부산대학교 도서관

Maintaining power balance between generation and demand, as well as frequency regulation, is more difficult in a microgrid (MG) power system, especially when the MG is operating in island mode with the integration of renewable energy (RE) sources and a varying load profile. In this instance, an optimized automatic load frequency control (ALFC) is more successful in lowering frequency deviations and enhancing the stability and resilience of the MG network. Hence, this paper proposes a modified sperm swarm optimization (MSSO) technique for ALFC of a bio and renewable energy (RE) integrated MG system. A chaotic search based on a one-dimensional (1D) chaotic map is adopted to intensify the exploitation and exploration characteristics of the sperm swarm optimization algorithm. The proposed MSSO technique is used to tune the gains of the proportional integral derivative (PID) controller to regulate the frequency of the MG system through the minimization of the integral time absolute error (ITAE) of frequency deviation. The effectiveness of the technique is evaluated in terms of steady-state and transient performance indices for the response of frequency deviation. According to the evaluated results of frequency deviation obtained under different dynamic conditions, the suggested MSSO-tuned PID controller significantly improved transient indices such as settling time, control error, and peak overshoot by a maximum of 39.8%, 11.7%, and 68.9%, respectively, over PID controllers tuned with other techniques (Salp swarm algorithm (SSA), particle swarm optimization (PSO), and sperm swarm optimization (SSO)). In addition, the steady-state indices such as IAE, ITAE, ISE, and ITSE were improved by a maximum of 86.6%, 93.9%, 96.2%, and 98.8%, respectively, using the suggested MSSO technique, as compared to other techniques. Additionally, a sensitivity analysis is performed under varying load conditions, changes in system parameters, and real-time variation in RE sources to validate the resilience. The proposed MSSO technique outperforms other techniques in terms of steady-state and transient indices for the response to frequency deviations, as determined by sensitivity analysis results. The real-time implementation of the proposed controller for the MG system is validated in hardware-in-loop analysis with its stability analysis in the frequency domain.