"Basic Requirements and Raw Material Specifications for Wind Turbine Cores"

The stator core of a wind turbine is a critical component that forms the magnetic flux path and secures the stator coils. Generally, the core is constructed by stacking laminations and compressing them with various fasteners into a single integrated unit.

The primary function of the wind turbine core is to establish the excitation magnetic field, which exerts an electromagnetic force on the current-carrying conductors within it.

Basic Requirements for Wind Turbine Cores:

1. Excellent Magnetic Properties: The core must possess high magnetic permeability and low core losses.

2. Mechanical Rigidity: It must have sufficient structural stiffness to withstand mechanical stresses and resist excessive vibration during operation.

3. Effective Ventilation: The structural layout must ensure optimal airflow for cooling purposes.

4. Dimensional Precision: After being stacked and compressed, the inner diameter and slot dimensions of the core must strictly meet the design tolerances.

In addition to these fundamental requirements, specific operational characteristics may demand further criteria. For instance, large hydroelectric generators require precise control over the air gaps at the joints of segmented cores; otherwise, it can lead to severe core vibration during operation. 

Manufacturing Process of Wind Turbine Cores:
Stator core laminations are typically stamped from hot-rolled or cold-rolled silicon steel sheets, or soft magnetic iron-nickel alloy plates, with standard thicknesses of 0.5 mm or 0.35 mm. Full-circle (annular) laminations are used for outer diameters under 1 meter, while segment-shaped laminations are utilized for diameters exceeding 0.99 meters. Ventilation duct spacers consist of channel steel and spacer strips, with one or two pieces of channel steel spot-welded onto each tooth of the spacer strip. For core compression, full-circle laminations are generally secured using external pressure rings, whereas segment-shaped laminations are assembled using internal radial compression.

Raw Material Requirements for Wind Turbine Cores:
Under normal circumstances, wind turbine cores are manufactured using silicon steel. Silicon steel is an iron-silicon alloy containing between 0.8% and 4.8% silicon. This material is chosen because it exhibits exceptionally strong magnetic permeability. When energized, it generates a high magnetic flux density, thereby significantly reducing the overall size and weight of the generator.