TY - JOUR
T1 - Model Reduction and Dynamic Aggregation of Grid-Forming Inverter Networks
AU - Ajala, Olaoluwapo
AU - Baeckeland, Nathan
AU - Johnson, Brian
AU - Dhople, Sairaj
AU - Dominguez-Garcia, Alejandro
N1 - Publisher Copyright:
IEEE
PY - 2023/11/1
Y1 - 2023/11/1
N2 - This paper presents a model-order reduction and dynamic aggregation strategy for grid-forming inverter-based power networks. The reduced-order models preserve the network current dynamics as well as the action of the inverter current-reference limiter. Inverters based on droop, virtual synchronous machine, and dispatchable virtual oscillator control are considered, a generic model for all three control strategies is presented, and a smooth function approximation is utilized to represent the action of the current-reference limiter. The network is assumed to be composed of lines with homogeneous l/r ratios. Given such a system, our approach involves three steps. First, time-domain Kron reduction is used to reduce the dimensions of the electrical network model. Next, dynamic aggregate models are developed for parallel-connected inverters. Finally, singular perturbation analysis is used to systematically eliminate fast-varying dynamics in both the network model and the grid-forming inverter single/aggregate models. Numerical simulation results benchmark the response of the reduced-order aggregate models against the full-order models from which they are derived, and we demonstrate significant savings in computation cost with limited loss of accuracy.
AB - This paper presents a model-order reduction and dynamic aggregation strategy for grid-forming inverter-based power networks. The reduced-order models preserve the network current dynamics as well as the action of the inverter current-reference limiter. Inverters based on droop, virtual synchronous machine, and dispatchable virtual oscillator control are considered, a generic model for all three control strategies is presented, and a smooth function approximation is utilized to represent the action of the current-reference limiter. The network is assumed to be composed of lines with homogeneous l/r ratios. Given such a system, our approach involves three steps. First, time-domain Kron reduction is used to reduce the dimensions of the electrical network model. Next, dynamic aggregate models are developed for parallel-connected inverters. Finally, singular perturbation analysis is used to systematically eliminate fast-varying dynamics in both the network model and the grid-forming inverter single/aggregate models. Numerical simulation results benchmark the response of the reduced-order aggregate models against the full-order models from which they are derived, and we demonstrate significant savings in computation cost with limited loss of accuracy.
KW - Current limitation
KW - dispatchable virtual oscillator control
KW - droop control
KW - dynamic aggregation
KW - grid-forming control
KW - reduced-order modeling
KW - singular perturbation analysis
KW - virtual synchronous machine
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U2 - 10.1109/TPWRS.2022.3229970
DO - 10.1109/TPWRS.2022.3229970
M3 - Article
AN - SCOPUS:85144777098
SN - 0885-8950
VL - 38
SP - 5475
EP - 5490
JO - IEEE Transactions on Power Systems
JF - IEEE Transactions on Power Systems
IS - 6
ER -