Method for suppressing vehicle network low-frequency oscillation and system thereof

Abstract

The invention discloses a method for suppressing vehicle network low-frequency oscillation and a system thereof. The method comprises the steps that a network side voltage instantaneous value, a network side current instantaneous value, DC side output voltage, DC side output current, a DC side output voltage given value, a network side filtering inductance value and a network side equivalent resistance value are acquired; a first initial modulation signal is obtained according to the network side voltage instantaneous value, the DC side output voltage, the DC side output voltage given value, the network side filtering inductance value and the network side equivalent resistance value; a second initial modulation signal is obtained according to the network side current instantaneous value, the resistance value of a preset virtual resistor and the network side voltage phase obtained according to the network side voltage instantaneous value; and difference processing is performed on the first initial modulation signal and the second initial modulation signal so that a difference value is obtained, and the difference value acts as an output PWM signal to the modulation signal of the PWM generator of a network side rectifier. The low-frequency oscillation of the vehicle network system can be effectively suppressed so that the stability of the vehicle network system can be enhanced without increasing hardware cost.

Description

technical field [0001] The invention relates to the technical field of electric locomotives, in particular to a method and system for suppressing low-frequency oscillation of a train network. Background technique [0002] The vehicle-network system includes catenary and locomotives, and the locomotive includes grid-side rectifiers, which provide modulation signals for the grid-side rectifiers ab (t) PWM generator, traction inverter and auxiliary inverter, in the prior art, after the electric locomotive lifts the bow, the grid (catenary) voltage and grid current side will oscillate, and the DC voltage output by the grid side rectifier Oscillation also occurs, a phenomenon also known as low-frequency oscillation of the vehicle network. The low-frequency oscillation phenomenon of the vehicle network exists in many railway bureaus in my country. After analysis, it was found that several low-frequency oscillation accidents actually occurred were related to the number and operati...

AI Technical Summary

Problems solved by technology

However, these suppression measures are passive, and the effect is not very ideal

In addition, there is also the use of SVG (Static Var Generator, static var generator) in the substation to change the impedance characteristics of the catenary to suppress the occurrence of system oscillation. This method has a certain effect, but additional investment, high cost

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