Abstract—This paper presents an analytical, linear, statespace
model of a Thyristor Controlled Series Capacitor (TCSC).
Firstly, a simplified fundamental frequency model of TCSC is
proposed and the model results are verified. Using frequency
response of the non-linear TCSC segment, a simplified non-linear
state space model is derived, where the frequency of the
dominant TCSC complex poles shows linear dependence on the
firing angle. The non-linear element is linearised and linked with
the AC network model and the TCSC controller model that also
includes a Phase Locked Loop model. The model is implemented
in MATLAB and verified against PSCAD/EMTDC in the time
and frequency domains for a range of operating conditions. The
model is sufficiently accurate for most control design applications
and practical stability issues in the subsynchronous range.