Taking certain measures in the motor design and manufacturing stages is a top-level approach to reducing losses and forms the basis for reducing stator copper losses. For instance, based on the premise of conforming to insulation structure and operational process, reducing the end dimensions of the stator windings, while considering the motor’s power factor and starting current, decreasing the number of stator windings and increasing the conductive area, are highly effective measures. However, due to various reasons, these measures often cannot be implemented. In such cases, it may be necessary to adopt measures such as increasing the iron length, enlarging the slot shape and wire diameter, and reducing the number of turns. However, these measures will inevitably lead to varying degrees of increase in material costs.
In addition to the above measures, changing the slot shape is also an effective one: for example, changing from the original open slot to a semi-open slot. For cast aluminum rotor motors, using a closed slot, the aim is to fully utilize the shape of the core slot, so as to make the motor air-gap coefficient as large as possible and the leakage reactance not too large, ultimately achieving the purpose of energy saving. For cast aluminum rotor motors, making full use of the process characteristics of liquid filling, optimizing the slot shape of the rotor laminations to the maximum extent, such as convex shape, knife shape, double cage shape, and closed slot design, are all very beneficial design improvements, which have played a positive role in improving the motor efficiency.
In terms of the manufacturing process, the processes related to winding the coils, embedding the wires, and insulation treatment are very important. How to ensure that the coils with smaller ends can smoothly fit into the slots, how to reduce the unnecessary length during the winding process, and how to better solidify the coils through insulation treatment – all these are effective methods to reduce losses. During the actual operation, it can be observed that for the same coil, the male coil winding results in a more regular coil than the female coil winding, and less material is needed for embedding; the coils wound by the automatic winding machine have good consistency, and through the adjustment of tension, the ineffective materials can be reduced to the minimum, which is beneficial and harmless to the loss control.
Post time: Oct-08-2025