Stability enhancement with SSSC-based controller design in presence of non-linear voltage-dependent load

The main objective of this paper is to investigate the power system stability improvement by tuning of static synchronous series compensator SSSC-based controllers in presence of non-linear voltage-dependent loads. Modern heuristic optimisation techniques such as the gravitational search algorithm GSA, particle swarm optimisation and differential evolution algorithm are employed for the purposed system to find out the optimal controller parameters. The performance of these optimisation techniques have been compared and analysed. The performance of the designed controllers has been evaluated under different disturbances and load parameters for both single and multi-machine power system. The effectiveness and robustness of the proposed controller are verified by changing the load parameters of voltage-dependent loads and type of disturbance. It is observed that when constant impedance load is considered in the proposed test systems, the stability of the power system is better when compared with that with constant power and constant current loads.