Water-Concentration Detection Using 325 Hz AC Impedance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional water-concentration detection devices in SF6 gas-insulated devices experience degraded measurement accuracy due to frequency components from commercial power supplies and their harmonics, particularly at 50 Hz or 60 Hz.
Innovation Solution
A water-concentration detection device with porous electrodes and a hydrogen-ion conductive solid electrolyte membrane, applying an AC voltage at 325 Hz or lower to minimize interference from commercial power supply frequencies, using a high-pass filter to suppress unwanted frequencies and a logarithmic amplifier for enhanced resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If AC voltage is applied at conventional frequencies (50 Hz or 60 Hz) to the porous electrodes, then the measurement process is simple and compatible with commercial power supply frequencies, but the measurement accuracy of water concentration degrades due to interference from commercial power supply frequency components and their harmonics
Solution Approach 1:
The patent changes the frequency parameter of the AC voltage from conventional 50 Hz or 60 Hz to 325 Hz or lower. This parameter change moves the measurement frequency away from commercial power supply frequencies and their harmonics, thereby eliminating measurement interference while maintaining the simplicity of AC impedance measurement methodology
2Measurement precision
If AC voltage frequency is changed to 325 Hz or lower to avoid commercial power supply interference, then measurement accuracy improves, but device complexity increases due to the need for specialized voltage application units capable of generating non-standard frequencies
Solution Approach 1:
The patent employs a voltage application unit that generates AC voltage at 325 Hz or lower, which can be implemented using cost-effective oscillation circuits or function generators. The solution accepts that specialized frequency generation is needed but implements it through relatively simple and inexpensive electronic components, balancing measurement accuracy requirements with device complexity and cost constraints
3Measurement precision
If different AC voltage frequencies are used in different regions or countries to match local commercial power supply frequencies, then measurement accuracy is maintained, but manufacturing cost increases due to the need for region-specific device configurations
Solution Approach 1:
The patent establishes a universal measurement frequency of 325 Hz or lower that can be used globally regardless of local commercial power supply frequencies (50 Hz or 60 Hz in different regions). This universal frequency setting eliminates the need for region-specific device configurations, allowing standardized manufacturing and simplifying global deployment while maintaining measurement accuracy by avoiding all major commercial power supply frequency harmonics
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 allows for accurate water concentration measurement while reducing the influence of commercial power supply frequencies and their harmonics, enabling cost-effective manufacturing by standardizing the AC voltage frequency across regions.
Implementation Method 1
a solid electrolyte membrane that is sandwiched between and fixedly attached to the electrodes, and has hydrogen-ion conductivity
Implementation Method 2
a voltage application unit that applies an alternating-current voltage to the electrodes at a frequency of 325 Hz or a frequency equal to or lower than 10 Hz; an impedance measurement unit that measures an alternating-current impedance between the electrodes
Data Source
AI summary
The water-concentration detection device for detecting a water concentration of insulating gas filled in a gas-insulated device includes: porous electrodes having porous properties that are arranged to face each other in the insulating gas; a solid electrolyte membrane that is sandwiched between and fixedly attached to the electrodes and has hydrogen-ion conductivity; a voltage application unit that applies an alternating-current voltage at a frequency of 325 Hz or a frequency of 10 Hz or lower to the electrodes; an impedance measurement unit that measures an alternating-current impedance between the electrodes in a state in which the alternating-current voltage is applied to the electrodes; and a water-concentration detection unit that detects the water concentration of the insulating gas based on the alternating-current impedance measured by the impedance measurement unit.