No abstract

No abstract

In this study, a new 36‐pulse rectifier with a hybrid DC‐reinjection circuit is proposed. It multiplies the AC‐side input voltage steps from 12 to 36 using a hybrid auxiliary circuit for voltage and current modulation. Both the AC and DC side harmonics of the rectifier system are efficiently suppressed when combined with filter capacitors at DC side. Only 2 more diodes and an IGBT are used in the proposed approach for constituting the injection circuit. The cascaded structure of rectifier bridges allows for significant voltage gain, making it appropriate for high power output rectification applications. The proposed 12‐pulse rectifier's phase shifting structure and 36‐pulse rectifier's operational theory are introduced. The injection transformer's turn ratio and the IGBT's conduction angle are both designed to have the lowest possible harmonic distortion of the voltage at AC side. Analyses are done on the rectifier's impedance matching feature and energy loss of IGBT. The operating performance of the rectifier is assessed when the active switch fails. With the help of a 1.8 kW prototype and a HIL system based on Starsim, the theoretical portion is confirmed. The results of the simulation and experiments support the effectiveness of the hybrid voltage harmonic injection method studied.

No abstract

Summary In single‐phase alternating current (AC) traction power supply system, to balance 3‐phase load of power system, each phase of electricity is used in rotation. Based on the 7‐section articulated split‐phase insulator of China Beijing‐Tianjin high‐speed railway line, different electromagnetic transient processes are deeply analyzed considering pantograph arc and viaduct's electrical coupling in this paper. First, based on the lumped parameter model, the process of high‐speed train passing the articulated split‐phase region, concluding the upper viaduct part and the lower viaduct part, is deeply studied. Second, through state‐space technique, 4 independent electromagnetic transient processes in articulated split‐phase region of high‐speed railway are derived and analyzed thoroughly considering the impact of pantograph arc and viaduct. Finally, the integral transient process is accurately simulated and analyzed by ATP‐EMTP software under several circumstances, such as different topologies, initial phase and phase difference of feeders, and specific suppression overvoltage measures. The independent and integral comparison results illustrate that the coupled viaduct can lead to the more complex topologies and electromagnetic transient processes. Also, the coupled viaduct can play a significant topology discharge and pantograph overvoltage suppression role for the high‐speed train passing articulated split‐phase region.

No abstract

No abstract

No abstract