Method for measuring input impedance of traction pulse rectifier and output impedance of traction network

Abstract

The invention discloses a method for measuring the input impedance of a traction pulse rectifier and the output impedance of a traction network. A high-speed train single-phase traction rectifier is taken as a measurement object, a disturbance injection device for the real-time closed-loop regulation of a disturbance harmonic amplitude according to the stable operation condition of the rectifier is designed, and the device can accurately measure impedance / admittance under a train network dq coordinate system on the premise of ensuring stable operation of the rectifier. On the premise of stableoperation of a traction alternating-current transmission two-level single-phase four-quadrant pulse rectifier, the impedance of the rectifier and traction network are accurately measured.

Description

technical field [0001] The invention relates to the technical field of electric traction AC drive, in particular to a method for measuring the input impedance of a traction pulse rectifier and the output impedance of a traction network. Background technique [0002] With the rapid development of high-speed railways in my country, high-speed trains based on AC-DC-AC traction transmission systems have been more and more widely used. In the train-traction network coupling system (hereinafter referred to as "vehicle-network system"), due to the The interaction with the traction network leads to the occurrence of various instability problems such as harmonic resonance, low-frequency oscillation and harmonic instability, which not only cause serious safety hazards in the traction power supply system At the same time, it will have a huge impact on the stable operation of the traction drive system of high-speed trains. [0003] The frequency range of low-frequency oscillation is usua...

AI Technical Summary

Problems solved by technology

The existing stability criterion of the single-phase system in the dq coordinate system can be used in the stability analysis of the vehicle network, but there are few methods for measuring the impedance in the dq coordinate system. At present, the main measurement method is the sinusoidal sweep in the single frequency injection method Usually, in order to ensure the accuracy of the measurement, the harmonic amplitude must be large enough to ensure a sufficient signal-to-noise ratio. However, if the harmonic injection amplitude is too large, it will interfere with the normal operation of the rectifier system and interfere with the harmonic source The value usually requires experimental experience to select. After the harmonic injection measurement, it is necessary to analyze whether the measured harmonic amplitude is appropriate according to the measurement results and the operation of the rectifier throughout the entire injection process. Then, after correcting the harmonic amplitude, re-inject The harmonics of the frequency point to be measured are measured and calculated, so that the measurement accuracy cannot be guaranteed, and the measurement efficiency is low

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