Reactive power provision to TSO/DSO by aggregators and conventional generators

Reactive power management is one of the imperative ancillary services provided by TSO (Transmission System Operator). This reactive power imbalance mainly occurs at transmission levels, and TSO pays generators for managing reactive power. DSO (Distribution System Operator), DER (Distributed Energy Resources), and DG (Distributed Generators) cannot take part in this provision to TSO due to regulations, specifically in Italy. The paper discusses the needs for reactive power management, and comparison of different existing compensation techniques. It talks about the regulatory restrictions, and some proposals for changes, for participation in ancillary market. The paper then discusses about the use of DER as an aggregated virtual power plant to serve as reactive power compensation technique.