Power line grounding line detection method and apparatus

Abstract

A power line grounding line detection method and apparatus. The method comprises: measuring a first impedance of a power line at a first measurement frequency, and measuring a second impedance of the power line at a second measurement frequency (S101); on the basis of the first measurement frequency and the first impedance corresponding thereto, and the second measurement frequency, and on the basis of the second impedance corresponding thereto, determining an impedance property of the power line (S102); calculating a third impedance of the power line on the basis of the impedance property of the power line, and calculating a reactance factor on the basis of the third impedance (S103); obtaining a grounding line installation state of the power line on the basis of the reactance factor, the third impedance, and the impedance property (S104). The present method resolves the technical problems in the prior art of low detection accuracy and insufficient validity, which make relatively large errors likely, causing detection faults.

Description

Ground wire detection method and device of power line TECHNICAL FIELD

[0001] The present application relates to the technical field of power grid state detection, and in particular to a ground wire detection method and device of a power line. BACKGROUND

[0002] If a ground wire or a ground knife is used for power transmission in a power system, the power grid accident caused by the power transmission is very serious, and it is easy to cause equipment damage, power grid accident and even personnel casualty. Therefore, before power transmission, how to check whether the ground wire of the power line has been completely removed and whether the ground knife has been completely opened, etc. is a key measure to prevent power transmission with a ground wire.

[0003] At present, in the prior art, there is a technical solution that a clamp-on meter is used to apply an induced voltage to a certain group of ground wires (ground knives) on the to-be-measured line (conductor), and then the current of the line is measured, and the line impedance is calculated according to Ohm's law, and then the existence of a closed loop in the line is analyzed to determine the ground line closing (i.e. grounding) state of the to-be-measured line. Since the induced voltage applied to the to-be-measured line (conductor) cannot be directly and accurately measured, and the magnetization curve of the clamp-on meter core is nonlinear at high frequencies, the amplitude and phase of the primary and secondary voltages cannot be measured according to the linear proportion, so the clamp-on meter measurement result is the total impedance. When the line impedance is basically resistive, the above detection system can effectively detect the installation state of the ground wire; however, when the proportion of reactance (capacitive reactance or inductive reactance) is large, the reactance of the line has a great influence on the total impedance of the line, which leads to the fact that the above detection system cannot effectively detect the installation state of the ground wire, and even a large error may occur to cause detection errors. SUMMARY

[0004] The present application provides a ground wire detection method and device of a power line to solve the technical problems of low detection accuracy, insufficient effectiveness and large error in the prior art.

[0005] To solve the above technical problems, the present application provides a ground wire detection method of a power line, comprising:

[0006] measuring a first impedance of the power line at a first measurement frequency and measuring a second impedance of the power line at a second measurement frequency; wherein the first measurement frequency and the second measurement frequency are different in size;

[0007] determining the impedance property of the power line according to the first measurement frequency and the corresponding first impedance, and the second measurement frequency and the corresponding second impedance;

[0008] According to the impedance property of the power line, a third impedance of the power line is calculated, and according to the third impedance, a reactance factor is calculated;

[0009] According to the reactance factor, the third impedance and the impedance property, a grounding wire installation state of the power line is obtained.

[0010] As a preferred solution, the first impedance of the power line is measured at a first measurement frequency, and the second impedance of the power line is measured at a second measurement frequency, specifically comprising:

[0011] The first impedance of the power line is measured by a first clamp-on meter at a first measurement frequency;

[0012] The second impedance of the power line is measured by a second clamp-on meter at a second measurement frequency;

[0013] The first clamp-on meter and the second clamp-on meter are respectively clamped on any group of grounding wires or grounding wires of the line grounding knife of the power line.

[0014] As a preferred solution, the impedance property of the power line is determined according to the first measurement frequency and the corresponding first impedance, and the second measurement frequency and the corresponding second impedance, specifically comprising:

[0015] When the first impedance is equal to the second impedance, the impedance property of the power line is resistive;

[0016] When the first impedance is greater than the second impedance and the first measurement frequency is less than the second measurement frequency, or the first impedance is less than the second impedance and the first measurement frequency is greater than the second measurement frequency, the impedance property of the power line is capacitive;

[0017] When the first impedance is less than the second impedance and the first measurement frequency is less than the second measurement frequency, or the first impedance is greater than the second impedance and the first measurement frequency is greater than the second measurement frequency, the impedance property of the power line is inductive.

[0018] As a preferred solution, after the impedance property of the power line is determined, it further comprises:

[0019] When the impedance property of the power line is resistive, a first resistance value and a first reactance value of the power line are calculated according to the first impedance and the second impedance; wherein the first reactance value of the resistive power line is 0;

[0020] When the impedance property of the power line is capacitive, a second resistance value and a second reactance value of the power line are calculated according to the first impedance, the second impedance, the first frequency, the second frequency and a preset power frequency;

[0021] When the impedance property of the power line is inductive, a third resistance value and a third reactance value of the power line are calculated according to the first impedance, the second impedance, the first frequency, the second frequency and a preset power frequency.

