Sebastian Lehnhoff

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The high operating costs of Internet Data Centers (IDC) are a major challenge for their owners worldwide. Therefore, more attention has recently been paid to the energy and cost management of IDCs. This paper investigates the optimal operational strategy for minimizing the electricity costs of a group of globally distributed IDCs in different locat...

As automation increases qualitatively and quantitatively in safety-critical human cyber-physical systems, it is becoming more and more challenging to increase the probability or ensure that human operators still perceive key artefacts and comprehend their roles in the system. In the companion paper, we proposed an abstract reference architecture ca...

We propose a reference architecture of safety-critical or industry-critical human cyber-physical systems (CPSs) capable of expressing essential classes of system-level interactions between CPS and humans relevant for the societal acceptance of such systems. To reach this quality gate, the expressivity of the model must go beyond classical viewpoint...

The NFDI4Energy consortium aims to establish new services filling a variety of needs for the energy system research community, from making FAIR research data easily accessible to promoting collaboration among community entities. Seven Task Areas (TAs) have been defined to achieve the consortium’s objectives, each with a specific focus. Task Area 4...

The increasing integration of renewable energy resources requires so-called smart grid services for monitoring, control and automation tasks. Simulation environments are vital for evaluating and developing innovative solutions and algorithms. Especially in smart energy systems, we face a variety of heterogeneous simulators representing, e.g., power...

Renewable energy sources generated locally are becoming increasingly popular in order to achieve carbon neutrality in the near future. Some of these sources are being used in neighbourhood (local, or energy communities) grids to achieve high levels of self-sufficiency. However, the objectives of the local grid and the distribution grid to which it...

Cartesian genetic programming is a popular version of classical genetic programming, and it has now demonstrated a very good performance in solving various use cases. Originally, programs evolved by using a centralized optimization approach. Recently, an algorithmic level decomposition of program evolution has been introduced that can be solved by...

The ongoing changes in modern power systems towards increasingly decentralized systems render the coordination of generation assets and the corresponding dependency on Information and Communication Technology highly relevant. This work demonstrates the impact of three types of ICT errors, namely delayed data, data loss and data corruption, on the c...

The ongoing changes in modern power systems towards increasingly decentralized systems render the coordination of generation assets and the corresponding dependency on Information and Communication Technology highly relevant. This work demonstrates the impact of three types of ICT errors, namely delayed data, data loss and data corruption, on the c...

Neural State Estimation (NSE) is a novel application of deep learning which is concerned with interpolating the state of a distribution power grid from a limited amount of sensor data and can be represented as a non-linear graph time-series nowcasting problem. Although several authors have proposed their solutions for NSE, there is neither a compar...

Locally generated renewable energy resources are gaining popularity with the aim of reaching carbon-neutral energy in the foresee- able future. Some of these sources have been deployed within the neighbourhood (local) grids to achieve high autarchy. However, the main objectives of the local grid and the objectives of the distribution grid where the...

Cartesian genetic programming is a popular version of genetic programming and has meanwhile proven its performance in many use cases. This paper introduces an algorithmic level decomposition of program evolution that can be solved by a multi-agent system in a fully distributed manner. A heuristic for distributed combinatorial problem solving is ada...

In this paper, a reliability-sensitive optimization approach for the provision of ancillary services from distributed energy resources is proposed. The main focus here is on small-scale renewable energy sources such as wind turbines and PV arrays, which are highly distributed, and the generated power is weather dependent and intermittent. Therefore...

Battery-electric mobility represents the most promising post-fossil mobility approach as the number of electric vehicles (EVs) worldwide has grown exponentially in recent years. However, the increased electricity demand resulting from EVs' charging processes was unknown when planning the electric grid of existing districts and nowadays may cause vi...

The increasing integration of renewable energy resources requires so-called smart grid services for monitoring, control and automation tasks. To develop innovative solutions and algorithms, simulation environments are used for evaluation. Especially in smart energy systems, we face a variety of heterogeneous simulators representing, e.g., power gri...

The strong interdependence between power systems and information and communication technologies (ICT) makes cyber-physical energy systems susceptible to new disturbances. State estimation (SE) is a vital part of energy management systems, for several monitoring, management, and control services. Failure of SE service leads to loss of situational aw...

Power systems are undergoing a transition from centralized generation to distributed renewable generation. That calls for more flexibility in balancing generation and consumption because distributed energy resources in most cases rely on weather-dependent resources and can, therefore, only be controlled to a certain degree. The necessary flexibilit...

Energy research itself is changing due to digitalization and the trend to open science. While this change enables new research, it also increases the amount of, and need for, available data and models. Therefore, a platform for open digital energy research and development is required to support researchers and practitioners with their new needs and...

