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Aufsatz
Cold Load Pickup Model Adequacy for Power System Restoration Studies
(2022-10-18)
When a grid section is re-energized after an interruption, the load behaviour can be significantly different from normal operation. In this manuscript, the impact of the phenomenon—known as cold load pickup—is investigated by evaluating 31 time series measured after network outages in Austria and Germany. Its impact on power system restoration and the adequacy of the most common type of simplified model for such investigations is assessed by the time domain simulation of a restoration setting involving the parallel ...
Aufsatz
Model selection, adaptation, and combination for transfer learning in wind and photovoltaic power forecasts
(2023-03-14)
There is recent interest in using model hubs – a collection of pre-trained models – in computer vision tasks. To employ a model hub, we first select a source model and then adapt the model for the target to compensate for differences. There still needs to be more research on model selection and adaption for renewable power forecasts. In particular, none of the related work examines different model selection and adaptation strategies for neural network architectures. Also, none of the current studies investigates the ...
Aufsatz
Time Series Optimization-Based Characteristic Curve Calculation for Local Reactive Power Control Using Pandapower-PowerModels Interface
(2023-05-29)
Local reactive power control in distribution grids with a high penetration of distributed energy resources (DERs) will be essential in future power system operation. Appropriate control characteristic curves for DERs support stable and efficient distribution grid operation. However, the current practice is to configure local controllers collectively with constant characteristic curves that may not be efficient for volatile grid conditions or the desired targets of grid operators. To address this issue, this paper ...
Aufsatz
Technoeconomic analysis of standalone hybrid renewable energy systems for telecommunication sector under different climatic conditions in Saudi Arabia
(2024-04-05)
Reliance on conventional fossil fuels to fulfil the extensively increasing energy demands due to industrial development is becoming a financial burden and a huge source of global warming. Saudi Arabia, possessing nearly 15% of the world's oil reserves, confronts an intricate scenario where approximately 53% of government revenue is oil-dependent, rendering it the 11th largest global emitter of carbon gases. This proclivity underscores the urgent need for transitioning towards renewable energy sources to alleviate ...
Aufsatz
PrOuD: Probabilistic Outlier Detection Solution for Time-Series Analysis of Real-World Photovoltaic Inverters
(2023-12-21)
Anomaly detection methods applied to time series are mostly viewed as black boxes that solely provide a deterministic answer for the detected target. Without a convincing explanation, domain experts can hardly trust the detection results and must conduct further time-series diagnoses in real-world applications. To overcome this challenge, we mathematically analyzed the sources of anomalies and novelties in multivariate time series as well as their relationships from the perspective of Gaussian-distributed non-stationary ...
Aufsatz
Analysis and Optimization of the Loss Distribution for a Two Stage AC/DC Power Supply
(2023-12-12)
This paper presents the analysis and optimization procedure of a two-stage bidirectional AC/DC power supply. The exemplary power supply consists of a silicon carbide based active front end and a dual active bridge DC/DC converter. It is designed to supply 600 V DC applications from universal low voltage AC grids with a power up to 6 kW. The paper includes the topology and design considerations, as well as an in-depth loss distribution analysis based on a validated loss model. The loss model is then utilized for an ...
Aufsatz
The relevance of proximity and work-related experience for the individual support for the expansion of power plants: An empirical analysis of wind, coal, and nuclear energy
(2024-06-14)
This paper empirically examines whether proximity to power plants and work-related experience in the wind, coal, and nuclear energy sectors are correlated with the individual support for the expansion of corresponding regional power plants. The data for this analysis stem from a large-scale computer-based survey among more than 3700 citizens in Germany. The econometric analysis with binary and ordered probit models reveals significantly positive correlations between work-related experience in a specific energy sector ...
Aufsatz
Mathematical modelling of a latent heat storage: Influence of PCM thermal conductivity and enthalpy-temperature relationship
(2024-06-08)
Mathematical modelling of latent heat storage units is useful to calculate their thermal performance for integration in larger systems. This requires the input of thermophysical properties of the phase change material (PCM) used, but data provided by manufacturers or published in the literature is often incomplete and/or varies between sources. However, it is not clear to what extent an accurate knowledge of these properties, including their phase dependency, is necessary to obtain reliable calculations, especially ...
Aufsatz
Self-generation and outage losses: A firm-level analysis for emerging and developing Asian countries
(2024-02-26)
Access to reliable and affordable electricity is critical to economic development in emerging and developing Asia. However, many firms in these regions face challenges in obtaining consistent and affordable electricity from the grid, leading them to invest in self-generation technologies. This paper examines the strategic decision of firms to self-generate electricity and the economic losses incurred during power outages. Using survey data from the World Bank Enterprise Survey (WBES) of 5639 manufacturing firms in ...
Aufsatz
Peak shaving at system level with a large district heating substation using deep learning forecasting models
(2024-05-20)
The decarbonisation of urban district heating (DH) systems requires increased heating grid flexibility. Therefore, this article examines the optimised operation of a tank thermal energy storage (TTES) on the secondary side of a new DH substation for an industrial site in a German city, in order to shave the peaks of the whole DH system and thus reduce the need for heat-only boilers (HOB). The accuracy of heat load and return temperature forecasts for both the industrial consumer and the DH grid is critical to the ...