Why Do Electric Cars Use AC Motors? (9 Good Reasons)

An electric car uses an AC motor to power its wheels. An AC motor is an induction motor that relies on the changing magnetic fields it generates.

The current-carrying magnetic field is created by a rotating coil (the stator), which interacts with a magnetized piece of metal (the rotor) to cause the rotor to spin at high speed.

The process generates rotational kinetic energy that’s transferred in the form of torque on the output shaft.

Let’s explore the top reasons electric cars use AC motors.

Table of Contents

1. AC Motors Have a Regenerative Feature

AC motors act like generators. In this sense, they are regenerative, meaning they can absorb and return energy. The process is done by reversing the current direction in the coil, where the rotor becomes a stator.

The spinning rotor generates a magnetic field that induces a current in another rotating wire.

The regenerative feature operates as a generator, which brings power back to the vehicle’s battery.

Therefore, the vehicle can recharge itself as you drive.

The main benefit of this feature is that, instead of just converting energy into motion, the motor can also convert it back into electricity.

It means you will have less drain on the battery because the AC motor can recharge its battery while you drive.

DC motors can achieve this but are not as efficient as AC ones.

They would also require modifications, making them a costly and complex option. AC motors achieve this function without extra modifications and are considered an ideal solution for electric vehicles.

2. AC Motors Offer a Better Grip in Rough Terrains

The AC motors in electric vehicles are highly adapted for rough terrain.

They offer high torque as well as high speed, which makes them ideal for these conditions. The motors have a large power output; therefore, they would overcome the tire resistance experienced in these locations.

If the power output in a vehicle is not high enough to cause wheel rotation, the car will experience challenges moving in rough terrain.

The power generated from the AC motor is higher than that from the DC motor. It offers more torque, making the electric car more powerful and robust in rough terrain.

AC motors are lighter.

Therefore, the vehicle will not experience a lot of added weight when it’s in motion.

It would, therefore, be easier for the electric car to roll through rough terrain than other vehicles using heavy DC motors.

3. AC Motors Offer Increased Power Output

One of the main advantages of AC motors is their enhanced power output, which is ideal for electric vehicles.

The power output in an electric car determines its acceleration and breaking speed.

A vehicle with an enhanced power output would feel faster due to how it responds to a push on the acceleration pedal. Therefore, AC motors make these vehicles more efficient regarding speed.

Varying frequency changes the speed of an Ac motor, thus determining how fast it can be. The higher the frequency, the quicker the motor spins.

A higher frequency would also increase the inertia and power output, thus resulting in faster acceleration.

The frequency is measured in hertz.

4. AC Motors Are Long-Lasting

When buying a vehicle, the aspect of lifespan is a major consideration to ensure the car is worth your investment.

You do not want to buy a vehicle needing repair after a few years. In case of a mechanical failure, an AC motor is replaced with a new one without any need to swap out batteries or control units. Therefore, electric cars use AC motors due to their enhanced lifespan.

AC motors do not experience damaged joints, broken gear teeth, and twisted shafts. They do not have commuters and brushes like in the case of DC motors.

These components require excessive maintenance and can affect the lifespan of your vehicle.

It would also cost you a lot to carry out regular check-ups. Fortunately, AC motors do not have these features and, therefore, require minimal maintenance.

They are highly rigged, which plays an important role in enhancing their lifespan.

The motors would last the vehicle’s lifetime, making them the best choice for electric cars.

5. Electric Vehicles Require High Torque and High Speed

AC motors are ideal for quick acceleration and high torque.

They are a perfect fit for electric vehicles since they require exceptional torque to increase their speed.

Torque refers to the rotational energy generated by the motor to power the wheels. It enables the vehicle to accelerate quickly.

AC Motors have no brushes, a factor that increases their torque speed.

A brush is a component that generates resistance from a rotating object. The resistance happens when the rotor spins and the magnetic field induces a current in the stationary stator.

The spinning of the rotor causes commutation in the stator.

The brushes, therefore, reduce torque and power output by a considerable degree. They are also prone to damage at a high RPM.

Without these brushes, AC motors have become an ideal choice for electric cars to meet the need for speed.

