A tracing load flow program for total transfer capability calculations

The paper presents a tracing load flow (TLF) program that is designed to calculate the total transfer capability (TTC) in addition to many other applications. TLF is basically a load flow program that has the flexibility to change any input parameters in a systematic way and trace the state variable changes. TTC calculations are based on running different load flow cases from the base case until hitting thermal, voltage, or transit stability limits. TLF is able to calculate area-to-area TTC or point-to-point TTC with any generation/load dispatch. TLF can be used in many different applications besides the calculations of TTC such as voltage collapse studies, contingency analysis, power systems studies under different dispatch conditions, and can also be used for analysis of impact of series compensators/shunt compensators on power systems. TLF is developed using MATLAB and has been tested for many power system models of different sizes up to 4,000 buses.