Stator Winding Configuration for Torque Ripple Reduction
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Solution Overview
Problem
In rotating electrical machines with dual winding groups, a magnetic imbalance can occur when one inverter fails, leading to increased torque ripple during motor operation, especially when the machine is driven by a single three-phase winding group.
Innovation Solution
The stator winding is configured with two independent three-phase windings, where the first three-phase winding is arranged in three teeth groups at 120-degree mechanical pitches, and the second three-phase winding is arranged in the remaining teeth, maintaining symmetry and balance between the winding units, even when driven by a single inverter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the motor is driven by a single three-phase winding group when one inverter fails, then the motor can continue to operate, but magnetic imbalance occurs and torque ripple increases
Solution Approach 1:
The stator winding is divided into two independent three-phase winding groups (first and second windings), each capable of independent operation. Each winding group is further segmented into three teeth groups arranged at 120-degree mechanical pitches, creating symmetric magnetic paths that reduce torque ripple when operating with a single inverter.
Solution Approach 2:
The patent employs a symmetric winding arrangement where both winding groups have identical structural characteristics but are positioned on different teeth. This symmetric design ensures that when one inverter fails and only one winding group operates, the magnetic flux distribution remains balanced across the air gap, preventing magnetic imbalance and reducing torque ripple.
2Ease of manufacture
If concentrated windings are arranged in three teeth groups at 120-degree pitches for the first three-phase winding, then the winding structure becomes compact, but the arrangement complexity increases
Solution Approach 1:
The 6N teeth are systematically divided into two sets: the first three-phase winding occupies three teeth groups (each with N adjacent teeth) at 120-degree mechanical pitches, while the second three-phase winding occupies the remaining three teeth groups at the same pitch angles. This segmented arrangement simplifies the winding process by providing clear spatial separation and repeating patterns.
Solution Approach 2:
The patent distributes windings across the circumferential dimension of the stator, utilizing the 120-degree mechanical pitch arrangement to create symmetric magnetic paths. This spatial distribution in the circumferential dimension simplifies the winding structure by creating repeating patterns that are easier to manufacture compared to conventional concentrated windings.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration significantly reduces torque ripple during one-side electrical current supply, maintaining motor balance and efficiency, and prevents heat generation imbalance when one inverter fails.
Implementation Method 1
a stator iron core including 6N teeth where an integer N≥2; and a stator winding including concentrated windings arranged to the respective 6N teeth
Data Source
AI summary
Provided is a rotating electrical machine in which torque ripple can be decreased at the time of one-side electrical current supply. A motor includes a stator coil constituted by concentrated windings arranged to teeth where an integer N≥2. The stator coil includes first and second winding units and each of which is constituted by windings and which are independent from each other, the windings constituting the first winding unit are arranged in three teeth groups, each of which includes adjacent teeth and which are provided at 120-degree pitches in terms of mechanical angle, and the windings constituting the second winding unit are arranged in teeth which are the teeth not included in the three teeth groups. That is, the windings constituting the second winding unit are also arranged in three teeth groups, which are provided at 120-degree pitches in terms of mechanical angle.