Enhancing Stability of Grid-Following Inverter for Renewables

The increasing penetration of wind and solar power sources in power networks has led to the need for advanced converters' control technologies to support the integration of these renewable energy sources into the grid. Inverters play a critical role in power networks, and understanding the benefits and limitations of different inverter types can facilitate the effective management of renewable energy sources and contribute to a more stable and sustainable power system. With multiple inverters connected to the grid, different instability phenomena can occur (ranging from low to medium to high frequencies). The main objective of this paper is to explore the instability phenomena related to grid-following inverters in weak power networks with high penetration of wind and solar power sources. These inverters have electronic circuits, such as the phase-locked loop (PLL), that provide information about the phase angle of the grid voltage waveform. This paper provides insight into the advantages and disadvantages of this type of inverter control and its impact on grid stability and intermittency management of renewable energy sources. It will also discuss the challenges associated with stability and propose a possible improvement of the grid-following control approach by introducing additional control circuitry emulating synchronverter [1]. The presented simulation results demonstrate the quality of the proposed modification of the grid-following control approach.