Electrified railway energy storage type traction power supply system and control method thereof

Abstract

The invention discloses an electrified railway energy storage type traction power supply system and a control method thereof. The system comprises a power flow controller, an energy storage system anda single-phase main traction transformer. The power flow controller comprises a high-voltage matching transformer, a grid side AC / DC converter, a traction side AC / DC converter, an intermediate DC side capacitor and a traction matching transformer. The energy storage system comprises a bidirectional DC / DC converter and an energy storage element, and the energy storage element is connected in parallel to the intermediate DC side capacitor through the bidirectional DC / DC converter. The control method comprises the following steps: collecting voltage and current data of a load at the outlet of asubstation, judging the operation condition of the system, and calculating the compensation power of the ports of the power flow controller and the energy storage device under each condition; adding the compensation power into double-loop control of a power outer loop and a current inner loop to obtain a modulation signal; and generating a switching signal of a control device through PWM modulation. Recovery and reutilization of the regenerative braking energy of trains are achieved, the utilization rate of the regenerative braking energy is increased, and negative-sequence electric energy quality treatment and compensation device capacity optimization are achieved.

Description

technical field [0001] The invention relates to the technical field of traction power supply for electrified railways, in particular to an energy storage type traction power supply system for electrified railways and a control method thereof. Background technique [0002] The single-phase power frequency AC power supply system of electrified railways and the characteristics of large power and asymmetry of traction loads have caused the power quality problems of the system mainly negative sequence, affecting the safe, reliable and efficient operation of electrified railways. At the same time, with the extension of electrified railway lines to high-altitude areas in western my country, there are often situations with large line slopes, many tunnels, and frequent regenerative braking of trains. For example, the maximum slope of the Baolan Passenger Dedicated Line and Xicheng Passenger Dedicated Line reaches 25‰, and the proportion of bridges and tunnels in the cross-mountain se...

AI Technical Summary

Problems solved by technology

On the one hand, when the train climbs, the load peak power becomes larger, thereby increasing the rated capacity of the traction transformer, but because the load rate of the traction transformer is not high, the utilization rate of the traction transformer is low and the economy is poor; on the other hand, The braking process of the train going downhill will generate more regenerative braking energy, which will either be sent back to the grid or lost by energy-consuming components, which will not only affect the grid, but also cause waste of electric energy

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