Replacing Induction Motors without Defined Efficiency Class by IE Class: Example of Energy, Economic, and Environmental Evaluation in 1.5 kW—IE3 Motors

Abstract

This paper shows the results obtained from the study on the variables that have the greatest influence on the decision to replace three-phase induction motors, without a defined efficiency class and installed in industrial applications, with IE3 efficiency class induction motors. The work has been carried out on motors with a nominal power of 1.5 kW due to the availability of laboratory tests that have allowed us to accurately quantify the selected study variables. According to IEC 60034-30, between 0.75 kW and 4 kW is the greatest potential for energy savings in electric motors installed within the industrial sector. The tests carried out have made it possible to assess different operating conditions of the motor: direct power supply from the grid, electronic power supply using scalar control, and electronic power supply using direct torque control. The study has focused on three aspects: energy evaluation, assessing the savings potential; economic evaluation, based on indicators such as Payback Period and Net Present Value; environmental assessment, quantifying the impact indicators proposed by the Methodology for Ecodesign of Energy-related Products (MEErP). A sensitivity analysis has been carried out to quantify, through ratios, different operating points from those directly analyzed in the article.

Keywords

• induction motor
• efficiency
• load index
• payback
• environmental impact