A kind of energy feedback device controller, rail transit traction power supply system and control method

Abstract

The invention discloses a controller of an energy feed device, the controller of the energy feed device is used to control the magnitude and direction of the transmission power of a regenerative electric energy feedback device; the controller of the energy feed device includes: an analog quantity input unit, a reactive power calculation unit ; The analog input unit is used to obtain the AC bus voltage of the traction station, the incoming line current of the traction station, the AC bus voltage of the main station, and the incoming line current of the main station; the reactive power calculation unit, according to the power factor target of the traction station Value output corresponding reactive power to compensate the power factor of the traction station; or, with the goal of improving the power factor of the main station, control the regenerative power feedback device to output a given reactive power. The present invention also provides a rail transit traction power supply system and a method for suppressing circulation of the system. By adjusting the output reactive power of the regenerative power feedback device, the AC output voltage of the regenerative power feedback device is stabilized, and the generation between the regenerative power feedback device and the traction rectifier is avoided. circulation.

Description

Technical field [0001] The present invention belongs to the field of urban rail transit, and in particular, the present invention relates to a feedforward device controller, a rail transit traction power supply system, and a circular suppression control method. Background technique [0002] In order to solve the increasing traffic problems of large cities, urban rail transit has entered a large-scale high-speed development due to its high timing, speed, comfort, and greater transportation power. At present, there is a demand for renewable energy in the field of domestic urban rail transit. The energy of the locomotive is in the process, the energy of the brake brake will feed back the traction network, will raise the DC traction network press, when the energy feedback set in the substation When the setting of the device is set, the device is put to start feedback and regenerative electrical energy. However, in the actual engineering, the DC traction network pressure is not only r...

AI Technical Summary

Problems solved by technology

However, in actual engineering, the DC traction grid voltage is not only related to the regenerative energy, but also to the AC bus voltage of the main station. The increase of the AC side voltage will also lead to the increase of the DC grid voltage. At this time, if the regenerative power feedback enters the feedback state, The DC traction network voltage has a downward trend, causing the AC voltage of the traction rectifier to be higher than the DC traction network voltage, and the energy is returned from the AC side to the DC side again, forming a circulating current

The circulating current affects the normal energy feedback of the regenerative power feedback device to the grid, reducing the utilization efficiency of regenerative energy; and the long-term existence of the circulating current will greatly increase the loss of the traction rectifier and the regenerative power feedback device, affecting the life of the equipment

[0003] In the prior art, there is a method of using a floating threshold to avoid circulating currents. The main principle of this method is to adjust the start-up threshold of the regenerative power feedback device according to the change of the AC voltage. When the AC voltage has harmonics or negative sequence, the threshold value setting will be inaccurate, which will affect the efficiency of energy feedback

(2) When the AC voltage changes frequently, the threshold value changes frequently, making the working state of the device unstable

(3) When the grid voltage rises, the threshold value rises. If the regenerative energy increases slightly at this time and does not reach the threshold value, the energy feedback device will refuse to operate, which will affect the feedback efficiency

(4) Although this method can solve the circulating current in the station, the AC voltage of the energy-feeding device of each traction station is different, and the threshold value is also different. Improper control will lead to circulating current between stations, which requires coordinated control between stations, which increases the complexity of the system

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