With the goal of improving fuel efficiency, increasing implement productivity, and enhancing other aspects of a 300-hp- (224-kW)-class agricultural wheeled tractor, a group of researchers in Russia decided to design and test an electromechanical drivetrain (EMD).
Also developed was a service computing system for special-purpose software (SCS) for an external personal computer. The SCS helps to simplify diagnosing and servicing, adjust the settings of the control system, selectively visualize the current values of variables, store and dynamically display them in an operator-friendly form, and ensure navigation and visualization of emergency logs of the high-level controller.
In addition, the researchers developed a set of options including a self-controlled power electric station, electric drive of the front power take-off (PTO), and electric drive of the diesel engine cooling fan.
In their work, the researchers from Production Association Minsk Tractor Works and Ruselprom-ElectricDrive Ltd. found that the use of electric drivetrains is especially beneficial for powerful tractors. In such tractors a standard mechanical drivetrain is sophisticated and expensive, especially in production. For example, the gearbox is very expensive because more shifting steps are needed. Control of a tractor with a high number of shift levels also is complex.
The electromechanical drivetrain completely solves this problem as there are only two operating modes (two gear steps): operational (0-18 km/h, or 0-11 mph) and transport (0-42 km/h, or 0-26 mph).
An alternative to EMD is a hydraulic drivetrain (HDT), which comes in various types. However, they require very precise mechanical machining during manufacture and use of high-quality oil. In addition, HDT efficiency is lower than that of the EMD, and service life is short.
In comparison to a conventional tractor, the prototype tractor equipped with EDM technology has additional advantages beyond better fuel consumption and improved implement efficiency. Among them are reduced dynamic loads on the tractor and diesel units; reduced wheel slippage; continuous variation of speed of the tractor and aggregated implements; reduced expenses on maintenance, repair, and spare parts; and increased total reliability, controllability, and comfort.
The tractor can be used as a power source.
This article is based on a technical paper jointly published by SAE International (2011-01-2296) and AVL List GmbH (ICPC 2011 – 3.3) by Alexey A. Puhovoy and Ivan N. Uss of Production Association Minsk Tractor Works; and Stanislav N. Florentsev, Dmitry B. Izosimov, and Lev N. Makarov of Ruselprom-ElectricDrive Ltd.