Fault current limiting by phase shifting angle control of TCPST

Limiting the short-circuit fault current value has become more and more important for high voltage circuit breakers in modern large scale power systems. Conventional fault current limiters, such as Superconducting Fault Current Limiters (SFCLs) will cause large amount of additional investments. Fast thyristor controlled FACTS devices have opened a new way of limiting the fault current, while maintaining their normal functions of power flow regulation or stability control. The chief objective of this paper is to utilize Thyristor Controlled Phase Shifting Transformer (TCPST) as a new type of fault current suppression equipment under proper phase shifting angle (PSA) control. The relationship between the equivalent impedance of TCPST and multiple PSA switching modes is investigated through theoretical analysis firstly. And simulation results on IEEE 14-bus power system have demonstrated the excellent current limiting capability through the PSA control induced impedances with various fault location.