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EP-4742505-A1 - MODULAR HAIRPIN WINDING AND STATOR STRUCTURE

EP4742505A1EP 4742505 A1EP4742505 A1EP 4742505A1EP-4742505-A1

Abstract

A modular hairpin winding structure consists of four types of hairpin wires and two flat wire conductors forming at least one phase unit within a phase winding. Each phase unit is distributed along a portion of the stator core circumference and functions as an independent modular structure to simplify wiring design and reduce assembly complexity.

Inventors

  • CHANG, CHIN-FENG
  • CHU, CHIH-MENG
  • CHEN, CHEN
  • CHANG, CHEN-HUI

Assignees

  • Fukuta Electric & Machinery Co., Ltd.

Dates

Publication Date
20260513
Application Date
20241107

Claims (4)

  1. A modular hairpin winding designed for installation within a stator core (100) to form each phase winding of a three-phase winding system, wherein each phase winding includes at least one phase unit (210), and the modular hairpin winding comprises multiple flat wire conductors connected in series to form each phase unit (210); wherein, the stator core (100) includes a yoke (101) and multiple teeth (102) arranged circumferentially along the yoke (101) to form N slots, each slot accommodating L+2 layers of the flat wire conductors, where N is a multiple of 12, and both N and L are positive integers; characterized in that , the flat wire conductors of each phase unit (210) comprise one first hairpin winding wire (U1), one second hairpin winding wire (U2), one third hairpin winding wire (U3), 2L fourth hairpin winding wires (U4), and two additional conductors (I1,I2), each of the first, second, third, and fourth hairpin winding wires comprising a crown portion (C1,C2,C3,C4), two extending segments (A1,A2) extending from opposite ends of the crown portion (C1,C2,C3,C4), and two welding segments (B1,B2) extending from the other ends of the extending segments (A1,A2); the crown portion (C1) of the first hairpin winding (U1) wire spans six slot pitches, with its two extending segments (A1,A2) arranged in the first layer of the slots, the crown portion (C2) of the second hairpin winding wire (U2) spans seven slot pitches, with its two extending segments (A1,A2) arranged in the (L+2)th layer of the slots, the crown portion (C3) of the third hairpin winding wire (U3) spans five slot pitches, with its two extending segments (A1,A2) arranged in the (L+2)th layer of the slots, the crown portion (C4) of each fourth hairpin winding wire (U4) spans five slot pitches, with its two extending segments (A1,A2) arranged across the second to (L+1)th layers of the slots, and the two extending segments (A1,A2) of the same fourth hairpin winding wire (U4) spanning the adjacent layers within the slots, and each of the two additional conductors (I1,I2) includes a connecting segment (A3,A4) arranged in the first layer of the slot, with each connecting segment (A3,A4) extending outwardly to form a welding segment (B3,B4); wherein, the two welding segments (A1,A2) of the first hairpin winding wire (U1) are each connected to one welding segment (B 1,B2) of the two fourth hairpin winding wires (U4) in the second layer of the slot, the welding segments (B3,B4) of the two additional conductors (I1,I2) are each connected to one welding segment (B 1,B2) of the two fourth hairpin winding wires (U4) in the second layer of the slot, the two welding segments (B1,B2) of the second hairpin winding wire (U2) are each connected to one welding segment (B1,B2) of the adjacent fourth hairpin winding wire (U4) in the (L+1)th layer of the slot, the two welding segments (B1,B2) of the third hairpin winding wire (U3) are each connected to one welding segment (B1,B2) of the adjacent fourth hairpin winding wire (U4) in the (L+1)th layer of the slot, and one welding segment (B1) in one of the remaining fourth hairpin wires (U4) is connected to one welding segment (B2) of another fourth hairpin wire (U4), where the extending segment (A1,A2) of the latter is located in the adjacent layer within the same slot.
  2. The modular hairpin winding according to Claim 1, wherein, the connecting segments (A3,A4) of the two conductors (I1,I2) are arranged in the slot n1 and the slot n1+6, respectively, where n1 is a positive integer, such that: the two extending segments (A1,A2) of the first hairpin winding wire (U1) are arranged in the slot n1+1 and the slot n 1 + 7, respectively, the two extending segments (A1,A2) of the second hairpin winding wire (U2) are arranged in the slot n1+5 and the slot n1+12, respectively, the two extending segments (A1,A2) of the third hairpin winding wire (U3) are arranged in the slot n1+6 and the slot n1+11, respectively, and one of the extending segments (A1,A2) of the fourth hairpin winding wire (U4) is located in the slot n1, the slot n 1 + 1, the slot n1+6, or the slot n 1 + 7.
  3. The modular hairpin winding according to Claim 1, wherein, the two welding segments (B1,B2) of each fourth hairpin winding wire (U4) are bent toward its crown portion (C4), one of the welding segments (B1) of the first hairpin winding wire (U1) is bent toward its crown portion, while the other welding segment (B2) is bent away from its crown portion (C1), one of the welding segments (B1) of the second hairpin winding wire (U2) is bent toward its crown portion, while the other welding segment (B2) is bent away from its crown portion (C2), one of the welding segments (B1) of the third hairpin winding wire (U3) is bent toward its crown portion, while the other welding segment (B2) is bent away from its crown portion (C3), and each welding segment spans two and a half slot pitches from its crown portion.
  4. A stator structure, comprising the modular hairpin winding according to any one of Claims 1 to 3, configured to form at least one phase unit (210) of any phase winding in a three-phase winding system.

