System Level Assessment of the Impact of High Penetration of PV Inverters with Grid Support Capability on Distribution Networks

Power systems simulations using PSCAD have been performed to evaluate the impact to the distribution grid of high photovoltaic (PV) penetration. Voltage regulation at load nodes, feeder short-circuit currents and power losses have been analyzed for penetration level up to 60% and compared with a baseline case referring to as no PV. Results show that high PV penetration impacts residential area and non-residential area networks differently. Also, depending on the grid strength, the performance of the network is different. PV micro-inverters, in some cases, can prevent voltage excursion beyond tolerance limits however, they are more effective for power losses reduction. Overall, up to 15% in energy losses can be saved at very high penetration levels. Regarding the short-circuit levels no adjustment in the network infrastructures is required as the PV systems will have inconsequential contribution in feeder short-circuit currents.