Voltage stability assessment and improvement of Ethiopian 230 kv wind-integrated grid using SVC and continuation power flow in PSAT

The increasing integration of wind energy into the Ethiopian 230 kV transmission grid introduces significant voltage stability challenges due to the intermittent and variable nature of wind power. The effects of Doubly Fed Induction Generator (DFIG) - based wind energy system penetration in power system have been investigated in this work. A Static Var Compensator (SVC) is employed to assess voltage stability limits, particularly the maximum loadability margin that ensures stable grid operation as wind penetration increases. The analysis considers various wind speed conditions-low, medium, and high-as well as different grid strengths (weak and strong), providing a comprehensive evaluation under practical operating scenarios. Using the Power System Analysis Toolbox (PSAT) in MATLAB, a continuation power flow (CPF) analysis is conducted to evaluate the system's voltage collapse margin and identify weak buses under different wind power scenarios. Simulation results reveal a considerable reduction in the maximum loading point and voltage margin in the absence of compensation. The inclusion of SVC at strategically selected buses significantly improves voltage profiles and increases the system's loadability limit. The IEEE 57-bus test system is employed to validate the proposed voltage stability enhancement approach prior to its application on the Ethiopian 230 kV transmission network using PSAT. Hence, the study demonstrates the effectiveness of SVC in mitigating voltage instability issues, thereby enabling secure and reliable integration of renewable energy sources particularly wind power in the Ethiopian grid.