Frequency Control in Modern Power Systems: How Should We Respond to Low Inertia Challenge?

Most power grids around the world are facing the, so-called, low-inertia challenge - when due to massive integration of renewable sources the amount of system inertia decreases, and frequency control becomes more difficult. The discussion about the need for new control approaches began more than a decade ago and since then there was a number of different methods developed. Recently, energy storage has become a promising solution (due to their excellent ramping capabilities) for providing fast control services and compensating for the lost inertia.  However, energy storage units are connected to power grids through power electronics converters, which allow to realize broad range of control strategies. Why then should we try to mimic the behavior of conventional generators then? In the present talk I will present some recent results with a new control approach - frequency shaping control, that allows to take full advantage of combined storage-power grid dynamics, and completely eliminate transient frequency drops (so-called, frequency Nadir). This can completely change the way frequency security assessment t is performed, reducing it to simple algebraic calculations, rather than dynamic simulations.