<b>Load Frequency and Voltage Regulation in Renewable-Dominated Multi-Source Dual-Area Power System Using Gradient-Based Optimization</b>

The fast growth of residential and industrial demands, combined with the incorporation of renewable energy sources (RESs) like wind and solar, is placing an increasing amount of strain on modern interconnected power systems (IPSs). System stability and dependability may be jeopardized by these additions since they cause notable variations in tie-line power, terminal voltage, and system frequency. Loops for automatic voltage regulation (AVR) and load frequency control (LFC) are essential for delivering high-quality electricity with the least amount of variance. For improved dynamic regulation in a two-area IPS, where one area is fueled by a traditional thermal generator and the other combines photovoltaic (PV) and wind energy sources, this research proposes a proportional integral derivative (PID) controller. Both domains incorporate battery energy storage systems (BESS) to facilitate frequency regulation. This work's unique contribution is the combination of a perturb and observe (P&O) MPPT-controlled permanent magnet synchronous generator (PMSG)-based wind energy system and a fuzzy-based maximum power point tracking (MPPT) PV system with BESS. A gradient-based optimizer (GBO), a meta-heuristic technique, is used to optimize the PID controller. The fitness function for assessing performance is the integral of time times the squared error (ITSE). A 5% step load perturbation (SLP) is used to compare the frequency, voltage, and tie-line power responses of the GBO-tuned PID controller to those of other GBO-based variants, such as integral–proportional–derivative (GBO-IPD), tilt integral derivative (GBO-TID), and integral–proportional (GBO-I-P) controllers. The suggested GBO-PID controller performs better in this hybrid power system setup, according to extensive simulations. The robustness and efficacy of the suggested controller are further confirmed by sensitivity analysis conducted under varied load fluctuations and parameter adjustments of ±25%. Findings show that the GBO-PID controller is a viable option for contemporary, RES-integrated power networks since it consistently stabilizes frequency, voltage, and tie-line power variations with quicker settling times.