TSO-DSO Interaction in Switzerland

Review state of the TSO-DSO interaction in Switzerland
Survey with participants of the Swiss electricity sector - identify most promising topic for detailed case study
Case study 1: Balancing energy from the distribution grid
Case study 2: TSO-DSO coordination for congestion management

Hierarchical organization of Swiss electricity system with grid levels and operators
Limited communication between TSO and DSOs
Increasing operational, organizational or security challenges simultaneously affecting both TSO and DSO.
Potential value from increased interaction, for example during congestions in meshed TSO-DSO networks.

Circle representing DSO-grid embedded in ellipse representing swissgrid-grid with 3 connection arrows representing trafos — 150-kV DSO-grid (EWZ) with 3 connections to the 220-kV TSO-grid (Swissgrid).

Current state of Swiss TSO-DSO coordination sufficient
Most interaction for repeating issues (planned outages, grid reinforcements)
Economic value and higher security through increased coordination
Possible increase of transit power flow across Switzerland by coordinated transformer control between Swissgrid and DSOs with meshed network.

3D polytope with 2D surface representing secure operating range of DSO-trafos — Secure trafo capacity and operating surface of the DSO-grid.

2D plot, y axis is additional import capacity as function of x axis (voltage level distribution). Different colors for different loads in DSO-grid. — Additional Swiss import capacity through coordination of EWZ-transformers. As a result, Switzerland can import around 500 MW more from Germany for many voltage and load scenarios.

Partners: ETHZ (FEN), EWZ, Swissgrid AG
Duration: 08/2016 - 02/2018
Funding: SGEN
Project Leader: ETHZ
Project Team: Dr. Alexander Fuchs

Project report (in German)