With steadily shrinking oil reserves and growing concerns about greenhouse emissions and the environment, the race is on for alternative fuel vehicles. Hyundai’s TB Hybrid Electric Vehicles provides a low polluting, energy efficient solution.

SEOUL, Korea, Oct. 31, 2003 - Imagine doubling your fuel economy. Imagine cleaner air in our cities. It’s not a dream but the mission of Hyundai Motor Co.’s Advanced Technology Center which is spearheading research into alternatives to the internal combustion engine (ICE).

Fuel cells, while highly promising, are prohibitively expensive and are seen more as a long-term solution. Besides the numerous remaining technical hurdles to be overcome, there is the question of the development of a whole new refueling and servicing infrastructure to support this 21st century technology.

Researchers and product planners are much more excited about the prospects of hybrid electric vehicles. “Hybrid is a fusion of fuel and electric, two reliable existing technologies that provides us with an immediate solution and utilizes the existing infrastructure,” explained Dr. Park Joon-Chul, senior vice president at the Advanced Technology Center.

The company’s first mass market hybrid electric vehicle, the TB HEV is on track for a pilot fleet test in 2004 and a market launch in near future. The TB HEV promises a 65 percent improvement in fuel efficiency and ULEV tailpipe emissions.

“The TB HEV is a response to market pull,” said Dr. Park. “People want more fuel efficient, cleaner running cars. Governments want to tackle the problem of pollution and deteriorating air quality in our cities. Hybrids offer a solution, here and now” he explained.

Hybrid incorporates two different propulsion systems to deliver power to the wheels: a conventional ICE, in the TB HEV’s case a modified 1.4-liter DOHC Alpha II engine and a 12kW electric motor. The car switches automatically between the two power sources.

Nearly 10 Years Experience
Hyundai first began experimenting with hybrid propulsion systems in 1994. At the 1995 Seoul Motor Show, the company’s unveiled its first hybrid, the FGV-1 concept car. It was a full-time electric drive vehicle with the ICE being employed solely to recharge the battery. This “series” type design was abandoned in favor of the “parallel” type design featured on the FGV-2 a second generation hybrid concept that was introduced at the 1999 Seoul Motor Show.

In the parallel setup, either the ICE or the electric motor can be utilized as a propulsion source, whichever is more optimal. Because of its numerous merits, parallel has become the preferred setup. “A series hybrid requires a rather larger battery and motor than a parallel solution. It’s more expensive so we favored the parallel setup,” explained Dr. Park.

Lessons learned on FGV-1 and 2 were then applied to production models and in 1999, Hyundai unveiled the Elantra HEV and the Accent HEV the following year.

High Volume TB Platform
Moving to the next stage, planners recognized that selecting the correct platform would be a highly crucial element in determining the success or failure of Hyundai’s first mass production HEV. Platform selection criteria included potential market volume and the target buyer’s sensitivity to fuel prices. All indicators pointed to the TB as the ideal platform for a mass market hybrid program.

The TB’s low weight figured as another major plus but the added weight of the large nickel metal hydride battery required structural engineers to apply a number of weight saving ideas including the use of lightweight aluminum as a substitute for steel in selected areas. As result, the TB HEV is just 70kg heavier than a conventional TB.

Configuration
The prototype TB HEV is powered by a second generation 1400cc DOHC Alpha engine, though the production version will be fitted with the even more efficient third generation powerplant. Power is delivered to the front wheels via a continuously variable transmission—a more expensive solution than a manual but one which yields improved fuel economy. Gasoline is stored in a 45-liter tank, the same size as a normal TB.

The engine is fitted with an integrated starter-generator and the entire electrical system is governed by a digital control system which was developed in-house.

Twelve kilowatts of power is served up by a synchronous AC motor. The TB HEV is equipped with a mobile electric motor which is somewhat different from stationary motors. Serving up a maximum of 12kW, it’s engineered to save weight, is extremely compact and runs much cooler than its stationary counterpart, all of which adds to the expense.

The motor is connected to a rear-mounted nickel metal hydride (Ni-MH) battery. The hybrid development team is investigating alternatives to Ni-MH which promise a much higher energy density at a lower cost but it’s too early to predict which vendors will supply which components for the 2005 production version.

“It’s always a tricky equation balancing quality and performance versus costs,” explained Dr. Park.

Performance
The TB HEV automatically switches back and forth between ICE-mode and electric-mode in a process that’s completely transparent to the driver.

Its performance is basically similar to conventional car. The unit has 860 km maximum operating range on a single tank of gas and can reach a top speed of 187km/h. Acceleration is reasonably brisk as it can climb from zero to 100km/h in just 12.3 sec.

Engineers are now tweaking the setup trying to improve gas mileage to 20km/l and in the final stage of the development process will devote their energies to NVH issues, that is, reducing noise, vibration and harshness for a smooth, quiet ride.

Operating Principle
The TB HEV’s Ni-MH electric storage battery is recharged by the ICE and by "regenerative" braking—energy collected when the brakes are applied. Battery power is delivered to an electric motor that supplements, or takes over for, the ICE.

When the car stops, the ICE automatically shuts off. The electric motor assists when the car is starting, climbing hills or accelerating sharply. At cruising speed, the ICE takes over while the electric motor shuts down.

Future
The TB HEV is due to begin fleet testing in 2004 in Korea. “It will give us the chance to observe performance under real world driving conditions,” explained Dr. Park. Another equally important aspect of the pilot program is raising public awareness about the arrival of more environment-friendly cars and soliciting stronger government support for alternative fuel vehicles. ““We see the government as our partner in this program. We really need to get the government on board behind this project,” he added.

That’s because for the time being, the higher cost of manufacturing hybrids is hindering mass appeal. For hybrid sales to take off, the price of hybrid vehicles will have to fall in line with that of ICEs and that’s where the government can step in by providing hybrid car purchasers with a subsidy or tax breaks.

Meanwhile, major players in the industry are cooperating and competing in the improvement and propagation of hybrid technology. And the lessons being learned from the TB HEV project are certain to be applied to larger car models down the road.

“In this game we must compete with the vastly larger resources of automotive giants like GM and Toyota so we are running a very tightly managed program that avoids waste. It’s a substantial investment with substantial risks and we prefer to move cautiously,” he summed up.

Headed by Dr. Kwon Moon-Sik, executive vice president, Hyundai’s Advanced Research Center is located within the Namyang R&D Center and is responsible for the company’s fuel cell program and development of recycling technologies as well as the hybrid program.

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