Field test results of an Italian 380 kV top-down Restoration strategy from neighboring power systems supplying very long restoration path

摘要

The paper describes the preparation and execution of a Top-Down Restoration strategy using 380 kV backbone supplied from a bordering national power system recently carried out as basic part of the scheduled tests recommended in ENTSO-E Operation Handbook (Policy 5) as well as in future European Network Code on Emergency and Restoration, entered in force on December 2017. Top-Down Restoration test here presented has very exceptional features basically due to the very high length of High Voltage (HV) Overhead Transmission Lines (OTLs) involved, specifically more than 1400 km from South of France to South of Italy. Actually, some tricky issues can be detected that must be properly considered during the preparation and execution of the test. Some of the findings described in the present paper are also outcomes of the preceding tests using the same strategy, in similar or analogous paths, performed in the past years on the Italian transmission system: this last test was successful also thanks to the improvements implemented in several system components, in the simulation models and in the procedure itself.