TY - CHAP A1 - Hahn, Christoph A1 - Burkhardt, Matthias A1 - Semerow, Anatoli A1 - Luther, Matthias A1 - Ruhle, Olaf T1 - Generic modeling of a self-commutated multilevel VSC HVDC system for power system stability studies T2 - 2015 IEEE Applied Power Electronics Conference and Exposition N2 - This paper provides a generic stability model of a self-commutated multilevel VSC (Voltage Source Converter) HVDC (High Voltage Direct Current) and its appropriate control. At first the approach of modeling depicts the independence of the AC and DC quantities and therefore two separate models - one for the AC and one for the DC side - can be figured out. The AC side model is developed in the dq frame out of the according differential equations. For the DC side no further transformation is required. Regarding the fact of balanced energy terms the two models can be merged. The consolidation of both models reveals a comprehensive large signal model of a multilevel based HVDC system which can be used for detailed analyses in power system stability studies. Due to the comparison of the generic stability model with an EMT (Electro-Magnetic Transient) HVDC model the consistence of the dynamic behavior is shown. Y1 - 2015 SN - 978-1-4799-6735-3 U6 - https://doi.org/10.1109/apec.2015.7104728 PB - IEEE Computer Society Press ER - 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 - Scheibe, Christian A1 - Semerow, Anatoli A1 - Menke, Jasmin A1 - La Seta, Piergiovanni A1 - Raab, Alexander A1 - Mehlmann, Gert A1 - Luther, Matthias T1 - A Novel Co-Simulation Concept using Interprocess Communication in Shared Memory T2 - 2019 IEEE Power and Energy Society General Meeting N2 - The paper describes a novel co-simulation concept for power system analysis using interprocess communication via shared memory. This innovative approach enables manufacturers, utilities and other parties a continuous and efficient use of simulation models within the phases of preliminary investigations, planning, design and operation. It paves the way for the practical implementation of the concept of a digital twin. Besides the technical specification of the process communication, the realization of process synchronization and the model interfaces are comprehensively discussed. Performance topics are practically treated. Finally, as an application of the novel concept, a successfully implemented study in a power system simulation tool is demonstrated in order to prove its practical feasibility. Y1 - 2019 SN - 978-1-7281-1981-6 U6 - https://doi.org/10.1109/PESGM40551.2019.8973964 SN - 1944-9925 PB - IEEE Computer Society Press 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 - Semerow, Anatoli A1 - Miltner, Andreas A1 - Horn, Stefan A1 - Dimitrovski, Robert A1 - Luther, Matthias T1 - Analysis of a disturbance localization method for incidents in continental Europe T2 - 2016 IEEE PES Innovative Smart Grid Technologies Conference Europe N2 - To localize incidents such as generator trips or load shedding, which cause transients in power systems, a technique from seismology is used in this paper: triangulation by means of information from Phasor Measurement Units (PMU). The synchronized observation of frequency change arrival times, which represent an electromechanical disturbance propagation, allows to approximate the disturbance location and thereby to support a reliable power system operation. For the verification and further development of this method a post analysis of three incidents of last years in the Continental Europe synchronous area (CESA) power system is done using two different numerical methods to solve the set of triangulation equations. The calculated deviations of estimated to real locations show on the one hand a relative good approximation to the real incident locations, but also a high dependency on the assumed electromechanical disturbance propagation speed and the chosen parameters of signal processing. Nevertheless, the method seems to be promising for future applications and is worth to be further developed. Y1 - 2016 SN - 978-1-5090-3358-4 U6 - https://doi.org/10.1109/isgteurope.2016.7856312 PB - IEEE Computer Society Press ER - TY - CHAP A1 - Semerow, Anatoli A1 - Horn, Stefan A1 - Schwarz, Bianca A1 - Luther, Matthias T1 - Disturbance localization in power systems using wide area measurement systems T2 - 2016 IEEE International Conference on Power System Technology N2 - There are different innovative concepts to localize disturbances with an electromechanical impact in power systems using synchronized frequency measurements from Wide Area Measurement Systems. This paper investigates five approaches, of which four are mainly discussed and one is novel: Gradient Search, Triangulation, Parzen Windows, Probability Circles and Time Distance Ratios. The similarities and differences of the methods are described and analyzed within a case study using publicly available frequency measurements and a dynamic study model. The cases are selected with the aim to point out the limits of the methods and to derive recommendations for improvements to be further developed. The study explicitly shows the challenges of the application and provides suggestions how to meet them. Y1 - 2016 SN - 978-1-4673-8848-1 U6 - https://doi.org/10.1109/powercon.2016.7753872 PB - IEEE Computer Society Press ER - TY - JOUR A1 - Glas, J. A1 - Semerow, Anatoli A1 - Luther, Matthias T1 - General analysis of frequency containment and restoration reserves of wind power plants in power