Introduction

The traction power supply of urban rail transit is generally supplied by the 10kV or 35kV power grid. In the traction substations, the 10kV or 35kV power is rectified into 1500VDC or 750VDC through a traction rectifier, and then the DC power is provided to the train through a third rail running all along the track of metro system.

When braking, the train uses regenerative braking as main braking method, and air braking as well as mechanical braking as auxiliary braking methods. Since urban rail vehicles brake very frequently, the amount of regenerative braking energy is considerable . As a rule of thumb, the regenerative braking energy of urban rail transit vehicles accounts for about 30% -50% of the electricity energy fed to the vehicles. Because the power flow in the traction substation is unidirectional, the regenerative braking energy can only be absorbed by the accelerating vehicles nearby and can not be fed back to the AC grid 

In most cases, if there is no accelerating vehicles nearby, the braking energy would still be dissipated via resistors to avoid DC bus over-voltage. This is especially the case when the service frequency of the line is low.

To avoid waste of regenerative braking energy, Hoteam HTRF regenerative braking energy recovery system is designed to convert the braking energy into AC power and feed it back to the AC grid. It consists of DC-AC converter and is connected between the DC bus and the AC grid.

Features

• Multi-DSP controller for minimum response time

• Patents for output ripple current reduction

• Modular converter and master-slave cabinet design for easy maintenance

• High conversion efficiency, feedback efficiency @ full load>98%

• Multiple working modes including energy feedback mode, back-up traction rectifier mode, reactive power compensation mode
  

• The system can work as Static Var Generator (SVG) to compensation capacitive reactive power during light-load condition or as back-up traction rectifier during heavy load condition

• Strict thermal design, guarantee the safe operation of system

• Extensive protect functions for safe and reliable operation of system

• 7-inch user-friendly HMI

• RS485 port, standard MODBUS RTU, has computer remote monitor function 

• Designed based on mature converter knowledge base

• All tested on dedicated testing platform before delivery

Specifications