Research on the series-parallel hybrid demand control system for railway traction power supply

To reduce the maximum demand of electrified railways and improve the energy efficiency of power supply, this paper proposes a series-parallel hybrid maximum demand control system used in phase-separating section. This system was constructed based on multiple independent AC-DC-AC converters and single-phase transformers. It significantly reduces the capacity configuration requirements for the active devices and improves the overall reliability and cost-effectiveness of the system. Based on application scenarios for demand regulation and the parameter constraints of the main components, a key parameter design method was derived for the demand control system. Additionally, a device-level grid-connected control strategy and a system-level energy dispatching algorithm were developed to achieve fast and precise control of the maximum demand in traction power supply systems. Results from joint commissioning and simulation experiments show that the maximum demand control system can effectively optimize demand control in traction power supply systems.