100 ms-Resolution Electrical Measurement Dataset of an OLTC-Induced Voltage Fluctuation Anomaly Across 0.4 kV, 20 kV, and 110 kV Networks with Diverse Loads and Distributed Energy Resources

This dataset contains electrical measurements collected from the energy infrastructure of KIT Campus North to investigate an operational voltage regulation anomaly caused by an on-load tap changer (OLTC) in a multi-voltage-level electrical network.

The dataset comprises synchronized measurements at the 110 kV, 20 kV, and 0.4 kV voltage levels. At the 110 kV and 20 kV levels, positive-sequence voltage and current measurements are provided with a temporal resolution of 100 ms. At the 0.4 kV level, three-phase measurements of voltage, current, active power, and reactive power are provided. The low-voltage measurements cover different types of loads and distributed energy resources, including heat pumps, photovoltaic systems, and electric vehicle charging.

The measurements capture the system behavior before, during, and after an operational anomaly in the OLTC voltage regulation system. During the anomaly, the downstream voltage exhibited recurring step-like fluctuations with a characteristic interval of approximately 30 s. The anomaly was associated with inconsistent OLTC regulation commands and was subsequently traced to increased contact resistance in the resistor-type tap selector mechanism. ... mehrLocalized corrosion of the resistor bridge affected the signal integrity of the control feedback path and resulted in erroneous or inconsistent tap changes.

The dataset enables the analysis of the temporal and spectral characteristics of the observed voltage fluctuations and their propagation across different voltage levels. In particular, the data allow the comparison of system behavior during normal operation and during the anomaly, as well as the investigation of the influence of different low-voltage loads and distributed energy resources on the observed voltage behavior.

The dataset is intended to support reproducible research on voltage regulation, OLTC-related operational anomalies, power quality, and voltage dynamics in multi-voltage-level electrical networks. It can be used for statistical and spectral analysis, cross-voltage-level comparison, anomaly characterization, and further investigation of voltage fluctuations in distribution networks.