Grid following converters stability study and control enhancements using
an improved test setup
Abstract
To insure a stable and reliable operation of the existing and future
grids, it is important to study the stability of the power electronic
based converters’ controls which can replace synchronous generation.
Most existing studies use a Thévenin equivalent model of the grid to
test the grid following controls. The present article demonstrates the
limits of these studies. An alternative setup is proposed and is shown
to provide more insight into the underlying mechanisms of the grid
following control behaviour in weak grids, using a linearized state
space model. These insights are exploited to propose further
improvements to the control. These improvements are shown to extend the
stability of the control while reducing the interactions among
converters.