Transformer Vibration Sensing for DC Magnetization Mitigation
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Solution Overview
Problem
Transformers, particularly medium frequency transformers (MFTs), face challenges with DC magnetization leading to core saturation, resulting in increased noise and higher order harmonics due to non-linearity. Existing solutions like series-connected capacitors are impractical, and acoustic sensors struggle to differentiate between transformer vibrations and ambient noise.
Innovation Solution
A method and system utilizing piezoelectric sensors to detect vibrations on the transformer surface, identifying specific frequency signals indicative of DC magnetization, and controlling the transformer by modifying the pulse pattern of the alternating signal to mitigate saturation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If acoustic sensors are used to detect transformer saturation, then saturation detection capability is improved, but the sensor becomes sensitive to vibrations from neighboring transformers and ambient noises
Solution Approach 1:
The patent divides the vibration detection task into specific frequency components by using Fast Fourier Transform (FFT) to analyze vibrations at the fundamental frequency and its harmonics. This segmentation allows the system to focus on transformer-specific vibration signatures rather than attempting to filter all ambient noise, thereby maintaining detection precision while reducing sensitivity to unrelated vibrations.
Solution Approach 2:
The patent replaces acoustic sensors (which detect sound waves through air) with vibration sensors that directly measure mechanical vibrations on the transformer surface. This substitution eliminates the propagation medium (air) that carries ambient noise, allowing the system to detect only the mechanical vibrations generated by the transformer itself, thus resolving the contradiction between detection capability and noise sensitivity.
2Object-affected harmful factors
If series-connected capacitors are used to remove DC components, then DC magnetization mitigation is improved, but the solution becomes impractical due to bulky high-current capacitors
Solution Approach 1:
The patent replaces the electrical approach (using capacitors to block DC components) with a control approach that uses vibration feedback to dynamically adjust the excitation signal. The vibration sensor detects core saturation conditions, and the controller modifies the excitation signal to prevent DC magnetization, eliminating the need for bulky capacitors while achieving the same mitigation effect.
Solution Approach 2:
The patent implements a closed-loop feedback system where vibration sensors continuously monitor transformer core vibrations, and the controller adjusts the excitation signal based on detected vibration patterns indicating DC magnetization. This feedback mechanism dynamically prevents saturation without requiring large passive components, resolving the contradiction between effectiveness and device complexity.
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
Effectively detects DC magnetization in transformers, preventing core saturation and reducing noise pollution by accurately identifying and addressing the underlying vibration patterns, thus enhancing operational efficiency and reducing unwanted noise.
Implementation Method 1
sensing, using at least one vibration sensor, at least one vibration on at least one surface of the transformer
Data Source
AI summary
The present disclosure relates to a method for detecting a DC magnetization in a transformer and controlling the transformer, the method including: sensing, using at least one vibration sensor, at least one vibration on at least one surface of the transformer or on at least one surface of a component connected to the transformer; measuring the sensed at least one vibration; detecting, based on the measured at least one vibration, the DC magnetization in the transformer; and controlling, based on the detected DC magnetization, the transformer. The present disclosure also relates to a respective device and system.