[Kim Yong-ju Column] Current Status of Hydrogen Fuel Cell Tractor Development

[Kim Yong-ju Column] Professor, Department of Smart Agricultural Systems and Machinery Engineering, College of Agriculture and Life Sciences, Chungnam National University

The hydrogen fuel cell tractor is a large-scale project of the Ministry of Agriculture, Food and Rural Affairs being carried out with an investment of about 30 billion won over 5 years from 2022. This project, led by Chungnam National University, involves Hyundai Motor Group, which supplies hydrogen fuel cells, as well as agricultural machinery manufacturers LS Mtron, Daedong, TYM and others, with a total of 19 organizations participating, making it the largest single project of the ministry. This research is organized into 4 research groups to design a 110kW-class hydrogen fuel cell tractor. E-powertrain and tractor design group, drive system and chassis design group, power system design group, and safety group.

This project has several challenging aspects beyond developing the world’s first hydrogen fuel cell tractor. First, the biggest challenge is applying hydrogen fuel cell technology, which has only recently been applied to eco-friendly vehicles, to tractors. To achieve this, power system design and optimization are needed so that the tractor can respond to continuous high-load work, and at the same time various legal·institutional improvements are required.
In particular, to apply high-pressure hydrogen components to tractors, it was necessary to review and revise related laws. The research team first applied for a sandbox for vehicle development, and based on what was learned during the development process, completed preparations to establish test codes through several advisory meetings in order to prepare regulations. 2027 and onward, related laws and regulations will be enacted, and all preparations have been completed so that hydrogen fuel cell tractors can also be commercialized institutionally.

The second is the design of a new tractor platform. Traditionally, tractors developed in Korea all use a frameless construction in which the engine·transmission·rear axle·housing are connected to support the vehicle body load(Frameless construction). The operator works by mounting and sitting in the driver’s seat placed on top of the tractor’s transmission. This structure has the advantage that electrification technology can be applied while using existing core components as they are, but it has spatial limitations when mounting various hydrogen fuel cell components such as the hydrogen fuel cell, hydrogen tank, and other parts.

Therefore, when a hydrogen tank is installed on an existing tractor structure, a method of mounting the hydrogen tank on the roof, as in Kubota’s hydrogen fuel cell tractor, must be adopted, but this structure makes it difficult to secure the safety of the hydrogen tank in the event of a rollover. In addition, because a dedicated roof including the hydrogen tank must be developed, it is also difficult to apply it to diverse tractor lineups.

To overcome these limitations, this project designed a dedicated frame for hydrogen fuel cell tractors that makes it easy to mount hydrogen tanks, and using this, designed a dedicated platform for hydrogen fuel cells. This platform can be considered a new attempt that has not yet been applied in Korea’s agricultural machinery sector. The dedicated platform has the advantage of securing the space needed to mount a hydrogen fuel cell system, while also being usable in common by multiple agricultural machinery companies. Finally, the platform commonization in this project goes beyond commonization by agricultural machinery company and is designed so that manned and unmanned tractors have the same platform.

Because the common hydrogen fuel cell platform was designed so that all drive components such as motors, inverters, transmissions, and energy devices such as hydrogen tanks can be mounted under the chassis, domestic tractor companies have the advantage of being able to use the entire platform by installing their own cabins, while also having the advantage that it can be used unmanned by excluding the cabin. Therefore, this hydrogen fuel cell project can be described as a challenging task that develops hydrogen fuel cell technology while also confirming the possibility of commonizing a new electrification platform.

In particular, to reflect the work characteristics of tractors, the hydrogen fuel cell tractor platform drives the tractor with three types of motors: a driving motor, PTO motor, and hydraulic motor3. This structure can have a relatively simple transmission structure compared with existing internal combustion engines, and through this, power transmission efficiency can be increased. In addition, because hydrogen fuel cell power packs are more efficient than engines, which are the power source of internal combustion engines, they have the advantage of being able to perform farm work more efficiently using the same energy source.

The hydrogen fuel cell tractor project has now completed development as a next-generation platform that can apply a new eco-friendly energy source, a commonizable electrification-dedicated platform, and both manned and unmanned operation at the same time, and is conducting tests for final vehicle stabilization. To verify the tractor’s performance, tests are being conducted in the same way as for existing internal combustion engine tractors according to the tractor performance test methods of the Korea Agriculture Technology Promotion Agency, but separate test methods are needed for the configuration of 3 motors. These test methods can be used not only for hydrogen fuel cells but also for all electric tractors that drive or perform work using one or more motors instead of existing internal combustion engines, and this research is developing those test methods.

Currently, the hydrogen fuel cell tractor has completed development of prototypes of both manned and unmanned tractors, and performance testing has been completed, finalizing preparations for commercialization. However, for actual use on farms, improvements to laws·systems, charging, and safety systems are needed. At the same time, it is necessary to prepare subsidies and other measures for eco-friendly agricultural machinery to expand the market.