Smart Grid Voltage Mitigation Using a Direct Load Control and Battery Energy Storage Approach in Solar Integration

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. It proposes a novel hybrid mitigation technique using Direct Load Control (DLC) 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 150 kW solar PV added to every single node. Four case studies were conducted to compare the impact of different mitigation techniques: the base network without any mitigation, the network with DLC mitigation, the network with CBES mitigation, and the network with hybrid DLC and CBES mitigation. The location and size of the CBES were determined using the Power Factory Cbc algorithm to address weaknesses in the network. DLC was used for peak shifting, and different levels of DLC 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 show that hybrid mitigation using DLC and CBES dramatically solves the voltage violation in the network and minimizes the loss of network and power from the grid.