DG planning method for enhancement of voltage stability margin in distribution system

This paper presents a new methodology for multiple distributed generator (DG) planning in a radial distribution system for enhancement of voltage stability margin. An index, called voltage collapse index, has been utilized in this paper for identification of nodes that are susceptible to voltage collapse and requiring DG integration. The size of DG unit to be integrated at the identified site is determined by optimizing a multiobjective index such that reduction in network power loss and improvement in node voltages are resulted without any violations in the network operating constraints. The effect of different types of DG and load models in the identification of grid integration points and size of DG units is also studied in detail. The proposed method is tested on 11 kV Indian 25 bus system and is found to be very effective in identifying the suitable location and size of multiple DG units for enhancement of voltage stability margin.