Modellbasiertes Netzschutzverfahren zur Fehlererkennung und -ortung in stromrichtergespeisten Netzen
Zusammenfassung der Projektergebnisse
The penetration of grids with power converters as energy sources and sinks is increasing inexorably. This affects all equipment and changes the behavior of the grid in normal operation and in the event of a fault, including grid protection technology. This requires the further development of grid protection algorithms. This research project is investigating a new type of grid protection solution based on model-based algorithms. Basis for that are grid models of fault-free operation and all fault scenarios to be detected in the state space, including all considered fault locations. The basic idea is to compare measured values and estimated values from the existing grid models. The estimation error quantifies the goodness of fit of the existing network models and thus allows conclusions to be drawn about the actual prevailing network state on the basis of the network model with the lowest estimation error and accomplishes the selective fault clearing. This is a centralized protection solution in the time domain. This approach is therefore advantageously applicable in digital switchgear with a process bus and can therefore also be described as so-called “hyper-differential protection”. Signal processing in the time domain makes the algorithm independent of the source behavior and converter control and is therefore particularly suitable in networks with high or even complete penetration with converters. The model-based protection solution was also supplemented with a method for limiting the shortcircuit currents of power converters in transient as well as steady-state operation. Aspects of model predictive control were used for limiting in the transient time range and a suitable cost function was defined. In addition, the phase currents are limited in the steady-state condition by pre-calculating the steady-state condition and checking the targeted operating points. This new method of current limitation increases the resilience of grid-forming power converters to grid faults in particular. The destruction of power semiconductor components as a result of exceeding thermal current limits is thus avoided. All control and protection algorithms were developed analytically and successfully tested in numerous simulation scenarios in the MATLAB/Simulink software environment and in the lab environment at the Chair of Electrical Energy Systems at FAU in Erlangen. The model-based protection solution has significant advantages in converter-fed grids and digital switchgear technology compared to conventional grid protection and therefore it has high application potential in future decarbonized grids.
Projektbezogene Publikationen (Auswahl)
-
Hybrid Energy Storage System for MVDC-Grids. 2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe). IEEE.
Mahr, Florian; Jaeger, Johann; Henninger, Stefan & Rubenbauer, Hubert
-
Advanced Fault Ride Through Operation of Grid-Forming Voltage Source Converters Using a Model Predictive Controller. 2021 IEEE 12th Energy Conversion Congress & Exposition - Asia (ECCE-Asia), 2248-2255. IEEE.
Mahr, Florian & Jaeger, Johann
-
Elektrische Energiesysteme. Springer Fachmedien Wiesbaden.
Mahr, Florian; Henninger, Stefan; Biller, Martin & Jäger, Johann
-
“Erdschlusskompensation mittels Stromrichtern nach dem Prinzip der virtuellen Impedanz”. In: 7. ETG Fachtagung Sternpunktbehandlung in Netzen bis 110 kV (D-A-CH) STE 2022 (Presentation) (2022)
F. Mahr
-
“Integrated Energy Management Concept for Residential Areas using Energy Packages”. In: NEIS Conference on Sustainable Energy Supply and Energy Storage Systems (2022)
F. Mahr & J. Jäger
-
“Regelung von Nullsystemgrößen mittels Stromrichtern”. In: VDE ETG/FNN- Tutorial 2022 Schutz- und Leittechnik (Presentation) (2022)
F. Mahr & J. Jäger
-
Ground Fault Current Control via Voltage Source Converters using Virtual Impedances in the Zero Sequence. 2023 25th European Conference on Power Electronics and Applications (EPE'23 ECCE Europe), P.1-P.7. IEEE.
Mahr, Florian & Jaeger, Johann
-
Operating Principles of VSCs in the Zero Sequence and Options for Neutral Point Treatment. In: VDE ETG Journal 01/2023 (2023)
F. Mahr & J. Jäger
-
“Modellbasierter Schutzalgorithmus für 100% stromrichterdominierte Netze”. In: VDE ETG/FNN-Tutorial 2024 Schutz- und Leittechnik (Presentation) (2024)
F. Mahr & J. Jäger
