Study on the minimum share of conventional generation units required for stable operation of future converter-dominated grids

In this contribution the authors analyze consequences of the transition from conventional synchronous generator based generation to converter interfaced generation utilized usually for renewable sources. The focus is on the dynamic behavior of the systems for maintaining stability. Based on simulation results the authors demonstrate the fundamental changes and control challenges in converter-dominated grids. As a conclusion, the authors give their recommendation for the maximum share of converter-interfaced units under the assumption of utilizing current converter control methods and established grid codes. In addition, the required control modification toward grid forming behavior is shown, which would allow the integration of much more renewables connected through converter interfaces to the grid.