CN109188096B - Contact resistance measuring method and device - Google Patents
Contact resistance measuring method and device Download PDFInfo
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- CN109188096B CN109188096B CN201811344934.1A CN201811344934A CN109188096B CN 109188096 B CN109188096 B CN 109188096B CN 201811344934 A CN201811344934 A CN 201811344934A CN 109188096 B CN109188096 B CN 109188096B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/08—Measuring resistance by measuring both voltage and current
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/20—Measuring earth resistance; Measuring contact resistance, e.g. of earth connections, e.g. plates
Abstract
The application provides a contact resistance measuring method and device, which are used for measuring contact resistance at contact ports of a preformed armor rod and a ground wire, and relate to the technical field of contact resistance measurement. The contact resistance measuring method comprises the following steps: acquiring alternating currents with two different frequencies which meet the change rate of the contact resistance of a preset requirement; loading alternating currents based on two different frequencies at a contact port of the preformed armor rods and the ground wire, and respectively measuring a first voltage and a second voltage at the contact port of the preformed armor rods and the ground wire; and obtaining the contact resistance of the preformed armor rods at the contact port of the preformed armor rods and the ground wire according to the first voltage and the second voltage. By using the contact resistance measuring method and the contact resistance measuring device, the alternating current contact resistance can be directly measured, and the error between the measured value and the actual value of the contact resistance is effectively reduced.
Description
Technical Field
The application relates to the technical field of resistance measurement, in particular to a contact resistance measurement method and device.
Background
The ground wire causes the occurrence of a disconnection accident due to overheating, which often causes the power failure of a large-area power grid, even causes secondary disasters, and seriously affects the safe and stable operation and personal safety of the power grid. The existing research shows that the inside of a preformed armor rod fracture (a contact port of the preformed armor rod and the ground wire) of the ground wire suspension string is a main heating bottleneck point, and the contact resistance of the preformed armor rod fracture is an important factor causing the breakage of the ground wire. Therefore, accurate measurement of the contact resistance of the preformed armor rods at the fracture is an important basis for researching and analyzing the heating characteristics of the preformed armor rods and providing related solutions.
The contact resistance measurement belongs to micro-resistance measurement, and the current main measurement method of the contact resistance is to obtain direct current contact resistance by a current-voltage method; when measuring the alternating current contact resistance, the direct current contact resistance is obtained by direct measurement by using a current-voltage method instead of the alternating current contact resistance.
However, when the skin effect is obvious, the above method of directly measuring and obtaining the direct current contact resistance by using the current-voltage method instead of the alternating current contact resistance causes a large error between the measured value and the actual value of the contact resistance.
Disclosure of Invention
An object of the present application is to provide a method and an apparatus for measuring contact resistance, which can directly measure ac contact resistance and effectively reduce the error between the measured value and the actual value of contact resistance.
In order to achieve the above purpose, the technical solutions adopted in the embodiments of the present application are as follows:
in a first aspect, an embodiment of the present application provides a contact resistance measurement method for measuring a contact resistance at a contact port of a preformed armor rod and a ground wire, the method including:
acquiring alternating currents with two different frequencies which meet the change rate of the contact resistance of a preset requirement;
loading alternating currents based on two different frequencies at a contact port of the preformed armor rods and the ground wire, and respectively measuring a first voltage and a second voltage at the contact port of the preformed armor rods and the ground wire;
and obtaining the contact resistance of the preformed armor rods at the contact port of the preformed armor rods and the ground wire according to the first voltage and the second voltage.
As described above, the step of obtaining the alternating currents of two different frequencies that satisfy the contact resistance change rate of the preset requirement includes:
randomly selecting a first frequency of a first alternating current, and obtaining a corresponding first skin depth according to the first frequency of the first alternating current;
and obtaining a second skin depth of the second alternating current and a second frequency corresponding to the second alternating current according to the first skin depth of the first alternating current and the contact resistance change rate required by the presetting.
As described above, the step of obtaining the contact resistance at the contact port between the preformed armor rod and the ground wire according to the first voltage and the second voltage includes:
respectively calculating to obtain a first impedance and a second impedance at the contact port of the preformed armor rods and the ground wire according to the first voltage and the first alternating current, and the second voltage and the second alternating current;
and obtaining the contact resistance of the preformed armor rods at the contact port of the preformed armor rods and the ground wire according to the first impedance and the second impedance.
