Research on Novel Uninterruptible Flexible Connector Device for Phase Separation in Electrified Railways

Abstract

Loss and recovery of power supply to electrified locomotives when passing neutral section will caused over voltage and over current in locomotives, which greatly threatens the safety of electrified railways and passengers. A novel uninterruptible flexible connector device is proposed, which comprises of two breakers, back-to-back converters and two transformers. This device can realize flexible switch between voltages of two traction feeders using phase shift technology at variable frequency and make locomotives run pass neutral section at rated power. System configuration, working principle, system-level and device-level control of uninterruptible flexible connector device are introduced and their correctness and effectiveness are validated through simulation.

Research on electromagnetic transient process in articulated split-phase insulator of high-speed railway considering viaduct's electrical coupling

“…By combining with transient characteristics of high peak value and short duration time aforementioned, pantograph overvoltage can be seen as interior operation overvoltage, and moment of HST passing articulated spilt‐phase insulator may be completely determined by adaptive HST speed. Therefore, based on the phase‐control switch technology, it is feasible to regulate the HST speed and control the action moment of HST phase switch, and guarantee that the different transient processes appear as the pantograph phase angle is around the integer times of 180°, which helps to realize the aim of suppressing operation‐type overvoltages.…”

“…Meanwhile, Gong drew the conclusion that the split‐phase overvoltage is caused by the high‐order circuit oscillation during HST passes the spilt‐phase insulator, LI et al considered that the split‐phase overvoltage is generated due to the induced voltage on neutral section, and Fan et al concluded that the split‐phase overvoltage is caused by the resonance of neutral section and locomotive high‐voltage transformer. Furthermore, focusing on the several articulated split‐phase, Wang et al have performed complex electromagnetic transient measurements and useful overvoltage suppressions, including installing overvoltage suppression filter, adopting interruptible control strategy and uninterruptible phase separation scheme, etc. However, the above studies mostly focus on the mechanism analysis and the experiment test for the process of HST passing articulated split‐phase region but have not considered the influence of operation condition in the rapidly changing TPSS, such as viaduct, tunnel, etc.…”

An Improved Power Supply System for Neutral Sections in Railway Electric Power Systems

“…Inevitably the train loses the speed while it goes through the section. One literature published in China [1] stipulated that more than 30 minutes of travel time can be saved if all of the neutral sections in the highspeed railway line between Beijing and Shanghai (total length of 1318 km) can be eliminated. More severe consequence one can imagine is the possibility of a train's being trapped in the section.…”