An insulation leakage monitoring device

Abstract

The embodiment of the application discloses an insulation electric leakage monitoring device, comprising: a Rogowski coil, a conditioning module, a comparison module and a processing module; the Rogowski coil is used for outputting a first voltage signal according to the real-time current of an insulator; the input end of the conditioning module is connected with the output end of the Rogowski coil, and is used for performing differential processing on the first voltage signal and outputting a second voltage signal; the input end of the comparison module is connected with the output end of the conditioning module, and is used for outputting a comparison signal according to the second voltage signal; the first input end of the processing module is connected with the output end of the comparison module, and is used for acquiring the comparison signal; the second input end is connected with the output end of the conditioning module, and is used for collecting the second voltage signal according to the comparison signal, and determining whether the insulator leaks according to the collection result. The above technical scheme realizes online monitoring of whether the insulator leaks, and improves the detection efficiency and detection accuracy of the insulator electric leakage.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric energy data monitoring, and in particular to an insulation leakage monitoring device. BACKGROUND

[0002] The insulators of overhead lines and other equipment are easily accumulated with dirt on the surface due to long-term exposure to the outside. When it is humid, rainy or snowy, the conductivity of the dirt on the surface of the insulator increases, so that the leakage current increases. This type of leakage current can cause different degrees of harm, such as transmission line tripping, and even cause personal harm in severe cases.

[0003] For example, monitoring the insulation leakage current on overhead lines, the current monitoring method is mainly offline, which cannot monitor the instantaneous and occasional leakage current and is not easy to install. Once the rainy day is over, the fault disappears, so that the specific fault point of the leakage cannot be determined when manually patrolling the line, and the leakage of the insulator cannot be monitored online. SUMMARY

[0004] The embodiment of the present application provides an insulation leakage monitoring device, which can monitor whether the insulator leaks online, improve the detection accuracy of the leakage, and reduce the operation and maintenance cost.

[0005] According to an aspect of the present application, an insulation leakage monitoring device is provided, comprising: a Rogowski coil, a conditioning module, a comparison module and a processing module;

[0006] The Rogowski coil is used to output a first voltage signal according to the real-time current of the insulator;

[0007] The input end of the conditioning module is connected with the output end of the Rogowski coil, and is used to perform differential processing on the first voltage signal and output a second voltage signal;

[0008] The input end of the comparison module is connected with the output end of the conditioning module, and is used to output a comparison signal according to the second voltage signal;

[0009] The first input end of the processing module is connected with the output end of the comparison module, and is used to obtain the comparison signal;

[0010] The second input end is connected with the output end of the conditioning module, and is used to collect the second voltage signal according to the comparison signal, and determine whether the insulator leaks according to the collection result.

[0011] Optionally, the conditioning module comprises a differential circuit;

[0012] The differential circuit comprises a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor and a first amplifier;

[0013] The output end of the Rogowski coil is connected with the first end of the first resistor, and the second end of the first resistor is connected with the first end of the first capacitor;

[0014] The non-inverting input end of the first amplifier is connected with the second end of the first capacitor and the first end of the second resistor respectively, the inverting input end of the first amplifier is connected with the first end of the second capacitor and the first end of the third resistor respectively, and the output end of the first amplifier is connected with the second end of the second resistor;

[0015] The second end of the second capacitor and the second end of the third resistor are grounded.

[0016] Optionally, the conditioning module further comprises an amplification circuit;

[0017] The amplification circuit comprises a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a second amplifier, a third amplifier and a fourth amplifier;

[0018] The negative output signal of the Rogowski coil is connected with the non-inverting input end of the second amplifier, and the positive output signal of the Rogowski coil is connected with the inverting input end of the third amplifier;

[0019] The inverting input end of the second amplifier is connected with the first end of the fourth resistor and the first end of the fifth resistor respectively, and the output end of the second amplifier is connected with the second end of the fourth resistor and the first end of the seventh resistor respectively;

[0020] The non-inverting input end of the third amplifier is connected with the second end of the fifth resistor and the first end of the sixth resistor respectively, and the output end of the third amplifier is connected with the second end of the sixth resistor and the first end of the eighth resistor respectively;

[0021] The non-inverting input end of the fourth amplifier is connected with the second end of the seventh resistor and the first end of the ninth resistor respectively, the inverting input end of the fourth amplifier is connected with the second end of the eighth resistor and the first end of the tenth resistor respectively, and the output end of the fourth amplifier is connected with the second end of the ninth resistor and the first end of the first resistor respectively;

[0022] The second end of the tenth resistor is grounded.

