Transformer Winding Stiffness Layout for Lower Acoustic Noise
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Solution Overview
Problem
Transformers face challenges in reducing noise emissions due to structural vibrations, as existing methods for damping or shifting resonance frequencies are either ineffective or risk introducing new resonance phenomena, and there is a need for a cost-effective solution to minimize acoustic power generated by windings.
Innovation Solution
The solution involves modifying the winding structure by creating sections with different stiffnesses and spacer distributions along the coil axis, which changes the vibration mode from symmetric to asymmetric, thereby reducing noise emissions by optimizing the dot products ϕn T< F to approach zero, without altering the resonance frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If damping is increased to reduce vibration levels, then noise levels are reduced, but it is difficult to add damping to the extent vibration levels are significantly reduced
Solution Approach 1:
The patent applies local quality by creating non-uniform spacer distributions in specific regions of the winding. Different spacer densities are implemented in different axial zones to locally modify stiffness characteristics, thereby reducing vibration and noise without requiring global damping additions that would be difficult to implement
2Reliability
If resonance frequencies are shifted to avoid resonance phenomena, then winding integrity is improved, but new resonance phenomena inevitably appear close to the exciting frequency
Solution Approach 1:
The patent employs asymmetry by implementing non-uniform spacer distributions that create asymmetric stiffness patterns along the winding axis. This asymmetric configuration modifies the vibration modes to be asymmetric, which reduces the dot product between force distribution and mode shapes, thereby minimizing acoustic power without simply shifting resonance frequencies that would create new resonance issues
3Object-generated harmful factors
If asymmetric winding resonance modes are promoted to reduce acoustic power, then noise emissions are reduced, but the winding structure becomes more complex
Solution Approach 1:
The patent achieves asymmetric vibration modes through local quality modifications using non-uniform spacer distributions. Rather than redesigning the entire winding structure, spacers are strategically placed with varying densities in different axial regions, creating the desired asymmetric stiffness profile with minimal structural complexity
Data Source
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AI summary
A winding (110) for a phase winding of a transformer (100). The winding (110) has coil turns (120) around a coil axis (z). The winding (110) is adapted to transform voltage in a transformer (100) at a predetermined frequency, when the transformer (100) is operating. The winding (110) 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 winding (110). The winding (110) has a set of vibration modes. Each vibration mode has a vibration mode frequency, wherein a main contributing vibration mode of the set of vibration modes is the vibration mode resulting in the largest acoustic power of the vibration modes. The winding (110) is excited by the load and a stiffness difference between a first winding portion stiffness and a second winding portion stiffness is such that the acoustic power is minimized at said main frequency.