systems JF - Renewable Energy and Power Quality Journal N2 - The increasing share of renewable energies, such as photovoltaics and wind power, lead to an all new situation in power systems over the past years. It changes the demand and possibilities of providing ancillary services like frequency containment (FCR) and restoration reserves (FRR). To cover the reduction of conventional generation units, which are usually used to provide those services, new possibilities have to be analysed. The aim of this paper is to show the possibilities of providing FCR and FRR by pitch-controlled wind power plants, regarding the overall dynamic system behaviour. Hence, a basic grid model with an integrated wind park, using pitch-control to adjust its power output, is being introduced and described. The simulation results of different wind situations during a power loss in the grid are then presented in order to assert the practicability of wind power plants providing FCR and FRR. As a conclusion, it is to ascertain that, pitch-control can be a way to support conventional units in providing ancillary services, but can’t be a stand-alone solution. © 2016, European Association for the Development of Renewable Energy, Environment and Power Quality. Y1 - 2016 U6 - https://doi.org/10.24084/repqj14.237 SN - 2172-038X VL - 1 IS - 14 SP - 96 EP - 101 PB - European Association for the Development of Renewable Energy, Environment and Power Quality (EA4EPQ) ER - TY - CHAP A1 - Kreplin, Sarina A1 - Höhn, Sebastian A1 - Semerow, Anatoli A1 - Luther, Matthias T1 - Generator modeling in the context of small-signal stability T2 - 2016 IEEE Power and Energy Society General Meeting N2 - Modal analysis is the well-established method for investigating small-signal stability. Dominant states of a particular oscillatory or monotonous mode can be identified by linearizing the system's differential equations. Since generator oscillation is predominantly influenced by the speed deviation and the rotor angle, whereas other state variables play a minor role, an approach to reduce a generator's state matrix to a lower order is presented in this paper. Fundamental, analytical investigations concerning generator modeling of synchronous generators connected to an infinite bus ensure the correct reproduction of the generator's electromechanical behavior without losing accuracy compared to higher-order models. Y1 - 2016 U6 - https://doi.org/10.1109/pesgm.2016.7741598 SN - 1944-9933 ER - TY - CHAP A1 - Semerow, Anatoli A1 - Muth, Lukas A1 - Luther, Matthias T1 - Investigation of impacts on the disturbance propagation in power systems T2 - 2016 IEEE International Conference on Power System Technology N2 - Disturbances as generation trips, load shedding or other switching events propagate measurably throughout power systems as electromechanical interactions and may cause undesirable phenomena as power oscillations. Therefore, it is essential to have a deeper understanding of the electromechanical phenomenon to improve current countermeasures. For this reason, the present study analyzes the impacts on the disturbance propagation speed as line, generator and operating parameters, by means of an exemplary power system model and numerical simulation. The used conventional speed determination method is presented and discussed with regard to further development. By varying each of the selected system parameters, the sensitive influence on the propagation speed is studied and compared to the theoretical expectations. Additionally, the impact of different incident locations in a power system is investigated to determine the influence of system structure on the propagation. Y1 - 2016 U6 - https://doi.org/10.1109/POWERCON.2016.7754061 PB - IEEE Computer Society Press ER - TY - CHAP A1 - Semerow, Anatoli A1 - Höhn, Sebastian A1 - Bauer, Benedikt A1 - Luther, Matthias T1 - An innovative method to develop power system equivalents with focus on inter-area oscillations and primary control representation T2 - 2015 IEEE Eindhoven PowerTech N2 - An innovative method to develop power system equivalents is presented in this paper. The purpose is the representation of system inertia, inter-area oscillations and primary control of large interconnected power systems by means of publicly available information. The approach to reach this target is based on a systematically developed load-flow model and the representation of system dynamics by means of standard dynamic models for generation units, their appropriate control and loads. The initial parameters of the standard dynamic models are tuned with regard to frequency measurements and published power system characteristics. The developed method allows general analysis of extensive influences on the dynamic behavior of a particular power system. Conceivable applications of the developed method are proposed for further system analysis. Finally an employment of the method is shown for the Continental Europe synchronous area (CESA). Y1 - 2015 U6 - https://doi.org/10.1109/PTC.2015.7232581 PB - IEEE Computer Society Press ER - TY - JOUR A1 - Höhn, Sebastian A1 - Semerow, Anatoli A1 - Luther, Matthias T1 - Comparison of transmission technologies with regard to their contribution to power system stability JF - Renewable Energy and Power Quality Journal N2 - The amount of power to be transmitted is increasing worldwide. Hence, a considerable number of bulk power transmission projects are going to be realized (e.g. [1]). Taking into account the recent technical