[0022] As a preferred solution, the third impedance of the power line is calculated according to the impedance property of the power line, and the reactance factor is calculated according to the third impedance, and specifically includes:

[0023] The third impedance of the power line is calculated according to the resistance value and the reactance value corresponding to the impedance property of the power line and a preset power frequency; wherein the resistance value includes the first resistance value, the second resistance value or the third resistance value, and the reactance value includes the first reactance value, the second reactance value or the third reactance value.

[0024] The reactance factor corresponding to the power line is calculated according to the third impedance and the reactance value corresponding to the impedance property of the power line.

[0025] As a preferred solution, the ground wire installation state of the power line is obtained according to the reactance factor, the third impedance and the impedance property, and specifically includes:

[0026] When the power line is capacitive, the ground wire installation state of the capacitive power line is obtained according to the reactance factor and the third impedance.

[0027] When the power line is resistive or inductive, the ground wire installation state of the resistive or inductive power line is obtained according to the third impedance.

[0028] The ground wire installation state includes an uninstalled state and an installed state.

[0029] As a preferred solution, the ground wire installation state of the capacitive power line is obtained according to the reactance factor and the third impedance when the power line is capacitive, and specifically includes:

[0030] When the power line is capacitive, the reactance factor corresponding to the power line is determined.

[0031] If the reactance factor is greater than a preset threshold, it is determined that the ground wire installation state of the capacitive power line is the uninstalled state.

[0032] If the reactance factor is less than a preset threshold value and the third impedance is greater than a preset resistance value, it is determined that the grounding wire installation state of the capacitive power line is an uninstalled state.

[0033] If the reactance factor is less than a preset threshold value and the third impedance is less than a preset resistance value, it is determined that the grounding wire installation state of the capacitive power line is an installed state.

[0034] As a preferred solution, when the power line is resistive or inductive, the grounding wire installation state of the capacitive power line is determined according to the third impedance, and specifically includes:

[0035] When the power line is resistive or inductive and the third impedance is greater than a preset resistance value, it is determined that the grounding wire installation state of the capacitive power line is an uninstalled state.

[0036] When the power line is resistive or inductive and the third impedance is less than a preset resistance value, it is determined that the grounding wire installation state of the capacitive power line is an installed state.

[0037] Correspondingly, the application also provides a grounding wire detection device for a power line, which includes a measurement module, an impedance module, a calculation module and a state module.

[0038] The measurement module is configured to measure a first impedance of the power line at a first measurement frequency and a second impedance of the power line at a second measurement frequency.

[0039] The impedance module is configured to determine the impedance property of the power line according to the first measurement frequency and the corresponding first impedance and the second measurement frequency and the corresponding second impedance.

[0040] The calculation module is configured to calculate the third impedance of the power line according to the impedance property of the power line and calculate the reactance factor according to the third impedance.

[0041] The state module is configured to obtain the grounding wire installation state of the power line according to the reactance factor, the third impedance and the impedance property.

[0042] Compared with the prior art, the embodiments of the application have the following beneficial effects:

[0043] The technical scheme of the present application measures the impedance of the power line through the first measurement frequency and the second measurement frequency respectively, and determines the impedance property of the power line as inductive, capacitive or inductive according to the first impedance and the second impedance obtained respectively corresponding to each measurement frequency, and then calculates the third impedance of the power line through the impedance property of the power line, so as to calculate the reactance factor of the power line, so as to determine the degree of influence of the power line on the reactance, which can effectively reduce the influence of the reactance, and finally combine the impedance property of the power line, the reactance factor and the third impedance to accurately and effectively detect whether the power line has a closed loop, and then obtain the installation state of the grounding wire of the power line, improve the detection accuracy of the installation state of the grounding wire of the power line, avoid the large error in measurement caused by the existence of the reactance, and improve the accuracy and effectiveness of the detection of the grounding state of the power line. BRIEF DESCRIPTION OF DRAWINGS

[0044] Fig. 1 is a step flow chart of a grounding wire detection method of a power line provided by an embodiment of the present application;

[0045] Fig. 2 is a schematic diagram of a principle of measuring the loop of a power line by a clamp meter provided by an embodiment of the present application;

[0046] Fig. 3 is a structural diagram of a grounding wire detection device of a power line provided by an embodiment of the present application. DETAILED DESCRIPTION

[0047] The technical scheme in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0048] Embodiment one

[0049] Please refer to Fig. 1, which is a grounding wire detection method of a power line provided by an embodiment of the present application, including the following steps S101-S104:

[0050] Step S101: measuring the first impedance of the power line at a first measurement frequency, and measuring the second impedance of the power line at a second measurement frequency; wherein the first measurement frequency and the second measurement frequency are different in size.

[0051] It should be noted that the first measurement frequency and the second measurement frequency can be any frequency, as long as the first measurement frequency and the second measurement frequency are different, in the embodiment, the specific values of the first measurement frequency and the second measurement frequency can be set according to the specific application of the actual power line grounding line detection. Preferably, the value range of the first measurement frequency can be 100Hz-10000Hz, the value range of the first measurement frequency can be 100Hz-10000Hz, for the measurement of small resistance power line grounding line, the first measurement frequency and the second measurement frequency can also be less than 100Hz; for the measurement of super large scale power line grounding line, the first measurement frequency and the second measurement frequency can also be greater than 10000Hz.

