TY - CHAP A1 - Raab, Alexander A1 - Frauenknecht, Dominik A1 - Wellhöfer, Anatoli A1 - Luther, Matthias A1 - Kuri, Ananya T1 - Hybrid EMT and Phasor based MMC-HVDC Model for Advanced Power System Simulation N2 - The objective of this paper is the implementation and comparison of a hybrid phasor-based (RMS) and electromagnetic transient (EMT) modular multilevel converter high voltage direct current (MMC-HVDC) model for advanced and detailed studies of large power systems. The general modeling approach for hybrid simulation of modular multilevel converters for HVDC applications with the corresponding control concepts is described. The HVDC model can be divided into AC and DC components with different simulation time steps and representation using network partitioning. The connected AC grids and converter models are considered in the phasor-based time domain, while the DC connection is simulated in the electromagnetic-transient time domain. The coupling of the models is established by the total energy control of the MMC. The hybrid approach is evaluated in comparison to an average MMC HVDC model in an EMT simulation. The results show the advantages of the hybrid model. The model can be simulated with comparatively low computational effort, while the DC transients can be represented in detail during disturbances. Y1 - 2022 UR - 10.1109/PESGM48719.2022.9917109 PB - IEEE ER - TY - CHAP A1 - Raab, Alexander A1 - Scheibe, Christian A1 - Wellhöfer, Anatoli A1 - Nguyen, T.T.-T. A1 - Frauenknecht, Dominik A1 - Mehlmann, Gert T1 - Converter-based Control using Co-Simulation with a Power System Simulation Tool T2 - NEIS 2021 - 9th Conference on Sustainable Energy Supply and Energy Storage Systems N2 - The objective of this contribution is to implement a Co-simulation approach for control systems within RMS-based stability analyses of power systems. Inter-process communication via shared memory connects the specialized and focused software environments and enables the data exchange between them. A model of a point-to-point VSC-HVDC system with main controls is presented as the test system to be investigated. Simulations with the model in a fault case show that the results generated with the new approach are similar to those of a single-instance simulation with converted models. Simultaneously, in contrast to the existing alternatives the presented approach exhibits the benefits of Co-simulation related to efforts, costs, efficiency and model continuity, while the models remain within specialized best-in-class tools. Y1 - 2021 SN - 978-3-8007-5651-3 SP - 25 EP - 30 PB - VDE Verlag ER - TY - CHAP A1 - Semerow, Anatoli A1 - Wolf, Thomas A1 - Wellhöfer, Sabine A1 - Luther, Matthias T1 - Power system model order reduction based on dominant modes in modal analysis T2 - 2017 IEEE Power & Energy Society General Meeting N2 - Investigations of small-signal stability of electrical power systems are usually performed by modal and time-domain analysis using descriptive differential equations of machines. Thereby, the modal analysis enables the identification of all dominant states of the linearized power system model, which are associated with electromechanical interactions and power oscillations. For reasons of simplification and due to computation capabilities, a reduction of the model order is often advantageous. This can be done by neglecting different physical effects within the machines, retaining the topology and the modal characteristics of the power system regarding its electromechanical behavior. This paper presents a modal analysis based approach for power system model order reduction. In order to reproduce the small-signal behavior of power systems accurately, damping and synchronizing parameters are introduced within the reduced-order model. Subsequently, each coefficient is determined analytically for a single machine infinite bus system and using the particle swarm optimization method for a multi-machine system. The deviation to the electromechanical reference modes of the higherorder power system model constitutes the objective function to be minimized. The results confirm that the approach is suitable for the aspired goals and fulfills the accuracy requirements. Y1 - 2018 U6 - https://doi.org/10.1109/pesgm.2017.8274669 SN - 1944-9933 SP - 1 EP - 5 PB - IEEE Computer Society Press ER - TY - CHAP A1 - Volkova, Anna A1 - Schmidhuber, Julian