Sheng-Yang Lin, CHINA STEEL CORPORATION / Min-Fu Hsieh, Electric Motor Technology Research Center
The performance of electric steels can change dramatically after punching. Electric motors manufactured with the punched electric steels may then suffer from performance degrade. This indicates that, to conform motor performance to the design specifications, either such defects should be considered in the design or the degraded steel magnetic properties should be restored (for example, through annealing).
In this research, the effects of annealing on the recovery of the punching damage are first investigated.
Experimental work is carried out using test samples to observe the punching impact on electromagnetic properties and SRM performance. Two SRMs are then designed using JMAG and fabricated. These two SRMs are identical except that electrical steel in one of the motors is annealed while the other is not. The SRMs are tested using the same electronic driver and testing system to measure the output torque. The output torque of annealed motor is found to be higher than that of non-annealed motor under the same rotating speed.
This punching effect is then considered in the simulation of SRMs using JMAG. The magnetic properties (previously measured) in the damaged zones are input to JMAG for simulation of SRMs. The simulation results are compared with the experiments discussed above and they agree well. Finally, a discussion over the design of SRMs considering the damage zone is provided as a conclusion.