[0052] As a preferred scheme of the embodiment, the first impedance of the power line is measured at the first measurement frequency, and the second impedance of the power line is measured at the second measurement frequency, specifically comprising:

[0053] The first impedance of the power line is measured by the first clamp meter at the first measurement frequency, and the second impedance of the power line is measured by the second clamp meter at the second measurement frequency; wherein the first clamp meter and the second clamp meter are respectively clamped on any group of grounding lines or grounding lines of the line grounding knife of the power line, and the first measurement frequency and the second measurement frequency are different in size.

[0054] In the embodiment, the first clamp meter and the second clamp meter can be a grounding resistance clamp meter or a loop resistance tester, and its working principle is to apply an induced voltage on a certain group of grounding lines (grounding knives) on the measured line (conductor) by using a clamp meter, and then measure the current of the line, so as to calculate the line impedance according to Ohm's law, as shown in FIG. 2. Since the induced voltage U applied by the clamp meter to the measured line cannot be directly measured (only the induced voltage output by the clamp meter can be obtained, and the accurate induced voltage applied to the loop cannot be measured, and the applied induced voltage is lost), and the clamp meter core magnetization curve is nonlinear at high frequency, the amplitude and phase of the primary and secondary voltages cannot be measured in linear proportion, so the clamp meter measurement result is the total impedance, and the influence of the electric reactance in the power line on the power loop cannot be determined. For example, in the normal state of the power grid, when the cable line is unloaded (the conductor is not grounded), the line impedance Z is basically the capacitive reactance X C , the capacitive reactance X C is inversely proportional to the size of the measurement frequency, and the capacitive reactance X C at 50Hz is 1 / 30 of that at 1500Hz, and even when the cable is open at 1500Hz, its X CThe value can still be small, even easy to misjudge as the end short-circuit grounding, for example, 10kV three-core XLPE cable (per kilometer) to ground capacitance can reach 0.4 μF / km, per kilometer cable to ground capacitive reactance X C 265 Ω If the 3-kilometer cable to ground capacitive reactance X C <100 Ω, which will cause misjudgment as the end with ground wire in actual test, and, in the power transmission and distribution network, the length of more than 3 kilometers of power lines are not uncommon, and with the increase of cable length, ground capacitive reactance X C Will further reduce, it can be seen that such capacitive reactance misleading problem is quite prominent.

[0055] In the embodiment, by adopting the mode of double clamp meter method to measure the resistance and reactance of the line, that is, using first and second clamp meters with different measurement frequencies, the resistance and reactance of the line can be measured at any group of ground wires of the power line, which can effectively reduce the influence of the reactance, accurately and effectively detect whether there is a closed loop in the line, and judge whether the remaining ground wires of the power line are removed, so as to realize the detection and perception of whether the ground wire is disconnected in the super-vision, full-chain, dead-angle-free and convenient and reliable way, greatly improve the timeliness and accuracy of the detection and perception of the installation state of the ground wire of the power line, and ensure that the double clamp meter method is used to measure the power line reactance and exclude interference, and accurately and effectively judge whether the ground wire of the power line is removed.

[0056] It can be understood that two clamp meters with different measurement frequencies are respectively clamped on the ground down conductor of any group of ground wires or line ground knife of the power line (see FIG. 2), the total impedance Z1 (the reading of the first clamp meter) and Z2 (the reading of the second clamp meter) of the power line are measured, and the resistance R and the reactance X of the line are calculated, then the influence of the reactance X is excluded, and then the resistance R is used to effectively detect whether there is a closed loop in the line, so as to accurately judge whether the remaining ground wires of the power line are removed.

[0057] Step S102: determining the impedance property of the power line according to the first measurement frequency and the corresponding first impedance, and the second measurement frequency and the corresponding second impedance; wherein the impedance property includes capacitive, resistive and inductive.

[0058] For example, the first measurement frequency of the first clamp meter and the second measurement frequency of the second clamp meter, and the first impedance measured by the first clamp meter and the second impedance measured by the second clamp meter can be used to accurately determine the impedance property of the power line.

[0059] As a preferred solution of the embodiment, the determining the impedance property of the power line according to the first measurement frequency and the corresponding first impedance, and the second measurement frequency and the corresponding second impedance specifically comprises:

[0060] When the first impedance is equal to the second impedance, the impedance property of the power line is resistive; when the first impedance is greater than the second impedance and the first measurement frequency is less than the second measurement frequency, or the first impedance is less than the second impedance and the first measurement frequency is greater than the second measurement frequency, the impedance property of the power line is capacitive; when the first impedance is less than the second impedance and the first measurement frequency is less than the second measurement frequency, or the first impedance is greater than the second impedance and the first measurement frequency is greater than the second measurement frequency, the impedance property of the power line is inductive.

[0061] In the embodiment, when Z1=R=Z2, the impedance property of the power line is resistive. Since the resistive power line does not exist reactance, no matter the measurement frequency of the clamp-on ammeter is, the reactance in the power line will not be affected (the reactance of the resistive power line is 0), and the resistance of the whole resistive power line is equal to the impedance value measured by the clamp-on ammeter, i.e. Z1=R=Z2.

