UPFC Ideal Transformer Model

This paper presents a unified power flow controller (UPFC) model, which consists of an ideal transformer with a complex turns ratio and a variable shunt admittance. In this model, the UPFC control variables do not depend explicitly on UPFC input and output currents and voltages. Accordingly, this model does not require adding extra busses for UPFC input and output. This model is easily combined with transmission line models using ABCD two-port representations, which can then be converted to Y-parameter representations. The complex turns ratio and the variable admittance can be mapped to actual UPFC control variables, such as UPFC injected series and shunt voltages and currents or other equivalent representations.