Analysis and Transient Stability Enhancement of Capacity-Constrained Grid-Forming Control in Inverter Dominated Networks

• Published in: IEEE Energy Conversion Congress and Exposition pp. 678 - 685
• Main Authors: Cen, Siye, Chakraborty, Rahul, Awal, M A, Husain, Iqbal
• Format: Conference Proceeding
• Language: English
• Published: IEEE 20.10.2024
• Subjects: capacity constraint; Contingency management; current limit; fault ride through (FRT); Frequency synchronization; Grid forming; Grid forming control (GFM); Inverter-based resource; Power system dynamics; Power system stability; Stability criteria; Synchronous generators; Transient analysis; transient stability; Voltage control
• ISSN: 2329-3748
• DOI: 10.1109/ECCE55643.2024.10861587

Grid-forming (GFM) control, considered a key enabler for heavy penetration of inverter based resources (IBRs) into the power grid, is subject to stricter current constraints compared to that experienced by legacy generation resources such as synchronous machines. Transient stability analysis plays a major role in the development and evaluation of ride-through strategies for such constrained GFM IBRs. Majority of literature leverage single-converter-infinite-bus (SCIB) configurations for transient stability assessment of GFM IBRs, which invariably leads to mutually exclusive study of contingency events such as voltage, phase, or frequency transients. However, loss of physical rotational inertia in IBR dominated grids, otherwise present in centralized generation architectures consisting of synchronous generators, attributes faster frequency changes as well as simultaneous voltage and frequency dynamics in response to contingencies. In this work, we revisit the adequacy of SCIB configurations for transient stability assessment of current-constrained GFM IBRs to be deployed in low-inertia networks. Furthermore, a two stage transient stability enhancement scheme is introduced to improve GFM control response under current constraints. Finally, effectiveness of the proposed ride-through scheme is verified through EMT simulations of full IBR penetration scenario in a modified IEEE 9-bus system.