Future power systems are expected to depend more on ICT for essential grid services such as voltage and frequency control, increasing the interdependencies between both systems. Therefore, disturbances from one system could propagate and impact the other, degrading the state of the interconnected system. This paper proposes a formalised hybrid mode...

Smart Grids interconnect stakeholders and technologies in the energy domain for the sake of enabling new ways of interacting within the energy system through the usage of information and communication technologies. However, the facilitation of new business models and competition in the energy domain is not purely a technological issue. Besides tech...

The future Information and Communication Technology (ICT) infrastructure in distribution grids requires a significant network and computational resources for potentially running all so-called Smart Grid Services (SGS). The insufficient infrastructure may create network and computational congestions and resource shortages, which can lead to e.g., de...

Co-simulation is commonly used for the analysis of complex cyber-physical energy systems (CPES). Different domain-specific simulation tools and modeling approaches are used to simulate all or parts of the system. The co-simulation framework mosaik is a powerful tool to couple these simulation tools and models. This paper identifies the limitations...

In the past years, power grids have become a valuable target for cyber-attacks. Especially the attacks on the Ukrainian power grid has sparked numerous research into possible attack vectors, their extent, and possible mitigations. However, many fail to consider realistic scenarios in which time series are incorporated into simulations to reflect th...

Machine learning and computational intelligence technologies gain more and more popularity as possible solution for issues related to the power grid. One of these issues, the power flow calculation, is an iterative method to compute the voltage magnitudes of the power grid's buses from power values. Machine learning and, especially, artificial neur...

The electrical energy grid is currently experiencing a paradigm shift in control. In the future, small and decentralized energy resources will have to responsibly perform control tasks like frequency or voltage control. For many use cases, scheduling of energy resources is necessary. In the multi-dimensional discrete case–e.g., for step-controlled...

Power Systems (PS) are becoming increasingly dependent on Information and Communication Technologies (ICT). ICT, on one hand enables the grid services which aid in the safe and secure operation of PS; on the other, also causes disturbances to propagate further due to the interdependencies between the two systems. In this paper, a simulation based a...

Power Systems (PS) are becoming increasingly dependent on Information and Communication Technologies (ICT). ICT, on one hand, enables the grid services which aid in the safe and secure operation of PS; on the other, also causes disturbances to propagate further due to the interdependencies between the two systems. In this paper, a simulation-based...

This study develops a comparative, sociotechnical design perspective for interdisciplinary teams of social scientists and computer scientists. Sociotechnical design refers to identifying both technical and governance challenges and to understanding the ways in which the two types of problems affect and define each other. Approaching design as an op...

To tackle the climate crisis, the European energy strategy relies on consumers taking ownership of the energy transition, accelerating decarbonisation through investments in low-carbon technologies and ensuring system stability and reliability by actively participating in the market. Therefore, tools are needed to better understand an increasingly...

In future energy systems, decentralized control will require delegation of liabilities to small energy resources. Distributed energy scheduling constitutes a complex multi-level optimization task regarding the underlying high-dimensional, multi-modal and nonlinear problem structure. The multi-level issue as well as the requirement for model indepen...

The demand for charging facilities is growing in parallel to the number of electric vehicles (EV). This demand will be predominantly covered by private charging points connected to the low-voltage grid . The increased load resulting from these charging processes may cause grid instabilities depending on operational factors, e.g. simultaneity factor...

While long-term wide-range blackouts have been studied extensively from a power systems perspective, the role of ICT in the recovery of smart energy systems has not been investigated to the same extent. This paper presents a flexible blackstart service to restore a smart distribution system alongside an impaired ICT system. We formulate the problem...

This paper addresses how a power system Digital Twin (DT) can be structured, what it should be able to do, and how it can possibly be implemented with already known methods. To this end, a structural framework for the design of power system DTs is presented. The framework consists of functional blocks such as model execution and model validation, w...

In order to prevent conflicting or counteracting use of flexibility options, the coordination between distribution system operator and transmission system operator has to be strengthened. For this purpose, methods for the standardized description and identification of the aggregated flexibility potential of distribution grids are developed. Approac...

Within SiNED research project, several members of the Energy Research Centre of Lower Saxony (Energieforschungszentrum Niedersachsen, EFZN) are working on various issues relating to the future provision of ancillary services and to future congestion management. The questions include energy technology, economic and energy law aspects as well as info...

The increasing digital transformation in energy supply systems allows greater control and possibilities for performance optimization and efficiency. This is accompanied by increasing complexity of the system, and thus requires the evaluation of interactions between energy and information and communication technologies (ICT) involved. One of the goa...

With the transition towards renewable energy resources, the impact of small distributed generators (DGs) increases, leading to the need to actively stabilize distribution grids. DGs may be organized in virtual power plants (VPPs), where DGs’ schedules must be coordinated to enable the VPP to act as a single plant. One approach to solving this probl...

