A High Accuracy AC+DC Current Transducer for Calibration

Area of Science:

• Electrical Engineering
• Metrology
• Sensor Technology

Background:

• Existing calibration standards for AC+DC measurement devices lack high accuracy.
• Simultaneous measurement of Alternating Current (AC) and Direct Current (DC) presents calibration challenges.

Purpose of the Study:

• To propose a high-accuracy measurement method for simultaneous AC and DC current.
• To develop a calibration standard for AC, DC, and AC+DC measurement devices.

Main Methods:

• A zero-flux self-oscillating fluxgate sensor is modified with an additional iron core and windings.
• The modified fluxgate operates in a zero-flux state, utilizing feedback from AC+DC magnetic potential.
• An AC+DC transducer prototype was designed and developed with optimized circuit parameters.

Main Results:

• The developed prototype successfully measures AC and DC currents simultaneously.
• Measurement accuracy achieved class 0.05 level within the nominal current range (AC: 0-500 A, DC: 0-300 A).
• The proposed transducer offers a simpler design with fewer cores compared to existing devices of similar accuracy.

Conclusions:

• The novel fluxgate-based transducer provides a high-accuracy calibration standard for AC, DC, and simultaneous AC+DC measurements.
• This method addresses the limitations of current standards, offering improved accuracy and a simplified transducer design.
• The developed transducer is suitable for calibrating a wide range of electrical measurement devices.