Wide-Adaptable Uninterrupted Power Supply System for Neutral Sections of ERs With Event-Triggered Flexible Power and Voltage Control

Neutral sections (NSs) in electric railways cause train speed loss, transient overvoltage, and arcing, posing threats to the system's safe operation. Thus, this article proposes a wide-adaptable uninterrupted power supply system (WUPSS) for NSs. It enables trains to pass through NSs without power interruption, transient overvoltage, and arcing, under various operation scenarios. This WUPSS consists of two auxiliary transformers, two auxiliary inverters, and a back-to-back converter (BTBC), having a lower converter investment than existing schemes. Then, a multipoint current-based pantograph positioning method is designed to accurately detect the train pantograph position in NSs. On this basis, an event-triggered flexible power and voltage control method and an unequal active power division rule are proposed to calculate output power and voltage references for the inverters and BTBC. These methods aim to achieve power transfer in the transition zones and voltage transition in the virtual neutral zone while compensating for reactive power. Additionally, an output power-adaptive virtual impedance control scheme is designed for inverters to suppress the separation current between the train pantograph and the catenary. Finally, the feasibility and adaptability of the WUPSS under different operation scenarios, including single pantograph, double pantograph, double track, and different speeds, are demonstrated via hardware-in-the-loop tests.