A 3L2C2 DC–DC three-port converter with topology-level power decoupling: conduction loss optimization via improved Gray Langurs Optimizer-based triple phase-shift modulation

Abstract This paper presents a 3L2C2 multi-resonant-element three-port converter (3L2C2-TPC) that transfers power through the fundamental and third-harmonic components while realizing topology-level decoupling between ports 2 and 3. Because the converter conduction loss is dominated by the resonant RMS currents, a converter-specific optimization model is established for the five triple phase-shift variables under two prescribed power-transfer constraints. An application-oriented improved Gray Langurs Optimizer (IGLO) combines Logistic-map initialization with dynamic opposition-based learning to improve initial coverage and reduce search stagnation. The optimizer is assessed through independent-run statistics and comparisons with representative population-based algorithms. A laboratory prototype verifies topology-level power decoupling and the optimized modulation. At the same power command, the measured weighted RMS-current metric decreases from 71.27 A 2 at a feasible nonoptimal point to 58.70 A 2 at the IGLO-derived point, corresponding to a reduction of approximately 17.6%. The results support the proposed method for the reported converter, voltage, and operating-point range; universal superiority over other optimizers is not claimed.