Ten years have passed since the start of operation of CEPCO's on-line TSC system in 1995. This paper reports on the results of our evaluation of the actual performance of the system. Using the actual performance data, we intend to clarify the various merits of the system as listed below: 1) Improvement of TTC (total transfer capability) through elimination of transient stability limitations; 2) selectability of ideal power shedding; and 3) reliability improved by configuration of different maker systems