Calculation And Analysis Of Loss Of High-speed Permanent Magnet Machine

Permanent magnet synchronous motors have high efficiency,simple structure,high power factor and good control characteristics,and are especially suitable for high-speed operation.They have been widely used in machining industry,power tools,flywheel energy storage,high-speed centrifuges,high-speed compressors and other fields.Accurate calculation of winding AC loss,stator core loss and rotor eddy current loss is a key issue for high-speed permanent magnet synchronous motors,and it is also a hot spot in electrical research in recent years.In this paper,the skin effect and proximity effect of windings caused by high-frequency current are deeply studied,the influence of inverter harmonic current on the AC loss of highspeed permanent magnet synchronous motor windings is analyzed,and the relationship between the AC loss of motor windings and the carrier ratio is obtained.changing laws.By analyzing the influence of the conductor diameter on the AC loss of the conductor,it is concluded that when the current frequency and amplitude are constant,the total conductor loss has a minimum value with the change of the conductor diameter.The method of keeping the total area of conductors equal and adopting multiple parallel windings to reduce the high-frequency AC loss is studied.The AC loss of the winding in the winding mode is larger than that of the winding without parallel winding.The magnetization and loss properties of amorphous alloy materials are seriously affected by processing,and the magnetization and loss properties of the processed amorphous alloy cores are seriously deteriorated.Based on the measured loss test data of amorphous alloy strips and laminated amorphous alloy cores at multiple frequencies,the loss correction coefficients of laminated amorphous alloy stator cores are summarized,and the discrete loss of iron is fitted.model coefficients.The influence of inverter harmonic current,magnetizing direction of permanent magnet and hypotenuse angle of magnetic steel on stator core loss of high-speed permanent magnet synchronous motor is analyzed by time-step finite element method.According to the summed loss discrete model coefficients,the no-load iron loss is calculated and verified for the strip-based loss characteristics and the modified strip-based loss characteristics.The three influencing factors are simultaneously applied to the overall loss of the motor in one prototype.The suppression effect was calculated and verified by finite element calculation.The effects of the width of the motor slot,the conductivity and thickness of the protective sheath and the copper shielding layer on the rotor eddy current loss were studied by using the time-step finite element method.According to the theory of the electromagnetic field of the motor,the eddy current loss of the permanent magnet of the high-speed motor is calculated by the analytical method in the Cartesian coordinate system.The above three methods of suppressing loss are applied to a prototype,and the unimproved and improved loss sizes are compared and calculated,which verifies the correctness of the previous analysis of influencing factors.