| Abstract |
The acoustic behaviour of vector controlled drives at transient operation is studied. Vector control
allows independent modulation of the currents controlling the flux and the torque, thus providing a
dynamic performance capability hitherto only possible with a d.c. motor drive. These currents have
been modulated with high frequency noise signals, in order to study the impact of radial and
tangential forces on the acoustical performance of small electrical machines, and the influence of
transient operation on the noise emission from vector controlled drives. Sound pressure and sound
intensity measurements were conducted at load and no load. The results indicated that, for the same
amplitude and frequency of the harmonic, modulating the flux produces more noise than the torque
by up to 7 dB, and the noise emissions are reduced at load by up to 13 dB compared with no load. |
