High voltage
An electrical voltage over 1,000 volts ( 1 kV ) is generally referred to as a high voltage. In the VDE regulations voltages up to 1 kV are referred to as low voltage and high voltage above 1 kV as uniform. In the electric power industry more conceptual subdivisions of the high voltage in the sub-concepts medium voltage, high voltage and high voltage are common, where the boundaries are not standardized.
The higher the AC voltage, the less loss electric power transmission is in otherwise identical environmental conditions.
In the energy transfer electrical energy to power lines is transmitted with the following standard nominal voltages:
- Medium voltage of 3 kV to 6 kV, 10 kV, 15 kV, 20 kV, 30 kV Application areas are in medium voltage networks for the supply of individual districts or several villages and mass merchandisers such as industrial plants.
- High voltage of 60 kV, 110 kV Applications are serving smaller cities and the overland supply. Even the connection of small power plants is carried out in this voltage level.
- Maximum voltage of 220 kV, 380 kV, 500 kV, 700 kV, 1150 kV These are used for bulk supply, integrated networks for inter-regional exchange of energy, connection of large power plants
To be distinguished from the nominal voltage is called the rated voltage. This indicates that the maximum voltage for which the isolation of the switching devices must be designed. The rated voltage is always higher than the nominal voltage.
Production and use
A natural source of very high voltages are thunderstorms. The discharge takes place in the form of flashes or Elmsfeuern.
For the artificial generation of high voltage band generators, electrostatic generators, influence machines, Tesla transformers, induction coils and Marx generators are used. In power plants, the alternating voltage generated in generators is converted by transformers for high voltage ( see substation ).
In addition to using the energy transport high voltage is used, among others in the following areas:
- Generation of spark ( ignition coil in gasoline engine oil or gas heating or lighter)
- Testing electromagnetic compatibility and immunity of components and devices (see also Marx generator )
- Anode voltage in cathode ray tubes (eg TV, X-ray tube ) or ionisation
- Acceleration of electrons and ions ( for example, in particle accelerators )
- In electric fences
- In electric fly swatters