Investigation of MV Distribution Networks with High-Penetration Distributed PVs: Study for an Urban Area

This study proposes a methodology to evaluate impacts of aggregated Low Voltage (LV) PV systems on Medium Voltage (MV) distribution level. The impacts of distributed PV systems are evaluated based on various load demands and PV penetrations using generation profiles gathered from a pilot PV application implemented in Riyadh City. Simulation results acquired from different scenarios are systematically arranged and also combined together in order to observe the overall network response as well as the individual network element responses. With this approach, distribution planners/operators can decide on the necessary electrical network investments and the optimal network operations by evaluating element (i.e., transformer and MV cables) loadings, voltage levels, and grid losses. The results of this study prove that the increase on PV injections postpones the necessary upgrades on some critical network elements (i.e., heavily loaded transformers and lines) and improves voltage profiles of MV/LV buses. In addition, in case of a voltage violation detected from a specific scenario, network operators can manage to control the output of PV power level (i.e., the level of P and Q generation) by the help of the pilot PV application.