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Apr 08, 2023

Mercedes

Mercedes-Benz revealed the latest member of its electric lineup, the EQE

Mercedes-Benz revealed the latest member of its electric lineup, the EQE SUV—which the company positions as the multipurpose variant of the EQE executive sedan. AMG also presented the 2024 AMG EQE SUV, the performance version of the EQE SUV and the first all-electric performance SUV from Mercedes-AMG.

EQE SUV (European model)

The EQE SUV is one of the most spacious representatives of its class, yet it is more compact than the EQE Sedan; at 119.3 inches, it has a wheelbase that is 3.5 inches shorter. The external dimensions are 191.5/76.4/66.4 inches (length/width/height).

As the fourth model after the two EQS and EQE Sedans, as well as the EQS SUV, the EQE SUV uses the new all-electric platform. Depending on the vehicle equipment and configuration, WLTP ranges of more than 550 kilometers (342 miles) can be expected for European vehicles (with the exception of AMG models).

All EQE SUVs have an electric drivetrain (eATS) on the rear axle. The versions with 4MATIC also have an eATS on the front axle. In the 4MATIC models, the Torque Shift function ensures intelligent, continuously variable distribution of drive torque between the rear and front electric motors and thus the use of the most efficient eATS in each case. The modular drive concept enables high overall performance and a long range.

To increase the range further, the electric motor at the front axle can be completely decoupled. This step is undertaken by what is known as the Disconnect Unit (DCU). The intelligent disconnection system works complete automatically depending on the driving situation and the required output. At low loads, the DCU switches into 4x2 driving mode, and both the electric motor and the relevant transmission at the front axle cease operation. This ensures that the drag losses otherwise normally experienced are largely eliminated.

2024 AMG EQE SUV (European model shown)

The electric motors on the front and rear axles are permanently excited synchronous motors (PSM). On a PSM, the rotor of the AC motor is fitted with permanent magnets and therefore does not need to be supplied with power. The magnets—and thus the rotor—follow the rotating alternating current field in the stator windings.

In the EQE SUV, Mercedes-Benz uses a pull-in winding for a particularly strong magnetic field. The motor is referred to as synchronous because the rotor turns at the same rate as the magnetic field of the stator. The frequency is adjusted in the power electronics inverters to the speed requirements of the driver. The advantages of this design include high power density, high efficiency and high power constancy. The motor on the rear axle is very powerful due to the six-phase design: it has two windings with three phases each.

A water lance in the shaft of the rotor cools it from the inside. Other cooling elements in the cooling circuit are fins on the stator, a needle-shaped pin-fin structure on the inverter and a transmission oil cooler. This also brings more efficiency during cold driving, because the heat exchanger then serves to heat the transmission oil and thus reduces friction in the transmission.

The EQE SUV offers several variants of energy recovery by means of recuperation. In this process, the high-voltage battery is charged by converting the mechanical rotary motion into electrical energy during overrun or braking mode. The driver can manually select the deceleration in overrun mode in three stages (D+, D, D-) as well as the coasting function via shift paddles behind the steering wheel. Also available: DAuto.

ECO Assist also offers situation-optimized recuperation; deceleration is so strong or weak that it ultimately results in the most efficient driving style. Recuperative deceleration is also used as far as possible for vehicles detected ahead until they come to a standstill, for example at traffic lights. The driver does not need to press the brake pedal for this; literally one-pedal driving.

The magnets are arranged inside the rotors in an NVH-optimized way (known as 'lamination'). This also reduces the use of rare earths. The shape of the winding, the stator tilt, also causes less vibration, especially at low speeds. The coils in the stator are at an angle in relation to the permanent magnets of the rotor. Otherwise, what is known as cogging torque could occur, they would lead to slight but unpleasant vibrations when driving very slowly.

In addition, the eATS have a special foam mat all around as an NVH cover. The inverter cover has a sandwich construction of three metal and plastic layers. The eATS are doubly decoupled from the body via elastomer bearings: at the front axle opposite a supporting frame and this against the body, at the rear axle with a subframe.

Highly effective spring/mass components provide continuous sound insulation from the cross member under the windshield to the floor of the load compartment. Acoustic foams are inserted into many members during construction of the bodyshell.

The electric refrigerant compressor has an NVH cover as encapsulation. In the rear-wheel-drive EQE SUVs it is also soft-suspended, while in the 4MATIC models it is bolted directly to the front eATS. The operating strategy of the refrigerant compressor also contributes to the low noise level of the vehicle. Certain rpm ranges at which disturbing resonances may be audible when stationary or in a traffic jam are avoided or quickly passed through.

A DC fast charging system with a charging capacity of up to 170 kW is fitted on board for fast charging via direct current in addition to the standard 9.6 kW charging capacity. High charging currents can be maintained for a long time through temperature and charging management.

Battery. In the EQE SUV, the lithium-ion battery consists of ten modules. This generation of batteries takes a big step towards the sustainability of cell chemistry: the optimized active material consists of nickel, cobalt and manganese in a ratio of 8:1:1. This has reduced the cobalt content to less than ten percent. The continuous optimization of the recyclability is part of Mercedes-Benz's holistic battery strategy. The aim is to be able to dispense entirely with materials such as cobalt through the use of innovative post-lithium-ion technologies.

The battery is integrated into the EQE SUV's intelligent thermal management system with heat pump as standard. If the intelligent Navigation with Electric Intelligence is activated, the battery is preheated or cooled as needed while driving. As a result, the temperature at the charging point is in an optimal range for efficient charging. The desired temperature range of the battery is achieved with the aid of the cooling circuit and a PTC (Positive Temperature Coefficient) booster heater integrated into it.

The battery management software, which was developed in-house, allows updates over the air (OTA). In this way, the energy management of the EQE SUV remains up-to-date throughout its entire life cycle.

Posted on 17 October 2022 in Batteries, Electric (Battery) | Permalink | Comments (0)