The Impact Of Tcsc On Power System Stability

TCSC (thyristor controlled series capacitor) is a device belonging to FACTS ( Flexible AC Transmission System) which began to develop in the seventies of last century. With the development of power electronics technology, thyristor controlled series compensation technology maturing, the device performance more reliable operation. Since TCSC can change the network structure by changing the line reactance to achieve the purpose of system control and cost less, the use of TCSC in power system will have a very bright future. With the development of modern power system, the system size increasing, more and more high-voltage level has been using, transmission capacity losing to keep up the load demand, electricity market operation system needing to use more control means, the use of TCSC in the grid to increase transmission capacity, control power flow, improve the stability of the system is urgent.Based on the work previously, I established flow mode and the transient control mode of TCSC for the system analysis. Through the analysis of YiFeng transmission system and the simulation, I obtained the limit of transient state transmission, and confirmed that TCSC can improve the limit of system steady state transmission and transient state transmission. Meanwhile, through the eigenvalue analysis of the YiFeng system and four-machine system, we can see that TCSC can improve small signal stability of the system too. Meanwhile, we can also see that only specific frequency oscillation can be suppressed obviously, and these oscillation modes are the area oscillation mode which the TCSC line connected. While we can know that the suppression of the other oscillation modes of the system by TCSC is not obvious.