Method of computing maximum loadability, using continuation power flow, case study sudan national grid

This work presents a method of finding a continuum of power flow solutions starting at some base load and leading to the steady state voltage stability limit (critical point). Continuation power flow calculation plays a key role to understand the limitation of power flow solutions in varying loads. It is a very useful for evaluation of the critical point of the PV curve in static voltage stability. P-V curves are constructed to calculate loadability margins and identify the weakest bus in the system. However, drawing the P-V curve is time consuming in large-scale power systems. As a result, the open source Power System Analysis Toolbox (PSAT) MATLAB software package is used for analysis. PSAT includes power flow, continuation power flow, optimal power flow, and small-signal stability analysis. In this work we used continuation power flow only. The proposed method is successfully applied to the National Grid. Our methods provided several results. The validity of results is investigated with the known IEEE 30-bus system as a bench mark.