The S 500 PLUG-IN HYBRID blends an ultramodern hybrid drive configuration with the unique innovations and the luxurious equipment and appointments of the S-Class. The luxury saloon with a long wheelbase impresses with unique dynamism and efficiency. Thanks to standard pre-entry climate control it also offers unique climate comfort. The S 500 PLUG-IN HYBRID has been available since September 2014 — a further milestone on the road to emission-free mobility.
“The new S 500 PLUG-IN HYBRID offers our customers the entire range of innovations that make our new S-Class so successful, and thanks to its intelligent operating strategy ensures outstanding driving pleasure and dynamism combined with the highest efficiency. Moreover, it allows completely emission-free driving for up to 33 km (21 mi),” says Ola Källenius, Executive Vice-President for Sales at Mercedes-Benz Cars.
“The S 500 PLUG-IN HYBRID is the first luxury saloon with the performance of a V8 and the fuel consumption of a compact model. The greatest challenge in this is to translate highest efficiency into superior performance. In this respect there is a highly interesting parallel with our successful Formula 1 racing car, which likewise has a turbocharged V6 engine and hybrid drive,” says Prof. Dr. Thomas Weber, member of the Daimler AG Executive Board responsible for corporate research and Mercedes-Benz Cars Development.
The Mercedes-Benz S 500 PLUG-IN HYBRID offers a system output of 325 kW and 650 Nm (479 lb-ft) torque, and in just 5.2 seconds sprints from 0 to 100 km/h (62 mph) and can drive up to 33 km (21 mi) purely electrically. The certified consumption is 2.8 litres/100 km, which corresponds to 65 g CO2/km emissions. Key elements of this impressive output are the V6 biturbo and the intelligent hybrid drive. Following the S 400 HYBRID and S 300 BlueTEC HYBRID the S 500 PLUG-IN HYBRID is the third hybrid model in the new S-class. Its new high-voltage lithium-ion battery can be externally recharged via the charging socket in the right side of the rear bumper.
In order to strengthen the customers’ trust in the new, innovative PLUG-IN HYBRID drive system, for the S 500 PLUG-IN HYBRID Mercedes-Benz is for the first time issuing a certificate and thus a promise to perform for the high-voltage battery and PLUG-IN HYBRID components (e.g. e-machine and power electronics). This ensures that every technical malfunction within a period of six years after initial delivery or registration, or up to a mileage of 100,000 kilometres, is corrected by Mercedes-Benz.
Hybrid drives, the combination of internal combustion engine and electric drive, help cut overall fuel consumption and boost performance, since the electric drive replaces or supports the combustion engine whenever the engine characteristics are unfavourable – normally in part-load operation when little power is required. The experience gained with the previous vehicles from Mercedes-Benz has shown that though batteries with a higher energy content permit more frequent electric driving, they provide no added benefit from a consumption viewpoint. The capacity for braking energy recuperation determines the optimal design of the capacity and energy content of the traction battery. Recharging by the internal combustion engine cannot compensate for the additional vehicle weight resulting from an oversized battery.
For this reason, in the S 500 PLUG-IN HYBRID Mercedes-Benz combines a high-energy battery with the ability to replenish the energy storage unit via the external electric mains. The advantages of emission-free electric driving thus are brought ideally into line with the tremendous consumption advantage of the parallel hybrid – and combined with a ride comfort and handling dynamics which meet the highest standards. And a range that imposes no restrictions whatsoever on the driver.
As with all hybrid vehicles from Mercedes-Benz, the ultraefficient drive system is integrated in the overall vehicle in a way that creates no space restrictions. Major adjustments to the packaging of the overall vehicle are unnecessary – this is a big advantage for the production of the hybrid vehicles, for example, but it also poses a huge challenge for the development of the electric motor and its integration in the power head of the transmission and for the development of the power electronics and the high-voltage battery.
The hybrid transmission is based on the 7G-TRONIC PLUS 7-speed automatic transmission. The plug-in hybrid system in the S-Class is based on the Mercedes-Benz parallel hybrid modular system. The common system-specific feature is the additional clutch integrated between combustion engine and electric motor. On the one hand, it decouples the combustion engine during purely electric operation; on the other hand, if the combustion engine is employed it affords the possibility to move off drawing on the performance of a wet start-up clutch. The clutch then substitutes for the torque converter and requires no additional space owing to its complete integration in the torque converter housing.
For the stop phases of the combustion engine the hybrid system has a high-voltage refrigerant compressor, and on the 12 V side an electrically assisted steering, an electric vacuum pump and an electric auxiliary oil pump for the transmission.
Completely integrated: the electric motor
The electric motor of the PLUG-IN HYBRID has been further developed from the previous hybrid vehicles. The modular design enabled longitudinal scaling from 6 to 9 rotor plate packs. Despite its compact design the electric motor delivers an output of up to 85 kW and torque of up to 340 Nm (251 lb-ft). The permanently excited synchronous motor is fully integrated into the hybrid transmission. Stator and rotor of the internal rotor motor are cooled by transmission oil.
The high-voltage battery feeds the electric motor through a water-cooled DC/AC converter, the power electronics. This too is a component from the Mercedes-Benz modular system and was first developed for the technology platform SLS AMG E-CELL, which went into production as the SLS AMG Coupé Electric Drive. The integration of the power electronics with an electric motor optimised for plug-in operation enables top performance in terms of comfort and output over the entire operating range.
The power electronics operate with a rated voltage of 325 V and supply 350 A maximum current, at the same time determining the position and status of the electric motor by means of a rotor position sensor as well as various component temperatures. Depending on operating situation, actuation of the electric motor is guided by the rotational speed or the torque, within the permissible limits. To optimise the effort for wiring, packaging and cooling, the DC/AC converter has been integrated into the engine space. A separate DC/DC converter at the rear of the vehicle supports the 12 V on-board power supply with an output of up to 3 kW.