Improving power flow convergence by Newton Raphson with a Levenberg-Marquardt method

This paper presents a comparative study of different techniques for improving the convergence of power flow by adjusting the Jacobian iteratively within the Newton Raphson method. These techniques can be used for improving the rate of convergence, increasing the region of convergence or just to find a power flow solution when traditional procedures may diverge or possibly oscillate until an iteration limit is reached even though a valid solution exists. Different techniques are first derived from an investigation of various schemes with the Newton process for the search of roots for a single variable function. The methods are then extended to the power flow problem. Comparisons of the region of convergence on a large power system are also presented to illustrate the effectiveness of the proposed methods.