Direct-On-Line Synchronous Reluctance Motor Efficiency Verification with Calorimetric Measurements

Direct-on-line motors are in the majority despite that an increasing number of new motor installations are equipped with frequency converter. However, regulations and environmental awareness are pushing the efficiency demands and the dominant induction motor technology is approaching its practical efficiency limits. Direct-on-line synchronous reluctance motor technology provides an alternative to the induction motor technology with the capability to reach higher efficiency levels especially in low power range. This paper presents efficiency verification measurements using calorimetric method for two 45 kW direct-on-line synchronous reluctance motor prototypes. The results are compared with high-efficiency induction motors available in the market.