Harmonic wave impedance measuring device and measuring method for traction power supply system

Abstract

The invention provides a harmonic wave impedance measuring device and measuring method for a traction power supply system. In the measuring device, a primary coil of a step-down transformer is connected to a power supply section overhead line and a steel rail, and a secondary coil is connected to a current sensor and a voltage sensor. The secondary coil is also connected to a harmonic wave current source injection device. The harmonic wave current source injection device has the following structures that an alternating end of a bridge rectifier circuit is directly used as an output end of the harmonic wave current source injection device, the other alternating end of the bridge rectifier circuit is connected to a cathode of a diode, and an anode of the diode is used as the other output end of the harmonic wave injection device; a switch is connected between the cathode and the anode of the diode; and two direct current ends of the bridge rectifier circuit are connected to a capacitor in parallel, after a resistor 1 is connected to a resistor 2 in series, the resistor 1 and the resistor 2 are connected to two direct current ends of the bridge rectifier in parallel, and the resistor 2 is connected to a switch 2 in parallel. The device can measure a resonant frequency of a power supply section on the site and the impedance frequency characteristics during electric locomotive or motor train unit operation, and provides more accurate and reliable actual measurement parameters for the design, operation and maintenance of the traction power supply system.

Description

technical field [0001] The invention relates to a device for measuring harmonic impedance of a traction power supply system and a measuring method thereof. Background technique [0002] In recent years, China's high-speed railway has been in a leading position in many aspects, but at the same time, technical standards are also improving, and there are correspondingly higher requirements for the safety and reliability of power supply equipment. When the frequency of the harmonic current of the electric locomotive or EMU in the traction power supply system coincides with the resonant frequency of the traction network itself in the section (usually a power supply arm), high-order harmonic resonance may be excited on the traction network. Generate resonance overvoltage or overcurrent, affecting power supply safety. A number of harmonic resonance accidents have occurred on site, resulting in overvoltage protection actions, tripping of circuit breakers, burnout and even explosion...

AI Technical Summary

Problems solved by technology

When the frequency of the harmonic current of the electric locomotive or EMU in the traction power supply system coincides with the resonant frequency of the traction network itself in the section (usually a power supply arm), high-order harmonic resonance may be excited on the traction network. Generate resonant overvoltage or overcurrent, affecting power supply safety

Many harmonic resonance accidents have occurred on site, resulting in overvoltage protection action, tripping of circuit breakers, burnout and even explosion of protectors, lightning arresters and other equipment, and failure of normal operation of parallel compensation devices, seriously affecting the reliability of power supply and the safe operation of high-speed railways

[0003] Due to the complex structure of the traction network, variable operating conditions, and unknown internal component parameters, even if the basic information of the electrified railway traction power supply system is mastered in detail, it is still impossible to calculate the traction network of each section through theoretical calculations. resonant frequency of

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