Hybrid AC Shipboard Microgrid Time Delayed LFC and AVR Controllers Tuning Through Gazelle Optimization Algorithm and Real-Time HIL Implementation

Efforts to reduce greenhouse gas emissions in maritime power networks have led to the integration of renewable energy resources into hybrid AC shipboard microgrid (hSMG) systems. However, challenges are introduced in maintaining voltage and frequency within acceptable limits due to the stochastic nature of power injection from renewable energy sources, the intermittent nature of the load due to the propulsion or the hotel loads and the sensors/communication link time delays. This article introduces for the first time a hardware-in-loop implementation of combining load frequency control and automatic voltage regulation within an autonomous hSMG comprising wave power generation, photovoltaic, diesel generator, proton exchange membrane fuel cell energy unit, battery energy storage system and flywheel energy storage system. The analysis also considers the significance of addressing time delays resulting from communication links between the sensors and the controllers. The stability of the hSMG model is assessed through comprehensive analysis under different scenarios and comparative performance of various controllers. The parameters of the controllers are fine-tuned using a recently developed bio-inspired approach, the Gazelle Optimization Algorithm. Furthermore, a sensitivity analysis of the best controller found is carried out. Experimental results demonstrate the resilience and effectiveness of the proposed frequency/voltage control approach.