학술논문

Impact of Inner Control Loops on Small-Signal Stability and Model-Order Reduction of Grid-Forming Converters
Document Type
Periodical
Source
IEEE Transactions on Smart Grid IEEE Trans. Smart Grid Smart Grid, IEEE Transactions on. 14(4):2812-2824 Jul, 2023
Subject
Communication, Networking and Broadcast Technologies
Computing and Processing
Power, Energy and Industry Applications
Power system stability
Voltage control
Power harmonic filters
Power filters
Analytical models
Transfer functions
Mathematical models
Grid-forming
converter control
model order reduction
small-signal stability
Language
ISSN
1949-3053
1949-3061
Abstract
The analysis and efficient dynamic simulation of power systems with a large number of distributed generators using grid-forming converter control requires reduced order models. The natural separation of time scales allows for the simplification of the inner control loops, i.e., voltage and current controller. This work provides a structured overview of model reduction approaches of the inner loops and introduces new reduced models based on transfer function approximation. The models are thoroughly tested using frequency response analysis, eigenvalues sensitivity analysis, time-domain simulation and stability regions for various scenarios, varying controller and electrical parameters. Furthermore, the influence of simplifications of the network lines is investigated. It becomes apparent that there is no single reduced model that is suitable for all scenarios. Models ought to be selected depending on the specific scenario. Guidelines for the model selection as well as the choice of controller parameters are provided.