Flat-Wire Motor Winding Layout for Lower Harmonic NVH
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Solution Overview
Problem
Conventional flat-wire motors with full-pitch windings suffer from high harmonic winding coefficients, leading to significant torque fluctuations and noise vibration harshness (NVH) issues, while short-pitch windings are limited by their winding form, making it difficult to implement odd-numbered layers of flat-wire conductors and effectively weaken the harmonic magnetic field.
Innovation Solution
The motor design includes a stator with evenly spaced stator slots, where flat-wire conductors are connected in a short-pitch configuration, allowing for odd or even numbers of layers, and hairpin coils are used to form connections without cross-layer plug-ins, simplifying the winding process and reducing harmonic magnetic fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If full-pitch winding is used, then copper fill ratio and heat dissipation are improved, but harmonic winding coefficient increases causing torque fluctuation and NVH issues
Solution Approach 1:
The patent changes the winding pitch parameter from full-pitch to short-pitch configuration. Specifically, the stator winding adopts a short-pitch structure where the coil span is less than the pole pitch, which reduces the harmonic winding coefficient while maintaining effective heat dissipation through the optimized flat-wire conductor arrangement in stator slots.
2Object-generated harmful factors
If short-pitch winding is used to reduce harmonic winding coefficient, then NVH performance improves, but winding form is limited and odd-numbered layers cannot be implemented
Solution Approach 1:
The patent segments the stator winding into multiple independent layers of flat-wire conductors (first layer, second layer, third layer, etc.) that can be independently connected. This segmentation allows flexible connection configurations where different layers can be connected in various patterns, enabling both odd and even numbered layer implementations while maintaining short-pitch configuration for harmonic reduction.
Solution Approach 2:
The patent creates a universal short-pitch winding structure that can accommodate different numbers of flat-wire conductor layers (odd or even) through flexible connection configurations. The stator winding design is multi-functional, supporting various layer arrangements while consistently achieving harmonic field reduction and NVH improvement across different implementations.
3Adaptability or versatility
If cross-layer plug-in is used for hairpin coils, then winding flexibility increases, but manufacturing complexity and connection difficulty increase
Solution Approach 1:
The patent transitions from three-dimensional cross-layer plug-in operations to two-dimensional same-layer connections. Flat-wire conductors are connected within the same layer horizontally, eliminating the need for complex vertical plug-in operations across multiple layers. This dimensional simplification maintains winding flexibility through in-plane connections while dramatically reducing manufacturing complexity and improving ease of assembly.
Data Source
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AI summary
This application provides a motor, a powertrain, and a vehicle. The motor includes a stator and a rotor. The stator includes a stator iron core and a stator winding. The stator iron core is provided with 54 stator slots. Each stator slot is provided with six layers of flat-wire conductors. Every two first-layer flat-wire conductors are connected to each other, and flat-wire conductors connected to each other are spaced apart by nine stator slots or six stator slots. Second-layer flat-wire conductors are respectively connected to third-layer flat-wire conductors, fourth-layer flat-wire conductors are respectively connected to fifth-layer flat-wire conductors, and two flat-wire conductors connected to each other are spaced apart by seven stator slots. Every two sixth-layer flat-wire conductors are connected to each other, and two flat-wire conductors connected to each other are spaced apart by eight stator slots.