Christoph Andres
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Christoph Andres has a total of 7 co-authors. Here are the top co-authors by number of shared publications:
- Aecio de Lima Oliveira
Laboratory for Analysis and Protection of Electrical Systems, Technology Center, Federal University of Santa Maria, Santa Maria 97105-900, RS, Brazil
1 shared publication - Ghendy Cardoso
Laboratory for Analysis and Protection of Electrical Systems, Federal University of Santa Maria, Santa Maria, Brazil
1 shared publication - Kaynan Maresch
Laboratory for Analysis and Protection of Electrical Systems, Federal University of Santa Maria, Santa Maria, Brazil
1 shared publication - Luiz Fernando Freitas-Gutierres
Laboratory for Analysis and Protection of Electrical Systems, Technology Center, Federal University of Santa Maria, Santa Maria 97105-900, RS, Brazil
1 shared publication - Martin Fritsch
Institute of Electrical Power Systems, Otto von Guericke University Magdeburg, Magdeburg, Germany
1 shared publication - Martin Wolter
Institute of Electrical Power Systems, Otto von Guericke University Magdeburg, Magdeburg, Germany
1 shared publication
Latest Publications
- Open Access
- 25 May 2026
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Access
- Vol. 14, 80440-80455
High-Frequency Current Transformers in Rotating Machines: A Critical Review
High-frequency current transformers (HFCTs) are widely used for online partial discharge (PD) monitoring in rotating machines due to their non-intrusive nature and high sensitivity to fast current transients. Unfortunately, the scientific literature often lacks detailed descriptions of the physical principles governing HFCT operation and the influence of sensor design parameters on PD detection are considered insufficiently. This paper presents a focused review of HFCT operating principles and their use in PD monitoring of rotating machines. The electromagnetic behavior of the sensor is revisited, highlighting the role of core geometry, material properties, air-gap configuration, and transfer impedance on the frequency response. In addition, the propagation of PD pulses along power cables is discussed to clarify the combined effects of signal attenuation and sensor bandwidth. The analysis contributes to a clearer understanding of HFCT behavior and supports more informed application of this technique in online PD diagnostics in rotating machines.
- 25 May 2026
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Access
- Vol. 14, 80440-80455
Open AccessHigh-Frequency Current Transformers in Rotating Machines: A Critical Review
High-frequency current transformers (HFCTs) are widely used for online partial discharge (PD) monitoring in rotating machines due to their non-intrusive nature and high sensitivity to fast current transients. Unfortunately, the scientific literature often lacks detailed descriptions of the physical principles governing HFCT operation and the influence of sensor design parameters on PD detection are considered insufficiently. This paper presents a focused review of HFCT operating principles and their use in PD monitoring of rotating machines. The electromagnetic behavior of the sensor is revisited, highlighting the role of core geometry, material properties, air-gap configuration, and transfer impedance on the frequency response. In addition, the propagation of PD pulses along power cables is discussed to clarify the combined effects of signal attenuation and sensor bandwidth. The analysis contributes to a clearer understanding of HFCT behavior and supports more informed application of this technique in online PD diagnostics in rotating machines.