220kV Substation Wittenwil Renewal of SAS and new Construction Building

Project Overview

The Wittenwil Substation was commissioned in the early 1990s and has since played an important role in the regional power supply. While the outdoor switchyard responsible for power transmission and distribution remains in good condition, the secondary systems and auxiliary installations have reached the end of their technical service life and require replacement to ensure long-term operational reliability.

In addition, the existing facilities are closely interconnected with infrastructure operated by the former asset owner. One of the key objectives of the project is therefore to significantly reduce these dependencies and increase the operational independence of the substation.

The project includes the renewal of the secondary systems and auxiliary installations as well as the construction of a new substation building. This modernization will ensure that the facility meets future requirements of the transmission network while improving operational reliability and maintainability.

Key Project Measures

• Construction of a New Substation Building
  A new substation building will be constructed to meet current and future operational requirements. The building will comply with the latest technical standards and enable a clear separation from the existing partner facilities. This will enhance both network stability and operational reliability.
• Renewal and Separation of Secondary Systems
  The existing secondary systems, which play a crucial role in the control, monitoring, and protection of the substation, will be completely renewed and technically separated from existing third-party systems.
• Modernization of Telecommunications Systems
  The telecommunications infrastructure will be replaced and fully separated from the existing systems. This will provide reliable and future-proof communications, enabling secure and efficient data exchange between the various network components.
• Renewal of Auxiliary Systems
  Auxiliary systems will be modernized and integrated into the new substation building. This will create a consolidated, efficient, and future-ready infrastructure with improved operation and maintenance capabilities.
• Enhancement of Physical Security
  The physical protection of the substation will be further enhanced. Measures include preventing unauthorized access and reducing security risks arising from external influences, ensuring the long-term resilience and reliability of the facility.

Functional Details of the Substation

Primary Systems

The Wittenwil Substation consists of a four-bay air-insulated switchyard (AIS) comprising two transmission line bays and two transformer bays. The single-busbar arrangement is operated without electromechanical busbar sectionalization. The primary equipment remains in good condition and will largely remain unchanged.

Secondary Systems

The existing secondary systems have reached the end of their technical service life and will be completely renewed as part of the project.

FGS Scope of Services

On behalf of Axpo Grid AG, Future Grid Solutions provides support in the following areas:

• Refurbishment Planning
• Primary Systems Engineering
• Overhead Transmission Line Engineering
• Preparation of Planning Approval Documentation
• Preparation of Tender Documentation
• Coordination of Subconsultant Services

For more information or inquiries, the team at Future Grid Solutions is happy to assist you. Please feel free to contact us for further details about this project or our other services.