Multi-Objective Optimization of Inverter Siting and Collector-Cable Routing for Fixed-Topology Offshore Floating Photovoltaic Plants with Inter-Block Gap Allowance

ABSTRACT: Offshore floating photovoltaic (OFPV) plants require cable allowance at interfaces between floating blocks to support maintenance access and accommodate relative motion. Because synchronized relative-motion records are often unavailable during early design, this allowance cannot be calibrated directly. This study proposes a fixed-topology multi-objective method for joint inverter siting and low-voltage collector-cable routing. CAD polylines are decomposed into fixed segments, and route-specific inter-block crossings, and a bounded gap-allowance factor is applied only at the crossings. NSGA-II generates nondominated layouts that minimize cable investment and the present value of resistive-loss cost while satisfying equipment-capacity, string-count, current, and voltage-drop constraints. The method is applied to a 5.1212 MWp grid-connected OFPV plant under the nominal routing case (γ_s = 1). Compared with the manual design, the selected compromise layout reduces collector-cable investment by 7.0% and the present value of power-loss cost by 14.9%, producing a 9.76% reduction in the modeled total collection-system cost. The results demonstrate the economic value of coordinated inverter siting and cable routing while identifying the data required for future dynamic-allowance calibration.