Stability Enhancement of DC Microgrids Under CPLs Using Secretary Bird Optimization Algorithm‐Tuned Backstepping‐GITSM Control: Design, Simulation, and Experimental Approach

ABSTRACT DC microgrids (DCMGs) play a pivotal role in integrating renewable energy sources into modern power systems. However, constant power loads (CPLs), such as motor drives and electronic devices, introduce negative incremental impedance (NII), posing serious stability challenges. This research addresses the destabilizing effects of CPLs in DC‐DC boost converters (DBCs) by proposing a robust composite control strategy that enhances system stability and dynamic performance. The control framework integrates global integral terminal sliding mode control (GITSMC) with the backstepping method, while the secretary bird optimization algorithm (SBOA) is employed to eliminate manual tuning and ensure precise regulation of DC‐bus voltage. A virtual capacitor is introduced to mitigate the low‐inertia effect, and exact feedback linearization transforms the nonlinear DBC model into Brunovsky's canonical form, effectively addressing both NII and non‐minimum phase behavior. An exponential reaching law further reduces chattering and ensures fast convergence, while Lyapunov theory confirms global stability. Simulation results demonstrate 52.15% faster settling time, 83.63% lower overshoot, and 86.87% reduced undershoot. Compared with BS‐SMC, SOSMC, and conventional SMC, the proposed controller achieves up to 81.74% improvement in settling time and up to 95% reduction in overshoot and undershoot. Experimental results further validate the controller's superior transient response and robustness, making it well‐suited for CPL‐dominated DCMGs.