System Efficient Energy Regulation and Control for Reversible Substations in Urban Rail System

The system efficiency of reversible substations (RSSs) in urban rail transit power supply systems has garnered significant attention. In particular, reverse power flow from the main substation (MS) has been observed in the real world, adversely impacting system efficiency. This article proposes a novel power supply structure for RSSs that effectively reduces reverse power flow. To further enhance system efficiency, an optimal model is established by leveraging the control characteristics of RSSs. Then, a system efficiency energy regulation and control framework considering complex scenarios is presented, with the lowest system losses as the optimization objective. The modified Cheetah Optimizer algorithm is adopted to optimize the control parameters of reversible converters (RCs). Simulations of actual engineering cases are conducted, and the results demonstrate the effectiveness of the proposed power supply solution and energy regulation control in various scenarios. The proposed method can improve energy efficiency by up to 3.25% and 2% compared with nonoptimized and existing offline optimized methods, and this value varies depending on the scenario. Additionally, performance analysis and evaluation highlight the fundamentals of energy regulation in enhancing system efficiency, including balancing bus load, appropriately increasing catenary voltage, and adjusting the proportion of regenerative braking energy (RBE) between the ac and dc sides based on different situations.