Fuzzy-logic method for adjustment of variable parameters in load-flow calculation

The paper presents a new approach using fuzzy logic to adjust variable parameters so as to meet constraints during load flow studies. Parameters to be adjusted include transmission line impedance, phase angle and transformer tap position and the constraints are transmission line power flow and bus voltage magnitude. Versatile apparatus which are used to tune these parameters include the thyristor-controlled series compensator, thyristor-controlled phase shifter, unified power flow controller and on-load tap changer. The proposed approach is particularly aimed at assisting convergence in load flow programs. The parameters to be adjusted are decoupled from the main body of the load flow formulation. The methodology for parameter adjustment is conducted by using fuzzy logic