▲Professor Kim Pil-su, Department of Future Automobile Engineering, Daerim University

“Electric car prices can be lowered with multi-speed automatic transmissions”

Electric vehicle reducers waste a lot of energy… Use relatively high capacity motors
High-speed transmission with 5 or more gears, all-solid-state battery, and increased driving range expected

The latest buzzword in electric vehicles is ‘half-price electric vehicles.’

Since the end of last year, sales of electric vehicles have been slowing down due to concerns that the overall cost-effectiveness of electric vehicles is lower than that of hybrid vehicles.

In addition to the rising cost of charging electricity, decreasing subsidies, and inconvenient charging infrastructure, there are many negative aspects to electric vehicles, such as electric vehicle fires.

There is an active movement to offset these shortcomings by significantly reducing the price of electric vehicles through 'half-price electric vehicles'.

The price of electric vehicles is gradually falling, with Chinese electric vehicle manufacturers and Tesla also starting to implement 'half-price electric vehicles'.

In the Chinese market, many electric vehicle manufacturers have already gone bankrupt due to competition to lower electric vehicle prices, and now only about 100 companies remain.

It is expected that only 10 to 20 companies will remain in the near future.

The decline in electric vehicle prices that has hit the global market has also affected the domestic market. It can be done without exception.

Since the latter half of last year, the Model Y imported into Korea from Tesla's Shanghai factory has been sold at a significantly lower price with fewer options and Chinese-made lithium iron phosphate batteries.

This trend is expanding into global markets.

Of course, there are limits to what global production companies can do.

As mentioned above, there are various methods being used, such as using lithium iron phosphate instead of lithium-ion batteries, improving the manufacturing method to use the gigapress method, boosting the automobile voltage, and using ferrite motors, but there is a significant limit to reducing the price.

The game changer that will make these 'half-price electric vehicles' a reality is the inclusion of high-speed automatic transmissions in electric vehicles.

Current electric vehicles use the characteristic of changing the high speed rotational speed of the motor to a low speed through a reducer and transmitting it to the wheels.

On the other hand, the use of reducers is very inefficient and wastes a lot of energy, so it requires a relatively high capacity motor and a larger battery, making it heavy and expensive.

In order to use a transmission in an electric vehicle, the basic characteristics of ‘light and compact’ are required.

It had to be light, thin, simple and compact, without using hydraulics.

This means that it must be developed as an integrated module with a small overall size when combined with a motor.

About five years ago, Porsche was the first in the world to implement a two-speed transmission in the rear wheels of its Taycan electric sports car, and it received positive reviews for its high efficiency.

The Volkswagen Group has since equipped the Audi e-tron with the same two-stage system.

Here is a Taiwanese motorcycle The manufacturer, Camco, has been mass-producing a two-speed transmission for electric motorcycles for four years, and Eaton, a global large-capacity transmission company in the U.S., plans to install a four-speed transmission it has developed in an electric bus at the end of last year.

This is about all the electric vehicle transmissions used in the global market.

If electric vehicles are properly equipped with high-speed transmissions of 5 or more speeds as development progresses in the future, it can be said that a revolution in electric vehicles will occur.

We can expect effects that go beyond the commercialization of all-solid-state batteries.

Equipping electric vehicles with these high-speed transmissions can increase their driving range by at least 30% and up to 50% with the same battery capacity.

This alone is already groundbreaking.

Additionally, climbing ability has been increased, so you can easily climb any hill no matter how high it is.

In this case, in the case of a general electric vehicle without a transmission, a large-capacity cooling device must be installed to lower the motor and battery temperature as the motor temperature rises rapidly, but if a high-speed transmission is installed, the motor temperature is maintained at around 60~70℃, allowing the vehicle to climb higher hills without requiring a lot of energy.

It can be said to be able to maintain normal room temperature even without a cooling device.

Ultimately, it can have a double benefit of simplifying the device, reducing its weight, extending the life of the motor, and reducing costs by eliminating the need for a cooling device, as well as increasing the driving range while reducing the battery capacity.

In other words, it is playing a leading role in the implementation of the previously mentioned 'half-price electric vehicle'.

'Half-price electric cars' will soon be a reality.

Korean companies are leading the way in the global market I hope to play a leading role.