Stability norms control using the virtual impedance concept for power frequency applications

In small-signal stability studies, various stability criteria have been proposed based on impedance or admittance norms to assess the stability of power systems. Controlling these norms can drag a system from a stable to an unstable operating condition. Therefore, finding a control variable that has a direct linear relation with these norms will facilitate the utilisation of data-driven control principles to build a control system based on small-signal impedance. For a STATCOM connected to a power network, the control system parameters of the STATCOM are tested to identify their relationships with the stability norms. Different types of virtual impedance are tested, and the suitability of each virtual impedance type and connection is examined and presented.