Architecture of urban rail transit power supply based on PET braking energy feedback

• Main Authors: Hao Liu, Zedong Zheng, Zheng Xu
• Format: Article
• Language: English
• Published: Wiley 2019-04-01
• Series: The Journal of Engineering
• Subjects: invertors; braking; power supply quality; power transformers; resonant power convertors; railway electrification; power supplies to apparatus; vehicle-to-grid; load flow; harmonics suppression; DC transit grid strong; energy leads; city grid; power electronics transformer; power flow; power transmission; power quality; urban rail transit power supply architecture; DC traction grid; pet braking energy feedback device; China; load oscillation; LLC series resonant converter; MATLAB-Simulink; energy transmission; three-phase H bridge device; harmonics reduction; energy conservation; voltage 1500.0 V to 1180 V
• Online Access: https://digital-library.theiet.org/content/journals/10.1049/joe.2018.8703

In recent years, the urban rail transit has a great development in many cities of China. It is important to keep the DC transit grid strong and the power transmitted/power transmission high quality. During the process of rail operation, braking energy leads to a wide range of load oscillation for the traction and city grid, which cannot be absorbed inside the rail transit system. In this study, a novel architecture of urban rail transit power supply based on power electronics transformer braking energy feedback is put forward. Based on the circle grid, the topology adds an inverter to LLC series resonant converter to carry the power from 1500 V DC traction grid to 1180 V AC. Analysis together with simulation on the topology and control strategy is made on the basis of MATLAB/Simulink. Process of braking energy feedback and transmission of energy are illustrated with simulation. By paralleling the three-phase H bridge and braking energy feedback device, double direction of the power flow is ensured. As a consequence, the power quality increases and harmonics reduce. The energy can be used more efficiently to achieve better effects on energy conservation.