This paper deals with the torque ripple minimization method based on the modulation of the phase currents of the permanent-magnet synchronous motor (PMSM) drive. The shape of the supply current waveforms reducing the torque ripple of the machine considered was determined on the basis of finite element analysis (FEA). In the proposed approach, the machine is supplied by a six-leg inverter in order to allow for the injection of zero sequence current harmonics. Two test PMSMs with fractional-slot concentrated windings (FSCW) and surface-mounted permanent magnets (SPMs) have been examined as a case study problem. Wide-range fractional analyses were performed using developed numerical models of the electromagnetic field distribution in the considered machines. The results obtained show that the level of torque ripple in FSCW PMSMs can be effectively reduced by the modulation of the phase currents under the six-leg inverter supply.

with cooperation the Tele-and Radio Research Institute deals with finite element analysis of six-phase, dual star permanent magnet synchronous motor. To reduce eddy current losses in the rotor of the machine the rotor back iron segments have been made of soft magnetic composite (SMC). SMC are composites of iron powder particles separated with an electrically insulated layer. This technology has many advantages in relation to classical laminated core solutions; among other lower manufacturing costs due to simpler technology and reduced eddy current losses out of order times lower conductivity. The mathematical model of machine utilizes field circuit approach assuming planar symmetry of the machine. The magnetic properties of the applied SMC material have been introduced into the model basing on BH curves and unit losses vs. frequency characteristics measured at Tele-and Radio Research Institute. Accuracy of developed numerical model has been verified by measurements of the machine performance under normal and drive fault conditions tested on the elaborated research stand. Streszczenie. prezentowane badania, prowadzone na Politechnice Poznańskiej we współpracy z Instytutem Tele-i Radiotechnicznym dotyczą analizy i weryfikacji eksperymentalnej sześciofazowego silnika synchronicznego z magnesami stałymi. W celu ograniczenia strat związanych z występowaniem prądów wirowych w obwodzie magnetycznym wirnika maszyny jego segmenty wykonano z miękkiego kompozytu magnetycznego (SMC). W stosunku do powszechnie stosowanych rdzeni laminowanych technologia proszkowych materiałów SMC posiada wiele zalet. Między innymi dzięki znacznie większej rezystywności materiały te pozwalają ograniczyć straty wiroprądowe w rdzeniu, a dzięki uproszczeniu technologii wytwarzania możliwe jest ograniczenie kosztów produkcji. W polowo obwodowym modelu maszyny założono symetrię płaszczyznową obwodu magnetycznego maszyny oraz uwzględniono magnetyczne właściwości zastosowanego materiału SMC na podstawie krzywych BH oraz charakterystyk stratności zmierzonych w Instytucie Tele-i Radiotechnicznym. Dokładność opracowanego modelu numerycznego została zweryfikowana poprzez pomiary wybranych parametrów testowanej maszyny przeprowadzone na opracowanym stanowisku badawczym. Analiza i weryfikacja eksperymentalna sześciofazowego silnika synchronicznego z magnesami stałymi

The paper presents the new approach for motor driver constructions and control systems. Authors of the work proposed the device that can control both AC and DC electric motors without any additional hardware modification. In order to meet this goal the universal motor driver has been constructed and some improvements in output waveform modulation system have been introduced. In the paper the three different method of a motor control have been discussed briefly and a hardware setup has been presented. Tests have been carried out for three types of electric motors, i.e. a magnetoelectric DC motor, single-phase and three-phase induction motor. The obtained results in form of output waveforms of current and voltage have been analyzed in terms of harmonic distortion using a popular Fast Fourier Transform FFT and discussed in the paper.

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