Ever noticed how quiet and, quite frankly, fast electric vehicles (EVs) travel along the roadways without a smoke trail? For electric vehicles with motor placement under the hood, that’s where the vehicle generates the all-powerful torque! But some vehicles have their electric motor placed near the wheels to free up the frunk (front trunk) for cargo space.
So, under the hood or near the wheels is where you find the electric engines powering EVs. But the question remains: how do electric engines work? Electric engines work differently from an internal combustion engine (ICE). Unlike ICE, it doesn’t burn fuel to generate power.
Read on as this post explores how electric engines work. The post will go through the basics of EVs and explain how EVs are different from traditional vehicles.
The Basics of Electric Cars
Electric vehicles, also called battery electric vehicles (BEVs), have essential components working together to make the vehicle functional.
Key Components of an All-Electric Car
Traction Battery Pack
Acting as the bloodline providing energy to the vehicle, the battery pack stores the electricity the vehicle needs to work. Every EV has this essential component, and the battery size varies across the board. You’ll find EVs with a 20 – 100 kWh battery size. Of course, a bigger size means more charge storage and increased range.
Electric Drive System
Electric motor(s) is the very beating heart of an electric vehicle. It is the engine converting electrical energy from the battery pack to mechanical energy that moves the car. While some EVs have only one motor, many EVs have multiple motors for better performance.
Power Inverter
It’s an essential component converting battery power from DC to AC for the electric motor(s). It makes sense that EVs use AC motors, especially PMSMs, for a higher efficiency. These motors convert up to 95% of battery energy into mechanical energy.
What’s more, it’s easier to control the RPMs of AC motors; you only need to vary the frequency of the AC power supply. There are other reasons why EVs use electric motors to drive the vehicle.
Charging System
It’s a system that draws electricity from the charging station to add energy to the battery pack. You connect your car’s charger to this system and let your car charge for some time, depending on the charging station’s speed.
How Do All Electric Cars Work?
Knowing the essential EV components allows you to know how EVs work. You’ll understand which component does what. The battery pack supplies DC power to an inverter, which converts it to AC. The inverter supplies the AC electricity to the electric motor.
AC electricity flows through a stator comprising a conducting coil in the motor. The flowing current creates a magnetic field that interacts with the permanent magnet in the motor; this interaction causes the motor shaft to spin. The inverter controls the AC frequency, thus controlling the motor spinning speed.
EVs use different mechanisms to transfer this rotary movement to the wheels. But, the most common mechanism is the use of a single gear reduction. It is a different transmission from the multi-gear transmissions in traditional vehicles. It trades the motor’s high RPM for more torque that can accelerate the vehicle.
What Types Of Electric Cars Are There?
Electricity supplies clean energy to power vehicles. And this fact has spurred the development of different types of electric cars. However, many people only know one type of electric vehicle: Battery Electric Vehicles (BEVs). So far, that’s the type we’ve discussed how it operates. But buckle up, as we’ve got more types!
Plug-in Hybrid Electric Vehicles (PHEVs)
These vehicles have a fuel tank in addition to a battery pack. Since they use two energy sources for propulsion, they’re a hybrid. The battery pack supplies electricity to the electric motor.
The vehicle travels some distance on electricity. When the power runs low, the internal combustion engine takes over to cover the rest of the distance. You can charge the battery pack in a charging station to go electric once more.
Hybrid Electric Vehicles (HEVs)
These electric vehicles also have an engine in addition to the electric powertrain. Unlike the plug-in hybrids, this one doesn’t require charging at a station; the gasoline engine produces enough electricity to charge the battery pack.
What’s more, these vehicles have regenerative braking that adds more charge to the battery pack. These vehicles have more range than traditional vehicles.
Fuel Cell Electric Vehicles (FCEVs)
Although still a new technology, fuel cells propel some electric vehicles. These vehicles have a technology that fuses hydrogen fuel with oxygen to produce energy. This fusion produces water vapor, which comes off the vehicle’s tailpipe.
If you have this vehicle, you drive into a hydrogen refueling station. Although this vehicle has more range than battery electric vehicles (BEVs), it faces the challenge of scarce hydrogen stations.
How Does the Electric Car Engine Work?
Understanding how the electric engine works requires you to look at the workings of the electric motor. You also want to understand the various types of electric motors and their parts.
What Is an Electric Motor?