[0062] Further, since the line inductive reactance X L is proportional to the size of the measurement frequency, and the line capacitive reactance X C is inversely proportional to the size of the measurement frequency, for example, the measurement frequency f1 of the first clamp-on ammeter is 1500 Hz, and the measurement frequency f2 of the second clamp-on ammeter is 2000 Hz, i.e. f1=1500 Hz

[0063] As a preferred solution of the embodiment, after the determining the impedance property of the power line, the method further comprises:

[0064] When the impedance property of the power line is resistive, a first resistance value and a first reactance value of the power line are calculated according to the first impedance and the second impedance; the first reactance value of the resistive power line is 0; when the impedance property of the power line is capacitive, a second resistance value and a second reactance value of the power line are calculated according to the first impedance, the second impedance, the first frequency, the second frequency and a preset power frequency; when the impedance property of the power line is inductive, a third resistance value and a third reactance value of the power line are calculated according to the first impedance, the second impedance, the first frequency, the second frequency and the preset power frequency.

[0065] In the embodiment, when the impedance of the power line is resistive, for any measurement frequency, the relationship between the first impedance, the second impedance and the resistance value of the power line is Z1=R=Z2. Therefore, the first resistance value of the resistive power line is equal to the first impedance or the second impedance (the values of the first impedance and the second impedance are the same), and the first reactance value is 0.

[0066] In the embodiment, it is assumed that the measurement frequency f1 of the first clamp-on ammeter is 1500 Hz, the measurement frequency f2 of the second clamp-on ammeter is 2000 Hz, and the preset power frequency is 50 Hz (the preset power frequency can be set according to the current or voltage frequency of the actual power line in normal operation, and is preferably 50 Hz). When the impedance of the power line is capacitive, then

[0067] In the formula, X is the reactance value at the power frequency 50 Hz. 50

[0068] Therefore, we have

[0069] In the embodiment, it is assumed that the measurement frequency f1 of the first clamp-on ammeter is 1500 Hz, the measurement frequency f2 of the second clamp-on ammeter is 2000 Hz, and the preset power frequency is 50 Hz. When the impedance of the power line is inductive, then

[0070] In the formula, X is the reactance value at the power frequency 50 Hz. 50

[0071] Therefore, we have

[0072] ​​​​Z1 and Z2 in the above formula can be Z1 or Z2 containing resistance R and reactance X information measured by various methods, including but not limited to Z1 and Z2 measured by two independent clamp-on meters (for example, a first clamp-on meter and a second clamp-on meter) with different frequencies; or Z1 and Z2 measured by one clamp-on meter integrating two different measurement frequencies (the first clamp-on meter and the second clamp-on meter can be the same clamp-on meter, and the difference between the first clamp-on meter and the second clamp-on meter is the measurement frequency, and the first clamp-on meter and the second clamp-on meter are only used to distinguish the impedance measured by the same clamp-on meter at different measurement frequencies), which mainly means that the impedance values Z1 and Z2 of the power line at two different measurement frequencies can be measured, for example, the first impedance value is measured by the first clamp-on meter set as the first measurement frequency, and the second impedance value is measured by the second clamp-on meter set as the second measurement frequency, that is, the first impedance of the power line is measured at the first measurement frequency and the first impedance of the power line is measured at the second measurement frequency by the clamp-on meter, which includes the first clamp-on meter and the second clamp-on meter.

[0073] Step S103: calculating a third impedance of the power line according to the impedance property of the power line, and calculating a reactance factor according to the third impedance.

[0074] As a preferred scheme of the embodiment, the third impedance of the power line is calculated according to the impedance property of the power line, and the reactance factor is calculated according to the third impedance, which specifically includes:

[0075] The third impedance of the power line is calculated according to the resistance value and the reactance value corresponding to the impedance property of the power line and the preset power frequency; the resistance value includes a first resistance value, a second resistance value or a third resistance value, and the reactance value includes a first reactance value, a second reactance value or a third reactance value; and the reactance factor corresponding to the power line is calculated according to the third impedance and the reactance value corresponding to the impedance property of the power line.

[0076] In the embodiment, since the power lines with different impedance properties have different resistance values and reactance values, the third impedance of the current power line can be calculated by determining the impedance property of the power line and the resistance value and the reactance value corresponding to the impedance property and the preset power frequency, that is, the impedance result measured by the double clamp-on meter method is converted to the third impedance at the power frequency of 50 Hz. In the embodiment, the third impedance Z 50 of the resistive power line is Z1=Z2=R, X 50 =0.

[0077] In the embodiment, the third impedance Z 50 at the power frequency of 50 Hz is combined with the reactance X 50Thus, the reactance influencing factor of the power line, i.e., the reactance factor, can be calculated It can be understood that the reactance factor The impedance ratio at any frequency can be converted, and the preset working frequency of 50 Hz in the embodiment is converted to the same frequency application scenario, which is the most extensive and relatively intuitive.

[0078] Step S104: obtaining the grounding wire installation state of the power line according to the reactance factor, the third impedance, and the impedance property.

