Factors Affecting the Accuracy of Rogowski Coils

Factors Affecting the Accuracy of Rogowski Coils

Although Rogowski coils offer many advantages, there are several factors that can affect their accuracy:

Positioning and Alignment: One such factor is the relative position of the Rogowski coil with respect to the conductor. Correct alignment must be ensured—for example, by placing the coil flat and perpendicular to the direction of the current—otherwise measurement accuracy cannot be guaranteed. This sensitivity to positioning can result in errors of up to 3%, which can quickly more than double the overall error in current transformer (CT) measurements.

Conductor Size and Distance: The horizontal dimensions of the conductor being measured relative to the Rogowski coil affect measurement accuracy. If the coil is too small to capture all magnetic flux lines, this will result in underestimated measurements.

External Interference:

Nearby equipment emitting electromagnetic interference (EMI) may affect the sensor’s measurement results. Best practices for shielding and installation must be strictly followed.

Temperature Changes:

Temperature changes affect the electrical characteristics of both the Rogowski coil and the conductor, which may lead to measurement inaccuracies.

Integrator Requirements:

The output from the Rogowski coil must be processed through an integrator circuit to obtain a usable current waveform.