Study of the B-Dot Sensor for Aircraft Surface Current Measurement

Area of Science:

• Electrical Engineering
• Electromagnetics
• Aerospace Engineering

Background:

• B-dot sensors, a type of Rogowski coil, are crucial for current measurement.
• Accuracy challenges in measuring aircraft lightning currents include numerical integration drift and high-frequency oscillations.
• Existing calibration methods struggle with high-frequency and strong magnetic fields.

Purpose of the Study:

• To develop and optimize a B-dot sensor system for improved accuracy in measuring aircraft high-frequency lightning currents.
• To address limitations of current B-dot sensor technology, including drift and calibration issues.
• To enhance the reliability and precision of lightning current measurements in aerospace applications.

Main Methods:

• Implemented a nonlinear least squares method for reconstructing current signals to correct numerical integration drift.
• Optimized the B-dot sensor by isolating sampling resistance and employing impedance matching with a voltage follower.
• Developed a low-cost coaxial loop calibration system for accurate high-frequency and strong magnetic field calibration.

Main Results:

• Achieved a significantly improved B-dot sensor accuracy.
• Demonstrated a measuring range of 30 kA/m with a low error rate of 3.1%.
• Attained a high-frequency response of 50 MHz, enabling precise measurement of rapid current changes.

Conclusions:

• The optimized B-dot sensor design and calibration system substantially enhance the accuracy of measuring aircraft high-frequency lightning currents.
• The developed methods effectively mitigate common B-dot sensor inaccuracies.
• This advancement offers a more reliable solution for critical aerospace safety and research applications.