Influence of Core Saturation on Overload Torque of Permanent Magnet Brushless DC Motor under Heat Restriction
The reasonable saturation point of the iron core can improve the torque of high overload permanent magnet brushless DC motor.The thermal limiting conditions in the optimization of torque rise will affect the optimal core saturation point.It is necessary to explore the influence of the degree of iron core saturation under thermal constraints on the torque in order to provide theoretical refer-ences for torque enhancement.Therefore,an equivalent magnetic circuit model considering iron core saturation and armature reaction was constructed.Based on this magnetic circuit model,expressions for torque,losses,and thermal constraints were derived,and an analytical relationship between torque and dimensions as well as thermal constraints was established.The influence of iron core satura-tion on torque under different thermal constraints was analyzed.The relationship between maximum torque and iron core saturation un-der conditions that simultaneously limit current density and copper loss density was discussed,and the effects of different materials on torque enhancement were compared.The research shows that there is a magnetic density point that maximizes torque under thermal con-straints,and different thermal constraints will affect the size of the optimal magnetic density point.The analytical results are validated using finite element simulation and experimental testing.The errors of the simulation results and experimental results are less than 2％and less than 10％respectively compared to the analytical values.The simulation and experimental results indicate that the constructed electromagnetic model considering saturation and the analysis calculation process have high accuracy.
permanent magnet brushless DC motorcore saturationheat restrictionhigh-overload
万方数据
维普
