Compliance of Distribution System Reactive Flows with Transmission System Requirements

Transmission system operators (TSOs) often set requirements to distribution (DSOs) regarding the exchange of reactive power on interface between two parts they operate, typically High Voltage and Medium Voltage. The presence increasing amounts Distributed Energy Resources (DERs) at networks complicates problem, but provides control opportunities in order keep within prescribed limits. Typical DER methods, such as constant cosϕ or Q/V functions, cannot adequately address these limits, while electronics interfaced DERs provide DSOs capabilities for complying more effectively with TSO requirements. This paper proposes an optimisation method set-points hourly exchanges transmission network. is tested via simulations using real data from substation Sundom Smart Grid, Finland, operating guidelines imposed by Finnish TSO. Results show advantages proposed compared traditional methods compensation DERs. application advanced Model Predictive Control techniques further explored.