Abstract
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.
Original language | English (US) |
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Pages (from-to) | 5475-5490 |
Number of pages | 16 |
Journal | IEEE Transactions on Power Systems |
Volume | 38 |
Issue number | 6 |
DOIs | |
State | Published - Nov 1 2023 |
Bibliographical note
Publisher Copyright:© 2022 IEEE.
Keywords
- Current limitation
- dispatchable virtual oscillator control
- droop control
- dynamic aggregation
- grid-forming control
- reduced-order modeling
- singular perturbation analysis
- virtual synchronous machine