Research projects in the field of electrical distribution systems are moving to a new philosophy of Smart Grids, where the effort is to use the maximum possible share of power from renewable energy potential. Under this philosophy the emphasis is on energy independence, reliability and safety of operation of energy distribution system. Research in this area leads for example to developing of autonomous local microgrids with the several specific requirements. However, the problem of parameters keeping of quality of electric energy can arise together with increased penetration of distributed generation in microgrids. This problem is caused by decreased short-circuit power of local renewable energy sources, stochastic supply of electric energy from renewable energy sources and operating of active distribution grid in autonomous mode without connection to the external distribution system. General introduction to the power quality evaluation in off-grid power system is introduced in this paper. Initial results from power quality analysis from small off-grids systém is presented in this text too.

 

Connecting of distributed generation of electricity from renewable sources into the grid carries its own risks. These are the so-called negative feedback effect to the operation of electric power system caused by unforeseen stochastic supply of electric power. This paper describes the optimization of devoted power system operation including renewable sources by created so called Solver platform, which is able to suggest an optimal topology connection of power system based on the prediction of power consumption points and generation of electricity from renewable sources.