Recent developments in hybrid optical current measuring techniques revolutionize the design of protection schemes of fixed and thyristor controlled series capacitor banks. The scheme, described in this paper, is completely independent of the line current, as an auxiliary power source for the current sensors, as well as for the gap trigger electronics on the platform.
Extensive tests using RTDS were performed to establish the performance of protection. An essential feature of the real-time simulation is the fairly accurate representation of the non linear characteristics of the MOV elements.
The functions tested included: a) Capacitance overload and unbalance b) Line current supervision supplemented by subharmonic current detection c) Gap and Platform Faults d) MOV overload protection.
The tests encompass simulation of different fault conditions including external and internal faults to confirm the design of MOV energy requirements.
Results and detailed discussions of these RTDS - tests are presented in this paper. One section of the paper highlights the different simulation techniques used, to enable the testing of all protection functions.
The reaction of protection on the control strategy of the TCSC scheme is also established ruing the RTDS tests.
A. Kumar, M. Wokusch, R. Krebs, S. Hofmann, In Proc. ICDS ’99, Vasteras Sweden, May 25-28, 1999