A vehicle with low torque requires pushing until it gains enough speed to start independently.

The process is not the best option for electric vehicles since they require minimal push and, therefore, should have high torque.

Therefore, AC motors offer high speed and torque, making them the ideal choice for electric cars.

The factor is ideal for electric vehicles since they require quick speed changes. AC motors show high torque at low speeds, making them ideal for quick acceleration.

The speed change is achieved by accelerating from zero to the desired rate in a short time.

In comparison, DC motors experience a slow change in speed.

Acceleration and torque are the two important features of an AC motor. They work on alternating current and therefore are much quicker to respond to the driver’s demand, a feature that normally attracts people to buy an EV as they want their car to be quick and fun to drive.

The torque on an AC motor is determined by the power required to turn the rotor and can be increased by fitting a larger rotor hence increasing the power.

DC motors only have one rotating field, which rotates concerning an “E” axis mounted parallel to the frame.

However, an AC motor has two rotating fields which are radially offset from each other and are mounted parallel to an “X” axis.

The two fields rotate at different speeds and produce different amounts of torque when the motor is switched on.

6. AC Motors Do Not Damage the Environment

The key aspect of electric vehicles is that they do not pollute the environment.

Unlike gas-fuelled vehicles, they run on AC motors that use magnetic fields to generate energy.

Therefore, they don’t produce emissions that could pollute the air.

Therefore, they are a great option for vehicles whose manufacturing aims to keep the environment clean.

The AC motor features a best-in-class efficiency rating of 94%, meaning that its conversion rate is 94% in converting electrical energy into mechanical energy. The speed is compared to the best DC motors, which have an efficiency rating of 75%.

The higher efficiency means that the AC motor doesn’t waste as much energy as other motors and therefore is more environmentally friendly.

7. AC Motors Reduce Noise Pollution

Most people driving an electric vehicle are aware of the noise created by the engine and tires.

Electric cars are known to be significantly quieter than traditional gas-powered vehicles.

The use of AC motors plays an important role in reducing noise in vehicles. These motors are much quieter than DC ones and generally have a lower amount of vibration.

Hence, this makes it ideal for electric vehicles whose design is to produce minimal noise pollution.

8. AC Motors Are Programable

Did you know that you can set the parameters of an electric vehicle to suit your driving style? The process is made possible by the use of AC motors. The AC inverters are designed to match the motor you buy with.

The design allows you to set all the necessary parameters according to your preferences.

For instance, if you want to stretch the vehicle’s range, set the battery’s voltage to a minimum for driving and maximum for regen.

The technology is not available in gas-fuelled vehicles.

Hence, electric car manufacturers find AC motors ideal in creating this major difference from other cars. DC motors wouldn’t be ideal in this case because they are not programmable.

Hence, they offer minimal options to the vehicle’s owner or driver.

9. AC Motors Enhance Safety

Safety is important in all EVs, particularly in lithium-based batteries used for storage and propulsion.

EVs use AC motors to ensure that they don’t overheat, which has been a problem with lithium batteries.

An AC motor also decreases costs by reducing the need for cooling systems, although some have installed condensers.

EVs use AC motors for their economic, environmental, and safety benefits. Since there is a constant supply of electricity, it doesn’t need to be stored in batteries or flywheels and can be utilized immediately when the car is moving or stopped.

In an AC motor, the voltage is switched on and off per the speed required to extract energy from it.

The feature makes them safe for use in EVs because they produce less heat thus keeping the surrounding parts cool.

In case of an accident, there is no risk of batteries exploding.

Effective AC motor cooling systems are important because the motors in some vehicles, such as the Tesla Model S, are placed directly beneath the battery.

They are also necessary because the batteries and motors share a common coolant system run by the air circulation fans and can become very hot during regeneration.

Therefore, higher speeds require better cooling to enable longer running time before heat build-up occurs.

Hence, the AC motor’s design and power train are essential for the efficient operation of EVs.

Given the current technological advancements, the need to speed and acceleration is common feature car buyers are looking for.

The best way for EV manufacturers to achieve this is by using AC motors.

Ac motors have many benefits, making them ideal for use on EVs.