CN211123234U

CN211123234U - Self-checking standard device for calibrating electric bridge method power cable fault locator

Info

Publication number: CN211123234U
Application number: CN201921900872.8U
Authority: CN
Inventors: 胡玉球; 刘晓夏; 郑鹏
Original assignee: Hangzhou Qunte Electric Co ltd
Current assignee: Hangzhou Qunte Electric Co ltd
Priority date: 2019-11-06
Filing date: 2019-11-06
Publication date: 2020-07-28
Anticipated expiration: 2029-11-06

Abstract

The utility model discloses a but self-checking standard ware for calibrating electric bridge method power cable fault locator, including the wave band switch, a set of series resistance group, series resistance group includes six resistance, the resistance is series arrangement in proper order and is R1-1 respectively, R1-2, R1-3, R1-4, R1-5, R2, wherein R1-1, R1-2, R1-3, R1-4, R1-5's resistance value equals, R1-1, R1-2, R1-3, R1-4, R1-5's resistance value is the 1/5 of R2 resistance value, the R2 one end of series resistance group is established to L o joint, the R2 other end is connected with R1-5, the R1-1 one end of series resistance group is established to Hi joint, the R1-1 other end is connected with R1-2, output switch ground connection and be equipped with the available detection source of the feasible test of the national test of the cable self-test of the family of the reasonable test set of the available test of the company of the family of the electric bridge method of self-based on the test.

Description

Self-checking standard device for calibrating electric bridge method power cable fault locator

Technical Field

The utility model belongs to the technical field of the electrical equipment technique and specifically relates to a but, self-checking etalon for calibrating electric bridge method power cable fault locater is related to.

Background

The electric power fault locator by bridge method is used for judging, analyzing and locating the fault property characteristics of the tested cable. By using the balanced bridge principle, the measured direct current resistance or resistance ratio can position the length or length ratio of the uniform cable. How to ensure the measurement accuracy of the positioning instrument needs to calibrate or detect the instrument according to the calibration rules or technical documents issued by the state or industry under the necessary conditions of specified calibration/detection methods, instrument equipment, environmental conditions and the like. However, at present, no basis or reference exists for corresponding technical documents and the like in the aspect of a cable fault locator, and the most reliable method is to follow the similar principle with the use working condition of a calibrated/detected instrument and adopt a known parameter cable as a reference standard; the problem is that the cable is several kilometers long, and the weight, the volume, the simulation fault, the inspection and the like of the cable are not proper methods and means.

Disclosure of Invention

The utility model relates to a but provide a self-checking etalon for calibrating electric bridge method power cable fault locater, the self-checking etalon of this scheme mainly is used for making direct current resistance ratio standard for convenient and fast's calibration/detection internal manufacturer utilizes a series of cable fault locater of electric bridge method measurement principle design, and the reasonable legal carrying out quantity value transmission and the source tracing of usable self laboratory current instrument and equipment self-calibration/examination.

In order to achieve the purpose, the technical scheme includes that the standard device capable of self-checking for calibrating the electric bridge method power cable fault locator comprises a wave band switch and a set of series resistor groups, the series resistor groups comprise six resistors, the resistors are sequentially arranged in series and are respectively R-1, R-2, R-3, R-4, R-5 and R, resistance values of R-1, R-2, R-3, R-4 and R-5 are equal, resistance values of R-1, R-2, R-3, R-4 and R-5 are R resistance values, one end of R of each series resistor group is set to be an o joint, the other end of R is connected with R-5, one end of R-1 of each series resistor group is set to be a Hi joint, the other end of R-1 is connected with R-2, the wave band switch is grounded and is provided with a six-gear output joint, the six-gear output joints are respectively set to be 10% of R, 20% of R-5 of R-1, the other end of R-1 is set to be a Hi joint, the other end of R-1 is connected with R-2 of R-5, the connecting line is provided with a six-4% of R-5, the connecting line is provided with a connecting line, the R-5 of R-5, and R-5 of R-3, the connecting line is provided with a connecting line, the R-5 of R-5 of R-3, and R-5R-3, and R-3-5R.

Preferably, two connectors are arranged at one end of R1-1 of the series resistor group, namely a Hi connector and a Hi 'connector, the cable fault locator is measured by a two-end bridge method, the cable fault locator is used as a standard device, a superior calibration/verification mechanism is required to transmit or transmit self-checking quantity, the method for calibrating/verifying has relatively high grade requirement, generally, 1/3 × 1/3 about ten times of grade requirement is required to be met according to the specified uncertainty requirement (the standard device is generally higher than the two grades required to be checked), the influence of a lead and contact resistance of two-end bridge measurement is considered, the scheme is designed into a three-end type at the low-resistance end of a line, such as L o, Hi and HI' in figure 2, namely, a two-end measurement method is required when the standard is used, and a four-end method can be used during self-checking, and the influence.

Preferably, the total resistance value of the series resistor group is 2 ohms or 200 ohms. According to the scheme, two groups of circuits with high resistance and low resistance are designed according to the type of the calibrated locator so as to adapt to the functional requirements of the measured instrument and obtain the highest sensitivity of calibration/detection; wherein, total resistance 2 ohm is suitable for cable fault locator location low resistance fault, and total resistance 200 ohm is suitable for cable fault locator location high resistance fault.

