Circuit Breaker Acoustic Sensing for Trip Current Estimation
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Solution Overview
Problem
Measuring trip current intensity in circuit breakers is costly and intrusive, requiring the integration of current sensors inside the conductors, which must withstand high trip intensities.
Innovation Solution
An acoustic device comprising a casing, a microphone, an attenuator, and an electronic control unit is used to estimate trip current intensity by measuring noise generated by the circuit breaker, with an attenuator to protect the microphone from saturation and mechanical vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a current sensor is integrated inside the circuit breaker to measure trip current intensity, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent introduces an intermediary acoustic measurement system that captures trip current information indirectly through noise emissions rather than direct electrical contact. The microphone and attenuator assembly acts as a mediator between the circuit breaker's electromagnetic events and the measurement device, avoiding the need to integrate sensors inside the breaker while still providing accurate trip intensity data through acoustic signal analysis
Solution Approach 2:
The patent replaces the electrical measurement system (current sensors integrated into conductors) with an acoustic measurement system. Instead of using electrical fields to measure trip current, the system uses acoustic fields (microphone capturing noise emissions) to detect and analyze trip events, thereby eliminating the need for intrusive electrical sensor integration while maintaining measurement capability
2Measurement precision
If a current sensor is integrated inside the circuit breaker, then measurement precision is improved, but ease of operation is worsened
Solution Approach 1:
The external acoustic measurement device serves as an intermediary that captures trip current information without requiring integration into the circuit breaker's internal structure. This allows the measurement system to be installed independently on the breaker's exterior, simplifying both installation and maintenance operations while maintaining accurate measurement capabilities through acoustic signal capture
3Measurement precision
If the microphone measures noise directly without attenuation, then measurement precision is improved, but reliability is worsened due to saturation and damage risk
Solution Approach 1:
The patent applies preliminary attenuation to the acoustic signal before it reaches the microphone. The attenuator is positioned in the acoustic path to reduce the intensity of noise emissions from the circuit breaker before they reach the microphone, preventing saturation and potential damage while preserving the signal's diagnostic information for accurate trip current intensity measurement
Solution Approach 2:
The attenuator acts as a protective cushioning element placed before the microphone to soften and reduce the intensity of incoming acoustic signals. This beforehand cushioning prevents the microphone from being exposed to excessively high noise levels that could cause saturation or damage, thereby protecting the sensor's reliability while still allowing accurate measurement of trip events
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
Estimates trip current intensity simply, non-intrusively, and at low cost, providing accurate measurements by attenuating noise and damping mechanical vibrations to prevent microphone saturation.
Implementation Method 1
the attenuator being configured to attenuate noise generated by the circuit breaker, the noise being representative of the trip intensity
Implementation Method 2
the microphone being configured to measure the noise attenuated by the attenuator and to emit an output signal representative of the attenuated noise
Data Source
AI summary
This invention relates to an acoustic device for estimating a trigger intensity of a trip current flowing in a circuit breaker, the device comprising:a casing (22);a plate (32);a support (40), a tab (42) connecting the support and the plate;a microphone (70);an attenuator (44), the support extending between the microphone and the attenuator, the attenuator comprising a housing (46) with a housing orifice (48) and an attenuating membrane (50); andan electronic control unit (38), connected to the microphone,the attenuator being configured to attenuate noise generated by the circuit breaker, the noise being representative of the trigger intensity, the microphone being configured to measure the noise attenuated by the attenuator, and emit an output signal, and the electronic control unit being configured to receive the output signal and estimate the trigger intensity.