Methodology for Matching Electric Motors to Agricultural Processes

Rational use of electricity could save energy and improve profitability. Electric motors are used extensively in the production of animal feed. The objectives of this research were: (i) to propose a methodology for adequate use of electric traction in feeding industry; (ii) to apply the proposed methodology to a commercial animal feed industry; (iii) to compare the sizing using the present motor with the sizing based on the manufacturer’s literature. This research was based on all the motor-load combinations of a feed mill located in the Minas Gerais State, Brazil. For each motorload combination, each of the following was compared energetically and economically: (1) the current motor, (2) an alternative motor that kept the load index as high as possible, (3) a more efficient motor with same power rating, (4) a more efficient and adequate motor, and (5) a motor sized according to the technical literature. The main conclusions were: (i) the potential economic savings in electrical energy used by motors was around 23%. These savings were in demand and energy costs; (ii) the average load index for the motors in the industry audited were 48.6% which was considered to be too low. Only 23.3% of the total number of motors that were analyzed had a load index higher than 81.0%; (iii) as much as possible, it is advisable to study the possibility to optimize the number of functioning hours in order to save with the electrical demand bill; (iv) more restricted security factors are needed for dimensioning electrical motors.