Hyundai Motor Group Reveals New Dedicated EV Platform

Hyundai Motor Group (HMG) is hardly new to producing electrified vehicles. In fact it even has a platform that is specifically designed for that purpose that underpins the current Hyundai Ioniq and Kia Niro. But that platform is actually a compromise that was designed to be available with hybrid, plug-in hybrid and battery electric (BEV) powertrains. With its new Electric-Global Modular Platform (E-GMP), Hyundai is following in its footsteps of rivals such Volkswagen Group, GM and Ford in developing an architecture fully optimized for BEVs.

These modern BEV platforms reverse one of the most prevalent trends of the last 40 years with the switch back to rear-wheel drive. Back in the 1970s as automakers responded to rising oil prices and new fuel economy and emissions regulations, most mainstream vehicles switched to transverse mounted engines driving the front wheels. This configuration saved weight and packaging space compared to the more traditional front engine rear wheel drive layout. But it compromised driving dynamics by forcing the front tires to handle tractive effort and steering. 

The compact size of modern electric motors allows them to be packaged below the floor at the axle they are driving thus making RWD more practical. With the workload now split more equitably between the front and rear wheels and much of the mass mounted down low below the floor for a reduced center of gravity, these modern BEVs provide excellent driving dynamics. 

One thing that E-GMP is not is a skateboard platform as some manufacturers have shown. The motors, suspension and battery are not integrated into a single structure. Instead, E-GMP utilizes an updated unibody structure to which the motors, suspension sub-frames and battery are attached. Securely attaching the battery to the floorpan in this way does enhance the overall structural integrity. This is similar to the approach used by VW for its MEB archictecture.

Beyond the basic layout, HMG has incorporated a number of distinct features in the E-GMP system to help vehicles built to achieve 300 miles of driving range on the WLTP test cycle. One of the biggest advantages that Tesla

TSLA
has had in recent years is its use of silicon carbide switches in the power electronics module that switches between the direct current of the battery and alternating current used by the motors. Silicon carbide provides more efficient power conversion that can yield a notable boost in range compared to the traditional silicon used in most current BEVs. 

E-GMP will be one of the first BEV platforms from an incumbent automaker to use silicon carbide in the power electronics. As part of the overall package, the silicon carbide inverter improves efficiency 2-3% with range increased 5% from the same battery capacity. The power electronics module itself is integrated into a single power electric module with the motor and transmission. The rear power electric module also has an integrated drive axle that includes the axle shafts and bearings. A five-link rear suspension layout is standard with E-GMP.

The permanent magnet motor design utilizes hairpin windings which allow for a greater fill ratio in the copper winding volume compared to using traditional round wire windings. The result is greater effiency and power and up to 70% higher maximum speeds for the motor enabling a smaller, lighter package. On dual motor all wheel drive variants, the transmission includes a clutch to decouple the motor when not needed, reducing overall drag. 

As with competing platforms, HMG has designed the battery pack around a standard module format that is filled with pouch-type lithium ion cells. A standard pack can be filled with varying numbers of modules to achieve the desired range for a particular application and price point. HMG engineers have put extra emphasis on the thermal management of the battery pack which the manufacturer claims has allowed it to pack in cells more tightly for 10% more energy density than its current batteries. 

Most current BEVs are designed around a 300-400V electrical architecture which can support DC fast charging rates of 50-150 kW. The new HMG architecture uses 800V which is more efficient and allows for slimmer and lighter wiring as well as charging at up to 350-kW. When plugged into a 400V charger with up to 150-kW output, the voltage is doubled to 800V. At 350-kW chargers which are becoming increasingly common in both North America and Europe, the battery can charge to 80% in 18 minutes or add 62 miles of charge in just 5 minutes. 

 E-GMP utilizes a new integrated charging control unit (ICCU) that enables bi-directional charging. Vehicles built on this platform will be able to feed power out at up to 3.5-kW, enough for a midsize air conditioner for 24 hours. HMG isn’t the first manufacturer with this capability. The Nissan Leaf has had vehicle-to-home capability since at least 2015 in Japan and 2017 in North America although there are few compatible devices available. The new Lucid Air also has bidirectional charging capabilities. HMG BEVs with this feature will even be able to siphon off some electrons to charge up other EVs that have run out.

The E-GMP architecture will provide the basis for 23 new dedicated BEV models across the three group brands, Hyundai, Kia and Genesis as well the robotaxi being developed by the Motional automated driving joint venture. The first of these new models arrives in 2021 as the new Ioniq 5 midsize crossover and it will be followed by the Ioniq 6 sedan and Ioniq 7 large crossover. Kia will launch its first purpose-built BEV next year as well, possibly based on the 2019 HabaNiro concept. Hyundai Motor Group is targeting sales of 1 million BEVs annually be 2025.