[Upcoming Hydrogen Economy] "Is the ride quality of hydrogen buses really like this?"... Test driving Hyundai Motor's Universe

Test Drive of Hyundai Hydrogen Electric Bus Universe on the 12th
World's First Application of 'MR Damper' Developed for Tanks in Commercial Vehicles
Planned Expansion to Corporate Commuter Buses This Year
Superior Safety, Eco-Friendliness, Ride Comfort, and Driving Range Compared to Electric Buses

On the 12th at Hyundai Motor Company's Cheonan Global Learning Center, Hyundai's hydrogen electric passenger bus 'Universe' was running on the track. When the engine was started, instead of a rumbling engine noise, only a low mechanical sound reminiscent of an airplane taking off was heard. When the bus made a sudden emergency stop, the press burst into exclamations. The bus smoothly and quietly reduced speed even during the abrupt stop. The hydrogen electric Universe is equipped with an 'MR damper' that maximizes ride comfort. Turning off the damper function and trying the emergency stop again, the vehicle jolted, causing the body to lurch forward against the front seat. This was distinctly different from the smooth stop when the damper function was on.

Hyundai Motor Company launched the mass production model of the hydrogen electric Universe in April this year. While another hydrogen electric bus, Elec City, is designed for city bus use, the Universe is intended for intercity and charter bus use. Hyundai first introduced the hydrogen electric Universe as a VIP protocol vehicle at the 2018 Pyeongchang Winter Olympics. In 2021, development continued for use as a police bus. After further development and improvements for general express bus use, the mass production model was born.

Currently, the hydrogen electric Universe is deployed on intercity bus routes running between Incheon Terminal and Seoul Station. Travel agencies also use it as a passenger transport bus. Recently, large corporations such as Samsung Electronics, SK Hynix, and POSCO have decided to switch their commuter buses to hydrogen vehicles. It is expected that hydrogen electric Universes will be seen as corporate commuter buses throughout the city this year. The launch price is 693 million KRW for the charter bus version. With subsidies and tax benefits, it can be purchased for 200 million KRW.

The hydrogen electric Universe's strength lies in its smooth ride comfort. Hyundai applied the 'MR damper' developed by Hyundai Rotem to the hydrogen electric Universe. This is the world's first application in a commercial vehicle. A damper is a device that absorbs vibration energy between the car's wheels and the body. The better the damper performance, the more the ride comfort improves. Due to cost, dampers are used only selectively in high-end off-road sports utility vehicles (SUVs) such as the Range Rover.

Initially, Hyundai Rotem developed the 'MR damper' for tanks that mainly run on rough terrain. This was to minimize the turret movement mounted on the tank and improve firing accuracy. Hyundai stated that applying the 'MR damper' to the Universe improved ride comfort by 30% during rapid acceleration and sudden braking, and improved steering stability by 12-15% during lane changes. Hyundai's analysis also showed that the impact when passing over speed bumps was reduced by more than 30%.

Hyundai Hydrogen Electric Universe Interior Passenger Seats
[Photo by Hyundai]

Another strength of the Universe is its long driving range. It can travel 635 km on a single charge. This is 85 km farther than the Elec City hydrogen bus, which is a city bus with a range of 550 km. The bus roof contains five hydrogen tanks (for intercity bus standards). A total of 34.3 kg of hydrogen is charged into the five tanks. Charging time is approximately 25 to 30 minutes. In addition to the 180 kW hydrogen fuel cell, a 48.2 kWh high-voltage auxiliary battery is installed to provide additional power. The motor's maximum output is 335 kW.

Hydrogen fuel cell system mounted on the rear of Hyundai Motor's hydrogen electric bus Universe
[Photo by Woo Su-yeon]

On this day, Hyundai also emphasized the safety of hydrogen electric buses. The hydrogen electric Universe is equipped with a total of eight hydrogen leak sensors. These sensors constantly check for any hydrogen gas leaks in the hydrogen tanks, fuel cell stacks, and powertrain room. Additionally, a safety valve is installed to block hydrogen gas inflow to the fuel cell in case of fire. When the temperature rises above 110℃, the metal part melts to block the valve, causing hydrogen gas to be released all at once through the roof. While ignition may occur, there is no explosion as commonly imagined.

Hyundai even conducted experiments shooting bullets at the hydrogen tanks to test their safety. The hydrogen tanks hit by bullets do not explode but tear. Hydrogen gas escapes through the torn gaps. This is because the tanks are made of carbon fiber, which is four times lighter and ten times stronger than steel. Lee Deok-jae, Hyundai Motor Company's High-Tech Development Team Manager, emphasized, "Hydrogen has an ignition point of 500℃, which is much higher than gasoline (246℃), so even in traffic accidents, hydrogen vehicles are safer in terms of safety."