Meaning
Deviant curvature in the high-frequency region of an electrochemical impedance spectrum. Signal interference or inductive leads usually cause high-frequency arc distortion, making the resulting data difficult to interpret without correction. Measurement accuracy depends on identifying these artifacts during the testing phase.
Inductive Interference
Long cables and metallic enclosures introduce parasitic inductance into the test circuit. While high-frequency arc distortion appears as a shift into the positive imaginary quadrant of a Nyquist plot, it does not represent an electrochemical process within the cell. These errors are particularly common when testing large battery packs with extensive wiring lengths.
Error Correction
Software algorithms can subtract the inductive component from the raw impedance data.
Measurement Accuracy
Validating the high-frequency portion of the spectrum is necessary for determining the ohmic resistance of the cell. If high-frequency arc distortion remains uncorrected, the reported internal resistance will be higher than the actual physical value. This discrepancy affects the precision of state of power estimations and thermal models used in battery management systems.
Quality control stations use standardized lead lengths to minimize these effects in production environments. Technicians verify the calibration of the equipment to ensure the signal remains clean across the entire measured bandwidth.
