Analysis of noise and heating for three-phase induction motor fed by inverter

The aim of this paper is to analyze the noises and heating produced by a three phase induction motor, power of 11kW, 1000 rpm, simple layer windings produced by the company Electroprecizia Sacele located in Brasov county, Romania. It was chosen this engine knowing that from 2015 it will be adopted the standard IEC 60034-30 IE3 category which provides noise limits and also efficiency limits for these induction motors. For the simulation of magnetic noise, was used Flux 2D finite element program and thermal measurements were performed by means of a fixed thermal cameras. Measurements of noises (in the audio spectrum) were performed in semi-anechoic chamber, of the enterprise, wich produced the induction motor. In order to analyze the functioning in variable speed regime it was considered the supply of motor through the inverter (variable frequency-variable speed) and directly from the network. In the simulation of magnetic noise has been taken into account also the transitional regime, which appears when the motor starts, given that the power is high. The analysis of the transient regime was performed to ensure t the start of the motor in safety conditions. It was studied the heating of the motor because this has direct implications in total efficency of induction motor.