Porsche’s Maximisation Of Efficiency, The Taycan’s Energy Recuperation Braking

Ever wondered how the Porsche Taycan generates new energy while driving, well, it does so when braking and this is possible with a unique recuperation management system.

First off, vehicles with an internal combustion engine convert kinetic energy into heat when the brakes are applied, which they’re unable to use. 

Electric vehicles, on the other hand, can recover a large portion of this energy, using the electric machines as generators when slowing down and store the power generated in the battery.

For example, the Porsche Taycan can use a significant amount of the braking energy for propulsion, which is referred to as recuperation. 

Moreover, kinetic braking energy increases twice as fast as speed, double the speed means four times the recuperation. 

As such, when braking from 100 km/h, the Taycan generates four times as much energy as when braking from 50 km/h. 

Significantly, this recuperation and the propulsion itself both play a key role in the efficiency of electric vehicles.

Porsche’s head of chassis development in Weissach, Ingo Albers, explained, “We incorporate the electric motors we produce in Zuffenhausen into the brake system for the purpose of energy recovery. Electric motors can generally be controlled in four-quadrant operation.”

In other words, an electric motor can work with both the rotation speed and torque running in the same positive direction. 

However, each electric motor can also function as a generator, in which case the motor continues to turn in the same direction, but is now powered by the wheels rather than powering them itself. 

It generates electrical energy, instead of consuming it. As it takes a lot to power the motor and thus turn the rotor against the magnetic resistance, this negative torque can be used for braking.

Therefore, the control units and power electronics of the electric motors in the Taycan are intelligently connected with the controls and logics of the brake control system. 

Meaning, the conventional hydraulic wheel brake and electric motors can slow down the vehicle together. 

The experts in Weissach have developed an intricate recuperation strategy. In milliseconds, the systems choose what percentage of the braking will be electric and what will be hydraulic. 

While the driver cannot feel the difference, they can see it in the power meter in the Taycan’s instrument cluster.

“Though, in extreme situations, such as full braking from a top speed in a fully loaded Taycan, a maximum braking capacity of more than two megawatts must be applied. The electric powertrain cannot do that alone. The conventional wheel brake is then applied to a higher degree,” furthered Albers.

Notably, around 90 percent of everyday braking is 100 percent electric, allowing the Taycan to recover energy. 

So, the conventional wheel brake may also be activated in such situations because the battery is already full and can no longer recharge through recuperation.

Regardless, thanks to the design of the electric motors and the electronics in conjunction with Porsche’s signature intelligent control, the Taycan can recuperate with up to 290 kW.

Fret not, the Taycan is still at the absolute top of the field according to Albers, as the hydraulic wheel brake is designed for high performance.

Conversely, some automakers have the electric drive’s recuperation system activated automatically the moment the foot is off the gas pedal, which is referred to as one-pedal driving.

Albers concluded, “We made the decision to go a different route with the Taycan. Drivers apply the brakes to slow down, which is a learned behaviour and it’s authentic. The driver receives consistent, predictable feedback. We have incorporated limited recuperation into the gas pedal, which the driver perceives to be efficient, smooth coasting particularly in rural areas. We also offer full integration of systems such as ABS and PSM.”

Always with the goal of maximum efficiency, the Taycan secures around one-third of its range with the recovery of brake energy, i.e., recuperation.

That said, with Porsche it’s a continuous optimization, as it even defines its own path when developing the first all-electric sports car, the Taycan.