How Does the KERS System in F1 Cars Work?
Reading Time: 4 minutesThe Formula 1 KERS kinetic energy system has links to how EVs recharge on the road.
Most track-based racecars have some tricks up their sleeve to edge out the competition. Being the pinnacle of motorsport, F1 cars are no stranger to complicated systems designed to make the cars go faster.
One such system is KERS. It was introduced in 2009 to support F1’s two-fold strategy to promote the development of environment-friendly and road car-relevant technologies in F1 racing but wasn’t widely adopted until 2011.
It has been present on every car since.
What Is KERS and How Does It Work?
KERS stands for Kinetic Energy Recovery System. Every time you brake to slow your car down, the kinetic energy is lost in the form of heat from the friction between the brake pads and the actual wheel. A KERS harnesses this energy instead and saves it to be deployed later when it’s beneficial to the driver.
There are two major types of KERS–mechanical and electrical. While any road car deployments might use a mechanical KERS, F1 constructors so far have all adopted electrical systems.
These are powered by an electric generator called Motor Generator Unit – Kinetic (MGU-K) that converts the heat produced from braking into electric energy. The converted electric energy is then stored in a battery with an FIA-regulated capacity of 2MJ per lap, called Energy Storage (ES).
When required, the driver can press a button on their steering wheel to deploy this power by merging it with the engine’s output thanks to an electric motor generally located at the front end of the crankshaft.
The total output of the MGU-K is also regulated by the FIA. Earlier systems were capped at 60kW (roughly 80bhp) but the limit was later raised to 120kW (nearly 160bhp) in 2014 to balance out the weaker 1.6-litre V6 which was replacing the older, more powerful 2.4-litre V8 engine.
While the exact specifications of an F1 constructor’s KERS system, called simply ERS in the sport, would be a closely guarded secret, the aforementioned system does form the basics of an electric KERS.
MGU-K vs MGU-H
An MGU-K shouldn’t be confused with an MGU-H (Heat), which is a separate electronic device forming the remaining part of an F1 ERS. It’s a similar concept, but instead of capturing the heat from the brakes, it captures thermal energy generated by the engine’s exhaust instead.
Combining the two systems means that the battery can now be charged even when the car is not actively under braking. Additionally, since the FIA doesn’t impose any regulations on the MGU-H, any energy generated by it can be fed directly to the MGU-K essentially bypassing any regulations on the latter.
The MGU-H also solves turbo lag by using a motor to power the compressor and hence doesn’t require the turbine to wait for the exhaust gases. The two systems combined form the ERS or Energy Recovery System on an F1 car.
As mentioned before, power deployment to the wheels is controlled by a button on the driver’s steering. Teams often help drivers brake more aggressively or shift gears in a certain manner to recharge the maximum amount of energy every lap or deploy it more tactically.
Is ERS Different From Regenerative Braking?
So far, if an ERS sounds a lot like the regenerative braking you see in electric cars on the road, you’re not wrong. They are essentially the same thing. Both systems harness a vehicle’s braking to recharge the car battery, which is then used to power the wheels.
However, an ERS is far more complicated and powerful than the simple regenerative braking applications you see in road cars. Road cars have regenerative braking systems that are geared towards charging the battery as much as possible without making the driver brake all the time to get anything out of the system.
This has helped achieve what is called single-pedal driving in most electric cars. When you let go of the gas, the system kicks in and slows the car down with an aggression that’s often controllable by the driver.
This ensures that the battery is being charged as much as it possibly can be during day-to-day commutes and road trips. An ERS instead would focus on charging the same battery with as less braking as possible, hence the combination of the MGU-K and MGU-H. The deployment of the stored energy is far more aggressive as well.
KERS in Road Cars
So could you drop in a KERS in a regular road car and have vehicles with an amazing range? Not exactly, considering an ERS is far more aggressive than regular regenerative braking, there’ll be a couple of problems, starting with the battery.
Batteries used in an ERS are far more resistant to fast charging and discharging as they bear the brunt of an F1 car hurling more than 60 laps around a track. They can take in large amounts of power to recharge themselves quickly, and then provide an equally large amount of power to add to the car’s total output.
Road car batteries are geared towards durability, longer life to sustain more charge cycles and more importantly, safety. That’s not to say an ERS isn’t safe, it’s just that a regular road electric or hybrid car’s battery won’t be able to keep up with the system.
Regenerative braking systems on cars also don’t generate nearly as much power to put back in the battery as it takes to move the car itself. This means that the charge gained is much smaller than what an MGU-K would provide.
Finally, the energy deployment is also rather different, especially if you’re driving a hybrid car, where electric systems are often meant to replace the car’s gas engine-produced power. On electric cars, there isn’t any electric deployment to do at all as the system only charges the battery.
In contrast, ERS in F1 or KERS, in general, is focused towards deploying the stored electric power to the engine’s existing output.
The Future of KERS
As advancements in F1 make batteries and regenerative systems more efficient, they eventually trickle down to the road cars we drive every day. This means that we will get cars that recharge faster, with improved range.
Until then, you can be proud of your vehicle’s existing regenerative systems for saving as much energy as they already do.
Reference: https://www.makeuseof.com/how-the-kers-system-in-f1-works/