Transformer station

Tower station. On the left the medium-voltage supply, on the right a low-voltage outlet.

In a transformer station , also called transformer station , network station , local network station or transformer station for short , the term substation is also common in Switzerland , the electrical energy from the medium-voltage network with an electrical voltage of 10 kV to 36 kV is transferred to the low-voltage networks (local networks) used 400/230 V for general supply transformed (converted). There are around 600,000 transformer stations in Germany.

Furnishing

Transformer inside a station (for size comparison: the station is designed as a car garage). Left parts of the switching technology.

A transformer station consists of the primary technology , which for larger systems consists of the building and power transformer ; for smaller systems, an open design on a mast in the form of a mast transformer , a medium-voltage switchgear and at least one low-voltage distributor is chosen for reasons of cost . In the case of simple transformer stations, the medium-voltage switchgear can also consist of just one medium-voltage disconnector with transformer fuses and the low-voltage distribution system can consist of just one low-voltage transformer switch.

Furthermore, transformer stations consist of the components of the secondary technology such as automation and telecontrol technology , energy meters and communication equipment. These components are not absolutely necessary.

Construction

Until the early 1980s, transformer stations in overhead line networks were designed as tower stations . Initially, these were conventionally bricked, from the 1960s onwards they were increasingly built using prefabricated construction. Tower stations were occasionally built up until the mid-1980s. In cable networks, brick-built ground-level buildings were used, and from the mid-1960s also prefabricated garages, which were converted into transformer stations. Some of the stations were also built on private property; a general obligation to tolerate such transformer stations basically follows from § 11 para. 3 AVBEltV. Today, the transformer stations are usually built as completely delivered, ground-level prefabricated stations with very small areas. A distinction is made between accessible and non-accessible transformer stations. The non-accessible transformer stations are called compact stations.

Such a “compact station” contains a transformer from medium to low voltage as well as the associated switching and control technology

Since around 2010, due to the increase in small regenerative power plants, transformer stations have been equipped with information and communication technology (ICT), controllable local network transformers , motorized medium-voltage fields, telecontrol and automation components and regulations for load flow control - secured by a UPS system - and used as "intelligent network stations" , English Digital Substation .

Transformer stations in industrial companies, but also in urban areas with little free space or if prefabricated buildings are not desired for urban planning reasons, are still installed in existing or newly constructed larger buildings. Mast stations have been used in rural areas since the 1950s. Since the beginning of the 1990s, for reasons of water protection, there is usually no oil retention device in the case of mast stations, low cost advantages compared to small-scale transformer stations and, for optical reasons, no or only very few mast stations have been built in Germany.

Norms

The transformer stations in Germany must at least be set up in accordance with the requirements of DIN EN 61936-1 or DIN VDE 0101 (systems with nominal voltages above 1000 V). The standard DIN EN 62271-202 applies to factory-assembled transformer stations (high-voltage switchgear and switchgear - Part 202: factory-assembled stations for high voltage / low voltage). In addition, the energy supply company (EVU) requires a second lock or a master key at company stations / transfer stations. This requirement primarily affects old company stations, which are usually set up in the basement and do not have a separate entrance from the outside. In the case of new transfer stations, access from the outside must be available so that in the event of a fault, the fault service of the RU can quickly rectify the fault.

Definition of terms

A station where several cables come together often also contains a remote-controlled switchgear . One speaks then of a switching station or a switching mechanism. Transformer stations between transport and transmission networks as well as between transmission and medium-voltage networks also basically consist of a high-voltage and low-voltage switchgear and intermediate transformers. Large substations with numerous branches, transformers and several voltage levels are called substations .

Also not to be confused with transformer stations are the electrical distribution boxes , which are often found in localities and contain no transformers, but fuse and switching elements for distributing electrical energy within the low-voltage network.

shielding

Since the beginning of the 1990s, as a result of the 26th amendment to the Federal Immission Control Act, attention has been paid to reducing the magnetic leakage flux of the transformer stations. In particular, it is ensured that the magnetic flux density in the vicinity of the system does not exceed a value of 100  µT .

Conversion and further use of tower stations

Sign at the NABU species protection tower Struthbach near Bad Berleburg - Diedenshausen

Many transformer stations are taken over by nature conservationists after their use has ended and converted into conservation towers. Nesting boxes for birds and bat boxes are installed in or on these conservation towers . In some cases, nesting opportunities for insects and hiding places for amphibians in the ground area are created. The energy supply companies such as RWE are giving nature conservation associations such as NABU the transformer towers that are no longer needed and some are still giving grants for the renovation. The task of the tower stations is taken over by new compact transformer stations.

Locomotives

→ Main article : Transformer station (electric locomotive)

Disused electric locomotives were also used as transformer stations on the railroad. Only their equipment for electric train heating was operated.

literature

• Sebastian Ackermann, Maria Dehling (Ed.): From tower to tower. Tips and tours around a piece of electricity history. Klartext Verlag, Essen 2011, ISBN 978-3-8375-0637-2 .
• Adolf J. Schwab: Electrical energy systems - generation, transport, transmission and distribution of electrical energy. Springer Verlag, 2006, ISBN 3-540-29664-6 .
• Illo-Frank Primus: network stations. VWEW Energieverlag, 2009, ISBN 978-3-8022-0962-8 , VDE Verlag, 2009, ISBN 978-3-8007-3153-4 .
• Illo-Frank Primus: History and faces of the transformer stations - 125 years of transformer stations in Germany. VDE VERLAG GmbH, 2013, ISBN 978-3-8007-3558-7 .
• Illo-Frank Primus: Network stations - system technology for electrical distribution networks. 2nd edition, EW Medien und Kongresse, 2014, ISBN 978-3-8022-1114-0 , VDE Verlag, ISBN 978-3-8007-3605-8 .

Web links

Commons : transformer station  - collection of pictures, videos and audio files

• Location of transformer stations on the Open Infrastructure Map (incomplete)
• Transformers at the Berlin Energy Museum
• The most beautiful transformer houses in Europe - material-rich photo collection with background information, links and literature list

Individual evidence

1. ↑ The most beautiful transformer houses in Europe
2. ↑ Convert the transformer house or water tower into an animal hotel.
3. ↑ Illo-Frank Primus, History and Faces of the Transformer Stations, Chapter V.
4. ↑ Sebastian Ackermann, Maria Dehling (Ed.): From tower to tower. Tips and tours around a piece of electricity history. Klartext Verlag.