Active Cable Vibration Damping for Modulated Current Noise

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Solution Overview

Problem

High modulated currents in electric and hybrid vehicles cause vibrations in electrical lines, leading to perceivable noise due to magnetic forces, which existing technologies have not effectively addressed.

Innovation Solution

A device comprising a sound or vibration sensor, an actuator, and a control circuit that counteracts oscillations in electrical lines by generating a force that disrupts or shifts the frequency of the oscillations, using electromagnetic or piezoelectric drives and optionally mounted in an elastically damping element, with the control circuit receiving signals about current strength and modulation to optimize actuator control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If modulated currents are used to control drive components, then electrical losses are minimized and power control is improved, but mechanical vibrations and audible noise are generated in electrical cables

Engineering Contradiction:
Improveelectrical lossesVSAvoidmechanical vibrations and audible noise
Core Design Contradiction:
Loss of energyVSObject-generated harmful factors

Solution Approach 1:

The patent uses the magnetic forces generated by modulated currents (which cause harmful vibrations) to drive actuators that generate counteracting vibrations. The harmful magnetic field interactions are converted into a beneficial active noise cancellation system where the same physical phenomenon is used to create opposing vibrations that reduce the net vibration and noise

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent applies mechanical vibration principles by using actuators to generate controlled vibrations in the electrical cable that are out of phase with the noise-generating vibrations. This creates destructive interference that reduces the overall vibration amplitude and audible noise while allowing the modulated current to continue flowing

Inventive Principle:
Principle #18Mechanical vibration

2Object-affected harmful factors

If actuators are mounted directly on the cable to counteract vibrations, then vibration damping is effective, but the actuators themselves may introduce additional vibrations or require complex mounting structures

Engineering Contradiction:
Improvevibration damping effectivenessVSAvoidmounting structure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent introduces a mounting structure as an intermediary between the actuator and the cable. This intermediary structure allows the actuator to be mounted without direct contact with the cable, enabling vibration isolation and preventing the actuator from becoming a source of additional vibrations while still allowing it to effectively counteract cable vibrations

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If multiple sensors and actuators are distributed along the cable to achieve precise vibration control, then vibration damping performance is improved, but device complexity and cost increase

Engineering Contradiction:
Improvevibration control precisionVSAvoidnumber of components
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent implements a simplified configuration with at least one sensor and at least one actuator, rather than requiring multiple distributed components. This partial action approach provides effective vibration damping for the most critical vibration modes while significantly reducing device complexity and cost compared to fully distributed systems

Inventive Principle:
Principle #16Partial or excessive action

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 reduces the vibration amplitude and perceived noise by using destructive interference or frequency shifting, allowing for continuous damping and adaptation to changes in the system.

Implementation Method 1

The at least one actuator can, for example, comprise an electromagnetic or piezoelectric drive, which is controlled by the control circuit in such a way that it generates a force that counteracts the force generated by the current flow

Methodology Applied
Scientific EffectElectromagnetic drive: Electromagnetic Induction

Implementation Method 2

The at least one actuator can, for example, comprise an electromagnetic or piezoelectric drive, which is controlled by the control circuit in such a way that it generates a force that counteracts the force generated by the current flow

Methodology Applied
Scientific EffectPiezoelectric drive: Piezoelectric Effect

Implementation Method 3

Optical microphones can detect changes in the optical refractive index within a vibrating medium, which are caused by local density changes generated by vibrations

Methodology Applied
Scientific EffectOptical refractive index changes: Refraction

Implementation Method 4

The actuator itself can introduce a vibration into the cable, which, through destructive interference, disrupts a vibration generated by the current flowing in the cable, thus resulting in an overall smaller vibration amplitude

Methodology Applied
Scientific EffectDestructive interference: Interference

Implementation Method 5

The actuator is preferably mounted on a structure on or in which the cable is laid in such a way that vibrations originating from the actuator or introduced into the structure are only transmitted in a damped manner or are first eliminated. The actuator can, for example, be mounted in an elastically damping element

Methodology Applied
Scientific EffectElastic damping: Damping

Data Source

PatentEP4220626B1Device for damping mechanical vibrations in electric lines through which modulated currents flow
Publication Date: 2024.12.11 NEXANS SA
  • EP4220626B1 patent drawingFigure 1
  • EP4220626B1 patent drawingFigure 2~3

AI summary

A device (100) for damping vibrations in electrical conductors (10) carrying modulated currents comprises at least one sound or vibration sensor (102) directed towards or attached to the conductor (10), at least one actuator (104) connected to the conductor, and a control circuit (106) to which signals representing sound or vibrations, generated by the at least one sound or vibration sensor (102), are supplied via respective signal lines (108). The control circuit controls the at least one actuator (104) via respective control lines (110) such that it counteracts the vibration of the conductor (10).