Optionally, in an embodiment, the step of obtaining a contact resistance at a contact port between the preformed helical wire and the ground wire according to the first impedance and the second impedance includes:
calculating to obtain the inductance at the contact port of the preformed armor rods and the ground wire according to the first impedance and the second impedance, wherein the contact resistance change rate is ignored in the calculation process;
and calculating the contact resistance at the contact port of the preformed armor rods and the ground wire according to the inductance and the first impedance or the inductance and the second impedance.
Optionally, in another embodiment, the step of obtaining a contact resistance at a contact port between the preformed armor rod and the ground wire according to the first impedance and the second impedance includes:
calculating an impedance angle at a contact port of the preformed armor rods and the ground wire according to the first impedance and the second impedance, wherein the change rate of the contact resistance is ignored in the calculation process;
and calculating the contact resistance at the contact port of the preformed armor rods and the ground wire according to the impedance angle and the first impedance or the impedance angle and the second impedance.
As described above, the contact resistance change rate of the preset requirement means that the contact resistance change rate is not more than five percent.
Optionally, in one embodiment, the first frequency is a high frequency value and the second frequency is a non-high frequency value.
Optionally, in one embodiment, the two alternating currents of different frequencies have the same effective value of current.
In a second aspect, an embodiment of the present application further provides a contact resistance measurement apparatus, including: the device comprises an acquisition module, a measurement module and a processing module;
the acquisition module is used for acquiring alternating currents with two different frequencies which meet the change rate of the contact resistance of a preset requirement;
the measuring module is used for loading alternating currents based on the two different frequencies at a contact port of the preformed armor rods and the ground wire and respectively measuring a first voltage and a second voltage at the contact port of the preformed armor rods and the ground wire;
the processing module is used for obtaining contact resistance at a contact port of the preformed armor rod and the ground wire according to the first voltage and the second voltage.
As described above, the contact resistance change rate of the preset requirement means that the contact resistance change rate is not more than five percent.
The beneficial effect of this application is:
in a first aspect, in the contact resistance measurement method provided in this embodiment of the present application, by obtaining two different frequencies of alternating currents that satisfy a preset requirement (e.g., the contact resistance change rate is not greater than five percent) of the contact resistance change rate, a first voltage and a second voltage when the two different frequencies of alternating currents are loaded at a contact port between the preformed helical wire and the ground wire are respectively measured, and the contact resistance change is ignored, so that the contact resistance of the contact port between the preformed helical wire and the ground wire can be calculated. Therefore, the contact resistance measuring method provided by the embodiment of the application can measure the alternating current contact resistance at the contact port of the preformed armor rod and the ground wire, and can effectively reduce the error between the measured value and the actual value of the contact resistance due to the fact that the change of the contact resistance can be ignored in the calculation process. In addition, the contact resistance measuring method provided by the embodiment of the application needs less detection data, so that the detection process is simple, the detection accuracy is higher, and the interference of external factors can be prevented on the basis of ensuring the detection accuracy.
In a second aspect, the contact resistance measuring device provided in the embodiment of the present application uses the contact resistance measuring method according to the first aspect, so that the device has all the beneficial effects described in the first aspect, and details are not repeated herein.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.
Fig. 1 is a schematic structural diagram of a ground wire suspension string provided in the present application;
FIG. 2 is a schematic flow chart of a contact resistance measurement method provided herein;
FIG. 3 is a schematic flow chart of a method for obtaining two different frequencies of alternating current at a contact resistance change rate that meets a predetermined requirement according to an embodiment of the present disclosure;
FIG. 4 is a schematic flow chart of a method for calculating contact resistance provided herein;
FIG. 5 is a schematic flow chart of a method for calculating contact resistance according to an embodiment of the present disclosure;
FIG. 6 is a schematic flow chart of a method for calculating contact resistance according to another embodiment of the present disclosure;
fig. 7 is a schematic diagram of a functional module of the contact resistance measuring device provided in the present application.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.
In the description of the present application, it is further noted that, unless expressly stated or limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.
