Magnetic Current Sensor Hysteresis Compensation
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Solution Overview
Problem
Existing magnetic current sensor technologies face challenges in achieving high-precision current measurement due to temperature dependence and hysteresis effects, leading to insufficient accuracy in current measurement.
Innovation Solution
A method involving a magnetic current sensor with a core that changes magnetic flux density based on a sensing current, where the sensing current is swept in both positive and negative magnetization directions to detect magnetic saturation, allowing for the calculation of the target electric current by specifying current values at demagnetization points, thereby eliminating hysteresis and temperature influence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the core-unsaturated area is used to calculate current value, then the measurement method is simple, but the current measurement accuracy deteriorates due to temperature dependence
Solution Approach 1:
The patent changes the operating parameter from unsaturated area to saturated area, and introduces temperature compensation by using a reference core with known temperature characteristics. This allows the measurement system to maintain accuracy across temperature variations while keeping the measurement method relatively simple.
Solution Approach 2:
The patent introduces a reference core as an intermediary element that experiences the same temperature changes as the measurement core. By measuring the reference core's magnetic characteristics, the system can compensate for temperature effects on the measurement core, thereby maintaining measurement accuracy without complex real-time temperature correction algorithms.
2Stability of the object's composition
If the core-saturated area is used to calculate current value, then the temperature independence is improved, but the current measurement accuracy deteriorates due to hysteresis effects
Solution Approach 1:
The patent employs feedback by measuring the reference core's magnetic characteristics during the measurement process. The reference core's response is used to compensate for hysteresis effects in the measurement core, allowing the system to maintain both temperature independence and measurement accuracy through continuous feedback correction.
Solution Approach 2:
The reference core serves as an intermediary that exhibits similar hysteresis characteristics to the measurement core but with known and controllable properties. By comparing the reference core's behavior with the measurement core's behavior, the system can cancel out hysteresis errors and maintain measurement accuracy while using the saturated area for temperature-independent operation.
3Stability of the object's composition
If the sensing current is applied from one saturated area to another saturated area, then the temperature independence is improved, but the hysteresis of the B-H characteristic causes error in the calculated current value
Solution Approach 1:
The system uses feedback from the reference core to continuously correct for hysteresis errors. The reference core's known characteristics allow the system to detect and compensate for hysteresis effects in real-time, maintaining measurement accuracy even when operating between saturated areas.
Solution Approach 2:
The patent replaces direct measurement of the measurement core's hysteresis characteristics with an indirect measurement approach using the reference core. Instead of trying to eliminate hysteresis effects directly, the system substitutes a controlled reference measurement that can be mathematically corrected to eliminate the harmful hysteresis error.
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 high-precision measurement of electric current by accurately determining current values regardless of core temperature and hysteresis, stabilizing accuracy across different measurement cycles.
Implementation Method 1
a core in which a magnetic flux density changes depending on the target electric current
Implementation Method 2
an electrically conductive device capable of changing the magnetic flux density of the core depending on a sensing current
Implementation Method 3
a first controlling process of sweeping the sensing current toward in a negative magnetization direction in a condition that the core is saturated magnetically in a positive magnetization direction due to the target electric current
Implementation Method 4
a hysteresis of the B-H characteristic causes an error in the calculated current value
Data Source
AI summary
An electric current measurement method is provided with: a first controlling process of sweeping a sensing current in a negative magnetization direction in a condition that a core is saturated magnetically in a positive magnetization direction; a second controlling process of sweeping the sensing current in the positive magnetization direction in a condition that the core is saturated magnetically in the negative magnetization direction; a first specifying process of specifying a value of the sensing current if the core is demagnetized in the first controlling process; a second specifying process of specifying a value of the sensing current if the core is demagnetized in the second controlling process; and a calculating process of calculating a value of a target electric current on the basis of the specified current values, the first and second controlling processes being performed repeatedly.