[0079] As a preferred scheme of the embodiment, the obtaining of the grounding wire installation state of the power line according to the reactance factor, the third impedance, and the impedance property specifically includes:

[0080] When the power line is capacitive, the grounding wire installation state of the capacitive power line is obtained according to the reactance factor and the third impedance; when the power line is resistive or inductive, the grounding wire installation state of the resistive or inductive power line is obtained according to the third impedance; wherein the grounding wire installation state includes an uninstalled state and an installed state.

[0081] In the embodiment, in the normal state of the power grid, there can be a single large capacitor between the power line conductor and the ground potential (such as an unloaded long cable), and there can be a large inductance (such as a parallel high resistance of a long line), but there is no single small inductance. Therefore, the inductive impedance is basically the same as the resistive impedance for judging the loop state, and only the third impedance needs to be judged to obtain the grounding wire installation state of the resistive or inductive power line. The capacitive impedance is disturbed by the large capacitance of the unloaded long-distance cable line, so the reactance factor is needed to determine the proportion of the reactance to the overall loop impedance, and then the grounding wire installation state of the capacitive power line is determined.

[0082] As a preferred scheme of the embodiment, the obtaining of the grounding wire installation state of the capacitive power line according to the reactance factor and the third impedance specifically includes:

[0083] When the power line is capacitive, the grounding wire installation state of the capacitive power line is obtained according to the reactance factor and the third impedance; when the power line is resistive or inductive, the grounding wire installation state of the resistive or inductive power line is obtained according to the third impedance; wherein the grounding wire installation state includes an uninstalled state and an installed state.

[0084] In the embodiment, according to the actual power maintenance test regulation, when the circuit is grounded to form a closed loop, the insulation resistance of the normal power line to the ground should be greater than the megohm (MΩ) level, specifically, usually greater than 1 MΩ; the tower grounding resistance should be less than the hundred ohm level (<100Ω), specifically, usually less than 30Ω, so in order to consider the error of the impedance measurement of the clamp-on meter, the threshold of the preset resistance value can be taken as the kilo-ohm (kΩ) level, preferably, the preset resistance value can be taken as 1200Ω. Specifically, the preset resistance value can be reasonably selected and set (preset resistance value) according to the actual engineering requirements, the measurement of the field environment temperature, humidity, soil resistivity, and the degree of contamination of the measured line insulator and other factors.

[0085] Further, the preset threshold of the reactance factor is greatly affected by the grounding resistance value of the power line (such as the outer sheath of the cable), which can be reasonably selected and set (preset threshold) according to the actual engineering requirements, the measurement of the field environment temperature, humidity, soil resistivity and other factors.

[0086] In the embodiment, the preset threshold can be set according to the actual situation, preferably, the preset threshold is 0.9, to exclude the interference of the large capacitance of the unloaded long-distance cable line to the ground, and to ensure the influence of the reactance on the impedance in the overall power line. For example, when the power line is capacitive, i.e. X 50 is capacitive reactance, and , the power line is not provided with a grounding wire, i.e. the installation state of the grounding wire of the capacitive power line is not installed; when the power line is capacitive, i.e. X 50 is capacitive reactance, and , the third impedance Z 50 is greater than 1200Ω, the power line is not provided with a grounding wire, i.e. the installation state of the grounding wire of the capacitive power line is not installed; when the power line is capacitive, i.e. X 50 is capacitive reactance, and , the third impedance Z 50 is less than 1200Ω, the power line is provided with a grounding wire, and the installation state of the grounding wire of the capacitive power line is installed.

[0087] As a preferred scheme of the embodiment, when the power line is resistive or inductive, the installation state of the grounding wire of the capacitive power line is determined according to the third impedance, specifically including:

[0088] when the power line is resistive or inductive, and the third impedance is greater than the preset resistance value, it is determined that the installation state of the grounding wire of the capacitive power line is not installed; when the power line is resistive or inductive, and the third impedance is less than the preset resistance value, it is determined that the installation state of the grounding wire of the capacitive power line is installed

[0089] In the embodiment, when the power line is resistive or inductive, that is, X 50 is resistive reactance or inductive reactance, and the third impedance Z 50 > 1200Ω, the power line is not provided with a grounding wire, that is, the grounding wire installation state of the resistive power line or the inductive power line is in an uninstalled state; when the power line is resistive or inductive, that is, X 50 is resistive reactance or inductive reactance, and the third impedance Z 50 < 1200Ω, the power line is provided with a grounding wire, that is, the grounding wire installation state of the resistive power line or the inductive power line is in an installed state.

[0090] It can be understood that, by using the mode of measuring the resistance and reactance of the line by the double clamp-on method, the line reactance influence factor The resistance and reactance of the line are measured at any set of grounding wires of the power line, which can effectively reduce the influence of the reactance, can accurately and effectively detect whether the line has a closed loop, can determine whether the remaining grounding wires of the power line are removed, can realize the detection and sensing of whether the grounding wire is disconnected in an over-the-horizon, full-chain, dead-angle-free and convenient and reliable manner, and greatly improves the detection and sensing timeliness and accuracy of the grounding wire installation state of the power line.

