Design and testing of a medium voltage Controllable Network Transformer Prototype with an integrated hybrid active filter

Dynamic control over real and reactive power flow is one of the key areas of concern for the modern grid. Traditional FACTS based devices have proven to be too costly and complex to achieve any significant market penetration. Modifying existing transmission assets to make them controllable may be a cost-effective method of increasing the grid controllability. Controllable Network Transformers (CNTs) have been shown theoretically to be an effective real and reactive power flow controller. The various options for filter design of a CNT are presented in this paper. The paper also discusses the design and testing of a medium voltage CNT prototype with an integrated hybrid active filter, rated at 200 kVA and 2.4 kV.