Validation of energy services in a hybrid AC-DC grid with an MVDC pilot link

This article aims to validate the benefits of an operational Medium Voltage DC (MVDC) link for grid reinforcement through voltage profile enhancement and Service Restoration (SR) for hybrid AC/DC grids. To investigate voltage profile enhancement with the MVDC link, the voltage profile is analyzed in a pure AC grid and compared with the same AC grid expanded with the MVDC link. An SR algorithm adapted for this analysis is utilized to investigate if a DC link can expand the candidate solutions for SR in hybrid AC/DC grids. The utilized SR algorithm optimizes re-energization by prioritizing bus groups and switch configurations using a Multiple Criteria Decision Analysis (MCDA) algorithm. To validate the aforementioned energy services, a CIGRE “MV Distribution Network Benchmark” in the European configuration is expended with a model of the MVDC link at RWTH Aachen University, Germany creating three test case scenarios. The results show that the MVDC link can support AC grids by improving voltage profiles and partially expanding feasible solutions for the SR algorithm due to limited DC power share.