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Generator stator coil 3701-02058

The insulating conductor assembly embedded in the stator slots of a rotating motor

The stator coil is the insulating conductor assembly embedded in the stator slots of a rotating motor, serving as the core of the winding and is applied in fields such as generators, traction motors, industrial motors, and new energy drive motors.

Its conductor is usually made of oxygen-free copper material and is connected through silver-copper welding technology. It is also subjected to curing treatment using F-class insulation and epoxy mica tape, etc. Modern stator coils adopt a flat wire structure and a comb-shaped conductor design to increase slot filling rate and power density. During manufacturing, six-axis numerical control insulation wrapping, stator injection molding, etc. processes are applied, and technologies such as X-Pin and Mini-Pin have been developed.

The stator coil is an insulated conductor component embedded in the stator slots of a rotating motor. The stator coil (winding) together with the stator core constitutes the stator assembly. The stator core has multiple slots, and the stator winding is embedded in the slots. The stator winding is formed by multiple hairpin coils wound in the slots in multiple layers (L layers). A typical stator winding can be formed by multiple hairpin coils wound in the slots in multiple layers (L layers), and each phase stator winding can include two sub-winding groups, each of which has multiple hairpin coils, these coils are distributed in different layers of the slots, including short-distance hairpin coils in the innermost layer (the first layer), long-distance hairpin coils in the outermost layer (the Lth layer), and intermediate hairpin coils in the middle layer.

Stator coils are mainly divided into two categories: round wire motors and flat wire motors. The stator winding of the flat wire motor uses rectangular cross-sectional conductors (flat copper wire), such as Hair-pin, Ipin, X-Pin, etc. The end structure of the flat wire motor winding is conducive to heat dissipation, and its slot fill rate (up to 60% or more) is significantly higher than that of the round wire motor (about 40%). The contact area between the flat wire windings is large, which can form an efficient heat conduction network and enhance the armature rigidity. The specific form of the flat wire motor is constantly evolving. Besides Hair-pin, it also includes X-Pin, Mini-Pin, Umini-Pin, Micro-Pin, etc., at the ends of which the height is shorter and more suitable for high-voltage platforms, aiming to further optimize space utilization, electrical performance, and manufacturing feasibility.

The conductors are made of oxygen-free copper material with a qualified electrical conductivity. The connection points between the coils are welded using silver-copper welding technology, and then wrapped with multiple layers of epoxy mica tape. After being heated and cured, an overall insulating structure is formed. The insulating materials mainly include organic materials (such as insulating paint, insulating paper) and inorganic materials (such as mica, ceramics). The insulation grades are A, E, B, F, and H, among which the F-grade insulation has the highest allowable temperature of 155°C. The VPI (vacuum pressure impregnation) process can improve the insulation performance and mechanical strength of the windings. For example, F-resin insulation (using mica tape as the insulating layer and vacuum impregnating with epoxy resin) is a high-performance insulation method for the stator windings of large high-voltage generators. The insulating system needs to be resistant to moisture and maintain elasticity to ensure no damage during disassembly.