Electric motors

Electric cars convert energy from the high-voltage battery into motion through one or more electric motors. The motor can also reverse this energy flow during deceleration and return electricity to the battery through regenerative braking.

Permanent-magnet synchronous motors

A permanent-magnet synchronous motor (PSM) uses permanent magnets in the rotor. Its magnetic field follows the rotating field created by the stator, which gives precise control, high power density and strong efficiency across much of the operating range.

Audi commonly uses a PSM as the main rear motor in newer electric platforms. Because this motor handles most everyday driving, its efficiency has a direct effect on consumption and range.

Asynchronous motors

An asynchronous motor (ASM), also called an induction motor, creates the rotor’s magnetic field electrically instead of using permanent magnets. It can be inactive with little drag when no torque is required, making it useful as a secondary motor in an all-wheel-drive system.

On quattro versions of the Q4 e-tron, Q6 e-tron and A6 e-tron, an ASM at the front can engage quickly when the car needs more traction or power. The rear PSM remains the primary drive unit during efficient cruising.

Inverter and transmission

The battery supplies direct current, while the traction motor operates with controlled alternating current. A power-electronics inverter converts and regulates that energy many times per second according to accelerator position, vehicle speed, available grip and thermal limits.

Audi’s electric drive units normally combine the motor, inverter and a single-speed reduction gear. An electric motor delivers useful torque from standstill and across a wide speed range, so a multi-speed gearbox is usually unnecessary. The e-tron GT is an exception, using a two-speed transmission on the rear axle to combine launch performance with high-speed efficiency.

Regenerative braking

During regeneration, the motor works as a generator. The vehicle’s kinetic energy is converted back into electrical energy instead of being dissipated entirely as heat in the friction brakes. The achievable regeneration level depends on battery temperature, state of charge, grip and the selected driving mode.

Audi blends regenerative and hydraulic braking so the requested deceleration remains predictable. Strong braking or a full battery requires a larger contribution from the conventional brakes.

Different motor layouts

• Single-motor rear-wheel drive: prioritizes efficiency, range and lower weight.
• Dual-motor quattro: adds a front motor for traction and higher system output.
• Performance layouts: may use two permanently excited motors or, in models such as the e-tron S, three motors for more precise torque distribution.

See the model-specific motor chapters for the Q6 e-tron and A6 e-tron, or read about the underlying electric vehicle platforms.