Urban rail medium voltage energy feedback power supply method and device with ring current eliminating function

Abstract

The invention discloses an urban rail medium voltage energy feedback power supply method and device with a ring current eliminating function. The method comprises the steps of arranging a high-power electronic power device in advance, detecting the direct current grid pressure of a direct current grid of an urban rail tractive power supply system and the no load voltage of a rectifier, and judging the operation state of a train, thereby controlling the throwing in and throwing off of a diode rectifier and an energy feedback converter and the on-off of the high-power electronic power device to eliminate ring current; the device comprises a high-voltage switch unit, a transformer, the diode rectifier, a first direct current switch unit, the energy feedback converter, a second direct current switch unit, the high-power electronic power device and switch device driving circuits. The device can ensure that the energy feedback converter and the diode rectifier do not form a loop when the urban rail train is in a traction power supply state, an energy feedback state and is switched between the two states, thereby realizing the ring current eliminating function, does not need to add an isolation transformer and an electric reactor, is lower in the cost, and has a compact structure.

Description

technical field [0001] The invention relates to an energy-feed power supply device of an urban rail traction power supply system, in particular to a medium-voltage urban rail energy-feed power supply device with the function of eliminating circulation. Background technique [0002] In the regenerative braking energy recovery device for urban rail, the energy-feedback power supply device can make full use of the regenerative braking energy of the train, has good energy-saving effect, and has good compatibility with the medium-voltage AC network. The use of equipment does not have the heating problem of energy-consuming resistors, and does not require other energy storage components, so it has become the most promising regenerative energy recovery solution for urban rail traction power supply systems. [0003] Urban rail energy-feedback power supply devices are divided into urban rail high-voltage type energy-feedback power supply devices, urban rail medium-voltage energy-feed...

AI Technical Summary

Problems solved by technology

[0009] To sum up, the main disadvantage of the existing urban rail medium-voltage energy-feeding power supply device is that there is a circulating current between the energy-feeding converter and the rectifier when the energy-feeding device is put into operation.

Circulating current will cause current distortion, increase system loss, reduce system performance and efficiency, all of which affect system stability and reliability

Several technical solutions for suppressing circulating currents currently exist have the disadvantages of increasing the cost of the device and increasing the volume of the device, and the solution of increasing the loop inductance can only minimize the circulating current, and the impact of the circulating current on the system still exists

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