Bird protection on medium voltage power lines - an experimental study on the Hungarian grid

Bird protection on overhead power lines is an important issue worldwide. In Hungary the share of overhead lines in the medium voltage grid is quite high. These lines often cross national parks and protected areas, where rare species of birds are especially endangered by electrocution. There are several solutions to protect birds against electric shock and prevent the subsequent fault of the power line. One of them is the covering the phase conductors with rigid plastic protectors. Under these protectors much higher electric field can develop than in normal operational conditions. In the Hungarian grid, numerous failures of the phase conductors of medium voltage overhead power lines are related to the use of bird protectors. The result of the corona discharge due to high electric field is the main reason of the damage of the conductors. This phenomenon has also influence on the surge protection coordination.