An electric motor is a device that uses AC electricity to spin the wheels. That makes it essentially the engine of an electric vehicle. The motor uses the principle of electromagnetism to function. If you take the motor apart, you’ll find it has a permanent magnet inside.
However, you’ll find some motors have an electromagnet; the polarity of this magnet is switchable to reverse the spinning. The permanent or electromagnet is in the stator. The rotor, on the other hand, is a shaft surrounded by a coil of copper wire.
If you step on the EV’s accelerator, you’re allowing electricity to flow through the copper wire windings. Now, you have two magnets inside the motor interacting to spin the motor shaft.
Types of Electric Motor
Although electric vehicles mostly use a specific type of electric motor, different types exist, and all can convert electricity into motion:
DC Electric Motor
In addition to use in electric vehicles, this motor powers some tools and drills. It relies on a commutator and brushes to keep the current flowing through the coil surrounding the rotor. The rotor coil and stator magnets constantly attract each other, resulting in the motor spinning.
AC Electric Motor
This is the motor you find in most electric vehicles. As alternating current passes through the conducting coil surrounding the shaft, it creates a magnet that interacts with the permanent magnet, resulting in the rotor spin.
- Synchronous Motors
It’s a type of AC motor. It spins at the same speed as the speed of the rotating magnetic field in the stator. If you want constant speed from a motor, this option is great for industrial use. These are the motors that power EVs!
- Induction Motors
You often find these motors in home appliances. They spin slower than how the rotary magnetic field rotates, offering a reduced speed.
Brushless DC Motor
Although some cars use it, you often find it in drones and PC cooling fans. Their stator has a controllable electromagnet, and the rotor has a permanent magnet. This arrangement offers precise speed control and high efficiency.
Stepper Motors
If you’re making a machine like a 3D printer or robotic arm, you don’t want to use a motor that spins fast instantly; a motor that spins in sequence is the best option. Stepper motors have a sequence of conductive coils to spin in sequence. These motors have the best precise control.
Parts of an Electric Motor
An electric motor has parts, each performing a specific function:
Stator
It’s the part housing everything else in the electric motor. The essential components it houses are electromagnets and permanent magnets. Usually, it has a permanent magnet that creates a permanent magnetic field.
Rotor
It’s connected to a shaft going through a coil made of a conductive wire such as copper. As electricity passes through the coil, it creates a magnetic field around the rotor, causing it to spin.
Bearings
The bearings support the rotor and ensure it spins with significantly reduced friction. The motor has a lot more parts playing an essential role in enhancing performance.
EV Batteries
EVs have a large battery pack underneath the floorboard to shift weight to the lower sides of the vehicles. This weight makes the EV very stable, even when going around a corner. The battery pack supplies electricity to various components, with the motor taking the biggest chunk. At some point, the battery power runs low and you’ll charge it.
How Does Charging Work?
First, you take the vehicle to a charging station; this station can be in your home or a public space and is connected to an electrical grid. You take a charger and hook it to the car’s charging port. The charger converts the AC electrical power to DC since your EV’s battery only stores DC power.
The charger puts charge into the battery at different volts, depending on how depleted the battery pack is. If the battery is very low, the charger pushes 400 – 450 volts to charge the vehicle fast; this is bulk charging.
As the percentage approaches 80, the charger puts more charge at reduced volts; this is absorption charging. After your battery pack is 100%, the charger only maintains this percentage by float charging.
EVs and Their Range
Your vehicle’s driving range depends on its battery capacity and driving conditions. If the battery has a bigger size (in kWh), it carries more charge and increases the car’s range. However, the range spectrum of EVs varies from 200 – 350 miles on a full charge.
Extreme weather also affects range. Extreme cold reduces the power supply from the battery pack. On the other hand, extreme heat forces the air conditioner to use more battery power.
Conclusion
Electric vehicles don’t have an internal combustion engine, but they provide efficient transportation. They rely on an electric motor or more motors to drive the wheels. The motor consumes more power from the battery since it’s the main electrical component driving the vehicle.
After driving some distance, your vehicle will run low on battery power. While some vehicles require a charge to travel more, hybrids switch to alternative energy sources and cover the rest of the distance. They seem better than fully electric vehicles. However, they pollute the environment since they also use fuel for propulsion.
Buy an electric vehicle that suits your driving habit and style and travel conveniently without harming the environment.
