Eight machine sets, each with a nominal output of 50 MVA, are installed in the Hohenwarte 2 pumped storage plant (PSW). The synchronous generators are designed for motor and generator operation in over- and underexcited areas. At the moment, excitation is carried out via static excitation devices with fully controlled bridges and energy consumption via a voltage transformer.

After approx. 30 years of operation, the reconstruction of the excitation devices of the synchronous machines in Halbwerk 2 is necessary and planned. The tender is for the renewal of the excitation device for PSS F as well as optionally for PSS E, G, and H.

The order is divided as follows:

- Renewal of excitation facility PSS F, planned for 2024

- Optional renewal of excitation device PSS E, planned for 2024

- Optional renewal of excitation device PSS G, planned for 2025

- Optional renewal of excitation facility PSS H, planned for 2025

The aim is to install four identical excitation devices with the same software versions in Halbwerk 2.

that are state-of-the-art and ensure safe plant operation

ensure all intended modes of operation. The given grid connection conditions must be met and repercussions of harmonics on the self-demand grid must be avoided.

Scope of services: Withdraw existing cables from the existing excitation device and place them on an intermediate terminal box to be procured and installed, as well as extend power cables professionally for reconnection in the new system (exception - power cables under 10m in length must be replaced) so that all existing cables continue to be used. The new system must be rewired from the intermediate terminal box so that the existing cables are continued one-to-one via the intermediate terminal box.

Dismantling of the installed excitation device excluding the voltage and third-party mains transformers, taking into account the overall inspection schedule and parking of the removed cabinets at a location to be specified by the client for reserve provision. The client reserves the right to remove and secure required plant components for other excitation facilities before disposal and to take over the disposal independently after the conversion.

Planning, project planning, assembly, delivery, installation, connection and commissioning, including preparation of the documentation of a static excitation device per PSS with further use of the respective voltage transformers (excitation transformers) and the third-party network transformers shared by two PSS.