Voltage-Secure Flexibility and Resilience in Low-Inertia Renewable-Dominated Power Systems: A Critical Review and the AVERT Framework

Abstract

Renewable generation and flexibility support sustainable electricity systems only when their response is network-deliverable and service can be restored after disturbances. This critical engineering review compares voltage-security, scheduling, converter and recovery models using an updated inventory of 150 publications. A source-linked appraisal of 40 studies separates thematic coverage from demonstrated evidence across steady-state, dynamic, field and service-recovery routes. Arrest, Voltage security, Energy reallocation, Restoration and Traceable operational coordination (AVERT) is an integrative framework implemented here through a claim-specific evidence protocol. Applications to South Australia 2016, Great Britain 2019, Texas 2021 and Iberia 2025 preserve the different event mechanisms and distinguish official findings from review interpretation. An Institute of Electrical and Electronics Engineers (IEEE) 14-bus example compares ideal active, reactive and combined support at three common locations, including equal-apparent-power allocations, under two reactive-limit treatments. Across 32 loading curves, enforcing non-reference reactive limits reverses the tested active-only versus combined-support ordering. The example establishes a static lower-voltage screening boundary, with low-inertia dynamics, physical collapse and restoration outside its scope. AVERT identifies the additional validation needed to turn a resource-level result into a network-deliverable operational claim. Hosting-capacity and renewable-utilization definitions distinguish installed MW from usable MWh, while scoped voltage, unbalance, flicker and harmonic criteria connect the assessment to normal-operation requirements.