Multi-objective optimal thyristor controlled series compensator installation strategy for transmission system loadability enhancement

Owing to the continuously increased electricity demands and power transactions, power systems are becoming more vulnerable to insecurity, generally incurred by overutilised transmission facilities or any contingency. In order for existing transmission networks to accommodate more power transfers with less network expansion cost, proper installation of thyristor controlled series compensator (TCSC) is validated to be one of the most `promising options´. The multi-objective optimal TCSC installation strategy proposed in the study first applies the performance index sensitivity factor technique to investigate which lines are most necessary for TCSC installation and with the lines specified for TCSC installation and the multi-objective function consisting of maximum system loadability and minimum TCSC installation cost, the problem to determine the capacity for each TCSC installation is then formulated as a multi-objective optimisation problem and solved by using the fitness sharing multi-objective particle swarm optimisation method. Finally, in the Pareto front set obtained, the solution with the TCSC installations that can make the power system provide the required loadability with biggest utilisation index value is recommended. The modified IEEE-14 buses, IEEE-118 buses systems and a practical power system are used to validate the performance of the proposed method.