A low-frequency impedance reshaping method for EMUs based on reverse reactive current injection

A current injection, low-frequency impedance technology, applied in reactive power compensation, power supply lines, circuit devices, etc., to achieve the effects of enhanced system stability, voltage support, and good applicability

Active Publication Date: 2021-10-22
SOUTHWEST JIAOTONG UNIV +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to realize the low-frequency impedance reshaping of the EMU without adding any oscillation detection module and filter, and has no effect on the dynamic performance of the locomotive, effectively solving the low-frequency oscillation problem of the electrified railway

Method used

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  • A low-frequency impedance reshaping method for EMUs based on reverse reactive current injection
  • A low-frequency impedance reshaping method for EMUs based on reverse reactive current injection
  • A low-frequency impedance reshaping method for EMUs based on reverse reactive current injection

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specific Embodiment approach

[0044] (1) Collect the output port voltage u of the secondary side output port of the EMU traction transformer through the voltage sensor s , voltage u s Obtain the voltage phase θ through the phase-locking of the synchronous phase-locked loop;

[0045] (2) Collect the output port current i of the secondary side output port of the EMU traction transformer through the current sensor s , current i s The quadrature current αβ component i is generated through the Second-Order Generalized Integrator (SOGI) module α and i β ;

[0046] (3) The current αβ component i α and i β Send it to the Park transformation module to transform to obtain the active current i in the dq coordinate system d and reactive current i q ;

[0047] (4) Using the first reference signal i of reactive current qref1 Subtract the extracted reactive current component i q , to obtain the disturbance component Δi of the reactive current q ;

[0048] (5) The disturbance component of reactive current Δi ...

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Abstract

The invention discloses a method for reshaping the low-frequency impedance of an EMU based on reverse reactive current injection, which mainly comprises an orthogonal voltage and current signal generation loop, a phase-locked loop, a DC voltage control loop, an AC current control loop, It is composed of reactive current injection loop and PWM modulation loop. Adopting the present invention can realize the low-frequency impedance reshaping of the EMU without adding any oscillation detection module and filter, and has no influence on the dynamic performance of the locomotive, improves the stability of the vehicle-network system, and effectively solves the low-frequency oscillation of the electrified railway question.

Description

technical field [0001] The invention relates to the field of rail transit traction power supply systems, in particular to a method for reshaping the low-frequency impedance of an EMU based on reverse reactive current injection. Background technique [0002] With the rapid development of electrified railway system, more and more locomotives adopt flexible converters in order to improve the running speed and carrying capacity of locomotives. However, due to the interaction between the locomotive and the traction network, the locomotive and traction network interactive system (hereinafter referred to as the vehicle-network system) has some instability problems, such as low-frequency oscillation, harmonic resonance, harmonic instability, etc. Among them, in a depot, when multiple trains of locomotives are hoisted at the same time, low-frequency oscillations are prone to occur. Low-frequency oscillation usually causes low-frequency fluctuations in the voltage and current of the ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H02J3/24H02J3/16B60M3/02
CPCB60M3/02H02J3/16H02J3/241Y02E40/30
Inventor 胡海涛周毅孟昭斐何正友
Owner SOUTHWEST JIAOTONG UNIV
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