Definitions

Saturation

a condition where an increase in the magnetic field strength (H) does not produce a proportional increase in the magnetic flux density (B) in a material. —Here the strength of a magnetic field is increasing but that strength cannot be distributed to more fields, the material is saturated with extra magnetic strength w no place to put it cause not enough field lines are produced.

• When a material becomes saturated, further increases in the applied magnetic field strength do not lead to a significant increase in the material's magnetic flux.
• Saturation occurs when the magnetic domains in the material are aligned to their maximum extent, and the material cannot exhibit higher magnetic flux despite increasing the magnetizing force.

Magnetic flux

The total amount of magnetic field lines passing through a given area. It's a measure of the quantity of magnetic field penetrating a surface or enclosed by a loop.

Magnetic flux (Φ) is given by the product of the magnetic field strength (B) and the area (A) through which the magnetic field lines pass, and the cosine of the angle (θ) between the magnetic field and the normal to the surface:

Φ = B * A * cos(θ)

Intensity of the magnetic field

(often denoted as H) represents the magnetizing force applied to a material that contributes to the alignment of its magnetic domains. It's typically measured in amperes per meter (A/m) and indicates the strength of the magnetic field within a given medium.

So, while the intensity of the magnetic field (H) contributes to the alignment of magnetic domains within a material, saturation occurs when these domains are fully aligned, and the material cannot exhibit increased magnetic flux despite further increases in the applied magnetic field strength.

Transverse end effect

• larger problem w LIMs using primary as the mover since the secondary must be wider & air gap larger than 10mm worsening the effect Source (abstract)

cross-gap flux density

The cross-gap flux density refers to the magnetic flux density across the air gap in an electric machine, such as a linear induction motor or a similar device. In a linear induction motor specifically, this term describes the magnetic flux density present in the air gap between the primary (stator) and the secondary (mover or translator) when the motor is operational.

The air gap flux density is a crucial factor in determining the motor's performance, efficiency, and the force exerted on the secondary element. A higher flux density generally correlates with higher force production but can also lead to increased losses and potential saturation of magnetic materials.

Engineers aim to optimize the cross-gap flux density by designing the motor to achieve a balance between:

1. Maximizing Force Production: A higher flux density often translates to stronger forces on the secondary element, which is essential for motor performance, especially in applications requiring high thrust or speed.
2. Minimizing Losses: Higher flux densities can result in increased losses due to phenomena like eddy currents and hysteresis losses in the motor's components. Managing these losses is crucial to maintain the motor's efficiency.