SPICE Model of Current Transformer

1. Summery : current transformer A current transformer (CT) usually used for measurement of currents (especially large values) when large values of current are expected, a CT reduces current proportional to the current in the circuit (primary current). Modeling Concept: Use the secondary side of a ‘voltage’ transformer model as a the current sensor then transform by 1/n to another side. All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 1 1 : n Isensed Isensed/n

4. CT Model and Application The current transformer model and its application (Isensed=1kA, VOUT=10V) All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 4 Isensed=1kA(peak) VOUT/n=10mV(peak) Isensed/n=1A(peak) VOUT=10V(peak)

6. This will limit the frequency range of the CTCT Model + Lm All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 5 Measured and Added to the model

9. Device Modeling Input the current transformer spec: 1:n Measure and input Lm, Rp, and Cp Measure and input Llk, Rlk, and Clk All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 8