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Mod 4 • CT Saturation

Push a current transformer past its limits and see how saturation distorts secondary current and misleads protective relays.

System Inputs

Not Saturated
Tip: Below knee, secondary tracks the primary (referred to secondary). Above knee, the tops flatten and distortion starts when X/R is high.

Current Waveforms (Secondary Amps)

Primary referred to secondary Secondary actual
Tip: Increase X/R to add a decaying DC offset. Increase Burden or lower Knee to force saturation.

Excitation Curve (V vs Iexc)

Dot follows the curve
V demand (peak): 0 V
Knee: 150 V
Isec (ideal RMS): 0 A