As shown in fig. 1, the structure of the ground wire overhang string is schematically illustrated. The ground wire overhang string includes: pole tower fasteners 101, pole towers 102, suspension clamps 103, preformed wires 104, ground wires 105, and preformed wire and ground wire contact ports 106; the preformed armour wire and ground wire contact port 106 is a major heating "bottleneck" point, and the contact resistance of the preformed armour wire and ground wire contact port 106 is an important factor causing the ground wire 105 to break.
At present, since most overhead lines run in an alternating current state, it is more practical to measure the contact resistance of the preformed armor rods at the contact port 106 with the ground wire in an alternating current manner. However, in the prior art, if the contact resistance of the preformed armor rods and the ground wire contact port 106 is measured in an alternating current manner, a detection device instrument such as an oscilloscope and the like for an impedance angle needs to be introduced to obtain a phase difference between a measured current and a measured voltage, so that the measurement process is complicated, measurement data is more, and an error is larger.
Therefore, to study and analyze the heating characteristics of the preformed armor rods and the ground contact port 106, the present application provides a contact resistance measurement method for measuring the contact resistance at the preformed armor rods and the ground contact port 106.
As shown in fig. 2, the method comprises the steps of:
s110, acquiring alternating currents with two different frequencies and meeting the change rate of the contact resistance of preset requirements;
specifically, the preset required contact resistance change rate means that when two alternating currents with different frequencies are loaded at the contact ports of the preformed armor rods and the ground wire respectively, the contact resistance change rate at the contact ports of the preformed armor rods and the ground wire is not greater than a preset threshold.
For example, in one embodiment of the present application, the preset required contact resistance change rate may be a contact resistance change rate of not more than five percent. According to the fact that the change rate of the contact resistance is not larger than five percent, alternating currents with the change of the contact resistance within five percent under two different frequencies are obtained, so that when the alternating currents with the two different frequencies are loaded at the contact port of the preformed armor rod and the ground wire respectively, the change of the contact resistance of the preformed armor rod and the contact port of the ground wire can be ignored, and therefore errors between the measured value and the actual value of the contact resistance can be effectively reduced.
S120, loading alternating currents based on two different frequencies at a contact port of the preformed armor rods and the ground wire, and respectively measuring a first voltage and a second voltage at the contact port of the preformed armor rods and the ground wire;
specifically, a first voltage at the contact port of the preformed armor rod and the ground wire can be obtained by loading a first alternating current with a first frequency at the contact port of the preformed armor rod and the ground wire and measuring the first alternating current, and a second voltage at the contact port of the preformed armor rod and the ground wire can be obtained by loading a second alternating current with a second frequency at the contact port of the preformed armor rod and the ground wire and measuring the second alternating current. When a first alternating current with a first frequency and a second alternating current with a second frequency are loaded at the contact port of the preformed armor rod and the ground wire respectively, the change rate of the contact resistance at the contact port of the preformed armor rod and the ground wire meets the preset requirement in the step S110.
Alternatively, when the first voltage and the second voltage are measured, a detection method, a sampling method, a thermoelectric method, a bolometric method, a compensation method, or the like may be used, and the present application is not limited thereto.
And S130, obtaining the contact resistance at the contact port of the preformed armor rod and the ground wire according to the first voltage and the second voltage.
Specifically, after the first voltage and the second voltage are measured in step S120, a first impedance and a second impedance at a contact port of the preformed armor rod and the ground wire when a first alternating current with a first frequency and a second alternating current with a second frequency are loaded at the contact port of the preformed armor rod and the ground wire respectively are calculated according to the first voltage and the first alternating current, and the second voltage and the second alternating current. Furthermore, the change rate of the contact resistance at the contact port of the preformed armor rod and the ground wire meets the preset requirement, so that the change of the contact resistance can be ignored, and the contact resistance at the contact port of the preformed armor rod and the ground wire can be obtained according to the first impedance and the second impedance.
In summary, the contact resistance measurement method provided by the application measures the first voltage and the second voltage when the alternating current based on the two different frequencies is loaded at the contact port of the preformed armor rod and the ground wire by acquiring the alternating currents of the two different frequencies of the contact resistance change rate which meets the preset requirement (if the contact resistance change rate is not more than five percent), and ignores the contact resistance change, so that the contact resistance of the preformed armor rod and the ground wire contact port can be calculated. Therefore, the contact resistance measuring method provided by the application not only can measure the alternating current contact resistance at the contact port of the preformed armor rod and the ground wire, but also can effectively reduce the error between the measured value and the actual value of the contact resistance due to the fact that the change of the contact resistance can be ignored in the calculation process. In addition, the contact resistance measuring method provided by the application needs less data to be detected, so that the detection process is simple, the detection accuracy is higher, and the interference of external factors can be prevented on the basis of ensuring the detection accuracy.
