REACTIVE POWER SYNCHRONIZATION METHOD FOR CONTROLLING GRID-FORMING CONVERTERS IN RENEWABLE ENERGY PLANTS

Abstract

In recent years, synchronous generators (SGs) from traditional power 
plants have been displaced by the tremendous influx of renewable 
energy sources into electrical networks. Because of the way they 
operate, electronic power converters, which are often used to link 
renewable energy facilities to power grids, are unable to provide the 
same power generating services as SGs. In an effort to mimic the 
performance of SGs, many ideas for electronic converter control have 
been put forward recently, leading to the creation of what are known 
as grid-forming converters (GFCs). In order to separate the 
synchronizing power and the active power management of a 
renewable generating source that has a converter linked, this study 
suggests a novel GFC control technique based on the reactive power 
synchronization (RPS) method. Three power sources are evaluated in 
this research for this purpose: photovoltaic (PV) plants, batteries, and 
full-converter wind turbines. Additionally, the research suggests 
models and controls for every one of these sources, whose dynamics 
have a significant impact on the grid services that renewable energy 
facilities provide. Subsequently, the research suggests a GFC–RPS 
control system and validates its efficacy in various scenarios. One such 
scenario is inertial response, which promptly supplies power via a 
rapid frequency response following a load fluctuation on a grid. PV 
plants, in contrast to wind turbines and storage systems, can only 
provide these services when they are not using their full power. The 
research also confirms the efficacy of the GFC–RPS control approach 
for controlling AC voltage at a converter's output terminals. Lastly, 
when feeding a dynamic load, the article evaluates GFC hot swapping 
during the switch from a grid-connected to an isolated operating mode. 
Findings showed that the voltage and frequency stay constant, proving 
that the suggested GFC-RPS control does, in fact, function as a real 
voltage source and mimic the characteristics of a traditional SG.