[0023] Optionally, the processing module further comprises an integration unit; wherein the integration unit comprises a first integration circuit and a second integration circuit;

[0024] The input end of the first integration circuit is connected with the output end of the conditioning module, for integrating the second voltage signal and outputting a third voltage signal;

[0025] The input end of the second integration circuit is connected with the output end of the first integration circuit, for integrating the third voltage signal and outputting a fourth voltage signal.

[0026] Optionally, the first integration circuit comprises an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a third capacitor, a fourth capacitor and a fifth amplifier.

[0027] The first end of the eleventh resistor is connected with the output end of the conditioning module, and the second end of the eleventh resistor is connected with the inverting input end of the fifth amplifier, the first end of the third capacitor and the first end of the twelfth resistor respectively.

[0028] The second end of the twelfth resistor is connected with the first end of the thirteenth resistor, the second end of the fourteenth resistor and the second end of the fourth capacitor respectively.

[0029] The output end of the fifth amplifier is connected with the second end of the third capacitor and the second end of the thirteenth resistor respectively, and the non-inverting input end of the fifth amplifier is grounded.

[0030] The first end of the fourth capacitor and the first end of the fourteenth resistor are grounded.

[0031] The second integration circuit comprises a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a fifth capacitor, a sixth capacitor and a sixth amplifier.

[0032] The output end of the fifth amplifier is connected with the first end of the fifteenth resistor, and the second end of the fifteenth resistor is connected with the inverting input end of the sixth amplifier, the first end of the fifth capacitor and the first end of the sixteenth resistor respectively.

[0033] The second end of the sixteenth resistor is connected with the first end of the seventeenth resistor, the second end of the eighteenth resistor and the second end of the sixth capacitor respectively.

[0034] The output end of the sixth amplifier is connected with the second end of the fifth capacitor and the second end of the seventeenth resistor respectively, and the non-inverting input end of the sixth amplifier is grounded.

[0035] The first end of the sixth capacitor and the first end of the eighteenth resistor are grounded.

[0036] Optionally, the processing module further comprises a pressure lifting circuit and an analog-digital conversion circuit.

[0037] An input end of the voltage lifting circuit is connected with an output end of the integration unit, for converting a negative voltage signal in the fourth voltage signal into a positive value, keeping a positive voltage signal in the fourth voltage signal unchanged, and outputting a fifth voltage signal;

[0038] An input end of the analog-digital conversion circuit is connected with an output end of the voltage lifting circuit, for converting the fifth voltage signal into a digital signal.

[0039] Optionally, the insulation leakage monitoring device further comprises a storage module;

[0040] The storage module is connected with the processing module, for storing the digital signal.

[0041] Optionally, the comparison module is configured to output a first comparison signal when the second voltage signal is higher than a voltage threshold value;

[0042] output a second comparison signal when the second voltage signal is lower than or equal to the voltage threshold value;

[0043] The processing module is configured to enter a wake-up state to collect the second voltage signal when the first comparison signal is acquired;

[0044] enter a sleep state to not collect the second voltage signal when the second comparison signal is acquired.

[0045] Optionally, the insulation leakage monitoring device further comprises a communication module;

[0046] The communication module connects the processing module with a terminal, for establishing a communication connection between the processing module and the terminal, so that the processing module transmits the insulation leakage information to the terminal.

[0047] Optionally, the insulation leakage monitoring device further comprises a power module;

[0048] The power module is connected with the Rogowski coil, the conditioning module, the comparison module and the processing module respectively, for providing electric energy for the Rogowski coil, the conditioning module, the comparison module and the processing module.

[0049] The Rogowski coil in the embodiment senses and outputs a first voltage signal which has a first-order derivative relationship with a real-time current of the insulator, the conditioning module outputs a second voltage signal which has a second-order derivative relationship with the real-time current of the insulator after performing differential processing on the first voltage signal, the second voltage signal is used as a comparison basis for the comparison module to generate a comparison signal, and thus the processing module collects the second voltage signal triggered by the comparison signal, so that the insulation leakage of the insulator is monitored online, and the detection efficiency and accuracy of the insulation leakage of the insulator are improved.

