Asymmetric Phase Windings to Minimize Transformer Acoustic Power
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Solution Overview
Problem
Transformers face challenges in reducing noise emissions due to symmetric vibration modes, which are inefficient in displacing air and generating noise, and existing methods to mitigate noise often lead to unintended resonance phenomena or limited design degrees of freedom for controlling noise.
Innovation Solution
The transformer design incorporates phase windings with varying stiffness and spacers of different moduli of elasticity to modify vibration modes from symmetric to asymmetric, minimizing acoustic power by optimizing dot products and reducing noise generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If symmetric vibration modes are used in transformer windings, then the structure is simple and easy to manufacture, but noise emissions are high due to efficient air displacement
Solution Approach 1:
The patent applies asymmetry by designing phase windings with different stiffness characteristics. Specifically, at least one phase winding has a non-uniform stiffness distribution along its length, creating asymmetric vibration modes that radiate less noise. This is achieved through varying the winding geometry, using different materials, or incorporating structural modifications that break the symmetry of traditional transformer windings, thereby reducing acoustic power while maintaining functional performance.
Solution Approach 2:
The patent implements local quality by introducing localized stiffness variations in specific regions of the phase windings. Rather than uniformly modifying the entire winding structure, the invention applies differential stiffness characteristics to specific segments or zones of the windings, allowing targeted control of vibration modes at noise-critical locations while preserving the overall structural integrity and electrical performance.
2Object-generated harmful factors
If damping is increased to reduce vibrations, then noise is reduced, but the transformer becomes more complex and costly to manufacture
Solution Approach 1:
The patent avoids complex damping systems by using asymmetric stiffness distribution in the windings themselves. The asymmetric structural design inherently generates vibration modes with lower noise radiation, eliminating the need for additional damping materials, viscoelastic layers, or active vibration control systems that would increase manufacturing complexity and cost.
Solution Approach 2:
The invention makes the winding structure itself serve the dual function of electrical conduction and vibration control. By designing windings with non-uniform stiffness, the structure automatically generates favorable vibration characteristics without requiring separate noise control components or systems, thereby simplifying manufacturing while achieving noise reduction.
3Object-generated harmful factors
If resonance frequencies are changed to avoid noise, then new resonance phenomena may appear at different frequencies
Solution Approach 1:
The patent uses asymmetric stiffness distribution to fundamentally alter the vibration mode characteristics rather than simply shifting resonance frequencies. The asymmetric design creates vibration modes with inherently lower noise radiation efficiency, and the patent specifically selects stiffness distributions that ensure the dominant vibration modes remain below audible frequency ranges, thereby avoiding new resonance problems while maintaining system reliability.
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 approach effectively reduces noise emissions by transforming symmetric vibration modes into asymmetric modes, minimizing acoustic power and noise radiation, while being cost-effective and maintaining transformer integrity.
Implementation Method 1
The transformer is excited by a mechanical load having a main frequency corresponding to the predetermined frequency multiplied by two and has vibration modes. The combination of load and vibration modes results in a vibration of the transformer.
Implementation Method 2
spacers of different moduli of elasticity to modify vibration modes from symmetric to asymmetric
Data Source
AI summary
A transformer comprising at least two phase windings, each phase winding having coil turns around a coil axis, wherein the at least two phase windings comprise at least a first type of phase winding and a second type of phase winding, each of the first type of phase winding and the second type of phase winding comprising a plurality of winding portions comprising at least a first winding portion and a second winding portion, the first type of phase winding comprising a first winding portion having a first winding portion stiffness and a second winding portion having a second winding portion stiffness, and characterized in that a stiffness difference between said first winding portion stiffness and said second winding portion stiffness of said first type of phase winding is such that the acoustic power is minimized at said main frequency.