Common-Core Generator Winding Layout for Low Ripple Output
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Solution Overview
Problem
Current generator topologies suffer from substantial DC-Link ripple and torque ripple due to individual phases being routed through separate stator slots, leading to increased weight, size, and reliability issues.
Innovation Solution
Implementing a variable frequency generator (VFG) with co-located phase-shifted windings in the same stator slots, where two sets of three-phase windings share common slots, allowing for reduced maximum flux and optimized flux sharing, thereby minimizing DC-Link ripple and torque ripple.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If individual phases are routed through separate stator slots, then the generator winding scheme is simple, but the generator produces substantial DC-Link ripple and torque ripple
Solution Approach 1:
The patent combines multiple phase windings into shared stator slots. Specifically, it uses co-located windings where phases are grouped together in the same slot, and distributed windings where phases are spread across adjacent slots. This merging approach reduces the number of separate windings needed while maintaining electrical performance, thereby eliminating torque ripple without significantly complicating the manufacturing process.
Solution Approach 2:
The patent segments the stator windings into distinct co-located groups and distributed patterns. By dividing the winding arrangement into specific segments with defined phase groupings, it achieves better current distribution and reduced ripple while keeping the overall structure manageable and manufacturable.
2Device complexity
If a 3-phase generator with transformer system is used, then the configuration is simple, but the system requires more volume and weighs more
Solution Approach 1:
The patent merges the functions of multiple phases into a unified stator structure with shared windings. By combining phase windings in co-located and distributed arrangements within the same stator, it eliminates the need for separate transformer assemblies, thereby reducing overall system weight and volume while maintaining the electrical functionality of a multi-phase system.
Solution Approach 2:
The stator structure is designed to perform multiple functions simultaneously - generating multiple phases, providing magnetic flux paths, and housing all windings in a single integrated component. This multi-functionality eliminates the need for separate transformer components, reducing both weight and complexity compared to a 3-phase system with an external transformer.
3Reliability
If a large capacitor bank is utilized to reduce DC-Link ripple, then the ripple is reduced, but the system size and weight increase
Solution Approach 1:
The patent extracts the ripple reduction function from the electrical filtering domain (capacitor banks) and relocates it to the magnetic domain through optimized winding arrangements. By implementing co-located and distributed windings that inherently balance current distribution, the system achieves ripple reduction without requiring large external capacitor banks, thereby eliminating their associated weight and volume.
Solution Approach 2:
The patent replaces the mechanical/electrical filtering system (capacitor banks) with a magnetic field-based solution through optimized winding geometry and distribution. The co-located and distributed winding arrangements create magnetic flux patterns that naturally balance current ripple, substituting the need for large passive filtering components and reducing overall system weight.
4Weight of stationary object
If co-located windings are implemented, then size and weight are reduced, but the winding structure becomes more complex
Solution Approach 1:
The patent segments the complex winding structure into standardized co-located groups and distributed patterns. By dividing the windings into repeating modular units with defined phase groupings, it simplifies the manufacturing process despite the reduced slot count, making the complex structure more manageable through systematic segmentation.
Solution Approach 2:
The patent changes the winding parameters - specifically the number of slots, turns per slot, and phase grouping arrangements - to optimize the balance between weight reduction and manufacturing complexity. By carefully selecting these parameters, it achieves significant weight savings while keeping the winding structure within acceptable manufacturing complexity limits.
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
The VFG achieves a reduction in size, weight, and harmonic content while improving torque quality and efficiency by utilizing co-located windings, resulting in negligible torque ripple and decreased harmonic voltage content.
Implementation Method 1
a rotor disposed on the shaft so as to be rotationally linked to the shaft and a stator located in the housing so as to at least partially surround the rotor
Data Source
AI summary
A variable frequency generator (VFG) may include a housing, a shaft, a rotor, and a stator with slots. The VFG also includes a first set of stator windings including a first subset of windings and a second subset of windings and a second set of stator windings including a first subset of windings and a second subset of windings. The windings of the first subset of the first set of stator windings are co-located with the windings of the first subset of the second set of stator windings so as to share a common slot of the plurality of slots of the stator. Further, the windings of the second subset of the first set of stator windings are co-located with the windings of the second subset of the second set of stator windings so as to share a common alternative slot of the plurality of slots of the stator.