2013. — 8 с.Different factors influence increasing complexity of modern power systems. Economical and environmental aspects prevent their growth compared to what has been a standard practice in the past. Under this consideration the introduction of different new technologies is a must, starting with controlled power electronic devices within the AC network as well as DC systems and introduction of other FACTS elements. All these help generally increasing system stability, however without their reliable operation the power system may become naturally unstable.
Environmental concerns have introduced non-conventional power sources, like wind and photovoltaic generation to our existing and new power systems. These elements influence to a great extent the operation of existing power systems on distribution as well as on transmission level.
