Local PTO response-based framework for a nearshore oscillating-arm wave energy converter

초록

This study presents a local PTO response-based framework for a nearshore oscillating-arm WEC with a reduced-order hydraulic cylinder-piston PTO representation. The system is intended for modular deployment, where repeated oscillating-arm WEC units are conceptually arranged along nearshore or coastal protection structures for distributed wave-energy harvesting, rather than a validated array-level performance assessment. A reduced-order model links the local heave response at PTO locations to piston motion, rectified hydraulic flow, and estimated mean electrical power. The framework sequentially refines the floating-arm geometry, PTO arrangement, hydraulic parameters, PTO installation position, and floating-body mass. The results indicate that the local PTO-location response provides a useful metric for evaluating geometric, hydraulic, and inertial effects on estimated power-generation performance. Among the investigated configurations, the four-PTO arrangement exhibits favorable hydraulic-throughput characteristics while maintaining a relatively simple modular configuration. Evaluation over T = 5-15 s and H = 1.0-3.0 m indicates similar period-dependent response trends under different wave heights. Under the adopted reduced-order formulation and regular-wave conditions, the refined system produces estimated mean electrical power from several kilowatts to several hundred kilowatts. These estimates are intended for comparative preliminary-design assessment rather than direct prediction of commercial electrical power. An additional irregular-wave assessment provides supplementary insight into applicability under more realistic sea-state conditions. The proposed framework provides a computationally efficient basis for preliminary energy-performance refinement of modular nearshore oscillating-arm WEC systems. Owing to linear-wave assumptions and a reduced-order PTO representation, multi-module hydrodynamic interaction, spacing optimization, coastal-integration effects, and techno-economic deployment assessment remain outside the scope of this study.

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