[0091] The above embodiment has the following effects:

[0092] The technical scheme of the application measures the impedance of the power line by the first clamp-on meter and the second clamp-on meter, respectively, and determines the impedance property of the power line to be inductive, capacitive or inductive according to the first impedance, the second impedance and the measurement frequency corresponding to each clamp-on meter, and then calculates the third impedance of the power line according to the impedance property of the power line, so as to calculate the reactance factor of the power line, so as to determine the degree of influence of the reactance on the power line, to effectively reduce the influence of the reactance, and finally to accurately and effectively detect whether the line has a closed loop by combining the impedance property of the power line, the reactance factor and the third impedance, so as to obtain the grounding wire installation state of the power line, improve the detection and sensing accuracy of the grounding wire installation state of the power line, avoid the detection error caused by the large measurement error due to the existence of the reactance, and improve the accuracy and effectiveness of the grounding state detection of the power line.

[0093] Embodiment two

[0094] Please refer to FIG. 3, which is a grounding wire detection device for a power line provided by the application, comprising a measurement module 101, an impedance module 102, a calculation module 103 and a state module 104;

[0095] The measurement module 101 is used to measure the first impedance of the power line at a first measurement frequency, and measure the first impedance of the power line at a second measurement frequency;

[0096] determining an impedance property of the power line according to the first measurement frequency and the corresponding first impedance and the second measurement frequency and the corresponding second impedance; wherein the impedance property comprises: resistive, capacitive and inductive;

[0097] calculating a third impedance of the power line according to the impedance property of the power line, and calculating an electric reactance factor according to the third impedance;

[0098] obtaining a grounding wire installation state of the power line according to the electric reactance factor, the third impedance and the impedance property.

[0099] As a preferred solution, the first impedance of the power line is measured at the first measurement frequency, and the first impedance of the power line is measured at the second measurement frequency, specifically comprising:

[0100] measuring the power line at the first measurement frequency by the first clamp-on ammeter to obtain the first impedance of the power line;

[0101] measuring the power line at the second measurement frequency by the second clamp-on ammeter to obtain the second impedance of the power line;

[0102] Wherein, the first clamp-on ammeter and the second clamp-on ammeter are clamped on any group of grounding wires or grounding wires of the line grounding knife of the power line, and the first measurement frequency and the second measurement frequency are different in size.

[0103] As a preferred solution, the impedance property of the power line is determined according to the first measurement frequency and the corresponding first impedance and the second measurement frequency and the corresponding second impedance, specifically comprising:

[0104] When the first impedance is equal to the second impedance, the impedance property of the power line is resistive;

[0105] When the first impedance is greater than the second impedance and the first measurement frequency is less than the second measurement frequency, or the first impedance is less than the second impedance and the first measurement frequency is greater than the second measurement frequency, the impedance property of the power line is capacitive;

[0106] When the first impedance is less than the second impedance and the first measurement frequency is less than the second measurement frequency, or the first impedance is greater than the second impedance and the first measurement frequency is greater than the second measurement frequency, the impedance property of the power line is inductive.

[0107] As a preferred solution, after the impedance property of the power line is determined, it further comprises:

[0108] When the impedance property of the power line is resistive, a first resistance value and a first reactance value of the power line are calculated according to the first impedance and the second impedance; wherein the first reactance value of the resistive power line is 0;

[0109] When the impedance property of the power line is capacitive, a second resistance value and a second reactance value of the power line are calculated according to the first impedance, the second impedance, the first frequency, the second frequency and a preset power frequency;

[0110] When the impedance property of the power line is inductive, a third resistance value and a third reactance value of the power line are calculated according to the first impedance, the second impedance, the first frequency, the second frequency and the preset power frequency.

[0111] As a preferred solution, the third impedance of the power line is calculated according to the impedance property of the power line, and a reactance factor is calculated according to the third impedance, specifically including:

[0112] The third impedance of the power line is calculated according to the resistance value and the reactance value corresponding to the impedance property of the power line, and a preset power frequency; wherein the resistance value includes the first resistance value, the second resistance value or the third resistance value, and the reactance value includes the first reactance value, the second reactance value or the third reactance value;

[0113] The reactance factor corresponding to the power line is calculated according to the third impedance and the reactance value corresponding to the impedance property of the power line.

[0114] As a preferred solution, the ground wire installation state of the power line is obtained according to the reactance factor, the third impedance and the impedance property, specifically including:

[0115] When the power line is capacitive, the ground wire installation state of the capacitive power line is obtained according to the reactance factor and the third impedance;

[0116] When the power line is resistive or inductive, the ground wire installation state of the resistive or inductive power line is obtained according to the third impedance;

[0117] The ground wire installation state includes an uninstalled state and an installed state.

[0118] As a preferred solution, when the power line is capacitive, the ground wire installation state of the capacitive power line is obtained according to the reactance factor and the third impedance, specifically including:

[0119] When the power line is capacitive, the reactance factor corresponding to the power line is determined;

[0120] If the reactance factor is greater than a preset threshold value, it is determined that the grounding wire installation state of the capacitive power line is an uninstalled state.

[0121] If the reactance factor is less than a preset threshold value, and the third impedance is greater than a preset resistance value, it is determined that the grounding wire installation state of the capacitive power line is an uninstalled state.

