Every time we talk about electric cars, what becomes the focus is the range, the quiet ride, the instant torque, and the fact that electric cars require only one forward gear. What is not so talked about is the heart of the electric car itself – the electric motor. When it comes to internal combustion engines, we can go on and on about every component between the intake and the exhaust. Intakes can have dual runners, cams can have two profiles, valve timing can be variable, you can have a single cam or a dual cam, pistons can be in different configurations, and the way fuel is delivered to the engine can also become a topic itself.

What about electric motors? Well, it takes time for most of us to study and familiarise this “new” method of vehicle propulsion. Manufacturers also do not seem to be to keen on sharing too much information on their electric motors. So, let’s take things easy and discover more as walk down this road of vehicle electrification. Similar to the ICE, improvements and new technologies will take time to be discovered and implemented. Even after more than 100 years of the ICE, we are still seeing innovation. Toyota just came up with a variable compression engine.

Let’s talk about electric motors.

Nissan Leaf power plant.

How many types of motors for electric cars are there?

2. So far.

AC Synchronous motor & AC Induction Motor.

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What does a motor look like?

Basically, there is a stator and a rotor.

What’s the difference between an AC synchronous motor and an induction motor?

The AC synchronous motor needs a DC supply for the rotor. The induction motor doesn’t.

What goes into the Motor?

A 3-phase AC power supply.

Where does the power come from?

The battery packs. Which is made up of Lithium Ion cells

How does the motor work?

For AC Synchronous:

1. A 3 phase AC power supply goes into the coils in the stator.
2. This creates a Rotating Magnetic Field (RMF).
3. The Rotor is powered by a DC power supply, creating a permanent magnet.
4. The RMF from the stator causes the rotor to rotate.
5. The rotor rotates in SYNCHRONY with the RMF.

For Induction/Asynchronous Motor:

1. A 3 phase AC power supply goes into the coils in the stator.
2. This creates a Rotating Magnetic Field (RMF).
3. The Rotor receives electricity via INDUCTION from the RMF. The rotor is constructed with iron core lamina to aid the induction.
4. The RMF from the stator causes the rotor to rotate.
5. The rotor will rotate with a lag. (ASYNCHRONOUS)

But power from the battery is DC?

That is why there is an inverter between the battery and the electric motor.

What electric cars use AC synchronous motors?

The Nissan Leaf, the Renault Zoe, the BMW i3, Tesla Model 3

What electric cars use induction motors?

The Tesla Model S, Tesla Model X, and Tesla Roadster.

How fast can an electric motor spin?

Up to 18,000 rpm, depending on the motor model. That’s faster than VTEC (yo!).

How do we judge performance figures for electric cars?

There is still the power rating in kilo Watts for the electric motor. 1kW is basically 1.341 hp.

A motor can either be induction or AC synchronous.

Range.

The overall weight of the car also plays a big part.

Can you further enhance the performance of an electric motor?

There’s still a lot of stuff to be messed around with. When more people get their hands on electric cars, we’ll get to see some creativity unleashed.

Is everything else about electric cars just the same as an ICE car?

There’s still a radiator. Tyres and suspension are still the same. Everything else is still pretty much the same.