development, three technologies are available for bulk power transmission: Direct current applications with voltage sourced or line commutated converters as well as the high-voltage AC technology up to 1200 kV. To select the most suitable technology for a particular project is often anything but trivial for the transmission system operator. Amongst other criteria, the influence on the electromechanical behavior of the power system is a decisive factor for network improvements that should be considered within the decision-making process. This paper aims at categorizing and analyzing this rather abstract term as a major criterion. The goal is to provide an indication, which factors are needed to be evaluated in advance of the well-considered choice. For that reason, several categories are introduced and thoroughly investigated within the scope of a theoretical approach. Where reasonable, simulation results are presented in order to enable the practical assessment of the impact on the electromechanical system behavior. As a conclusion, it is recommended to perform concise ex-ante studies with regard to the electromechanical dynamics as a decision-making basis to identify the most suitable transmission technology for a particular project. © 2015, European Association for the Development of Renewable Energy, Environment and Power Quality (EA4EPQ). Y1 - 2015 U6 - https://doi.org/10.24084/repqj13.318 SN - 2172-038X VL - 1 IS - 13 SP - 327 EP - 332 PB - European Association for the Development of Renewable Energy, Environment and Power Quality (EA4EPQ) ER - TY - CHAP A1 - Semerow, Anatoli A1 - Höhn, Sebastian A1 - Luther, Matthias A1 - Sattinger, Walter A1 - Abildgaard, Hans A1 - Garcia, Agustin Diaz A1 - Giannuzzi, Giorgio T1 - Dynamic Study Model for the interconnected power system of Continental Europe in different simulation tools T2 - 2015 IEEE Eindhoven PowerTech N2 - This paper describes the development process of the Dynamic Study Model (DSM) for the synchronously interconnected power system of Continental Europe in different simulation tools 1 . The model was developed by the European Network of Transmission System Operators for Electricity (ENTSO-E) working group System Protection and Dynamics 2 and the University of Erlangen-Nuremberg within a collaboration. The paper describes the DSM scope, input and necessary steps towards an adequate basis for the novel dynamic data enhancement process by means of standard dynamic models for generation units and allocation criteria. Through a parameter variation process the DSM has been successively tuned to match a frequency measurement of a system event with respect to system inertia, frequency containment reserve and one of the typical oscillation modes within Continental Europe. Finally, the DSM behavior has been verified by means of previous experience from operation. Y1 - 2015 SN - 978-1-4799-7693-5 U6 - https://doi.org/10.1109/PTC.2015.7232578 PB - IEEE Computer Society Press ER - TY - CHAP A1 - Hahn, Christoph A1 - Semerow, Anatoli A1 - Luther, Matthias A1 - Ruhle, Olaf T1 - Generic modeling of a line commutated HVDC system for power system stability studies T2 - Proceedings of the IEEE Power Engineering Society Transmission and Distribution Conference N2 - This paper will reveal a novel comprehensive approach for generic modeling and control design of line commutated HVDC systems. The model will be developed based on the essential HVDC equations and transfer functions. Due to comparing the generic model with an EMT (Electro-Magnetic Transient) HVDC model the consistence of the dynamic behavior will be shown. Furthermore modeling of additional HVDC system facilities like transformer tap-changers and AC filters will be annotated. Control design schemes for line commutated HVDC systems will be derived and the interactions of the controllers applied to the developed model will be investigated. © 2014 IEEE. Y1 - 2014 SN - 978-1-4799-3655-7 U6 - https://doi.org/10.1109/TDC.2014.6863308 PB - Institute of Electrical and Electronics Engineers ER - TY - JOUR A1 - Höhn, Sebastian A1 - Semerow, Anatoli A1 - Luther, Matthias T1 - A comprehensive approach to classify reactive power consumption in transmission technologies JF - Renewable Energy and Power Quality Journal N2 - Reactive power consumption is an essential feature of any electrical equipment applied in electrical power systems. To accomplish its main task, i.e. the transfer of active power, an electrical device interacts with the system it is connected to. A common aim is to reduce the reactive power flow on the terminals of the equipment to a minimum. Therefore it’s necessary to compensate the reactive power consumption by means of adequate measures. This can’t be reached without precise investigation on the sources of reactive power emergence. This paper investigates the physical phenomena underlying the reactive power behavior of HVAC and HVDC transmission technologies. After having introduced a common mathematical definition of active, apparent and reactive power, reactive power is categorized and the concept is applied to analyze the aforementioned technologies. © 2013, European Association for the Development of Renewable Energy, Environment and Power Quality (EA4EPQ). Y1 - 2013 U6 - https://doi.org/10.24084/repqj11.351 SN - 2172-038X VL - 1 IS - 11 SP - 501 EP - 506 PB - European Association for the Development of Renewable Energy, Environment and Power Quality (EA4EPQ) 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 -