Application of Niching Genetic Algorithms in System-wide Voltage Sag Mitigation Studies

The paper presents an approach to optimally select and allocate flexible AC transmission system (FACTS) devices in distribution network in order to minimize the number of voltage sags at network buses. The method proposed is based on optimization of pre-selected objective function using niching genetic algorithms (NGA). The objective of the optimization is to achieve the improvement in overall system sag performance of the network. Using proposed NGA based optimization, multiple solutions are found with optimized location, type and rating of six (in total) FACTS devices. Three types of FACTS devices are implemented in this study, namely, static VAr compensator (SVC), static compensator (STATCOM) and dynamic voltage restorer (DVR). The performance of the proposed algorithm is tested and illustrated on 295-bus generic distribution system (GDS).