[0050] It should be understood that the matters described in this section are not intended to identify key or important features of the embodiments of the present application, nor are they intended to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0052] Figure 1 is a structural schematic diagram of an insulation leakage monitoring device provided by an embodiment of the present application;

[0053] Figure 2 is a partial structural schematic diagram of an insulation leakage monitoring device provided by an embodiment of the present application;

[0054] Figure 3 is a partial structural schematic diagram of another insulation leakage monitoring device provided by an embodiment of the present application;

[0055] Figure 4 is a partial structural schematic diagram of another insulation leakage monitoring device provided by an embodiment of the present application;

[0056] Figure 5 is a partial structural schematic diagram of another insulation leakage monitoring device provided by an embodiment of the present application;

[0057] Figure 6 is a partial structural schematic diagram of another insulation leakage monitoring device provided by an embodiment of the present application;

[0058] Figure 7 is a structural schematic diagram of another insulation leakage monitoring device provided by an embodiment of the present application;

[0059] Figure 8 is a structural schematic diagram of another insulation leakage monitoring device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0060] In order to make the technical personnel in the art better understand the present application scheme, the technical solutions in the embodiments of the present application will be described clearly and completely in the following with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0061] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, unless the context otherwise requires. The use of the terms "first", "second" and other such numberals does not imply a sequence or order unless specifically stated. It is to be understood that where the application is described herein as comprising or having parts such as elements, it is taken to mean that the application comprises elements, and there is no requirement that the elements be encased in a physical casing or that they be kept together in any way. It is to be understood that the data used herein can be interchanged, where appropriate, to enable the embodiments of the application described herein to be carried out in sequences other than those illustrated or described herein. Furthermore, the terms "comprise", "comprising", "include", "including" and "includes" are intended to be used as specific language to convey that the process, method, system, product, or apparatus that is described by the claims includes, but is not limited to, the stated features. It is to be understood that the terms "comprise", "comprising", "include", "including" and "includes" are not used in a restrictive sense, but are used in a permissive sense.

[0062] In the prior art, the detection of whether the insulator has current leakage is completed based on a Rogowski coil sensor. The Rogowski coil is used to collect the current at the insulator, and then the output voltage of the Rogowski coil is restored through an integral element to complete the measurement of the to-be-measured current. At this time, the size of the to-be-measured current (not containing a direct current component) is equal to the result of the integral of the output voltage of the Rogowski coil with respect to time multiplied by a coefficient. The restored output voltage is used as the judgment condition of a comparator trigger circuit. If the restored output voltage is higher than a set voltage value, it represents that the current at the insulator is too large, and current leakage occurs, and then a leakage alarm is triggered.

[0063] However, the insulation leakage current generally has a high-frequency characteristic and is a kind of fast discharge current. The rising edge part of this type of current is very similar to the rising edge part of the spike current and belongs to the fast rising type. The first link after the collection of the to-be-measured current by the above detection device is an integral element. Whether the to-be-measured current is a leakage current is judged through the restored voltage. However, this type of circuit will also output a voltage with a large amplitude for the collected spike current. If a comparator trigger circuit is connected subsequently, the false triggering phenomenon will be easily generated. In addition, the duration of part of the leakage current is short, and the rising edge part contains more complex current information. If the waveform of the leakage current is completely recorded after the judgment of the leakage of the insulator, and the rising edge part of the current waveform is collected, it is necessary to make a faster judgment and trigger the comparator. Therefore, an accurate and efficient detection device is needed to realize the leakage monitoring of the insulator on the overhead line.

[0064] Figure 1 is a structural schematic diagram of an insulator leakage monitoring device provided by an embodiment of the application. The embodiment can be applied to monitor the leakage of the insulator on the overhead line. Figure 1As shown, the insulation leakage monitoring device 100 comprises: a Rogowski coil 1, a conditioning module 2, a comparison module 3 and a processing module 4; the Rogowski coil 1 is used to output a first voltage signal according to the real-time current of the insulator; the input end of the conditioning module 2 is connected with the output end of the Rogowski coil 1, which is used to perform differential processing on the first voltage signal and output a second voltage signal; the input end of the comparison module 3 is connected with the output end of the conditioning module 2, which is used to output a comparison signal according to the second voltage signal; the first input end of the processing module 4 is connected with the output end of the comparison module 3, which is used to obtain the comparison signal; the second input end is connected with the output end of the conditioning module 2, which is used to collect the second voltage signal according to the comparison signal, and determine whether the insulator leaks according to the collection result.