Furthermore, the contact resistance measuring method can avoid direct detection of the impedance angle, detection equipment such as an oscilloscope and the like is not required to be introduced, so that the number of the measurement equipment is small, the practical application is more convenient, and other measurement errors caused by too many detection equipment can be avoided.
In one embodiment, as shown in fig. 3, the step of obtaining the alternating currents with two different frequencies that satisfy the contact resistance change rate of the preset requirement includes:
s111, randomly selecting a first frequency of a first alternating current, and obtaining a corresponding first skin depth according to the first frequency of the first alternating current;
specifically, when measuring the contact resistance of the preformed armor rods and the ground wire contact port, the first frequency of the first alternating current can be arbitrarily selected, for example, the first frequency is selected to be a high-frequency value or a non-high-frequency value. After the first frequency is selected, a corresponding first skin depth can be obtained according to the first frequency of the first alternating current, and the specific process is as follows:
wherein d is1Is the first skin depth, ω is angular frequency, μ is magnetic permeability, γ is electrical conductivity, f1Is a first frequency.
And S112, obtaining a second skin depth of the second alternating current and a second frequency corresponding to the second alternating current according to the first skin depth of the first alternating current and the preset required contact resistance change rate.
Specifically, after the first frequency of the first alternating current is obtained in step S111 to obtain the corresponding first skin depth, the second skin depth of the second alternating current may be obtained according to the obtained first skin depth of the first alternating current and the contact resistance change rate (for example, the contact resistance change rate is not greater than five percent) that is preset to be required, and the specific process is as follows:
wherein, Delta R is the variation of contact resistance under different frequencies, R1Contact resistance corresponding to the first frequency, S1Is the skin area corresponding to the first frequency, Δ S is the variation of the skin area at different frequencies, d1Is a first skin depth, d2And r is the section radius of the contact port of the preformed armor rods and the ground wire.
After the second skin depth of the second alternating current is obtained, a second frequency of the second alternating current can be obtained according to the second skin depth, and the specific process is as follows:
wherein f is2At a second frequency, μ is permeability, γ is conductivity, d2Is a first skin depth.
In an embodiment, as shown in fig. 4, the step of obtaining the contact resistance at the contact port between the preformed helical wire and the ground wire according to the first voltage and the second voltage includes:
s131, respectively calculating a first impedance and a second impedance at a contact port of the corresponding preformed armor rods and the ground wire according to the first voltage and the first alternating current, and the second voltage and the second alternating current;
specifically, the values of the first voltage and the second voltage are measured in step S120, and the magnitudes of the first ac current and the second ac current can be manually set or adjusted to known values before loading. Therefore, the first impedance and the second impedance can be calculated by the following process:
wherein Z is1Is a first impedance, U1Is a first voltage, I1An effective value of the first alternating current;
wherein Z is2Is a second impedance, U2Is a second voltage, I2An effective value of the second alternating current.
Alternatively, the effective values of the first alternating current and the second alternating current may be the same, so as to facilitate the calculation of the first voltage and the second voltage during the measurement process, or to facilitate the loading of the first alternating current and the second alternating current at the contact port of the preformed helical wire and the ground wire. The effective values of the first alternating current and the second alternating current can be set according to specific measurement requirements, and the present application is not limited thereto.
And S132, obtaining the contact resistance of the preformed armor rod at the contact port of the preformed armor rod and the ground wire according to the first impedance and the second impedance.
Specifically, after the first alternating current and the second alternating current are obtained in step S131, and the first impedance and the second impedance at the contact port of the preformed armor rod and the ground wire are respectively corresponding to the first alternating current and the second alternating current, the contact resistance at the contact port of the preformed armor rod and the ground wire can be obtained according to step S132.
