Interline power flow controller（IPFC）can achieve power orientation

quantitative interaction between different lines and solve uneven distribution of grid flow and has a very good application prospect.However

the IPFC model is not developed in the mainstream software for the calculation and analysis bulk power grid

which makes it difficult to evaluate its control potential and application prospects. In this paper

the modeling method of IPFC based on PSASP is studied. Firstly

the mathematical expression of the IPFC device is derived by the use of power injection method. On this basis

the steady control model of IPFC is set up based on the user-defined（UD）function of PSASP software

and the flow calculation principle and achievement method of IPFC is given

thus interactive iteration between PSASP flow program and user definition model is finished. The effectiveness and correctness of the set up model in the paper is verifiedbythesimulationandcalculationexample.