Measurement of current distribution using infrared thermography

Area of Science:

• Electrical Engineering
• Non-destructive Testing
• Thermal Imaging

Background:

• Current distribution measurement is vital for medical, semiconductor, and structural integrity applications.
• Existing methods like electrode arrays and magnetic sensors lack high spatial resolution.
• A need exists for non-contact, high-resolution current distribution imaging techniques.

Purpose of the Study:

• To propose and validate a non-contact current distribution measurement method using infrared thermography.
• To achieve high spatial resolution in current distribution imaging.
• To accurately quantify current amplitude and reconstruct current direction.

Main Methods:

• Utilizing thermal variations detected by infrared thermography to quantify current amplitude.
• Reconstructing current direction based on electric field passivity.
• Employing calibration fitting for low-frequency current quantification and first-order derivative for high-frequency estimation.

Main Results:

• Accurate current amplitude measurement demonstrated, with relative error ±3.66% at 50 Hz (1.05-3.45 A) using calibration fitting.
• Effective high-frequency current amplitude estimation achieved using temperature variation derivative.
• High-resolution 2D current distribution images obtained, verified by eddy current detection (256 KHz) and simulations.

Conclusions:

• The proposed infrared thermography method offers accurate current amplitude measurement.
• The technique significantly enhances spatial resolution for 2D current distribution imaging.
• This non-contact approach provides a valuable advancement for current distribution analysis.