A traditional shunt reactor has a fixed rating and is either connected to the power line all the time or switched in and out depending on the load.
Recently [1] variable shunt reactors (VSRs) have been developed and introduced on the market.
[2] VSRs are considered[1] technically advanced products and are mainly supplied by larger global manufacturers.
The variability brings several benefits compared to a traditional fixed shunt reactors.
The VSR can continuously compensate reactive power as the load varies and thereby stabilise the voltage.