Owing to the intermittent characteristics of renewable energy sources (RESs) and the unpredictability of load demand, integrating multiple RESs and energy storage systems (ESSs) has become imperative. Modular Multiport Converters (MMPC) have emerged as a viable solution to meet this need, offering superior performance, efficiency, and reliability compared to multiple SISO DC/DC converters. To this end, this paper presents a comprehensive model of an MMPC, which is bidirectional and capable of operating in both step-up and step-down modes. Following the derivation of the converter model, a robust μ-controller using the D − G − K iterative procedure is designed. This controller addresses the cross-coupling challenges inherent in MIMO systems and effectively overcomes the parametric uncertainties associated with the converter. Finally, hardware-in-the-loop (HIL) test results derived from OPAL-RT 4610, and experimental results from a prototype are used to validate this control approach.

Mooring failures significantly threaten the stability of Floating Offshore Wind Turbines (FOWT) under extreme environmental conditions. This study presents an innovative integrated damping mooring system incorporating Seaflex dampers to improve structural stability and operational reliability. Dynamic simulations under 1-year and 50-year return period sea states demonstrate the system's effectiveness. Under Ultimate Limit State (ULS) conditions, the system reduces surge displacement by 59%, pitch angle by 47%, and mooring line tension by 72%. Under Accidental Limit State (ALS) conditions, it mitigates load spikes, reduces drift displacement by 60%, and improves safety factors by 50%. The comparison shows chain and wire rope configurations have better load reduction performance in the integrated damping scheme. Lightweight and adaptable, the Seaflex dampers enhance broad-spectrum damping without affecting platform buoyancy. This study offers a robust solution for enhancing FOWT safety and durability in harsh marine environments, thereby enabling large-scale offshore wind energy development.

The reliability of mooring systems has long been a challenge for expanding floating wind turbines into deeper waters. The performance of the mooring system directly determines the service life and survival capability of floating wind turbines. To address this issue, our team has developed a shared damping mooring system. This system reduces the fatigue impact from operating sea conditions and effectively minimizes dragging damage at the fairlead. In this study, two widely used dampers were selected to construct the shared damping mooring system, and their effectiveness in enhancing the reliability of semi-submersible wind turbines was explored. Compared to traditional mooring methods, it was found that this shared damping approach can effectively increase the service life of mooring lines, reduce the local stress and tension levels at the fairlead, and improve the stability of semi-submersible wind turbines. Simulation results indicate that the shared damping mooring system can effectively alleviate fatigue damage, and the shaped memory alloy damper provides significant damping force under low-frequency environmental loads. This characteristic significantly enhances the floating foundation's stability and extends the mooring system's lifetime.