Improving Power Flow Convergence By Leveraging Region of Attraction Visualization

This paper both highlights the ease with which the Newton-Raphson power flow can converge to undesired alternative solutions and then presents techniques that can be used to improve power flow convergence by leveraging insights gained from visualizing the power flow solution region of attraction. The paper shows that, particularly for large-scale power systems, the common "flat start" initial voltage guess of one per unit with an angle of zero may not be in the region of attraction (ROA) for the desired power flow solution. Computationally tractable solution options are presented to reduce the likelihood of the power flow converging to an undesired solution. Results are demonstrated on power systems ranging in size from two to 23,600 buses.