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What Are the Most Popular EV Motors?

Tesla - electric vehicle (EVs)

People are progressively becoming more interested in electric vehicles (EVs). They dislike budgeting for the cost of gas and feel concerned about the impact of fuel-reliant cars, for example. Some individuals also embrace the idea of being early adopters of the newest innovations.

Electric vehicles appeal to them because they allow being on the cutting edge of progress.

The Broad EV Motor Categories

There are two main types of electric motors that you’ll see associated with EVs. Let’s go over them here.

Asynchronous Motors

Asynchronous motors — or induction motors — have electrically-powered components called stators that create rotating magnetic fields. A stator is a coiled wire within the engine. It features a magnet on a shaft. As the magnet turns, it generates alternating current.

The resulting magnetic field pulls the accompanying rotors, making them turn. It’s this action that creates the energy that turns the car’s gears, and ultimately, its wheels.  Engineers often choose these EV motors for vehicles that people will drive at high speeds for prolonged periods.

Synchronous Motors

In the synchronous motor, the rotor behaves as an electromagnet and creates a magnetic field. Whereas an induction motor’s stator fields turn faster than the rotor, the rotor and stator turn at the same rate in a synchronous motor. The overall speed depends on the current’s frequency that powers the motor.

Electric vehicles marketed to people interested in urban driving often have synchronous motors. That’s because they’re well-suited to frequent stopping, as well as starting at slow speeds, as someone might do during high-traffic times.

How Reliable Are Electric Motors?

Even though electric vehicles are relatively new, people use electric motors in various industries that require continuous operation from machinery.

Some industrial electric motors contain dozens or hundreds of parts that work together to ensure functionality. Aspects like temperature, humidity, and excessive dust can all shorten the life of an industrial electric motor. However, company leaders typically subject the components to periodic testing as a preventive measure.

As far as EVs go, their main moving part is the armature, which is the component containing the coils. Most such vehicle warranties centre on driving time. For example, you may see warranties for 80,000-100,000 kilometres or miles, depending on the metric used in your market.

The Specific Types of EV Motors

Beyond the categories of electric motors mentioned earlier, there are three types most often used in EVs: brushless asynchronous induction motors, brushed externally excited synchronous motors, and brushless permanent magnet synchronous motors.

Brushless Permanent Magnet Synchronous Motors

Brushless permanent magnet synchronous motors are like the induction motors mentioned earlier in that they have stators and rotors. Moreover, the rotor features rare-earth metals like neodymium and dysprosium. Those are ferromagnetic materials, which enable permanent magnetization.

A controller activates the stator’s electromagnetics in sequence, creating a magnetic field that turns around the rotor. Then, the rotor’s magnetic fields try to keep up with the rotating field at the same speed that it moves — thus the “synchronous” part of the name. These actions make the rotor spin.

This type is the most common type of EV motor, seen in cars such as the Nissan Leaf and vehicles with some autonomous features, such as the Tesla Model 3. Many people hope that driverless cars will change our society by improving transportation options while reducing automobile ownership.

Brushless Asynchronous Induction Motors

This type of motor has stators and rotors consisting of electromagnetic coils. As the stator’s magnetic fields rotate, they create an electric current and magnetic field in the rotor’s windings. This happens when the stator fields turn slightly faster than the rotor.

The Tesla Model S is one example of an electric vehicle that has this type of motor. You’ll also see this kind of induction motor in high-performance cars since they can produce more power than the ones with magnets.

However, an advantage of the magnet-type synchronous motors discussed earlier is that they are more efficient than those using induction motors. That’s because there is no need to use electricity to create the magnetic field. The magnets are always activated. Designers commonly select magnet-type motors for smaller and lighter automobiles.

Brushed Externally Excited Synchronous Motors

These motors also have stators and rotors, but the main difference between this category and induction motors is that the rotors connect to a DC power source via a rotating electrical contact called a slip ring. That approach generates the magnetic field, making these motors function like the permanent magnet types.

The Renault Zoe is one example of a vehicle that uses that type. China is the primary source of rare-earth metals, and manufacturers face increasing difficulty sourcing them for permanent magnet motors. There’s an ongoing push to build motors that function like those options but don’t require special metals.

These externally excited types are one solution. As they become more widespread, you should see them more frequently in cars that formerly had permanent magnet-style motors.

EV Motors Are Part of a Bigger Picture

When people shop for electric cars, they don’t only think about the EV motors in the models on their shortlists. They also care about battery life, charging time, safety features, and driver assistance options.

However, this overview shows that electric motors are crucial parts of today’s electric vehicles. Each type functions differently and provides performance best suited for certain usage. Thus, if you’re thinking about buying an electric car soon or may work on projects concerning them, understanding how the motors work is essential for positive outcomes.

Emily Newton is the Editor-in-Chief of Revolutionized Magazine. She has over six years experience writing articles for the tech and industrial sectors. Subscribe to the Revolutionized newsletter for more content from Emily at https://revolutionized.com/subscribe/
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