Basic Requirements and Raw Material Requirements for Wind Turbine Generator Cores

The core of a wind turbine generator is a crucial component that forms the magnetic flux path and secures the stator windings. Generally, the core of a wind turbine generator is constructed by stacking laminated steel sheets and compressing them with various fasteners to form an integral unit.

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

The fundamental requirements that a wind turbine generator core must meet include:
First, it must possess excellent magnetic permeability and low core losses.
Second, it must have good structural rigidity and excellent vibration characteristics.
Third, the structural layout of the core must ensure effective ventilation.
Fourth, after being stacked and compressed, the inner diameter and slot dimensions of the core must meet the design precision requirements.

In addition to the above requirements, considering specific operational characteristics, the core must also meet other criteria. For example, in large hydroelectric generators, it is essential to ensure a proper fit at the joints of segmented cores; otherwise, it will cause core vibration during motor operation.

Manufacturing Overview of Wind Turbine Generator Cores:
The stator core laminations are typically stamped from hot-rolled or cold-rolled silicon steel sheets, or iron-nickel soft magnetic alloy sheets, with a thickness of either 0.5 mm or 0.35 mm. Laminations with an outer diameter of less than 1 m are stamped as full circles, while those larger than 0.99 m are stamped as fan-shaped segments. Ventilation duct sheets consist of duct steel and duct laminations, with one or two duct steel bars spot-welded onto each tooth of the duct lamination. For core fastening, full-circle laminations are generally assembled using external compression, whereas fan-shaped laminations are assembled using internal compression.

Raw Material Requirements for Wind Turbine Generator Cores:
Under normal circumstances, wind turbine generator cores are made from silicon steel sheets. Silicon steel is a steel alloy containing silicon, with a silicon content ranging from 0.8% to 4.8%. Silicon steel is used for the cores of transformers and wind turbine generators because it is a highly permeable magnetic material. When used in energized coils, it can generate a high magnetic flux density, thereby reducing the overall volume of the transformer or generator.