The common bridge method cable fault locator has the working principle that a cable which is determined to be normal and equal to the length of the fault cable is selected and connected with the fault cable to form a complete bridge with two bridge arms in the locator, the cable fault point can be located by only measuring two percent of length without measuring the resistance, the balance bridge property in the figure 1 of the attached drawing can be obtained by R2 × R3-R4 × (R2 × -1+ R1-2+ R1-3+ R1-4+ R1-5), the R1-1+ R1-2+ R1-3+ R1-4+ R1-5) and the R375842-R3527-4 + R1-5) can be obtained by comparing R1-1+ R1-2+ R39463-R1-4 + R355 with R4% and the fault locator can be accurately calibrated by comparing R1% with R1% R1/8424% of the fault locator, and the fault locator can be accurately calibrated and the fault locator can be obtained by comparing R3780% R5930% of the fault locator, the ratio can be found by comparing R5930% of the design.

The standard device of the scheme is actually a standard cable simulator, and the standard device is debugged into a series circuit form with known accurate resistance values, such as R2 and R1(R1-1, R1-2, R1-3, R1-4 and R1-5) in FIG. 1, so that the total resistance of the red-black two-end bridge arm with the standard R1 to the standard is equal to the property of the R3 to the total resistance (R3+ R4) to be calibrated/detected through the switching of a switch k. The change-over switch can output known accurate standard proportion, such as 10%, 20%, 30%, 40%, 50% and 100% to be compared with the detected fault locator to achieve the purpose of calibration/detection.

Therefore, the utility model discloses following beneficial effect has: a series of cable fault position indicators designed by domestic manufacturers by utilizing the bridge method measuring principle can be calibrated/calibrated conveniently and quickly, the existing instruments and equipment in a laboratory can be used for self calibration/detection, and the quantity value transmission and the source tracing are carried out reasonably and legally.

Drawings

Fig. 1 is a schematic diagram of the present invention.

Fig. 2 is a schematic diagram of the low resistance measurement circuit of the present invention.

Fig. 3 is a schematic diagram of the high resistance measurement circuit of the present invention.

Detailed Description

The present invention will be further described with reference to the accompanying drawings.

As shown in fig. 2 and 3, a self-checking standard device for calibrating a bridge method power cable fault locator comprises a wave band switch and a set of series resistor sets, wherein each series resistor set comprises six resistors, the resistors are sequentially arranged in series and respectively have R-1, R-2, R-3, R-4, R-5 and R, the resistance values of R-1, R-2, R-3, R-4 and R-5 are equal, the resistance values of R-1, R-2, R-3, R-4 and R-5 are R resistance values, one end of R of each series resistor set is an o joint, the other end of R is connected with R-5, one end of R-1 of each series resistor set is a Hi joint, the other end of R-1 is connected with R-2, the wave band switch is grounded and is provided with a six-gear output joint, the six-gear output joints are respectively a 10% joint, a 20% joint, a 30% joint, a 40% joint, a 50% joint and a 100% joint, the wave band switch is further provided with a connecting line, a connecting line is provided with a connecting line R-1, a connecting line R-2, a R-4 is connected with R-5, a R-5 joint is provided with a connecting line, a connecting line connecting a R-4 joint, a R-3 joint is provided with a R-4 joint, a R-5 joint is provided with a connecting line;

one end of R1-1 of the series resistor group is provided with two connectors which are respectively a Hi connector and a Hi' connector and are suitable for a low-resistance measuring circuit;

the total resistance value of the series resistor group is 2 ohms or 200 ohms, wherein the total resistance 2 ohms is suitable for a cable fault locator to locate low-resistance faults, and the total resistance 200 ohms is suitable for the cable fault locator to locate high-resistance faults.

The specific implementation process is that when the bridge method power cable fault locator is calibrated, the actual operation wiring is to connect the red-black end of the locator to the red-end of the standard device in the scheme, the grounding end is connected to the k-end of fig. 1 or the grounding symbol end of fig. 2 and 3, then the operation can be carried out according to the requirements of the bridge method power cable fault locator, and a typical bridge circuit is formed by bridge arm resistors R3 and R4, a galvanometer G, a direct-current power supply and the standard device in the visible fault locator in fig. 1; given a position of e.g. 10% of a switch k, the fault locator dial is adjusted to zero the galvanometer, i.e. an absolute error or a relative error of 10% of the scale of the fault locator, and so on 20%, 30%, etc.

Claims

1. The standard device capable of self-checking is used for calibrating a bridge method power cable fault locator and is characterized by comprising a wave band switch and a set of series resistor groups, wherein each series resistor group comprises six resistors, the resistors are sequentially arranged in series and are respectively R-1, R-2, R-3, R-4, R-5 and R, the resistance values of R-1, R-2, R-3, R-4 and R-5 are equal, the resistance values of R-1, R-2, R-3, R-4 and R-5 are R resistance values, one end of R of each series resistor group is set to be an o joint, the other end of R is connected with R-5, one end of R-1 of each series resistor group is set to be a Hi joint, the other end of R-1 is connected with R-2, the wave band switch is grounded and provided with a six-gear output joint, the six-gear output joints are respectively set to be a 10% joint, a 20% joint, a 30% joint, a 40% joint and a 50% joint, and a 100% joint, the wave band switch is provided with a connecting line, the connecting line is provided with a connecting line, the R-1-2 is connected with a R-3 joint, and the R-5 is connected with a R-5 joint, and the connecting line is provided with a connecting line.

2. The standard capable of self-checking for calibrating an electrical cable fault locator according to claim 1, wherein two terminals, i.e., a Hi terminal and a Hi' terminal, are provided at one end of R1-1 of the series resistor group.

3. The apparatus of claim 1 wherein the series resistor bank has a total resistance of 2 ohms or 200 ohms.