Small high-speed induction motors

This paper presents the design, construction and testing of two high-speed induction motor prototypes. Both machines have a laminated squirrel-cage rotor and a rated torque of 0.29 Nm at 50000 rpm, i.e. a rated power of 1.5 kW. The main difference between the machines is the number of poles, one 2-pole design and one 4-pole design. The machines are compared regarding harmonics, based on measurements and the interaction between harmonics in the time and space domains are theoretically discussed. Harmonic analysis of the measured phase current at different frequencies and inverter modulations is also compared.