Device and method for evaluating local defect of cable based on impedance spectrum analysis

Abstract

The invention relates to the technical field of measurement and analysis of a transmission line impedance spectrum, and particularly relates to a device and a method for evaluating a local defect of acable based on impedance spectrum analysis. The device at least includes a signal generation unit, a signal acquisition unit, an analysis control unit and a data storage unit. The signal generation unit is for transmitting an incident signal to one end of a cable being tested and for transmitting a reference signal, the incident signal and the reference signal are the same in amplitude and phase,the signal acquisition unit is used for synchronous acquisition of the incident signal and a reflected signal, and the reflected signal is a signal which is generated when the incident signal is reflected after passing through the cable being tested. According to the method, the impedance spectrum of the cable being tested in a frequency sweeping band is measured and calculated via a frequency sweeping method, a spectrum function is transformed in a frequency domain, defects can be located in a new transformed domain, and evaluate severity of the defects can be evaluated. Compared with conventional cable fault positioning technologies, the device and the method disclosed in the present invention are advantaged by strong noise immunity, wide range of application, and capability of quantitative evaluation.

Description

technical field [0001] The invention relates to the technical field of measurement and analysis of transmission line impedance spectrum, in particular to a device and method for evaluating local defects of cables through spectrum measurement, frequency domain transformation and analysis. Background technique [0002] A transmission line is a linear structure that transmits electromagnetic energy, located between a signal source and a load, and a cable is a typical transmission line. Transmission line theory is a relatively mature theory, which is widely used in professional fields such as communication engineering and electronic circuits. The characteristics of a transmission line depend on the difference between its length and the wavelength of the electrical signal it carries. When the length of the transmission line is much smaller than the signal wavelength, the transmission line hardly affects the behavior of the electrical circuit. At this time, viewed from the signal ...

AI Technical Summary

Problems solved by technology

However, under field conditions, signal attenuation in the cable and environmental noise (especially for cables longer than 1000 meters) limit the sensitivity of this method, making it difficult to detect the initial state of local defects in the cable, let alone reflect local defects. development trend

[0023] The cable local defect evaluation method based on impedance spectrum analysis lacks relevant work in China, and there is still a lack of dedicated research equipment and technology

Images