Load flow analysis of integrated AC-DC power systems

The development of an AC-DC load flow program based on the fast decoupled algorithm is dealt with. Variables of the DC link which have been chosen for the problem formulation are the converter terminal DC voltages, converter transformer tap ratios, firing angle of the rectifier, extinction angle of the inverter, and current in the DC link. Equations relating these seven variables and their solution strategy are discussed. The model developed is independent of a particular control mode of the DC link. The flow chart of the algorithm and the results of a sample run obtained using a MicroVAX-II computer are included. Use of multiple DC links in a large AC system is also described