Voltage Control of Microgrids for Grid Synchronization

The Kingdom of Saudi Arabia aims to install and generate 60 GW of power from renewable sources such as PV and wind in the coming years. A microgrid is a small-scale power grid...d composed of distribution energy resources (DERs) such as PV and wind that can work in parallel with the grid or as an independent power island. The microgrid can be disconnected from the main grid intentionally or unintentionally. Before an islanded microgrid is reconnected to the main grid its voltage, frequency, and phase angle must be matched to those of the grid network within specified limits recommended by IEEE Standard 1547.4-2011 to avoid transient instability caused by differences in the real and reactive power at the point of common coupling (PCC). An efficient voltage balancing and grid synchronization control strategy increases the stability and reliability of DERs based microgrid. In this project, an efficient voltage balancing and grid synchronization control strategy for microgrids supplying critical and non-critical loads will be proposed and implemented. The microgrid will be based on PV, DFIG based wind and diesel generator. Seamless synchronization of the microgrid is aimed to increase the penetration of renewable energy for reducing the GHG emissions and achieving net-zero energy buildings. Decoupled d-q current control strategy will be proposed and implemented for the voltage source converters (VSCs) used to interface the PV and the DFIG based wind source. Switched capacitor banks will be connected at the PCC to balance the voltage by providing the necessary reactive power for microgrid synchronization. The size of the capacitors will be developed for seamless synchronization of the microgrid.