selecting materials which enable electron sharing between electrodes to generate an electric potential difference (voltage). Furthermore, cell chemistry determines energy capacity measured in ampere-hours.
Each cell in an electric vehicle battery is a discrete unit connected electrically into packs to achieve the required voltage and current capacity. Each pack also houses a battery management system (BMS), a microprocessor-controlled device which monitors individual cell temperatures, interconnection points and battery pack voltage levels; this allows BMS to identify any cells not performing as they should and to trigger alarms before any serious damage can occur.
Lithium batteries for electric vehicles offer high energy densities. Due to its low melting point, lithium can easily be cast into thin sheets that can then be laminated together into packs for greater durability and resistance to shocks, heat, and vibration.
After their service life is up, electric vehicle batteries can be recycled in several ways. Reusing them as high performance EV batteries or using them as backup power supplies for homes and facilities that generate their own electricity through solar panels are just two possibilities for recycling; sometimes refurbished EV batteries even find new use as forklift batteries or emergency backup power sources in retail shops needing constant energy sources.
Electric vehicles (EVs) are put through rigorous tests in labs for both operating range and energy consumption. They’re driven on a dynamometer – like a treadmill for cars – with multiple driving schedules to simulate city and highway motoring, charging/discharging cycles to test storage/delivery capacity and finally results compared with manufacturer claims; those equipped with larger, high performance battery packs tend to complete testing faster.
Motor
An electric motor provides propulsion power while also acting as the brakes of an EV vehicle. Electric motors convert more than 77% of electrical energy to mechanical energy at the wheels (compared with 20-25% conversion efficiency for traditional gasoline vehicles) with reduced emissions; this process is known as energy conversion efficiency.
The onboard charger transforms AC electricity from the grid into DC energy for charging of the traction battery, as well as monitoring its voltage, temperature, state of charge and other characteristics to ensure optimal performance of both batteries. An auxiliary battery provides power for running radio, lights, windshield wiper and washer systems and other devices within the vehicle and is not charged from its main traction pack; rather it receives its own 12 V charge from an onboard charger; all EV’s power systems are microprocessor controlled.
Most EVs utilize permanent-magnet AC induction motors, which consist of an outer stator with an inducing core rotating internally, similar to a crankshaft, that receives mechanical energy from their transmission and transfers it directly to their wheels – this reduces rotational inertia while increasing acceleration performance of drive vehicles.
Electric motors offer an enjoyable driving experience, superior performance and lower emissions than internal combustion engines. Regenerative braking utilizes electricity generated from their use to slow the vehicle by producing electricity itself and is highly efficient compared with internal combustion engine vehicles – in fact, electric traction motors alone in an EV produce less tailpipe pollution due to fuel combustion emissions versus exhaust emissions from combustion.
EVs can be powered by both an all-electric or plug-in hybrid (PHEV) drive system. All-electric vehicles operate solely off of electrical power until their batteries become depleted; at that point, their traction motor switches over to running on gasoline-fueled internal combustion engine power until recharged again. Plug-in hybrid EVs may be recharged via home 120V electrical outlets, charging stations or the grid; no tailpipe pollution emissions occur and they require less maintenance than their conventional ICE counterparts.
Control System
An electric motor vehicle’s internal combustion engine is replaced by a motor controller which directs both motor and battery performance for maximum efficiency. This electronic component contains an automotive-grade microcontroller as well as algorithms designed to maximize motor performance – such as Field-Oriented Control which takes into account both speed and torque to deliver precise motor control.
Sensors in this layer monitor the performance of both motors and an Energy Storage System (ESS), known as Power Control Module. Sensors monitor key parameters like temperature, voltage and current. Inverters convert direct current from batteries into AC voltage for use by motors and ESS.
The Hardware Abstraction Layer (HAL) is the core element of a motor controller. Here, an electric vehicle’s microcontroller gathers all data from various lower levels and transforms it to physical values before passing them along via input/output ports to various actuators/sensors in their lower levels.
Motor Control System
No matter if it’s an AC induction motor or brushless DC brushed motor, motor control systems are very similar. An automotive-grade microcontroller works alongside various algorithms that ensure each motor operates at its optimum performance. At the heart of an EV is its motor controller utilizing Field-Oriented Control algorithm or FOC; an advanced algorithm which considers both speed and torque to achieve precise motor control.
As one can imagine, the complexity of an electric vehicle’s control system is considerable. Consisting of multiple modules interacting with other vehicle systems like braking, heating and ventilation; its dynamic behavior depends on driver input such as accelerator or brake pedal position or gearbox setting and torque demands to switch states quickly and smoothly.
As soon as an accelerator pedal is depressed, the motor controller can send a signal to the inverter to start spinning the wheel and increase rotational velocity of motor; this increases regenerative braking ability of vehicle; finally the controller calculates optimal motor torque split for maximum regenerative braking and overall vehicle acceleration performance.
Range Selector
An electric motor vehicle (EV) does not feature physical gear shifts like traditional vehicles do; rather, its range selector acts like an electronic input switch to change how the drive system functions.
It’s an innovative concept because drivers can still enjoy the feel of shifting a car without risking accidentally engaging the clutch while moving in reverse, or having their engine start running when they intend to stop. Plus, since reverse doesn’t really “shift”, this vehicle will only allow its driver to change gear when it is safe.
An electric vehicle’s control system must be complex in order to respond rapidly to different conditions. For instance, it needs to quickly process feedback signals from its motor controller and motor in order to determine how much power is available for use by the vehicle; while also responding to operator commands to move at specified speeds or directions.
One reason many fear EVs may eliminate the need for manual transmission is that driving them will become less enjoyable. Toyota doesn’t share this view, as they recently patented mechanisms which would enable an EV to mimic shifting a traditional transmission down to every gear-grinding detail.
Patent claims demonstrate how a gear-shift control 21 designed as a foot switch 22 or 24 can easily and conveniently issue shift commands without disrupting driver concentration on traffic. Furthermore, manual shifts into preselected gear-range levels identified as optimal by electronic control unit 7 may also be released manually or into neutral or reverse travel positions (N and R).
While it may appear to be only a minor part of an EV’s overall functionality, its range selector is actually extremely important. It determines how long an individual battery charge lasts on a single charge and the total energy needed for transport from point A to B; this number determines how many batteries need to be carried and weight added for reaching an electric-only driving range.