General estimation of the impact of additional DG sources on distribution grids

Abstract

Nowadays, DG sources have a major effect on the operation of distribution grids. Due to in the future even more power will be fed in decentrally, it is imperative that small producers offer system services like reactive power provision and voltage control in the distribution layer. In this paper the impact of different types of DG sources on voltage bounds and grid losses are analyzed depending on the installed capacity and the location in the grid. It can be seen that DG sources at first positively effect grid losses but after exceeding a certain amount — which is almost reached nowadays — grid losses will virtually always rise. Generally, injected power leads to higher voltages especially in the low voltage layer. It is shown that the most limiting constraint of DG sources is not the transport capacity of the grid but the voltage tolerance band.