[0122] If the reactance factor is less than a preset threshold value, and the third impedance is less than a preset resistance value, it is determined that the grounding wire installation state of the capacitive power line is an installed state.

[0123] As a preferred solution, when the power line is resistive or inductive, the grounding wire installation state of the capacitive power line is determined according to the third impedance, specifically comprising:

[0124] When the power line is resistive or inductive, and the third impedance is greater than a preset resistance value, it is determined that the grounding wire installation state of the capacitive power line is an uninstalled state.

[0125] When the power line is resistive or inductive, and the third impedance is less than a preset resistance value, it is determined that the grounding wire installation state of the capacitive power line is an installed state.

[0126] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described device can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0127] The above embodiments have the following effects:

[0128] The technical solution of the present application measures the impedance of the power line by the first clamp meter and the second clamp meter respectively, and according to the obtained first impedance, second impedance and the measurement frequency corresponding to the clamp meter, the impedance property of the power line is determined to be inductive, capacitive or inductive, and then the third impedance of the power line is calculated according to the impedance property of the power line, so as to calculate the reactance factor of the power line, so as to determine the degree of influence of the reactance on the power line, and to effectively reduce the influence of the reactance. Ultimately, combined with the impedance property of the power line, the reactance factor and the third impedance, the existence of the closed loop of the power line can be accurately and effectively detected, and the grounding wire installation state of the power line is obtained, the detection accuracy of the grounding wire installation state of the power line is improved, the measurement error caused by the existence of the reactance is avoided, and the accuracy and effectiveness of the detection of the grounding state of the power line are improved.

[0129] Embodiment three

[0130] Correspondingly, the application also provides a terminal device, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor implements the grounding wire detection method of the power line according to any one of the above embodiments when executing the computer program.

[0131] The terminal device of this embodiment comprises a processor, a memory, and a computer program stored in the memory and executable on the processor. The processor implements each step in the above embodiment one, such as steps S101-S104 shown in FIG. 1, when executing the computer program. Alternatively, the processor implements the functions of each module / unit in the above device embodiment, such as the impedance module 102, when executing the computer program.

[0132] Illustratively, the computer program can be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the application. The one or more modules / units can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program in the terminal device. For example, the impedance module 102 is configured to determine the impedance property of the power line according to the first measurement frequency and the corresponding first impedance and the second measurement frequency and the corresponding second impedance; wherein the impedance property comprises resistance, capacitance and inductance.

[0133] The terminal device can be a desktop computer, a notebook computer, a palm computer, a cloud server and other computing devices. The terminal device can include, but is not limited to, a processor and a memory. Those skilled in the art can understand that the schematic diagram is only an example of the terminal device and does not constitute a limitation on the terminal device, which can include more or fewer components than the diagram, or combine certain components, or different components, for example, the terminal device can also include an input / output device, a network access device, a bus, etc.

[0134] The processor can be a central processing unit (CPU), and can also be other general-purpose processors, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor or the like, and is a control center of the terminal device, which connects all parts of the terminal device through various interfaces and lines.

[0135] The memory can be used to store the computer programs and / or modules, and the processor realizes various functions of the terminal device by running or executing the computer programs and / or modules stored in the memory, and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application program required by a function, etc.; and the data storage area can store data created according to the use of the terminal device, etc. In addition, the memory can include a high-speed random access memory, and can also include a nonvolatile memory, for example, a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other volatile solid-state memory device.

[0136] The modules / units integrated in the terminal device, if realized in the form of software function units and sold or used as independent products, can be stored in a computer readable storage medium. Based on this understanding, all or part of the processes in the above-mentioned embodiment methods can also be completed by a computer program instructing related hardware, and the computer program can be stored in a computer readable storage medium. The computer program can realize the steps of each method embodiment when executed by a processor. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or some intermediate forms, etc. The computer readable medium can include any entity or device, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc. that can carry the computer program code. It should be noted that the contents included in the computer readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer readable medium does not include electrical carrier signals and telecommunication signals.

[0137] Embodiment four

[0138] Correspondingly, the present application also provides a computer readable storage medium, comprising a stored computer program, wherein the computer program controls a device where the computer readable storage medium is located to perform the grounding wire detection method of the power line as any one of the above embodiments when the computer program is running.

[0139] The above specific embodiments further illustrate the purpose, technical solutions and advantages of the present application. It should be understood that the above description is only for specific embodiments of the present application and is not intended to limit the protection scope of the present application. It is particularly pointed out that any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method of detecting a ground line of a power line, characterized by, The method comprises: measuring a first impedance of the power line at a first measurement frequency and a second impedance of the power line at a second measurement frequency; wherein the first measurement frequency and the second measurement frequency are different in size; determining an impedance property of the power line according to the first measurement frequency and the corresponding first impedance and the second measurement frequency and the corresponding second impedance; wherein the impedance property comprises resistance, capacitance and inductance; calculating a third impedance of the power line according to the impedance property of the power line, and calculating an electric reactance factor according to the third impedance; obtaining a grounding wire installation state of the power line according to the electric reactance factor, the third impedance and the impedance property.

