Primary & Secondary Systems for the Substation Windischbach (Kärnten Netz GmbH)


Medium voltage switchgear (duplex) including station control system for high and medium voltage switchgears

As part of the Kärnten Netz GmbH (Kärntner Elektrizitäts-Aktiengesellschaft), the Kärnten Netz GmbH acts as the power grid operator for electricity and natural gas in Carinthia. In order to increase grid quality in Middle Carinthia, the Kärnten Netz GmbH built a new substation “Umspannwerk Windischbach”.

The substation “Windischbach” supplies electricity to a part of Middle Carinthia. Sprecher Automation was assigned by the Kärnten Netz GmbH to deliver the 20 kV switchgear together with the complete secondary systems for the 110 kV and the 20 kV voltage levels.


SPREPOWER MV-M6: air-insulated medium voltage switchgear with pressure release outwards

Innovative medium voltage concept with secondary systems

SPREPOWER Medium voltage switchgear

The delivered 24 kV medium voltage switchgear (SPREPOWER MV-M6, 25 kA/3 sec., 2000 A) consists of 16 duplex bays (32 single bays).

The switchgear is type-tested against the latest standards (EN 62271-200), which was the main reason in favour of Sprecher technology completed by other quality characteristics such as integrated pressure release duct and the compartment concept of the switchgear.

The cubicles are devided into the following compartments:

  • 2 busbar compartments
  • 2 circuit-breaker compartments
  • 1 cable terminal compartment
  • 1 transformer compartment
  • 2 compartments for secondary systems (only one compartment fully assembled at the operator’s side)
Cubicle overview: SPREPOWER-MV-M6 switchgear
SPRECON-E-C bay computer and DSZW4 overcurrent-time protection (backup protection) for the 110 kV transformer bay

SPRECON-E station control system

Beside the medium voltage switchgear, Sprecher Automation also delivered the complete control system for the substation, which is organised in four fibre-optic rings for the four substation parts (IEC 60870-5-104).

In addition to the medium voltage level, Sprecher also installed SPRECON-E-C bay computers and DSZW4 overcurrent-time protection for the 110 kV switchgear.

The cubicles of the SPREPOWER MV-M6 medium voltage switchgear are also equipped with SPRECON-E-C bay computers. Beside a control panel, on which the whole substation is visualised, an additional alarm panel is connected to the SPRECON-E-C station computer.

As a specific feature of the system, the high voltage level, medium voltage level, station computer and the general systems (auxiliary systems, transformer protection, neutralpoint connection) are connected via redundant switches.

This ring-based architecture results in an independence of all substation parts (for service and maintenance) and in a redundant communication. Therefore, communication can be maintained in case of a line failure within a subsystem.

Beside engineering and design of circuit diagrams, Sprecher Automation also performed the overall installation and commissioning works.

In October 2007, all delivered systems were put into full operation.

SPRECON-E station control system for the substation Windischbach