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Hermann de Meer

Publications and source records attributed to Hermann de Meer.

6 recordsLinked to original sources

Toward an Energy-Optimized Operation of Data Centers Located in Wind Farms Using Reinforcement Learning

This paper studies Reinforcement Learning as an online controller for curtailment-aware workload shifting in wind-turbine-integrated high-performance computing (HPC) data centers. We introduce a reproducible fixed-day simulation framework with synthetic wind and price signals and delayed completion feedback, designed to be extensible toward more complex scenarios. As a controlled benchmarking basis, we then focus on the minimal case with one wind turbine and one co-located data center. In this setting, pure Reinforcement Learning exhibits a pronounced credit-assignment problem and tends to underuse free wind energy early in the day. We therefore evaluate two complementary countermeasures: optimization-based Imitation Learning and potential-based Reward Shaping. Across multi-seed training and a 200-day test set, Proximal Policy Optimization (PPO) and a Soft Actor-Critic (SAC) variant with an additional on-policy update routine achieve strong empirical performance among learned policies, and both Imitation Learning and Reward Shaping provide improvements in relevant configurations. A performance gap to the optimizer remains, which is expected: the optimizer plans offline with full-day foresight, whereas Reinforcement Learning must decide online from current observations without future realizations. The benchmark and ablation results provide a transparent basis for extending the approach toward richer multi-site and continuous-time scenarios.

cs.LG

Two-Stage Photovoltaic Forecasting: Separating Weather Prediction from Plant-Characteristics

Several energy management applications rely on accurate photovoltaic generation forecasts. Common metrics like mean absolute error or root-mean-square error, omit error-distribution details needed for stochastic optimization. In addition, several approaches use weather forecasts as inputs without analyzing the source of the prediction error. To overcome this gap, we decompose forecasting into a weather forecast model for environmental parameters such as solar irradiance and temperature and a plant characteristic model that captures site-specific parameters like panel orientation, temperature influence, or regular shading. Satellite-based weather observation serves as an intermediate layer. We analyze the error distribution of the high-resolution rapid-refresh numerical weather prediction model that covers the United States as a black-box model for weather forecasting and train an ensemble of neural networks on historical power output data for the plant characteristic model. Results show mean absolute error increases by 11% and 68% for two selected photovoltaic systems when using weather forecasts instead of satellite-based ground-truth weather observations as a perfect forecast. The generalized hyperbolic and Student's t distributions adequately fit the forecast errors across lead times.

cs.LG

Community Detection in Energy Networks based on Energy Self-Sufficiency and Dynamic Flexibility Activation

The global energy transition towards distributed, smaller-scale resources, such as decentralized generation and flexible assets like storage and shiftable loads, demands novel control structures aligned with the emerging network architectures. These architectures consist of interconnected, self-contained clusters, commonly called microgrids or energy communities. These clusters aim to optimize collective self-sufficiency by prioritizing local energy use or operating independently during wide-area blackouts. This study addresses the challenge of defining optimal clusters, framed as a community detection problem. A novel metric, termed energy modularity, is proposed to evaluate community partitions by quantifying energy self-sufficiency within clusters while incorporating the influence of flexible resources. Furthermore, a highly scalable community detection algorithm to maximize energy modularity based on the Louvain method is presented. Therefore, energy modularity is calculated using linear programming or a more efficient simulation-based approach. The algorithm is validated on an exemplary benchmark grid, demonstrating its effectiveness in identifying optimal energy clusters for modern decentralized energy systems.

cs.SI

Being Accountable is Smart: Navigating the Technical and Regulatory Landscape of AI-based Services for Power Grid

The emergence of artificial intelligence and digitization of the power grid introduced numerous effective application scenarios for AI-based services for the smart grid. Nevertheless, adopting AI in critical infrastructures presents challenges due to unclear regulations and lacking risk quantification techniques. Regulated and accountable approaches for integrating AI-based services into the smart grid could accelerate the adoption of innovative methods in daily practices and address society's general safety concerns. This paper contributes to this objective by defining accountability and highlighting its importance for AI-based services in the energy sector. It underlines the current shortcomings of the AI Act and proposes an approach to address these issues in a potential delegated act. The proposed technical approach for developing and operating accountable AI-based smart grid services allows for assessing different service life cycle phases and identifying related accountability risks.

cs.AI

Two-Step Blackout Mitigation by Flexibility-Enabled Microgrid Islanding

Blackouts are disastrous events with a low probability of occurrence but a high impact on the system and its users. With the help of more distributed and controllable generation and sector-coupled flexibility, microgrids could be prepared to operate in islanded mode during a blackout. This paper discusses a two-step blackout mitigation approach for highly renewable microgrids that utilizes user flexibility and energy storage systems for power balance in islanded grid operation. The proposed method includes a proactive flexibility reservation step, which derives a minimal reservation schedule for microgrid resources under uncertainty considering related operational costs. As a second step, during a blackout, a fully distributed control is implemented to maximize the usage of available resources based on a sequence of max and min-consensus rounds. This paper focuses on the second step, for which the effectiveness of blackstart and long-term coordination is shown. Load shedding can be reduced by 40\% compared to the forecast value. A hardware-in-the-loop simulation of a grid-forming converter further showed a fast convergence toward the optimal operation point.

eess.SY

A Tutorial on Resilience in Smart Grids

A key quality of any kind of system is its ability to deliver its respective service correctly. Often the unavailability of commercial systems may lead to lost revenue, which are minor compared to what may be at stake when critical infrastructures fail. A failure to deliver critical services, such as clean water or electricity may have dire consequences that endanger human lives and may even halt or break other infrastructures. The services provided by critical infrastructures need to be supplied continuously even when faced with re-configurations, outside disturbances and systemic changes. A system is called resilient if it fulfils this property. From the many critical infrastructures that exist, power systems may be the most important ones, because they are supplying the required electricity for other critical infrastructures. At the same time, a power system itself may be exposed to several disturbances from internal sources, e.g., fluctuations in the energy demand, and external sources, e.g., heavy storms. Especially, fast dynamic effects caused by these disturbances may lead to deviations of grid frequency, short-circuits, or, in severe cases, a total power system failure. As future scenarios will include more distributed renewable sources and less centralized generation from fossil fuels, ICT-based communication and coordination will play an increasing role. This paper examines the notion of resilience, how it has been traditionally ensured for the power system, and novel approaches to maintain the frequency, protect people and devices against short circuits and recover from a blackout. A special focus is on communication and the role that distributed renewable generation plays for these processes.

cs.NI