Energy Recovery System Overview

How the Energy Recovery System (ERS) works

INFINITI is technical partner of the Renault Sport Formula One Team for the co-development of the Power Unit’s Energy Recovery System (ERS), which incorporates two motor generator units and a battery.

After five years as sponsor in Formula One, in 2016 INFINITI made the daring move to become a technical partner for one of the most sophisticated technologies in motorsport, leveraging its expertise in hybrids and contributing engineering resources to the Renault Sport Formula One Team.

The ERS recovers otherwise lost energy and either deploys it as acceleration performance immediately or stores it for later use. The ERS adds some 160 hp to the Power Unit’s total power output of over 900 hp.

ERS components include:

MGU-K

The Motor Generator Unit-Kinetic (MGU-K) is connected to the crankshaft of the internal combustion engine.

Under braking, the MGU-K operates as a generator, recovering some of the kinetic energy dissipated during braking. It converts this into electricity that can be deployed throughout the lap (limited to 120 kW or 160 hp by the rules).

Under acceleration, the MGU-K is powered from the battery and/or from the MGU-H and acts as a motor to propel the car.

MGU-H

The Motor Generator Unit-Heat (MGU-H) is connected to the turbocharger. Acting as a generator, it absorbs power from the turbine shaft to convert energy from the exhaust gasses that spin the impellor and shaft, allowing the compressor to generate energy.

The electrical energy can be directed either to the MGU-K or to the battery to be stored for later use. The MGU-H is also used to control the speed of the turbocharger to match the air requirement of the engine (e.g. to slow it down in place of a wastegate, or to accelerate it to compensate for turbo lag).

One major challenge here is that the MGU-H mechanically connects to the turbocharger spinning at speeds more than 100,000rpm, so it needs a highly complex design process to manage the rotational dynamics.

High rotational speeds produce the alternative current at a very high frequency, so the inverter design must be optimized for this specific requirement.

Battery or energy store

Recovered energy can be consumed immediately if required, or used to charge the battery. The stored energy can be used to propel the car with the MGU-K or to accelerate the turbocharger with the MGU-H.

Within a Formula One car, the energy store is installed directly next to and in front of the engine, low down and at a safe distance from the driver’s seat, encouraging optimal weight distribution and safety in a race environment setting.

Animations

See animations of the ERS components in action in the gallery.