Description

FIELD OF INVENTION The present disclosure relates to a hairpin winding layout, in particular a modular hairpin winding layout. BACKGROUND OF THE INVENTION The stator of a three-phase induction motor contains three symmetrically distributed coil windings. When a three-phase alternating current is passed through these windings, a rotating magnetic field is generated at the same frequency as the alternating current, causing the rotor to rotate. In recent years, a type of copper wire known as hairpin winding wire has been increasingly used to form flat wire windings. The flat wire windings (also called rectangular wire windings) provide a higher current carrying capacity than conventional windings with circular wire cross-sections and are also advantageous for motor operation at high power densities and efficiencies due to their improved heat dissipation. In the assembly of the hairpin windings, the multiple flat copper wires are initially bent sequentially into hairpin conductors. According to the wiring diagram, these hairpin conductors are radially stacked and arranged circumferentially in a ring shape. The open ends of these conductors are then inserted axially into slots of the stator core. Finally, the open ends of the hairpins are subjected to twisting, levelling, and welding processes to complete the formation of the flat wire windings. Existing hairpin conductor units can be structurally categorized into Hairpin (or U-pin), I-pin, X-pin, and S-winding forms. Considering that the assembly of the hairpin winding wires involves complex processes and requires high precision, simplifying the winding method would significantly reduce the design complexity. SUMMARY OF THE INVENTION The present disclosure provides a modular hairpin winding structure designed for installation in a stator core to form each phase winding of a three-phase winding system. Each phase winding includes at least one phase unit, and the modular hairpin winding comprises multiple flat wire conductors connected in series to form each phase unit. The stator core includes a yoke and multiple teeth arranged circumferentially along the yoke to form N slots, each slot accommodating L+2 layers of the flat wire conductors. Where N is a multiple of 12, and both N and L are positive integers. The flat wire conductors of each phase unit include a first hairpin winding wire, a second hairpin winding wire, a third hairpin winding wire, 2L fourth hairpin winding wires, and two additional conductors. Each of the first, second, third, and fourth hairpin winding wires comprises a crown portion, two extending segments extending from opposite ends of the crown portion, and two welding segments extending from the other ends of the extending segments. The crown portion of the first hairpin winding wire spans six slot pitches, with its two extending segments arranged in the first layer of the slots. The crown portion of the second hairpin winding wire spans seven slot pitches, with its two extending segments arranged in the (L+2)th layer of the slots. The crown portion of the third hairpin winding wire spans five slot pitches, with its two extending segments arranged in the (L+2)th layer of the slots. The crown portion of each fourth hairpin winding wire spans five slot pitches, with its two extending segments arranged across the second to (L+1)th layers of the slots, and the two extending segments of the same fourth hairpin winding wire spanning the adjacent layers within the slots. Each of the two additional conductors has a connecting segment arranged in the first layer of the slot, each connecting segment extending outwardly to form a welding segment. The two welding segments of the first hairpin winding wire are each connected to one welding segment of the two fourth hairpin winding wires in the second layer of the slot. The welding segments of the two additional conductors are each connected to one welding segment of the two fourth hairpin winding wires in the second layer of the slot. The two welding segments of the second hairpin winding wire are each connected to one welding segment of each adjacent fourth hairpin winding wire in the (L+1)th layer of the slot. The two welding segments of the third hairpin winding wire are each connected to one welding segment of each adjacent fourth hairpin winding wire in the (L+1)th layer of the slot. One welding segment in one of the remaining fourth hairpin wires is connected to one welding segment of another fourth hairpin winding, where the extending segment A1 of the latter is located in the adjacent layer within the same slot. The conductor layout described enables the hairpin windings that form each phase unit to be distributed along only a portion of the circumference of the stator core, allowing each phase unit to function as a modular structure that simplifies wiring design and reduces assembly complexity. Additionally, when the connecting segments of the two conductors are arranged in the slot n1 and the