Automatic Adjustment of Generator Voltages in Newton-Raphson Mehtod of Power Flow Solutions

A method of considering the reactive power (var) limits of generators and their voltage adjustments, as a part of the Newton-Raphson power flow solution, is presented in this paper. The approach considers an extended Jacobian matrix of the standard Newton- Raphson method to include these variables in the problem formulation. Then, by suitable matrix manipulation techniques, the procedure estimates the generator voltage adjustments required to eliminate respective var limit violations. By the use of an efficient logic, the procedure limits the voltage adjustments to a minimum number of generators. The proposed technique complements other automatic adjustment features such as area interchange, transformer tap and phase-shifter controls that are already available with the Newton-Raphson technique.