Mitigation Technique Using a Hybrid Energy Storage and Time of Use (TOU) Approach in Solar Grid Connection

A power system can experience voltage failure if the voltage drops below a certain level, leading to equipment damage, power outages, and other issues. In the context of large-scale solar power systems, voltage failures can occur due to various factors, such as the intermittent nature of solar power generation and the variability of solar irradiance. This study investigates the impact of large-scale solar PV penetration on typical power systems in South Africa and proposes a novel hybrid mitigation technique using Time of Use (TOU) and Community Battery Energy Storage (CBES) to minimize lower limit voltage violation. The network considered in this study includes two parallel 132/11kV transformers, four feeders, and 81 loads connected to the 11kV busbar, with a 150kW solar PV added to every single node. Four case studies were conducted to compare impact of different the mitigation technique including: the base network without any mitigation, the network with TOU mitigation, the network with CBES mitigation, and the network with hybrid TOU and CBES mitigation. The location and size of the CBES were determined using the Power Factory Cbc algorithm to address weaknesses in the network. TOU was used for peak shifting, and different levels of TOU were applied. The results from Power Factory dynamic simulations show that both mitigation techniques applied to the network significantly reduce the lower limit voltage violation, but a few nodes still remain. In addition, the findings shows that the hybrid mitigation using TOU and CBES dramatically solves the voltage violation in the network and minimizes the loss of network as well as power from the grid.