[0065] Specifically, the Rogowski coil 1 is a hollow annular coil for measuring alternating current, which is made of a tightly wound wire. When monitoring insulation leakage, the Rogowski coil 1 is sleeved on the monitored insulator. Based on Faraday's law of electromagnetic induction and Ampere's law, when the real-time current of the insulator passes through the center of the Rogowski coil 1 along the axis, a corresponding changing magnetic field is generated in the volume surrounded by the annular winding, thereby inducing a first voltage signal corresponding to the real-time current at both ends of the Rogowski coil 1 and outputting, wherein the first voltage signal is proportional to the second derivative of the real-time current of the insulator with respect to time. The input end of the conditioning module 2 is connected with the output end of the Rogowski coil 1, which receives the first voltage signal output by the Rogowski coil 1, and performs differential processing on the first voltage signal through the conditioning module 2, to generate a second voltage signal that is a second derivative of the real-time current of the insulator and output. The input end of the comparison module 3 is connected with the output end of the conditioning module 2, and the comparison module 3 receives the second voltage signal output by the conditioning module 2 as a judgment unit, judges the condition of the second voltage signal based on a preset rule, and outputs a comparison signal corresponding to the condition of the second voltage signal. The first input end of the processing module 4 is connected with the output end of the comparison module 3, and the second input end is connected with the output end of the conditioning module 2. The processing module 4 receives the comparison signal output by the comparison module 3, and when the comparison signal meets a preset condition, it collects the second voltage signal through the second input end. After collecting the second voltage signal, it is analyzed through a corresponding algorithm to analyze the characteristics of the real-time current of the insulator, which can include the maximum value, the effective value, the duration, etc. Finally, through the analysis of the mathematical model, it is determined whether the real-time current is a leakage current. If the characteristics of the real-time current are the same as those in the mathematical model of the leakage current, the processing module 4 determines that the insulator leaks; if the characteristics of the real-time current are different from those in the mathematical model of the leakage current, the processing module 4 determines that the insulator does not leak.

[0066] It can be understood that when the insulator has a leakage fault, the current signal will change significantly in a very short time, and the second voltage signal which has a second-order derivative relationship with the real-time current of the insulator reflects the change of the change rate of the real-time current signal of the insulator, and the second voltage signal is used as the judgment basis of the comparison signal generated by the comparison module 3 to the collection action of the processing module 4, which helps to realize the fast response between the comparison module 3 and the processing module 4; at the same time, the second derivative amplitude of the glitch current is small, and the second voltage signal processed by the conditioning module 2 has a second-order derivative relationship with the real-time current of the insulator, which eliminates the interference of the glitch current in the comparison module 3, thereby avoiding the false triggering phenomenon of the comparison module 3 generating the comparison signal of the collection action of the processing module 4.

[0067] The first voltage signal having a first-order derivative relationship with the real-time current of the insulator is inducted and output by the Rogowski coil, and after the first voltage signal is differentiated by the conditioning module, the second voltage signal having a second-order derivative relationship with the real-time current of the insulator is output, and the second voltage signal is used as the comparison basis of the comparison signal generated by the comparison module, so that the processing module is triggered by the comparison signal to collect the second voltage signal, realizing online monitoring of whether the insulator has a leakage, and improving the detection efficiency and accuracy of the leakage of the insulator.

[0068] On the basis of the above embodiments, Figure 2 is a partial structure schematic diagram of an insulator leakage monitoring device provided by the embodiment of the application, Figure 2 The structure of the conditioning module in the insulator leakage monitoring device is described. Figure 2 As shown in the figure, the conditioning module 2 includes a differential circuit 211; the differential circuit 211 includes a first resistor R21, a second resistor R22, a third resistor R23, a first capacitor C21, a second capacitor C22 and a first amplifier A21; the output end of the Rogowski coil 1 is connected with the first end of the first resistor R21, the second end of the first resistor R21 is connected with the first end of the first capacitor C21; the inverting input end of the first amplifier A21 is connected with the second end of the first capacitor C21 and the first end of the second resistor R22 respectively, the non-inverting input end of the first amplifier A21 is connected with the first end of the second capacitor C22 and the first end of the third resistor R23 respectively, the output end of the first amplifier A21 is connected with the second end of the second resistor R22; the second end of the second capacitor C22 and the second end of the third resistor R23 are grounded.

