Impact assessment of different PV generation levels on low-voltage distribution networks

PV systems could be connected to the transmission or distribution systems. Connecting the PV system to the low distribution grid brings technical and environmental benefits to the conventional distribution network, for example, enhancing reliability, line loss minimization, voltage levels enhancement, equipment's thermal capacity improvement, and network upgrade investment deferment. The performance of the distribution grid is assessed by calculating voltage levels, equipment loading and power losses. A more efficient distribution grid has acceptable levels of voltages within the boundary limits (between 0.95 to 1.05 p.u) and low levels of power losses. This paper uses Network PLAN (NEPLAN) electrical power system analysis software to assess PV generation on a low-voltage distribution grid. The paper's main objective is to determine the maximum allowable hosting capacity. The network is simulated using actual grid parameters, loads, and weather data. The voltage levels, voltage profile, and power losses are determined using different PV penetration levels (0%, 50%, 65%, and 75%). Generally, the results under different cases of PV generation showed that connecting rooftops PV systems enhances the voltage levels and voltage profile, reducing equipment's (transformers and lines/feeders) loading and decreasing power losses. On the other hand, high PV penetration levels lead to voltage rise and increase the system power losses. As a result, the maximum allowable hosting capacity of solar energy system penetration must not exceed 65%. At this figure, the grid operates at acceptable voltage levels, minimum loss percentage, and thermal capacity.