Current Transformer Circuit Dynamic Load Switching
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Solution Overview
Problem
Current transformer circuits require large sizes for accurate measurement, leading to high costs and space usage, and they often saturate, causing inaccurate current measurements, while also needing to function as power supplies, which complicates switching between measurement and power modes.
Innovation Solution
A current transformer circuit with a microcontroller-controlled switch mechanism that dynamically switches between burden resistors and low resistance loads, allowing for efficient power supply and measurement modes, reducing the risk of saturation and enabling smaller transformer sizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a current transformer is made large for accurate measurement, then measurement accuracy is improved, but cost and space occupation increase significantly
Solution Approach 1:
The patent applies dynamic switching between two operational modes: measurement mode and power supply mode. The system dynamically changes the burden resistance connected to the current transformer based on operational requirements, allowing the same transformer to serve dual purposes accurately without requiring oversized dimensions for continuous measurement operation.
Solution Approach 2:
The system periodically switches between measurement mode (with higher burden resistance for accuracy) and power supply mode (with lower burden resistance for power delivery). This periodic switching allows the current transformer to achieve accurate measurement performance when needed while maintaining power supply capability, effectively resolving the size-accuracy tradeoff.
2Reliability
If a current transformer is made large to prevent saturation, then measurement accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The system dynamically adjusts the burden resistance based on operational mode. In measurement mode, higher burden resistance is used to prevent saturation and ensure accuracy. In power supply mode, lower burden resistance is used to deliver adequate power. This dynamic adjustment prevents saturation without requiring an oversized transformer design.
Solution Approach 2:
The system changes the electrical parameters (burden resistance values) based on operational requirements. By switching between different resistance values, the system adapts the transformer's operating characteristics to prevent saturation during measurement while maintaining power delivery capability, avoiding the need for increased transformer size.
3Area of stationary object
If the current transformer is used for both measurement and power supply functions, then space and cost are saved, but switching between modes becomes complex
Solution Approach 1:
The patent implements a universal current transformer that performs both measurement and power supply functions through a single device. The microcontroller coordinates the switching between modes, managing the dual functionality without requiring separate dedicated transformers for each purpose, thus saving space while maintaining operational capability.
Solution Approach 2:
The microcontroller acts as an intermediary that manages the switching between measurement and power supply modes. It controls the burden resistance switching based on operational requirements, simplifying the overall system architecture by providing intelligent control rather than complex hardware switching mechanisms.
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 solution allows for accurate current measurement and power supply functionality in a compact form, minimizing cost and size while preventing saturation, thus enhancing measurement accuracy and operational efficiency.
Implementation Method 1
a current source circuit including at least one current transformer to produce a current output wave
Implementation Method 2
a voltage sensor to sense a voltage across the respective at least one burden resistor
Data Source
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AI summary
Current transformer circuit systems and methods dynamically switch a load. The current transformer circuit includes a current source circuit including at least one current transformer to produce a current output wave. A burden circuit includes at least one burden resistor and a voltage sensor, at least a portion of the current output wave to be passed through the burden resistor, and the voltage sensor to sense a voltage across the respective at least one burden resistor. A switch circuit includes at least one switch, the switch circuit coupled to the burden circuit. A microcontroller circuit includes a microcontroller, the microcontroller circuit coupled to a power circuit and the switch circuit, the microcontroller being configured to control the switch circuit to dynamically switch a secondary loading of the at least one current transformer between the burden resistor and a low resistance load.