Analysis of unstable phenomenon in TCSC by experiment and simulation

Abstract

In this paper, we have investigated damping effect of

power oscillation and unstable phenomena by TCSC

(Thyristor Controlled Series Capacitor) which is one of

FACTS (Flexible AC Transmission Systems) controller.

In this paper, we changed the capacitance of capacitor

in TCSC prototype from 146µF to 73µF to enhance the

damping effect of power oscillation. But we found that

the thyristor in TCSC could not work correctly under

some operating conditions. It is called an unstable

phenomenon of TCSC. So we have examined the

unstable phenomenon by means of both experiment and

simulation.

As a result, we conclude that reducing the capacitance

of capacitor in TCSC is generally effective in damping

oscillation, but we also found that it is necessary to

grasp the region of stable operating conditions where

the TCSC can operate normally.