The processing method of TCSC in the electromechanical transient analysis

The thyristor controlled series capacitor (TCSC) is one of the most promising components in flexible AC transmission system (FACTS). It can adjust the power flow and improve the stability of power system. In the electromechanical transient analysis of power system, TCSC is simulated as a variable reactance and can be simulated as a general line. However, we need to modify the admittance matrix and triangular factorization in every step, which usually needs a large amount of calculation. This paper presents two methods to solve this problem. The first is the improved modifying matrix method, which keeps the buses connected with TCSC aftermost when sorting the order of the buses. The second is the compensation method, which replaces the variance of each TCSC with a pair of injection current. These two methods have been realized in a Chinese version of BPA power system analysis software and the simulation results shows that these two methods can realize the function of the TCSC effectively.