Instruments and Systems: Monitoring, Control, and Diagnostics Annotation << Back Feasibility study of increasing the number of electric drive phases SH. I. VAFIN, A.G. LOGACHEVA Distribution of frequency converters as power supply to asynchronous motors marked such a problem as the negative impact of nonsinusoidal voltage to the motor characteristics. One of the possible ways to minimize this effect is to increase the phase number of the “frequency converter ‒ induction motor” system. But increasing the number of phases in the converter is primarily due to an increase in number of component parts; particularly the number of inverter switches increases. This paper is devoted to the economic evaluation of the feasibility of replacing the three-phase inverter with multiphase one in terms of inverter transistor switches cost. For this purpose, the IGBTs were analyzed in terms of price to rated collector-emitter voltage, switching frequency and maximum collector current. Using MATLAB tool original data were approximated by Hermite polynomials and a graphical representation of the conditional price of the frequency converter on the number of phases of the inverter built on 8-30 kHz 1200 V IGBTs was found. Keywords: multiphase induction motor; frequency converter; inverter; transistor; IGBT; price. Contacts: E-mail: vafinshi@yandex.ru Pp. 54-59.