Optimization Power System Stabilizer and Energy Storage Using Ant Colony Optimization

A sudden and severe load change may result in dynamic stability issues and adverse effects to the generator performance because of the frequency and rotor angle oscillations. Power system stabilizer (PSS) is usually used to overcome this issue however, it may fail to suppress large dynamic oscillations. This paper presents a complimentary suppression scheme using superconducting magnetic energy storage (SMES) and capacitor energy Storage (CES) systems. SMES has a rapid response to any disturbance while the CES features large storage capacity. Combination of SMES and CES can improve the performance of power systems significantly, if their control parameters are properly optimized. Traditionally, the control parameters of SMES and CES are adjusted by trial and error approach which is time consuming and does not warrant optimum performance. In this paper, ant colony optimization technique is used to simultaneously tune the SMES-CES-PSS parameters. The proposed system along with the optimized parameters is tested on a single machine-infinite bus system to assess its robustness to improve the frequency response and rotor angle profiles under severe load dynamic change. Simulation results reveal the effectiveness of the proposed controller in suppressing large oscillations and improving system stability during such disturbance events. From the optimization process, the minimum fitness function value is 6.183e-08 at the 30th iteration.