Stability Analysis of Virtual Power Plant with Grid Forming Converters

A virtual power plant is a system containing multiple distributed generators aggregated and flexibly coordinated to act as a single power source. This study investigates the active power, reactive power, frequency, and voltage support provided by a virtual power plant interconnected with the grid. The investigation encompasses the analysis of grid-forming (GFM)-controlled wind and solar power plant units, considering the fluctuating power generation from solar and wind sources. The real hourly wind and solar generation profiles from currently operational plants are used as the active power set points. The stability and power reference tracking of grid-connected converters are analyzed using dispatchable virtual oscillator control (dVOC) and droop control-based methods. The results show that both control strategies substantially improve the virtual power plant's ability to ensure grid stability and accurately track power references, despite the inherent variability of wind and solar energy generation.