A measuring equipment for the measurement of the electricquantities at the terminals of an inverter-fed induction motor

摘要

This paper is concerned with the problem of measuring the electricquantities at the terminals of an inverter-fed induction motor. Thecritical point in performing such measurements lies in the heavydistortion of both voltages and currents, which requires special care inthe evaluation of rms values and powers. A measuring device is proposedfor the measurement of voltage and current rms values, their frequency,their frequency-domain components and the active power consumed by themotor. The measuring instrument is based on digital signal processingtechniques and is organized as a Virtual Instrument. The results of someexperimental work done on a 3 kW induction motor supplied by a six-stepinverter are reported