The increase of generation capacity in the area of responsibility of the distribution system operator (DSO) requires strengthening of coordination between transmission system operator (TSO) and DSO in order to prevent conflicting or counteracting use of flexibility options. For this purpose, methods for the standardized description and identificati...

Over the next two decades, the energy transition and the growth of digitalisation will result in new risks to the electricity supply. A resilience strategy will be required to manage these risks and reliably prevent blackouts and their damaging impacts on society. The “Resilience of digitalised energy systems” working group of the Academies’ Projec...

The transition of the power system to more decentralized power plants and intelligent devices in a smart grid leads to a significant rise in complexity. For holistic and integrated designing and testing of new technologies before their implementation in the field co-simulation is an important approach. It allows to couple diverse software simulatio...

The integration of ICT into power systems has increased the interdependencies between the two systems. The operation of power system depends on several ICT-enabled grid services which manifest the interdependencies. ENTSO-E system state classification is a tool that is widely used by operators to determine the current operational state of the power...

Modern power systems are cyber-physical systems with increasing relevance and influence of information and communication technology. This influence comprises all processes, functional, and non-functional aspects like functional correctness, safety, security, and reliability. An example of a process is the data acquisition process. Questions focused...

The challenge of reliable operation in Cyber-Physical Energy Systems (CPES) is constantly increasing due to more participating actors and associated disruptive events. The supporting automation systems for monitoring, communication and control is a vital part for reliable operation, realized by grid services such as voltage control, frequency contr...

The rapidly changing paradigm in energy supply with a shift of operational responsibility towards distributed and highly fluctuating renewables demands for proper integration and coordination of a broad variety of small generation and consumption units. Many use cased demand for optimized coordination of electricity production or consumption schedu...

Provision of grid services in modern power systems is highly dependent on their automation systems for monitoring,communication and decision making. These automation systems are vital for the reliable operation of the grid during and after disruptive events. This papers explores the concept of Grid Function Virtualization (GFV) as a potential appro...

The traditional electricity grid is ought to become a smart grid. One reason is the integration of volatile renewable energy generation, which poses the demand for advanced communication and control technology. This results in a change of the overall system dynamics, which in turn require testing to be done in early stages and with a more holistic...

The future smart grid has to be operated by rather small and hardly flexible energy resources. Such duty comprises different planning tasks. Virtual power plants powered by multi-agent control are seen as a promising aggregation scheme for coping with problem size and for gaining flexibility for distributed load planning. If agents are allowed to f...

In modern power systems, reliable provision of grid services (e.g., primary and ancillary services) are highly dependent on automation systems in order to have monitoring, processing, decision making and communication capabilities. The operational flexibility of automation systems is essential for the reliable operation of power systems during and...

Currently, a transition of the electrical power system occurs that results in replacing large-scale thermal power plants at transmission grid level by small generation units mainly installed in the distribution grid. A shift from the transmission to the distribution grid level and an increase in ancillary service demand is a direct result of this t...

An adequate Orchestration of individually configured and operated distributed energy resources within the smart grid demands for multi-objective optimization with integrated constraint handling. Usually, no closed form description is available for the individual operation constraints of many renewable energy units. Possible operation and restrictio...

The traditional electricity grid is ought to become a smart grid. One reason is the integration of volatile renewable energy generation, which poses the demand for advanced communication and control technology. This results in a change of the overall system dynamics, which in turn require testing to be done in early stages and with a more holistic...

In the research project Designetz, the use of flexibilities is investigated with both simulation models and with the use of factual flexibility projects. These flexibility projects use a variety of different technologies and approaches to utilize flexibility for the power system [1]. By connecting the different flexibility projects with ICT-technol...

In the research project NEDS – Sustainable Energy Supply Lower Saxony, conceivable transition paths towards a power supply based on renewable energies in Lower Saxony by 2050 are developed and examined for their sustainability and feasibility. Both the different technical focal points and the joint development of methods and models represent import...

Practical optimization problems from engineering often suffer from non-convexity and rugged, multi-modal fitness or error landscapes and are thus hard to solve. Especially in the high-dimensional case, a lack of derivatives entails additional challenges to heuristics. High-dimensionality leads to an exponential increase in search space size and tig...

This paper proposes a standardized simulation environment to evaluate current and to design future multi-level grid control strategies in terms of a safe and reliable operation in future converter-dominated grids. For this, the first step is to develop a taxonomy for the uniform description of multi-level grid control strategies, to define relevant...

Abstract Surrogate models are used to reduce the computational effort required to simulate complex systems. The power grid can be considered as such a complex system with a large number of interdependent inputs. With artificial neural networks and deep learning, it is possible to build high-dimensional approximation models. However, a large data se...

This report describes the future scenarios and their development in the project NEDS. The future scenarios contain descriptions of possible future states of the power system in the German federal state Lower Saxony for the year 2050.