Characteristic impedance matching method in cable transmission attenuation characteristic test
A technology of attenuation characteristics and characteristic impedance, which is used in the field of characteristic impedance matching in the test of cable transmission attenuation characteristics, can solve problems such as poor test, and achieve the effect of improving test accuracy and increasing reliability.
Active Publication Date: 2017-01-11
CHINA ELECTRIC POWER RES INST +2
View PDF3 Cites 4 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
The partial discharge signal is a high-frequency weak-amplitude signal, and the characteristic impedance of the power cable line at high frequency presents a pure resistance characteristic, which is not easy to carry out accurate on-site testing
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0015] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided for more thorough understanding of the present invention, and to fully convey the scope of the present invention to those skilled in the art.
[0016] like figure 1 The connection relationship shown in the present invention provides a method for on-site measurement of characteristic impedance of high-voltage cross-linked cables at high frequency, which is suitable for on-site matching of characteristic impedance in the transmission attenuation characteristic test of high-voltage and ultra-high-voltage cross-linked cables.
[0017] The implementation steps of the on-site matching metho...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention relates to a characteristic impedance matching method in cable transmission attenuation characteristic test, comprising the following steps: a signal generator capable of outputting a variable-frequency sinusoidal voltage signal is connected to the head end of a cable, a non-inductive adjustable resistor is connected in series between a conductor wire core and a metal sleeve at the tail end of the cable, and a signal output end and a voltage signal of the non-inductive adjustable resistor are connected to a measurement device; the signal generator inputs sinusoidal voltage waves of different frequencies in turn, an oscilloscope is used to measure the voltage signal of the non-inductive adjustable resistor and the tail-end voltage wave amplitude under the sinusoidal voltage wave of each frequency, and the non-inductive resistance value is recorded when the change of the amplitude of tail-end voltage waves and the peak of input sinusoidal voltage waves is within + / -3%; and a linear regression analysis is made of the non-inductive resistance values under different frequencies, singular points are eliminated, and the tail-end matching impedance is obtained. Through the method, the characteristic impedance value of a coiled cable at high frequency can be measured accurately, and the test accuracy is improved.
Description
technical field [0001] The invention relates to a characteristic impedance matching method, in particular to a characteristic impedance matching method in cable transmission attenuation characteristic testing. Background technique [0002] Partial discharge (PD) is a phenomenon of repeated breakdown and extinguishment that occurs locally inside the insulating medium. This kind of discharge occurs at the local defect of the insulation, and the discharge amount is very small. In the initial stage of partial discharge, it will not affect the insulation capacity. However, long-term PD occurs under the action of voltage, which will gradually damage the insulation and shorten the service life of the insulation. PD is the main manifestation of cable accessories insulation failure in the early stage. It is not only one of the main causes of insulation degradation, but also the main characteristic quantity that characterizes the insulation condition. Both operating experience and re...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Applications(China)
IPC IPC(8): G01R31/12
CPCG01R31/1272
Inventor 杨丹王昱力夏荣蒙绍新赵健康刘松华张振鹏章红军刘红武李利红
Owner CHINA ELECTRIC POWER RES INST