On acoustic noise reduction procedure for inverter-fed induction machines

Converter-fed variable speed drives are undesired sources of acoustic noise. Due to principle of operation magnetostriction and mechanical torque oscillations cause noise. For the prevailing variable speed realization through PMW inverter and induction machine mainly the machine with its outer components like cooling fins and ventilator hood can be the emitter of noise in audible area. Cooling fins practically shall stay metal material. Fan and fan hood favorably are from plastic material and could be made of composite material. Careful investigation of types of resonant bodies and their specific degree of freedom in mechanical resonant deformations help establish suitable designs for noise reduction. In addition, we shall take into consideration the advanced damping opportunities linked to composite material and the opportunity to define material stiffness parameters. This contribution provides a composite material based promising approach for efficient noise reduction.