Three-in-one Renewable Generation and its Application to Grid-connected and Standalone Operations

This paper proposes a three-in-one generation system with a target to reduce the usage of iron, copper and aluminum. The same machine system is used to harness water potential energy, wind tower-based energy, solar energy and gravity storage-based generation. By doing so, its service time across a year is greatly increased. It could potentially alleviate pressure from overuse of metals when solving energy crisis. Multiple units of such a generation system could be used to construct large-scale DC microgrids which are integral forming components in large-scale autonomous AC microgrids. Such a system is also suitable for grid-connected operation for harnessing water and wind energy and for gravity storage when there is extra power from the grid. This paper further presents results from the modeling of an AC microgrid formed by three-phase inverters, each of which is composed of three single-phase multistage inverters. The proposed three-in-one generations together with the multistage high-voltage inverters pave the way for building large-scale AC microgrids.