Systematic approach for optimal placement and sizing of STATCOM to assess the voltage stability

Reactive power deficient systems are more prone to voltage collapse. Improving reactive power handling capacity by modern FACTS devices is one of the best remedies for such systems. Choosing the optimal location and size of the FACTS devices to get benefits in terms of improvement of voltage stability is a challenging task. This paper presents the systematic approach for the optimal location and sizing of STATCOM. Voltage stability assessment has been carried out by tangent vector method, with and without STATCOM using user-friendly power system analysis toolbox (PSAT) of MATLAB. Results tested on a standard IEEE-6 bus and IEEE-14 bus test systems show that optimally placed and sized STATCOM not only improves loadability margin but also voltage profile of the system. The novelty of the work lies in developing the systematic approach assessing the voltage stability under different conditions, like the screening of contingencies, the establishment of loadability and novel loading scenario before and after placement of STATCOM in the system. This is very useful for getting maximum benefits of reactive compensation methods which depend greatly on the placement and sizing of FACTS devices.