Procedure determination for efficiency measurement of a squirrel-cage induction motor fed by a frequency inverter

This paper presents a procedure to measure the efficiency on a induction motor fed by a frequency inverter. The article describes the procedure, instrumentation precision requirements described by international standards, the research for an accurate data measurement, information processing, power calculations and also efficiency calculations. The paper also describes and analyzes the different power calculations implemented and researched, which correspond to the algorithms used by the commercial instrumentation. The losses on the group induction engine - frequency inverter/speed control are shown and analyzed. Finally, the procedure for efficiency measurement is implemented through lab tests.