In an embodiment, as shown in fig. 5, the step of obtaining the contact resistance at the contact port between the preformed helical wire and the ground wire according to the first impedance and the second impedance includes:
s1321, calculating to obtain inductance at a contact port of the preformed armor rods and the ground wire according to the first impedance and the second impedance, wherein the contact resistance change rate is ignored in the calculation process;
specifically, the first impedance and the second impedance may be expressed by the following expressions, respectively:
wherein Z is1Is a first impedance, R1For a corresponding contact resistance, ω, when a first alternating current is applied1At the angular frequency of the first current, L is the inductance;
wherein Z is2Is a second impedance, R2For a corresponding contact resistance, ω, when a second alternating current is applied2At the angular frequency of the second current, L is the inductance;
since the contact resistance change rate is ignored in the calculation process, when the first alternating current and the second alternating current are respectively loaded in the expressions of the first impedance and the second impedance, the corresponding contact resistances can be considered to be equal, that is:
R1＝R2；
therefore, it is possible to obtain:
by the expression of the first impedance at this time:
and an expression of the second impedance:
the inductance obtained in parallel is:
and S1322, calculating to obtain the contact resistance at the contact port of the preformed armor rods and the ground wire according to the inductance and the first impedance or the inductance and the second impedance.
Specifically, the contact resistance at the contact port of the preformed armor rods and the ground wire is as follows:
or
In another embodiment, as shown in fig. 6, the step of obtaining the contact resistance at the contact port between the preformed helical wire and the ground wire according to the first impedance and the second impedance includes:
s1323, calculating an impedance angle at a contact port of the preformed armor rod and the ground wire according to the first impedance and the second impedance, wherein the contact resistance change rate is ignored in the calculation process;
specifically, the first impedance and the second impedance may be expressed by the following expressions, respectively:
wherein Z is1Is a first impedance, R1For a corresponding contact resistance, ω, when a first alternating current is applied1At the angular frequency of the first current, L is the inductance;
wherein Z is2Is a second impedance, R2For a corresponding contact resistance, ω, when a second alternating current is applied2At the angular frequency of the second current, L is the inductance;
since the contact resistance change rate is ignored in the calculation process, when the first alternating current and the second alternating current are respectively loaded in the expressions of the first impedance and the second impedance, the corresponding contact resistances can be considered to be equal, that is:
R1＝R2；
therefore, it is possible to obtain:
by the expression of the first impedance at this time:
and an expression of the second impedance:
the inductance obtained in parallel is:
from the inductance, the impedance angle is:
or
S1324, calculating to obtain the contact resistance at the contact port of the preformed armor rods and the ground wire according to the impedance angle and the first impedance or the impedance angle and the second impedance.
Specifically, the contact resistance at the contact port of the preformed armor rods and the ground wire is as follows:
RC＝Z1cosθ
or
RC＝Z2cosθ。
In another embodiment, the contact resistance measuring method according to the present application is based on any of the above embodiments, and in step S110, the first frequency of the first ac current is selected as the high frequency value
Wherein d is1Is a first skin depth, f1For the first frequency, ω is the angular frequency, μ is the magnetic permeability, γ is the electrical conductivity, and we know:
when the first frequency is a high frequency value, the first skin depth approaches 0, and when a preset contact resistance change rate requirement (for example, the contact resistance change rate is not more than five percent) is satisfied, the first frequency is represented by the expression described in the first embodiment:
therefore, the following steps are carried out: the second skin depth corresponding to the second AC current cannot approach 0, therefore, the second skin depth corresponding to the second AC current is not close to 0
Therefore, the following steps are carried out: the second frequency of the second alternating current is a non-high frequency value.
Therefore, when the first frequency of the first alternating current at the contact port of the preformed armor rod and the ground wire is a high-frequency value and the second frequency of the second alternating current is a non-high-frequency value, the contact resistance change rate (the contact resistance change rate is not more than five percent) of the preset requirement can be met.
It should be noted that, in another embodiment of the contact resistance measuring method provided by the present application, the expression of the first impedance or the second impedance is:
or
It can be known that the reactance omega L is in direct proportion to the frequency of the alternating current, and the change rate of the contact resistance meets the ignorable preset requirement, so that the reactance change range caused by the high-frequency alternating current and the non-high-frequency alternating current is far larger than the change range of the contact resistance, the impedance change is mainly caused by the reactance change, and the neglect of the resistance change does not cause too large influence on the measurement result, so that the contact resistance measurement method provided by the application can not only measure the alternating current contact resistance at the contact port of the preformed armor rod and the ground wire, but also can effectively reduce the error in the measurement process, thereby improving the measurement accuracy.
