Permanent magnet eddy-current loss calculation method for fractional-slot four-layer winding permanent magnet motor

Abstract

The invention discloses a permanent magnet eddy-current loss calculation method for a fractional-slot four-layer winding permanent magnet motor. The method comprises the following steps of dividing amotor region into a permanent magnet region, an air gap region, a stator notch region, a slot body upper-layer winding and a slot body lower-layer winding region; determining current density functionsof two layers of windings contained in the upper-layer winding area and the lower-layer winding area of the slot body, and expanding the current density functions into Fourier series expressions respectively; establishing vector magnetic potential equations in the five regions; boundary conditions of interfaces of all the areas being applied, vector magnetic potential equations of the five areasbeing determined, and a permanent magnet motor armature reaction magnetic field distribution expression being obtained; and establishing an analytical model of the permanent magnet eddy current loss,and calculating to obtain the total eddy current loss of the permanent magnet motor and the eddy current loss caused by armature reaction field harmonics. The method not only can accurately calculatethe total permanent magnet eddy current loss, but also can calculate the eddy current loss generated by each harmonic of the armature reaction field, and provides a quick and accurate research means for motor armature winding optimization design and performance analysis.

Description

technical field [0001] The invention relates to a method for calculating eddy current loss of a permanent magnet of a fractional slot four-layer winding permanent magnet motor, belonging to the technical field of permanent magnet motors. Background technique [0002] Fractional slot permanent magnet motors have the advantages of short winding ends, high slot utilization, low cogging torque, and strong fault tolerance, and have received more and more attention in recent years. However, the armature field of this motor contains high-amplitude low-order harmonic components. When the motor is running at high speed, the harmonic magnetic field will induce a large eddy current loss in the permanent magnet, which will cause the rotor of the motor to heat up and reduce the efficiency. In severe cases, it will even cause the permanent magnet to demagnetize and damage the motor. [0003] To suppress the permanent magnet eddy current loss in the fractional slot permanent magnet motor,...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the problem that the structure of the four-layer winding is complex and it is difficult to establish an analytical model, the present invention provides a calculation method for the eddy current loss of the permanent magnet of a permanent magnet motor with a fractional slot four-layer winding, which expands the application range of the subdomain model and obtains the fractional slot four Distribution of armature reaction field and permanent magnet eddy current loss of surface-mounted permanent magnet motor with layer winding

Images