High Voltage Network Expansion
The aim of this activity is to evaluate two alternative grid expansion plans in the Zurich regional network with regard to system security at the 380/220/150/132 (SBB) kV voltage levels. The analysis consists of load flow simulations, N-1 security calculations and selected N-2 outage scenarios. In particular for N-1 security calculations outages for all 220 kV lines and for all transformers feeding into the 150 kV urban grid are considered. The N-2 outage scenarios consist of cases where a given system component is out of service for maintenance work. For each such case the aforementioned N-1 security calculations are then successively performed.