As shown in fig. 7, the present application also provides a contact resistance measuring apparatus including: an acquisition module 210, a measurement module 220 and a processing module 230; the obtaining module 210 is configured to obtain a first frequency of the first alternating current and a second frequency of the second alternating current according to a preset required contact resistance change rate; the measuring module 220 is configured to respectively measure a first voltage and a second voltage at a contact port of the preformed armor rod and the ground wire by loading a first alternating current with a first frequency and a second alternating current with a second frequency at the contact port of the preformed armor rod and the ground wire; the processing module 230 is configured to obtain a contact resistance at a contact port between the preformed armor rod and the ground wire according to the first voltage and the second voltage.
The contact resistance measuring device provided by the present application uses the contact resistance measuring method described in any of the above method embodiments. Therefore, the contact resistance measuring device provided by the present application has all the advantages described in any of the above method embodiments, and details are not repeated herein.
As described above, in the contact resistance measuring apparatus provided by the present application, the contact resistance change rate that is preset as a requirement means that the contact resistance change rate is not more than five percent.
The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims (9)
1. A contact resistance measurement method for measuring contact resistance at a contact port of a preformed armor rod and a ground wire, the method comprising:
acquiring alternating currents with two different frequencies which meet the change rate of the contact resistance of a preset requirement;
loading alternating currents based on the two different frequencies at a contact port of the preformed armor rods and the ground wire, and respectively measuring a first voltage and a second voltage at the contact port of the preformed armor rods and the ground wire;
obtaining a contact resistance at a contact port of the preformed armor rods and the ground wire according to the first voltage and the second voltage;
wherein, the step of obtaining two different frequencies of alternating currents that satisfy the contact resistance change rate of the preset requirement includes:
randomly selecting a first frequency of a first alternating current, and obtaining a corresponding first skin depth according to the first frequency of the first alternating current;
and obtaining a second skin depth of a second alternating current and a second frequency corresponding to the second alternating current according to the first skin depth of the first alternating current and a preset required contact resistance change rate.
2. A contact resistance measuring method according to claim 1, wherein the step of obtaining the contact resistance at the contact port of the preformed helical wire and the ground wire according to the first voltage and the second voltage comprises:
respectively calculating a first impedance and a second impedance at the contact port of the corresponding preformed armor rods and the ground wire according to the first voltage and the first alternating current, and the second voltage and the second alternating current;
and obtaining the contact resistance of the preformed armor rods at the contact port of the preformed armor rods and the ground wire according to the first impedance and the second impedance.
3. A contact resistance measuring method according to claim 2, wherein the step of obtaining the contact resistance at the contact port of the preformed helical wire and the ground wire according to the first impedance and the second impedance comprises:
calculating to obtain the inductance at the contact port of the preformed armor rods and the ground wire according to the first impedance and the second impedance, wherein the change rate of the contact resistance is ignored in the calculation process;
and calculating the contact resistance at the contact port of the preformed armor rods and the ground wire according to the inductance and the first impedance or the inductance and the second impedance.
4. A contact resistance measuring method according to claim 2, wherein the step of obtaining the contact resistance at the contact port of the preformed helical wire and the ground wire according to the first impedance and the second impedance comprises:
calculating to obtain an impedance angle at a contact port between the preformed armor rods and the ground wire according to the first impedance and the second impedance, wherein the change rate of the contact resistance is ignored in the calculation process;
and calculating the contact resistance at the contact port of the preformed armor rods and the ground wire according to the impedance angle and the first impedance or the impedance angle and the second impedance.
5. The contact resistance measuring method according to claim 1, wherein the preset required contact resistance change rate means that the contact resistance change rate is not more than five percent.
6. A contact resistance measurement method according to claim 1, wherein the first frequency is a high frequency value and the second frequency is a non-high frequency value.
7. A contact resistance measuring method according to claim 1, wherein the two different frequencies of alternating current have the same effective value of current.