A1 - de Meer, Hermann A1 - Hess, Robin A1 - Schilling, Klaus A1 - Wellhöfer, Anatoli A1 - Zink, Markus T1 - Design and Simulation of LEO Satellite Communication Networks for Reliable Monitoring and Control in Power Systems T2 - The 14th DACH+ Conference on Energy Informatics Y1 - 2025 UR - https://energy.acm.org/eir/design-and-simulation-of-leo-satellite-communication-networks-for-reliable-monitoring-and-control-in-power-systems/ ER - TY - CHAP A1 - Raab, Alexander A1 - Frauenknecht, Dominik A1 - Mehlmann, Gert A1 - Luther, Matthias A1 - Wellhöfer, Anatoli T1 - Hybrid Phasor- and EMT-based Multi-Terminal MMC-HVDC Model with Grid-Forming Control T2 - 2023 IEEE Power & Energy Society General Meeting (PESGM) N2 - The objective of this paper is to apply a hybrid phasor-(RMS) and electromagnetic transient-based (EMT) simulation approach to a multi-terminal modular multilevel converter high voltage direct current (MT MMC-HVDC) model. The MMC of the MT-HVDC are implemented with grid-following and grid-forming control. An overview of the MT MMC-HVDC is given and the grid-forming and voltage droop control are described. The AC and DC networks of the MMC are divided into an RMS and an EMT partition with different simulation time steps. The grid-forming and grid-following control with inner AC current control are assigned to the RMS partition. The total energy and inner converter control are assigned to the EMT partition. The model is initialized for a correct transition from power flow to time domain simulation. The approach is implemented in a meshed power system model, where grid-forming MMC provide voltage and frequency for an offshore wind farm and a synchronous grid. The simulations are performed with the AC networks in RMS and the DC networks in EMT. The results show that the interactions between the AC and DC grids can be studied in a hybrid simulation framework. The DC system response is detailed, while the AC system is reduced to machine and controller dynamics. Y1 - 2023 SN - 978-1-6654-6441-3 U6 - https://doi.org/10.1109/pesgm52003.2023.10253370 SN - 1944-9933 PB - IEEE ER - TY - CHAP A1 - Frauenknecht, Dominik A1 - Schweinshaut, Bernd A1 - Raab, Alexander A1 - Mehlmann, Gert A1 - Luther, Matthias A1 - Wiest, Pascal A1 - Heyde, Chris Oliver A1 - Wellhöfer, Anatoli ED - VDE ETG, T1 - Stability Analysis of Converter-Dominated Power Systems by Phasor-Based and Electromagnetic Transient Simulation T2 - 15. VDE ETG/VDI/VDE-GMA-Fachtagung „Netzregelung und Systemführung“ Y1 - 2024 SN - 978-3-8007-6292-7 ER - TY - JOUR A1 - Walle Biyazne, Likenesh A1 - Berhanu Tuka, Milkias A1 - Mekonnen Abebe, Yoseph A1 - Wellhöfer, Anatoli T1 - Enhancing MPPT performance of a grid-connected Doubly-Fed induction generator-based wind power plant using hybrid ANFIS-PI control strategy JF - Nature Scientific Reports N2 - This paper focuses on an effective control technique for enhancing the Maximum Power Point Tracking (MPPT) performance of a grid-connected DFIG-based wind power plant under continuously varying wind conditions. However, rapid fluctuations in wind speeds, uncertainties in parameters, and grid disturbances are key challenges to enhancing the MPPT performance capability. Considering these struggles, this study aims to model a modified dynamic DFIG-based wind turbine system and develop a hybrid Adaptive Neuro-Fuzzy Inference System (ANFIS) with a Proportional-Integral (PI) controller on the back-to-back converter at the rotor and grid sides. The actual limited ranges of wind speed and output power generation data of the Adama II wind power plant in Ethiopia are utilized as input and output variables for the ANFIS controller. The simulation results from the latest version of R2024a MATLAB-Simulink software show that the proposed ANFIS-PI reached an MPPT of 2.22 MW compared to the FLC-PI controller attained 2.2 MW using the benchmark as the reference value of 1.561 MW in the PI controller, by improving the maximum power coefficient of 0.5504 compared to 0.5473 using the baseline as the reference value of 0.4109, respectively, at a rated wind speed of 12.5 m/s and an optimal pitch angle of 0°. KW - Adaptive Neuro-Fuzzy inference system KW - Doubly-Fed induction generator KW - MATLAB-Simulink software KW - Maximum power point tracking KW - Proportional-Integral Y1 - 2026 UR - https://doi.org/10.1038/s41598-026-36021-3 VL - 16 ER -