Carraro Advances Electrification of Agricultural & Construction Machinery 

Traditional lines of equipment by Carraro of Italy are field tractors but it also makes sophisticated transmissions and powertrains for off-road OEMs worldwide. Now the company has built a full range of electrified propulsion components powered by permanent-magnet motors. 

Devoted to thoughtful and innovative engineering, agricultural and construction equipment manufacturer Carraro Group of Italy is bringing advancements in electrified mobility to workfields. It has developed a sophisticated cadre of hybrid and fully electric propulsion systems for powering off-road equipment without compromise compared to traditional internal combustion engine systems. The new machines use permanent-magnet synchronous motors in tandem, or instead. 

“Carraro considers vehicle electrification as a significant opportunity to limit emissions without reducing productivity and efficiency,” explains Giacomo Fiocchi, ePower Systems Director of the venerable company. Established 90 years ago in rural Italy as a manufacturer of machinery for seeding agricultural fields, today it makes its own brand of specialized tractors while also providing sophisticated power systems for many of the world’s leading manufacturers of agricultural, construction and material handling equipment. 

To support its electrification, transition the company has founded a dedicated division, e-Power Systems, focused on the development of e-mobility variations as well as associated digital and electronic products and services, which integrates and completes the existing product offering. Fiocchi shared with Magnetics Magazine recently his company’s path to product development for the transition, and provided details of the process, using its telescopic handlers as an example. 

“The ePower electrification process defines five macro-phases in order to minimize designing and material costs then emphasizing virtual activities,” he notes. “The process starts with three simulation steps: vehicle mission definition, components and architecture identification and performance simulation. Only in the last two phases are real objects realized to complete the components bench tuning and testing and the last step: vehicle testing.” 

All data coming from the vehicle are acquired to have a clear definition of all the working cycles and system performances. After this, the simulation tool developed from ePower can create the digital twin where the most important parameters (eg. tractive effort, fuel consumption) are mapped. The real electric process can now start based on the ePower library where all the key components are already built and available for any simulation loop. The library allows ePower engineers to tune all the major parameters in order to obtain different results according to level of customization. 

“The telescopic handler is one the most interesting vehicles for the electrification process due to its size and duty cycle,” explains Fiocchi. “It’s also becoming very attractive thanks to the wide range of applications from agriculture to construction equipment.” The ePower engineering team developed hybrid (range extender) and full-electric as two alternatives and both can be used with the P3 or P4 architectures as shown in the accompanying diagrams. If the cost or size of the battery is excessive, the hybrid solution could be a good option. As a second step, when battery costs decrease, a larger battery can be installed in order to have a full electric vehicle. P3 and P4 are two architecture alternatives, identifying where the e-motor is installed; both can exist with the full-electric or hybrid approach. 

Hybrid version for telescopic handler 

For the hybrid version, the Carraro proposal is based on Hybrid Range Extender where a downsized 18kw combustion engine is used at constant speed (best efficiency point) in order to support an electric generator. The traction mission is achieved by the connection of a 40kw peak power eMotor and a dedicated dropbox (eTB220) able to supply front and rear axle. A 10kwh Lithium battery and an additional eMotor for hydraulics support full electric operations, where the power demand is limited, for at least two hours. The P3 solution is supplied at 96V minimizing safety impacts, cost and complexity. The achievable cost fuel saving is in range of 20-50% and it’s related to three main contributions: the downsize of the original 55kW diesel engine, increased efficiency during all the impulsive transition and full-electric operations The vehicle cost increase for this solution is estimated to 8-10% and it will be compensated along the entire vehicle life with a final total cost of ownership saving of 1-2%. The main advantages are related to the extended vehicle functionalities, notably precise traction control, noiseless operations along full-electric and reduced noise during hybrid and limited maintenance. 

Carraro’s P4 solution is fully electric, depicted here for telescopic handler platform 

For the full electric version, the proposed solution is a P4 architecture where both the axle are independent and leaded from an integrated 40kW peak electric motor; any dropbox is present into the vehicle with significant advantages in term of layout. An additional electric motor for the hydraulics services is present together with an increased 25kWh Lithium Battery to support the permanent full-electric operations. 

The vehicle cost increase for this solution is estimated to 15% and will be compensated along the entire vehicle life, reaching a final TCO saving of 3-6% thanks to the achievable cost fuel saving of 45-50%. 

The main advantages are related to the extended vehicle functionalities and include precise traction controls, noiseless operations, limited maintenance and compact layout, in other words able to fit with already existing vehicle platforms. 

Overall, its engineers have developed an integrated portfolio of ePower systems and modules to suit various applications. Examples of some are shown below. 

Mild hybrid powertrain (P1) offers a new paradigm for agricultural equipment. By combining an internal combustion engine and a 48V 20 kW electric motor, this unique powertrain is ideal for agriculture which can generate the same power as a 100 hp combustion engine while optimizing fuel consumption and reducing emissions. 
The Hybrid (P2) configuration with a 20 kw electric motor marks a real turning point in the agricultural mechanization of specialized tractors, says Carraro. The complex parallel-type architecture enables the power delivered to be optimized according to the various operations to be performed by the tractor. Operators can choose whether they wish to work in pure electric mode: for use inside closed structures, greenhouses and stables or for municipal applications; or in diesel only for road transportation or when not transporting heavy loads; or in hybrid mode for transport operations when towing or carrying loads and for heavy PTO operations. 
Its e48.16M axle, used in the P4 Solution, provides complete integration of electric motors with scalable horsepower and an inverter located in the central part of the axle. This architecture has been specifically designed for compact machines such as compact wheel loaders or dumpers.  
The EC50 eAxle is designed particularly for counterbalanced forklift trucks with integrated e-motor. 
eTransmission (P3) is designed for “zero impact” operating machines. Work sites and construction equipment are moving towards full sustainability. To meet this need, Carraro has developed a series of transmissions which integrate electric motors to meet legal requirements and reduce emissions whilst guaranteeing performance and productivity. The eTCH90 Long Drop is a torque converter full powershift transmission designed to become an integrated powertrain for hybrid and full-electric vehicles. Combines compact electric motors with scalable horsepower at both low and high voltage. 
eTB220C transmission was specially developed for full-electric based applications which can minimize power losses even at high input rotation speed. OEMs can create high flexibility by integrating one or more compact electric motors for multi-stage solutions. The group of integrable electric motors offers scalable horsepower and can operate at both low and high voltage. 

Based in Campodarsego north of Padua, Carraro is particularly well known for its highly efficient power transmission systems. The company’s main market is agriculture, accounting for about half of its output. In addition to its own brand of specialized tractors, it makes gears, transmission systems and special tractors for the world’s primary agricultural machinery manufacturers. Construction equipment accounts for nearly a third of its business, developing transmission systems for backhoe loaders, general loaders, telehandlers, wheeled excavators and compaction rollers. Other areas for its products are forklifts for material handling, automotive and robotic components. One of the company’s hallmarks is that it can manufacture the smallest gear up to complete tractors. For more info, see