What is the relation between the overhang specific permeance and the slot pitch?

The relation between the overhang specific permeance and the slot pitch is found within the context of electrical machines design, particularly in the design of electric motors and generators. Overhang specific permeance relates to the magnetic permeance offered by the part of the winding that lies outside the slots (overhang). This aspect is crucial for determining the magnetic flux linkage with the winding, thereby influencing the machine’s electromagnetic performance.

Slot pitch is the distance between similar points on two adjacent slots. Typically, it is measured along the circumference of the armature in the air-gap surface. This measurement is crucial because it affects how the windings are distributed around the armature, thereby impacting the machine’s magnetic circuit.

The relationship between overhang specific permeance and slot pitch is significant for a few reasons:

1. Design Optimization: The overhang specific permeance and slot pitch must be optimized to ensure efficient flux linkage and to minimize magnetic losses. A shorter overhang can reduce the length of the end winding, leading to lower resistive losses, while an appropriately selected slot pitch can help in achieving a more uniform distribution of the magnetic field, enhancing the machine’s performance.

2. Magnetic Saturation: The right combination of overhang specific permeance and slot pitch helps in avoiding magnetic saturation in the cores adjacent to the slots, improving the machine’s efficiency and operational stability.

3. Harmonic Reduction: The interaction between overhang specific permeance and slot pitch has implications on the generation of harmonic content in