Guest Editorial: Oscillations in Power Systems with High Penetration of Renewable Power Generations

In modern power systems the increasing penetration of renewables and power electronics, particularly converter-based wind and solar power generation, is transforming system dynamics and bringing new stability concerns. One major issue that is currently attracting considerable attention is the wide range of power oscillations associated with renewable power generators (RPGs). The unique characteristics of RPGs, especially their low inertia, power-electronic interface and wide-band response, not only impact the classical electromechanical and torsional oscillations of the power system (that were previously dominated by synchronous machines), but they also cause emerging oscillatory stability problems, such as sub/super-synchronous interactions, medium/high-frequency oscillations and harmonic instability. This Special Issue covers the analysis, modelling, monitoring and control of power oscillations associated with renewable power generations. The theme of the Special Issue is broadly divided into: Section 1 subsynchronous interaction: analysis & mitigation, Section 2 monitoring of subsynchronous oscillation, Section 3 modelling and stability of converter-interfaced RPGs, Section 4 low-frequency oscillations associated with RPGs, Section 5 virtual inertia techniques to support low-inertia RPGs and Section 6 power quality and ferroresonance issues in distributed RPGs. A brief discussion of the authors' contributions is given in this Editorial.