Comprehensive Study of Static Voltage Stability Methods for Proper Placement and Sizing of STATCOM to Enhance Voltage Stability

Voltage stability assessment and its enhancement have become the important aspects for modern power system operation and control. Static and dynamic are the two most important methods, to analyze the voltage stability. This paper presents a comprehensive study of almost all static voltage stability analysis methods such as PV-QV curve, Modal analysis, Load flow based voltage stability indices and continuation power flow method, for enhancement of voltage stability. Implementation of FACTS device like STATCOM, in the system, which is having fast and very flexible control, to achieve the maximum enhancement of loading margin in the power system is also presented. This enables one to identify the system’s critical area and to develop systematic approach for proper placement and sizing of STATCOM in the power system network.

The main contribution of this paper is identification of weak buses of power system using static voltage stability analysis methods and deciding proper location and size of STATCOM for voltage stability enhancement, under a novel load increase scenario i.e. active and reactive loads have been changed simultaneously at all the load buses under consideration. The study has been carried on various standard IEEE test systems using MATLAB programming as well user friendly Power System Analysis Toolbox (PSAT) of MATLAB. The results of standard IEEE14 and IEEE6 bus test systems have been presented in this paper.