Current Measurement Device Using Multiple CTs for Self-Powered Operation
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Solution Overview
Problem
Conventional electric current measuring devices face challenges such as slow measurement of low electric currents, need for external power sources, and increased size and production costs due to multiple core coils in power line configurations.
Innovation Solution
An electric current measuring device utilizing multiple current transformers to measure electric currents across power lines, where switching circuits and a power supply section store electricity from these transformers, allowing for efficient measurement and operation without external power sources, and reducing device size by sharing sensing and microcomputer components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a single current transformer is used to power the measuring device, then the device size is reduced, but the charging speed becomes slow when electric current is low
Solution Approach 1:
The patent combines multiple current transformers (plurality of current transformers) to collectively power the measuring device. This merging approach allows the device to aggregate power from multiple sources, thereby maintaining compact size while ensuring sufficient charging speed even when individual transformers produce low electric current.
Solution Approach 2:
The measuring device is designed to universally accept power from multiple current transformers simultaneously. The power supply section can draw and accumulate electric current from any or all of the connected current transformers, making the power sourcing flexible and adaptable to varying current conditions while keeping the device compact.
2Adaptability or versatility
If multiple core coils are provided in power lines, then measurement capability is improved, but device size and production costs increase
Solution Approach 1:
The patent merges the functions of multiple current transformers into a single integrated measuring device. Instead of having separate measurement systems for each power line, the device combines multiple CTs and uses a shared power supply section, sensing circuit, and microcomputer, thereby maintaining comprehensive measurement capability while reducing overall device size and production costs.
Solution Approach 2:
The measuring device is designed with multi-functionality to handle measurements from multiple current transformers and power lines through a single unified system. The sensing circuit and microcomputer can process signals from any connected CT, providing versatile measurement capability without requiring separate dedicated circuits for each transformer.
3Reliability
If external power sources are used, then reliable operation is ensured, but device portability and installation flexibility are reduced
Solution Approach 1:
The measuring device is designed to be self-powered by drawing electric current from the connected current transformers. This self-service approach eliminates the need for external power sources, thereby ensuring the device can be freely installed in various locations without requiring access to external power supplies, while still maintaining reliable operation through adequate power accumulation from the CTs.
4Measurement precision
If measurement is performed on low electric current, then measurement precision is improved, but charging speed deteriorates
Solution Approach 1:
The patent combines multiple current transformers to provide sufficient total power for charging while maintaining the ability to accurately measure low electric currents. The power supply section accumulates electric current from multiple CTs to ensure adequate charging speed, while the sensing circuit maintains high measurement precision for low current conditions through dedicated low-current measurement circuitry.
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
Enables reliable and efficient measurement of electric currents across multiple power lines with reduced size and power consumption, storing electricity effectively from multiple transformers to power the device, thus overcoming previous limitations.
Implementation Method 1
causing a current transformer provided to a power line to measure an electric current flowing through the power line
Implementation Method 2
storing electricity by use of electric currents from multiple transformers to power the device
Data Source
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AI summary
A microcomputer section (23) operates by use of electric power from a power supply section (21). The microcomputer section (23) carries out control so that any one of a plurality of switching circuits (20) is selected, the selected one of the plurality of switching circuits (20) causes an electric current from a corresponding current transformer (CT) of a plurality of current transformers (CT) to flow to the microcomputer section (23), whereas the other unselected switching circuits (20) cause electric currents from respective current transformers (CT) of the plurality of current transformers (CT) to flow to the power supply section (21), and the selection is carried out successively with respect to each of the plurality of switching circuits (20).