MW级电磁轴承高速永磁电机空气摩擦损耗特性研究OA

The air friction loss of a motor rotor increases rapidly with the increase in rotational speed.Especially for a high-speed motor supported by magnetic bearings,since the air-gap structure is complex,mastering its air friction loss characteristics is particularly important.A 2 MW、15 000 r/min high-speed permanent magnet motor with magnetic bearings was taken as the research object,and the entire air domain inside the motor was modeled.Firstly,based on the fine simulation technology of computational fluid dynamics(CFD),the distribution characteristics of air friction loss on the rotor surface were obtained.Then,the effects of rotational speed,ventilation wind speed,surface roughness height,air gap structure,and rotor eccentricity on the air friction loss characteristics of the rotor were analyzed in detail.Finally,a dual-motor drag test was conducted,and the air friction loss of the rotor was obtained by the loss separation method.The research results indicate that the air friction loss of the rotor is mainly concentrated in the air gap of the motor.At a rotational speed of 15 000 r/min and a ventilation wind speed of 2.5 m/s,it accounts for approximately 70.1％of the total air friction loss.Meanwhile,the air friction loss at the thrust collar cannot be ignored,accounting for about 23.9％of the total air friction loss under the non-ventilation condition.The synergistic thermal effect of cooling enhancement and loss increase caused by ventilation needs to be comprehensively considered.When the ventilation wind speed increases from 2.5 m/s to 5.0 m/s,the cooling heat transfer coefficient on the rotor surface increases from 315.7 W/(m2•℃)to 469.1 W/(m2•℃),and the air friction loss also increases by 3.13 kW.The maximum error between the experimentally measured values and the simulation calculation results is 8.60％.