Techno-economic capacity configuration strategy of interphase-bridging inverter-based three-port topology for railway energy router

The interphase-bridging inverter-based three-port railway energy router (IBI-RER) is a promising technology compared to conventional schemes due to its simple architecture and reduced equipment power rating. However, the three-port structure is strongly coupled, resulting in complex interactions among alpha/beta-phase AC-side active and reactive power and DC-side power, which have a significant impact on the system capacity. Therefore, this paper proposes a techno-economic capacity configuration strategy considering the power decoupling control strategy for the IBI-RER. The capacity configuration strategy considers several objectives, including regenerative braking energy (RBE) utilization, power quality, comprehensive benefit, and payback period. To address the strong coupling of active and reactive power, a multi-layer optimal control strategy considering capacity constraints is proposed to ensure that the capacity configuration objectives can be achieved. Furthermore, a multithreshold energy allocation strategy is designed to target the reduction of the power demand charge and the energy charge, based on the objective of maximizing the comprehensive benefit. The simulations and experiments based on the measured data of a traction substation verify the superiority of the proposed method.