Grid-Forming Converters for Frequency Stabilization of Power Systems with High Penetration Level of Renewable Energy Sources

The frequency stability of electrical grids is supported by the inertia of synchronous generators. However, the penetration of renewable energy resources (RES), which have zero inertia, affects negatively the grid stability. The absence of inertia in RES is due to either the absence of the electromechanical machines, like photovoltaic (PV) systems or the power electronic converters (PECs) isolation between the electromechanical and the bus of the injected power in wind energy systems. The absence of inertia affects the frequency stability and may lead to several blackouts in case of any disturbance in the RES. Therefore, new electrical grids with energy mix between RES and synchronous machine-based sources require a virtual inertia to compensate for the RES penetration. Energy storage along with PECs are controlled to perform as a virtual inertia system. Such a combination aims to achieve grid stability by controlling the injected active power according to the frequency variation. This type of converter is referred to as Grid-Forming Converter (GFM). On the other hand, the PEC-based RES is known as a Grid-Following Converter (GFL). The GFL is operated such that achieving the maximum power from the RES. However, the GFM aims to stabilize the grid frequency and establish a virtual inertia source. The new research roadmap uses RES with GFM as a virtual inertia source. However, the control techniques and establishing a standard for GFM converters are still under investigation. This proposal aims to develop the GFM-based RES with efficient control strategies to enhance the power grid stability with high renewable energy penetration. First, a complete power system including RES operating with traditional inertia-based sources will be developed. The PECs prototype will be designed, built, tested, and implemented. In addition, experimental hardware in the loop (HIL) setup will be established to validate the simulation results