Maximizing the active power flow controllability in a distribution system with optimum SOP placement

The classical distribution system has recently begun evolving with the introduction of new assets, such as distributed energy resources and electric vehicles. Although these technologies help nations reduce their greenhouse gas emissions, their adoption at the distribution level presents challenges for system operators. For example, distributed generation can raise network voltage, and uneven electric vehicle use across neighborhoods can lead to feeder imbalance. Soft open points (SOPs) offer a potential solution to these issues without compromising radial operation. However, given their high investment costs, determining their optimal placement in the network is crucial. This paper proposes a linearized approach for optimal SOP placement, designed to maximize network controllability by analyzing the distribution system's behavior and solving the problem using mixed-integer linear programming. The proposed approach can be applied to ring-designed but radial-operated systems by considering various open branches. The strategy is tested on both the IEEE 33-bus test system and the METU distribution system. Using this approach, optimal SOP locations can be determined for all possible radial operation scenarios in a ring-designed system.