Flux Gate Current Sensor with Adjustable Frequency
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Solution Overview
Problem
Conventional flux gate current sensors face limitations in achieving high temporal resolution and low interference susceptibility due to design compromises, leading to high power consumption and aliasing effects that restrict their practical application range.
Innovation Solution
A current sensor arrangement using a ferromagnetic core with a controlled voltage source to reverse magnetization before saturation, employing a partial hysteresis method for current measurement, which allows for flexible operation and reduced power consumption by varying the sensor frequency to mitigate aliasing effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the inductance of the sensor arrangement is increased to reduce susceptibility to interference, then the sensor frequency decreases, but the temporal resolution deteriorates
Solution Approach 1:
The patent applies dynamics by making the sensor frequency adjustable during operation. The control device can vary the sensor frequency dynamically to optimize performance for different measurement conditions, resolving the fixed compromise between inductance and frequency in conventional designs.
Solution Approach 2:
The patent changes the operating parameters of the flux gate sensor by allowing the sensor frequency to be varied. This enables optimization of both temporal resolution and interference susceptibility depending on the specific measurement requirements, rather than being locked into a fixed design compromise.
2Speed
If the sensor frequency is increased to improve temporal resolution, then the inductance must be reduced, but the susceptibility to interference increases
Solution Approach 1:
The patent makes the sensor frequency dynamically adjustable, allowing the system to adapt to different operational requirements. This resolves the fixed trade-off by enabling frequency optimization independent of fixed inductance constraints.
Solution Approach 2:
The sensor arrangement is designed to serve multiple frequency ranges and application scenarios through adjustable frequency operation, making it universally applicable rather than optimized for a single fixed frequency point.
3Measurement precision
If the magnet system is completely remagnetized periodically to avoid hysteresis error, then measurement precision is improved, but power consumption increases
Solution Approach 1:
The patent applies partial action by performing only the necessary portion of the magnetization reversal process. Instead of complete periodic remagnetization, the system uses partial hysteresis loops that are sufficient to eliminate hysteresis errors while consuming less energy.
Solution Approach 2:
The system maintains continuous measurement capability while optimizing the magnetization process. By using appropriate sampling points within the hysteresis loop and controlling the remagnetization frequency, the system achieves continuous useful measurement action without the energy penalty of complete periodic remagnetization.
4Adaptability or versatility
If the sensor frequency matches or is close to the primary current frequency, then measurement coverage is expanded, but aliasing effects cause measurement errors
Solution Approach 1:
The patent applies dynamics by making the sensor frequency adjustable and adaptable to different primary current frequencies. The control device can vary the sensor frequency to avoid aliasing conditions while maintaining measurement coverage across different frequency ranges.
Solution Approach 2:
The system changes the sensor frequency parameter dynamically to avoid problematic frequency relationships with the primary current. This allows the system to maintain versatility across different measurement scenarios while preventing aliasing errors through parameter optimization.
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 enables accurate current measurement across a wide range from milliamperes to kiloamperes with reduced power consumption and minimizes aliasing issues, enhancing the sensor's practical application by allowing higher sampling rates and transient process detection.
Implementation Method 1
a ferromagnetic core for magnetically coupling the primary conductor to a secondary conductor
Implementation Method 2
a controlled voltage source which is connected to the secondary conductor and is designed to provide a bipolar voltage of a specific amplitude, so that a resulting secondary current causes the remagnetization of the ferromagnetic core
Data Source
Figure 1a~1b
Figure 2a~2b
Figure 3a~3b
AI summary
The current sensor arrangement has a ferromagnetic core (10) for magnetic coupling of the primary conductor in a secondary conductor. A control device has a controlled voltage source (Q), which is connected with the secondary conductor. The controlled voltage source is formed to provide a bipolar voltage of determined amplitude, so that a resultant secondary current (i-s) causes unmagnetization of the ferromagnetic core. An independent claim is included for a method for measuring a primary current in a primary conductor.