Stability definitions and characterization of dynamic behavior in systems with high penetration of power electronic interfaced technologies

A task force set up jointly by the IEEE Power System Dynamic Performance Committee and the CIGRE Study Committee (SC) 38, currently SC C4 – System Technical Performance, had addressed in [1] the issue of stability definition and classification in power systems from a fundamental viewpoint and had closely examined the practical ramifications. At the time this document was published in 2004, the dynamic behavior of power systems was predominantly determined by the dynamic performance of synchronous generators and their controls as well as the dynamic performance of the loads. Consequently, [1] primarily dealt with fairly slow, electromechanical phenomena, typically present in power systems dominated by synchronous machines, while fast transients related to the network and other fast-response devices were considered out of scope and thus neglected. Thus, for the purposes of stability analysis in the bandwidth of interest, all fast electromagnetic transients are neglected as they typically decay rapidly [2].
Since the publication of [1], however, electric power systems worldwide have experienced a significant transformation, which has been predominantly characterized by an increased penetration of power electronic converter interfaced technologies. Among these new technologies are wind and photovoltaic generation, various storage technologies, FACTS devices, HVDC lines, and power electronic interfaced loads. With significant integration of converter interfaced generation (CIGs), loads, and transmission devices, the dynamic response of power systems has progressively become more dependent on (complex) fast-response power electronic devices, thus, altering the power system dynamic behavior. Accordingly, new stability concerns have arisen which
need to be appropriately characterized, classified, and defined.
This report focuses on CIG, while the effects of converter connected loads on stability are briefly discussed, where relevant. [1] P. Kundur, J. Paserba, V. Ajjarapu, G. Andersson, A. Bose, C. Cañizares, N.
Hatziargyriou, D. Hill, A. Stankovic, C. Taylor, T. Van Cutsen, and V. Vittal,
“Definition and classification of power system stability,” IEEE Trans. Power Syst.,
vol. 19, no. 3, pp. 1387–1401, May. 2004.