AC-DC Priority Control of an Interlink Converter

Abstract

Over the past decade, global efforts to combat climate change have focused on transitioning from fossil fuels to renewable energy sources and battery-based energy storage. This shift is essential to meet the rising global energy demand and integrate renewable power into the grid. However, the current AC based grid infrastructure poses challenges for incorporating DC based renewable sources like photovoltaic (PV) systems and battery storage. A rapid transition from AC to DC systems is impractical, necessitating a grid system that leverages the existing AC infrastructure while integrating DC systems. Hybrid microgrids (HMGs) have emerged as a solution to this challenge.

Our research focuses on a crucial component of HMGs: the Interlink Converter (ILC). Ideally, the two subgrids in a hybrid microgrid generate power to meet their respective demands. When one subgrid cannot meet its demand, the other supports it through the ILC. This system works effectively most of the time. However, during simultaneous power deficiencies in both subgrids, current standards prioritize AC loads, transferring power from the DC to the AC subgrid. This can lead to voltage fluctuations or blackouts in the DC subgrid, which is increasingly problematic as critical DC loads like EV charging stations and data centres grow.
The thesis titled ‘AC-DC Priority Control of an Interlink Converter’ aims to develop an optimal control strategy for ILCs, enhancing their ability to prioritize power transfer between AC and DC subgrids based on priority modes. This research is crucial for future grid stability and the integration of renewable energy sources.