8. A contact resistance measuring device, comprising: the device comprises an acquisition module, a measurement module and a processing module;
the acquisition module is used for acquiring alternating currents with two different frequencies which meet the change rate of the contact resistance of a preset requirement;
the measuring module is used for loading alternating currents based on the two different frequencies at a contact port of the preformed armor rods and the ground wire and respectively measuring a first voltage and a second voltage at the contact port of the preformed armor rods and the ground wire;
the processing module is used for obtaining a contact resistance at a contact port of the preformed armor rod and the ground wire according to the first voltage and the second voltage;
the obtaining module is specifically configured to:
randomly selecting a first frequency of a first alternating current, and obtaining a corresponding first skin depth according to the first frequency of the first alternating current; and obtaining a second skin depth of a second alternating current and a second frequency corresponding to the second alternating current according to the first skin depth of the first alternating current and a preset required contact resistance change rate.
9. The contact resistance measuring device according to claim 8, wherein the preset required contact resistance change rate means that the contact resistance change rate is not more than five percent.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811344934.1A CN109188096B (en) | 2018-11-12 | 2018-11-12 | Contact resistance measuring method and device |
| CN202010607619.4A CN111707872B (en) | 2018-11-12 | 2018-11-12 | Contact resistance measuring method and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811344934.1A CN109188096B (en) | 2018-11-12 | 2018-11-12 | Contact resistance measuring method and device |
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| CN112269060B (en) * | 2020-09-09 | 2024-01-02 | 国联汽车动力电池研究院有限责任公司 | Contact resistance and contact conductivity identification method and system |
| CN113203894B (en) * | 2021-03-19 | 2022-11-18 | 深圳供电局有限公司 | Impedance testing method and testing device thereof |
| CN113705132A (en) * | 2021-08-20 | 2021-11-26 | 广东电网有限责任公司 | Direct current loop resonance analysis method, device, equipment and storage medium |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103713198A (en) * | 2014-01-08 | 2014-04-09 | 国家电网公司 | Method for measuring phase to phase mutual impedance of long-distance extra-high voltage common-tower double-circuit transmission line |
| CN105675657A (en) * | 2016-01-12 | 2016-06-15 | 中国地质大学（武汉） | Skin effect-based sample surface coating nondestructive test method and system |
| CN107102208A (en) * | 2017-04-25 | 2017-08-29 | 南方电网科学研究院有限责任公司 | The measuring method and device of a kind of impulse earthed resistance |
| CN108344898A (en) * | 2018-01-31 | 2018-07-31 | 华南理工大学 | A kind of preformed armor rods incision position contact resistance experimental measurement method based on heat to electricity conversion |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101398369A (en) * | 2007-09-30 | 2009-04-01 | 通用电气公司 | Device and method for monitoring surface corrosion |
| FR2985032B1 (en) * | 2011-12-23 | 2014-01-17 | Chauvin Arnoux | GROUND CLAMP FOR MEASURING THE EARTH RESISTANCE OF ELECTRICAL INSTALLATIONS |
| CN108416097A (en) * | 2018-02-01 | 2018-08-17 | 华南理工大学 | The finite element thermal analysis equivalent method of ground wire and preformed armor rods contact port contact resistance |
| CN108334695B (en) * | 2018-02-01 | 2021-07-20 | 华南理工大学 | Finite element setting method based on contact resistance of ground wire and preformed armor rods |
| CN108414837B (en) * | 2018-02-06 | 2019-06-18 | 华南理工大学 | A kind of experimental measurement method of aerial earth wire and preformed armor rods contact port contact resistance |
| CN108761241B (en) * | 2018-06-07 | 2021-04-20 | 中国电子科技集团公司第五十四研究所 | Nonlinear effect modeling method of radio frequency coaxial connector |
-
2018
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103713198A (en) * | 2014-01-08 | 2014-04-09 | 国家电网公司 | Method for measuring phase to phase mutual impedance of long-distance extra-high voltage common-tower double-circuit transmission line |
| CN105675657A (en) * | 2016-01-12 | 2016-06-15 | 中国地质大学（武汉） | Skin effect-based sample surface coating nondestructive test method and system |
| CN107102208A (en) * | 2017-04-25 | 2017-08-29 | 南方电网科学研究院有限责任公司 | The measuring method and device of a kind of impulse earthed resistance |
| CN108344898A (en) * | 2018-01-31 | 2018-07-31 | 华南理工大学 | A kind of preformed armor rods incision position contact resistance experimental measurement method based on heat to electricity conversion |
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| CN111707872A (en) | 2020-09-25 |
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