optimal dg placement based on dg cost, voltage stability, loses active and ractive and variations load

the paper provides a new index in order to determine optimal size and location of dg units, minimize system power loses and dg cost, optimize voltage profile and increase voltage stability margin. a multi- objective optimization method is used in order to size and allocate dg units; optimized imperialist competitive algorithm (ica) is used for this aim. the load variations effects on optimal dg capacity are studied in this paper. the load variations effects on voltage profile, voltage stability and loses are determined after bus and capacity identification. linear load variations are considered from 50 to 150% of base load (with 10% steps). present constraints are system voltage, feeders flow and dg capacity limitations. offered method is used for 34 bus experimental system. all experiments are simulated in matlab software. the simulation results show considerable effects of system loses, voltage profile improvement and increased voltage stable margin through expending the least cost.