Dennis Helder

Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Electrical Engineering


During the late 1970's the sharp rise in petroleum costs produced a flurry of activity to develop alternate energy sources. A primary goal was to produce efficient, cost-effective electric vehicles. Until recently no consideration had been given to producing electric farm vehicles. However, a shortage of diesel fuel for farmers in the early 1980's prompted a USDA-DOE grant to study the feasibility of electric farm tractors. Research in this area has shown that a significant amount of study the feasibility of electric this area has shown that a farm work can be performed by electric vehicles. Tasks which are particularly suitable have characteristics of being regular routines performed on or near the farmstead which require stop-and-go operation. These tasks are particularly inefficient for internal combustion vehicles since they require only short intermittent bursts of power. Predictions of increasing petroleum prices make electric powered vehicles more attractive for farm use since electricity can be generated by several sources. Other advantages include lower energy operating costs, less maintenance, longer vehicle life, quieter operation, easier starting, and elimination of noxious gases. Possibilities also exist for the electric farm tractor to serve as an auxiliary power source. To further investigate the feasibility of electric farm vehicles, a project was undertaken to develop a battery-powered chore tractor. The philosophy of this project was that technology currently available would allow the use of standard components to assemble the vehicle. In the interest of time, a decision was made to build a tractor suitable for a majority of farm chores and to modify it accordingly as deficiencies appeared during testing. A Versatile 160 tractor was chosen as the basis from which to start. This is a four-wheel drive tractor with an articulated frame. diesel engine through a transmission. The unique It is powered by an 85 hp three-speed hydrostatic design of this tractor provided a frame which could be easily modified to suit the particular needs of an electric tractor. Two electric motors are used: one to provide tractive power and the second to drive the Power Take Off (PTO) and hydraulic systems. The PTO/hydraulic (PTO/HYD) motor is located beneath the cab and the traction motor is located behind and beneath the batteries which are behind the cab. It is the purpose of this thesis to describe the control systems of the tractor and its instrumentation. After the introductory material and literature review in Chapter I, Chapter II describes methods of motor control. Chapter III discusses auxiliary and instrumentation systems required to support and protect the drive circuitry as well as provide an adequate interface for the operator. An improved speed control system for the PTO/Hydraulic motor is analyzed in Chapter IV.

Library of Congress Subject Headings

Electronic vehicles



Number of Pages



South Dakota State University


No Copyright - United State