Modelling and analysis of a three-phase quadrature phase shifter with a hybrid transformer

This paper deals with a quadrature phase shifter based on a hybrid transformer (HT) for power flow control and for transient stability improvement in AC transmission systems. This paper presents an operational description, a modelling and a theoretical analysis of the properties of the proposed solution. The steady-state analysis is based on the averaged state-space method and four terminal descriptions, and is verified both by means of the simulation and experimental investigations.