Integration and intelligent control of micro-grids with multi-energy generations: A review

A typical micro-grid with multi-energy generators (MGMEG) is composed of renewable energy generation systems including wind, photovoltaic, biomass etc., and fuel cells, energy storages and local loads. The most important feature of a MGMEG is its ability to separate and isolate itself from the utility system, during a utility grid disturbance. Power electronic interfaces, typically voltage source inverters (VSIs) for the grid side, play a key role in the integration and intelligent control of MGMEG to insure its operation as a single aggregated system to be connected to or disconnected from grid seamlessly and reliably with high power quality. This paper gives a review on recent significant research initiatives carried out regarding operation and control strategies of the MGMEG all over the world. The results show that so far, power vs. frequency droop characteristic control strategy of VSIs is validated to be a fundamental and effective control method to accomplish the ldquoplug and playrdquo capability for installing future distributed energy resource units and loads in different MGMEGs in Labs. However, there is a need for more intelligent control strategies for VSIs from the perspective of the whole MGMEG to make the VSI perceptive and self-adaptive to the change of the MGMEG, the loads and the market to add value to the MGMEG. And the multi-agent technique is one of promising control methods for the MGMEG.