2. The method of claim 1, wherein the step of detecting the ground line of the power line comprises the steps of: detecting the ground line of the power line by using a ground line detection circuit; and detecting the ground line of the power line by using a ground line detection circuit. The method of measuring a first impedance of the power line at a first measurement frequency and a second impedance of the power line at a second measurement frequency specifically comprises: measuring the power line at a first measurement frequency by a first clamp-on ammeter to obtain a first impedance of the power line; measuring the power line at a second measurement frequency by a second clamp-on ammeter to obtain a second impedance of the power line; wherein the first clamp-on ammeter and the second clamp-on ammeter are clamped on any set of grounding wires or grounding wires of a line grounding knife of the power line.

3. A method of detecting a ground line of a power line according to claim 2, wherein The method of determining an impedance property of the power line according to the first measurement frequency and the corresponding first impedance and the second measurement frequency and the corresponding second impedance specifically comprises: when the first impedance is equal to the second impedance, the impedance property of the power line is resistance; when the first impedance is greater than the second impedance and the first measurement frequency is less than the second measurement frequency, or the first impedance is less than the second impedance and the first measurement frequency is greater than the second measurement frequency, the impedance property of the power line is capacitance; when the first impedance is less than the second impedance and the first measurement frequency is less than the second measurement frequency, or the first impedance is greater than the second impedance and the first measurement frequency is greater than the second measurement frequency, the impedance property of the power line is inductance.

4. A method of detecting a ground line of a power line according to any one of claims 1 to 3, wherein After determining the impedance property of the power line, the method further comprises: when the impedance property of the power line is resistance, calculating a first resistance value and a first electric reactance value of the power line according to the first impedance and the second impedance; wherein the first electric reactance value of the resistance power line is 0; when the impedance property of the power line is capacitance, calculating a second resistance value and a second electric reactance value of the power line according to the first impedance, the second impedance, the first frequency, the second frequency and a preset power frequency; when the impedance property of the power line is inductance, calculating a third resistance value and a third electric reactance value of the power line according to the first impedance, the second impedance, the first frequency, the second frequency and the preset power frequency.

5. A method of detecting a ground line of a power line according to claim 4, wherein The method of calculating a third impedance of the power line according to the impedance property of the power line, and calculating an electric reactance factor according to the third impedance specifically comprises: According to the resistance value and the reactance value corresponding to the impedance property of the power line, and a preset power frequency, a third impedance of the power line is calculated; wherein the resistance value comprises a first resistance value, a second resistance value or a third resistance value, and the reactance value comprises a first reactance value, a second reactance value or a third reactance value; According to the third impedance and the reactance value corresponding to the impedance property of the power line, a reactance factor corresponding to the power line is calculated.

6. A method of detecting a ground line of a power line according to claim 5, wherein The ground wire installation state of the power line is obtained according to the reactance factor, the third impedance and the impedance property, and specifically comprises: When the power line is capacitive, the ground wire installation state of the capacitive power line is obtained according to the reactance factor and the third impedance; When the power line is resistive or inductive, the ground wire installation state of the resistive or inductive power line is obtained according to the third impedance; The ground wire installation state comprises an uninstalled state and an installed state.

7. A method of detecting a ground line of a power line according to claim 6, wherein When the power line is capacitive, the ground wire installation state of the capacitive power line is obtained according to the reactance factor and the third impedance, and specifically comprises: When the power line is capacitive, the reactance factor corresponding to the power line is determined; If the reactance factor is greater than a preset threshold, it is determined that the ground wire installation state of the capacitive power line is in the uninstalled state; If the reactance factor is less than the preset threshold and the third impedance is greater than a preset resistance value, it is determined that the ground wire installation state of the capacitive power line is in the uninstalled state; If the reactance factor is less than the preset threshold and the third impedance is less than the preset resistance value, it is determined that the ground wire installation state of the capacitive power line is in the installed state.

8. The method of claim 6, wherein the step of detecting the ground line of the power line comprises the steps of: detecting the ground line of the power line by using a ground line detection circuit; and detecting the ground line of the power line by using a ground line detection circuit. When the power line is resistive or inductive, the ground wire installation state of the capacitive power line is obtained according to the third impedance, and specifically comprises: When the power line is resistive or inductive and the third impedance is greater than the preset resistance value, it is determined that the ground wire installation state of the capacitive power line is in the uninstalled state; When the power line is resistive or inductive and the third impedance is less than the preset resistance value, it is determined that the ground wire installation state of the capacitive power line is in the installed state.

9. A ground line detection device for a power line, characterized by It comprises: a measurement module, an impedance module, a calculation module and a state module; The measurement module is configured to measure a first impedance of the power line at a first measurement frequency and a first impedance of the power line at a second measurement frequency; The impedance module is configured to determine an impedance property of the power line according to the first measurement frequency and the corresponding first impedance, and the second measurement frequency and the corresponding second impedance; wherein the impedance property comprises resistance, capacitance and inductance; The calculation module is configured to calculate a third impedance of the power line according to the impedance property of the power line, and calculate a reactance factor according to the third impedance; The state module is configured to obtain the ground wire installation state of the power line according to the reactance factor, the third impedance and the impedance property.

Images