PSO‐Optimised Double Integral Sliding Mode Direct Power Control of a DAB Converter for Standalone PV Systems With Constant‐Voltage Source Characterisation

ABSTRACT Standalone PV DC microgrids face voltage instability under rapid solar changes, as conventional controllers (PI, MPC, ANFIS) and basic sliding‐mode variants cannot simultaneously ensure fast dynamics, low overshoot, and zero error without retuning. This study proposes a PSO‐optimised Double Integral Sliding Mode Direct Power Control (DISM‐DPC‐PSO) for DAB converters, validated via a two‐stage framework (constant voltage then PV with 50% irradiance steps). Under constant voltage, it achieves a 0.84 ms rise time, 0.92% overshoot, and 0.082 V error. Under PV, it shows exceptional robustness: for downward steps (1000→500 W/m 2 ), settling time is 80% faster (1.2 ms) with 43% lower undershoot; for upward steps (1000→1500 W/m 2 ), settling time is 58% faster (3.6 ms) with 87% lower undershoot and a 0.037 V static error. The results confirm the proposed controller consistently outperforms PI, DISMC, and DISMC‐DPC, ensuring superior dynamic response and stable DC‐link regulation across fluctuating solar conditions.