Lamination Magnet

Laminated rare earth magnets can reduce eddy current losses in high-efficiency motors. Smaller eddy current losses mean lower heat and higher efficiency.

In permanent magnet synchronous motors, the eddy current losses in the rotor are ignored because the rotor and stator are rotating synchronously. In fact, stator slot effects, non-sinusoidal distribution of winding magnetic forces and harmonic magnetic potentials generated by harmonic currents in the coil winding also cause eddy current losses in the rotor, rotor yoke and metal permanent magnets binding the permanent magnet sheath

Since the maximum operating temperature of sintered NdFeB magnets is 220 ° C (N35AH), the higher the operating temperature, the lower the magnetism of the NdFeB magnets, the lower the conversion and power of the motor. This is called heat loss! These eddy current losses can lead to elevated temperatures, leading to local demagnetization of permanent magnets, which is particularly severe in some high speed or high frequency permanent magnet synchronous motor.

Heat loss is mainly caused by electromagnetic eddy current during motor operation. Therefore, multiple stacking methods (which require insulation between each magnet) to reduce this heat loss.