Simplified approach to analyze voltage rise in LV systems With PV installations using equivalent power systems diagrams

As the photovoltaic (PV) sources capacities in distribution networks continue to grow,more operational challenges are expected to be encountered. One of these challenges is the voltage rise within distribution networks due to reverse power flow from the PV sources toward the grid. In this paper, a simplified analytical approach is presented which allows the voltage rise possibility to be tested and the performance of its mitigation techniques to be evaluated. Equivalent transformations are used to represent complicated power systems using simplified circuits. Then, formulas are derived to determine the PV power limits beyond which a voltage rise will be encountered considering the PV sources capability of absorbing reactive power. Moreover, the system losses in each case are estimated using the proposed formulas. Consequently, the proposed analysis method could be used for a number of applications related to PV sizing and losses minimization. The validity of the proposed method is verified through a number of case studies where its findings are compared with results obtained from DIgSILENT software tools.