Computation of Loadability Limit in Power System based on Newton-Bisection Algorithm

Finding the maximum loadability limit in a power system is an important issue for planning and operational purposes. The proposed approach is based on a variation of the conventional Newton Raphson load flow method and bisection method for computation of closest loadability limits of power networks. This paper presents a way by which a bisection search technique can be used along with power flow solutions to reach near the solvability boundary. The constraints on power balance equations and on the minimum singular value of the power flow Jacobian were introduced for finding the solution close to maximum loadability limit. Lanczos algorithm was also employed for computing minimum singular value as an improvement in the overall computation time for the Newton-Bisection algorithm. The method was developed to check the loadability limits for different IEEE networks, results were also compared with a continuation Newton Raphson algorithm for validation. Results from different test networks are presented in the simulation section.