Performance comparison of TCSC with TCPS and SSSC controllers in AGC of realistic interconnected multi-source power system

The primary goals of employing series flexible ac transmission system (FACTS) in automatic generation control (AGC) studies of interconnected power systems are mitigating area frequency and tie-line power oscillations. This paper compares dynamic performance of thyristor controlled series capacitor (TCSC) as damping controller with thyristor controlled phase shifter (TCPS) and static synchronous series compensator (SSSC) which are series FACTS damping controllers. Commonly used lead-lag controllers are used in structure of damping controllers. The effect of TCSC in tie-line power exchange is modeled mathematically based on the Taylor series expansion for small-signal load disturbance. The performance of the proposed TCSC controller in coordination with integral AGC is compared with cases of TCPS–AGC and SSSC–AGC. An improved particle swarm optimization (IPSO) algorithm and integral of time multiplied squared error (ITSE) performance index are used to design the damping controllers. A two-area power system having generations from reheat thermal, hydro, and gas units in each area is evaluated regarding nonlinearity effects of generation rate constraint (GRC) and governor dead band (GDB). The simulations results in MATLAB/SIMULINK environment show that the proposed TCSC–AGC yields superior performance than others in damping of area frequencies and tie-line oscillations. Furthermore, sensitivity analyses are performed to show greater robustness of TCSC–AGC.