Energy efficiency improvement adopting synchronous motors

There is a growing interest in adopting electrical motors exhibiting high efficiency. Therefore, induction machines are often replaced by more efficient electrical drive solutions. Variable-speed drives are often chosen instead of the traditional grid-connected solutions, so as to avoid unefficient regulations at constant speed, when the machine operates at part load. This paper aims to compare different types of electric motor drives for high efficiency applications: an induction motor drive, a synchronous reluctance motor drive, and a permanent magnet assisted synchronous reluctance motor drive. The innovative field-oriented analysis technique is applied to estimate the motor drive performance. This method of analysis is particularly advantageous in comparing the induction motor performance to those of synchronous machines. The comparison among the capabilities of the three electric drives is carried out combining both analytical and finite element methods. The analysis strategy adopted has been arranged so as to obtain rapidly the motor drive capability.