- What are electromagnetic fields?
- Static and low-frequency fields
- What are static and low-frequency electric and magnetic fields?
- Direct and alternating voltage
- Effects of static and low-frequency fields
- Reports & Evaluations
- Radiation protection relating to the expansion of the national grid
- Basics transfer of electrical power
- High-frequency fields
- What are high-frequency fields?
- Applications high-frequency fields
- Radiation protection in mobile communication
- What is mobile communication?
- Reports and evaluations
- What is optical radiation?
- UV radiation
- What is UV radiation?
- Sun but safe!
- Effects of UV radiation
- Protection against UV radiation
- UV index
- Infrared radiation
- What is ionising radiation?
- Radioactivity in the environment
- Where does radioactivity occur in the environment?
- What is the level of natural radiation exposure in Germany?
- Air, soil and water
- Building materials
- Industrial residues (NORM)
- BfS laboratories
- Applications in medicine
- Applications in daily life and in technology
- Radioactive radiation sources in Germany
- Register high-level radioactive radiation sources
- Type approval procedure pursuant to RöV and StrlSchV
- Cabin luggage security checks
- Radioactive materials in watches
- Ionisation smoke detectors (ISM)
- What are the effects of radiation?
- Acute radiation damage
- Effects of selected radioactive materials
- Consequences of a radiation accident
- Cancer and leukaemia
- Genetic radiation effects
- Individual radiosensitivity
- Epidemiology of radiation-induced diseases
- Ionising radiation: positive effects?
- Risk estimation and assessment
- Radiation protection
- Basic informations
- Occupational radiation protection
- Nuclear accident management
- What happens in an emergency?
- Federal and state tasks
- In the event of an emergency
- Measuring networks
- Exercises for emergency situations
- Nuclear accidents
- Defence against nuclear hazards
- Service offers
- Radon measurements
- Incorporation monitoring
- Biological dosimetry
- Online library
- About us
- Science and research
- Research concept
- Scientific collaborations
- EU research framework programme
- BfS research programme
- Third-party funded research
- Departmental research
- Selected research projects
- Selected research results
- Professional opinions
- Laws and regulations
- BfS Topics in the Bundestag
Public power supply and traction power network
- In many places, the public power supply at low-voltage grid level is provided by means of underground cables.
- The main frequency is 50 hertz.
- Railway overhead lines and the electrical traction power network supplying the overhead lines are operated at a frequency of 16.7 hertz.
- In contrast to mainline railways, trams and underground trains as well as the Berlin S-Bahn (rapid transit railway in Berlin) are supplied with direct current.
Public electricity supply networks
In many places, the public power supply at low-voltage grid level is provided by means of underground cables. Overhead power lines are mainly used for the national distribution and transmission of electricity over long distances. The main frequency is 50 hertz. Low-frequency magnetic fields occur in the vicinity of the lines; in the case of overhead power lines electric fields are also produced. Houses, elevations on the ground or vegetation may result in distortions of the electric field below overhead power lines.
In addition to lines, substations and transformer stations are further components of public electricity supply networks.
Traction power network
Railway overhead lines and the electrical traction power network supplying the overhead lines are operated at a frequency of 16.7 hertz. Railway overhead lines are strung above the tracks as contact wires; traction power network lines are generally constructed as overhead power lines.
Local rail traffic
In contrast to mainline railways, trams and underground trains as well as the Berlin S-Bahn (rapid transit railway in Berlin) are supplied with direct current generated in rectifier stations from the public alternating current grid. The overhead contact wires of trams and the power rails of underground railways produce static electric and magnetic fields.
Exposure from electric and magnetic fields
Both with overhead power lines as well as underground cables, the field strengths drop off rapidly with increasing distance. Electric fields occur only in the case of overhead power lines. In this context, it is interesting that construction materials used for the walls of a house can shield its interior against up to 90 per cent of the external electric field acting on the house, whereas shielding buildings against external magnetic fields is not possible without great effort.
State of 2017.05.26