Identification of harmful time harmonic interactions in a high power squirrel-cage traction machine

Analysis of rotor's eccentricity influence on bearing load of induction machine

“…Let be the angular position of the rotor denoted by . Then the external force expressing the influence of rotor eccentricity in (10) can be expressed as…”

“…Using these two bearing matrices, a global bearing matrix R , can be assembled in such a way that the matrices and are placed at positions corresponding to generalized coordinates of nodes 3 and 6 defined by vectors and . The complex mathematical model of dynamic behavior of the rotor can be then expressed as , (10) where is damping matrix of shaft structure and it can be determined as . Similarly, the bearing damping matrix is supposed to be proportional to bearing stiffness matrix .…”

“…The findings are concluded in the second part. The mechanical model is based on the methodology presented in [10] and is further improved to determine the bearing coupling stiffness more precisely.…”

Influence of Skewed Squirrel Cage Rotor with Intermediate Ring on Magnetic Field of Air Gap in Induction Machine

“…Their amplitudes are therefore inversely proportional to their order and have relatively strong influence even in case of high considered harmonic order. According to (5), all magnitudes of orders cQ1 + 1 subtract from their respective slot harmonics no matter how the winding is chorded. The same rule holds for orders cQ1 -1, but they add to the respective slot harmonics.…”

“…These features strongly predefine the spectrum of the air gap magnetic flux density [1]- [4]. It includes many harmonic components (space harmonics) producing parasitic torques, additional losses and acoustic noise even under common operational states [5]- [10]. Reduction of the high frequency components of the spectrum is therefore an important issue that must be considered prior to designing the machine.…”