[0069] Specifically, the first resistor R21 is a sampling resistor, the first end of the first resistor R21 is connected to the output end of the Rogowski coil 1, for converting the analog signal (i.e. the first voltage signal) output from the Rogowski coil 1 into a voltage signal, and transmitting the voltage signal to subsequent circuit components through the first resistor R21, to ensure that the circuit input end of the differential circuit 211 can reliably work under any condition, and to improve the stability of the differential circuit 211. The first capacitor C21 is an input capacitor, the first end of the first capacitor C21 is connected to the second end of the first resistor R21, and the second end of the first capacitor C21 is connected to the inverting input end of the first amplifier A21, for coupling the input signal from the first resistor R21, which helps to remove high-frequency noise, thereby improving the quality of the signal and ensuring the integrity and stability of the signal transmission to the first amplifier A21. The second resistor R22 is a feedback resistor, the first end of the second resistor R22 is connected to the inverting input end of the first amplifier A21, and the second end is connected to the output end of the first amplifier A21, for feeding back a part of the output signal of the first amplifier A21 to the inverting input end, to stabilize the working state of the amplifier, and the output end of the first amplifier A21 outputs a second voltage signal which has a second-order derivative relationship with the real-time current of the insulator according to the received first voltage signal. The second capacitor C22 is a compensation capacitor, and the third resistor R23 is a compensation resistor, the first end of the second capacitor C22 and the first end of the third resistor R23 are both connected to the non-inverting input end of the first amplifier A21, the second end of the second capacitor C22 and the second end of the third resistor R23 are both grounded, and the two are connected in parallel between the non-inverting input end of the first amplifier A21 and the ground end, for improving the stability of the differential circuit 211.

[0070] It should be noted that the accuracy of the differential circuit 211 in differentiating the first voltage signal is mainly determined by the differential constant (i.e. R22*C21), the degree to which the integrated operational amplifier satisfies the deep negative feedback, and the stability of the operational amplifier device. The stability and accuracy of the differential constant can be controlled by selecting high-precision, low-temperature-coefficient resistor and capacitor elements; and the accuracy and stability of the integrated operational amplifier device can be controlled by selecting high-precision, low-drift device.

[0071] In addition, the values of the second capacitor C22 and the third resistor R23 can also obtain higher detection accuracy, and the values of the two satisfy: C22 = (10*C21*R22) / R23.

[0072] It can be understood that, in addition to selecting appropriate parameter values of resistors and capacitors, the degree of deep negative feedback of the first amplifier A21 also needs to consider the working frequency of the circuit. When the working frequency increases, the open-loop gain of the operational amplifier decreases, the feedback coefficient decreases, and the feedback depth decreases, which will increase the operation error. When the working frequency decreases, the open-loop gain of the operational amplifier increases, and the feedback depth increases, which is beneficial to improve the operation accuracy.

[0073] The embodiment sets the differential circuit between the Rogowski coil and the comparison module, differentiates the first voltage signal related to the first-order derivative of the real-time current of the insulator, provides the second voltage signal related to the second-order derivative of the real-time current of the insulator as the first-level judgment data of whether the real-time current is the leakage current, and improves the detection accuracy of the insulator leakage.

[0074] Optionally, with reference to Figure 1 , the comparison module 3 is configured to output a first comparison signal when the second voltage signal is higher than a voltage threshold, and output a second comparison signal when the second voltage signal is lower than or equal to the voltage threshold; and the processing module 4 is configured to enter a wake-up state to collect the second voltage signal when the first comparison signal is acquired, and enter a sleep state to not collect the second voltage signal when the second comparison signal is acquired.

[0075] Specifically, the positive input port of the comparison module 3 inputs the second voltage signal output by the conditioning module 2, and the negative input port inputs the voltage threshold set in advance, where the voltage threshold can be a voltage signal related to the second-order derivative of the minimum current value of the insulator leakage. The comparison module 3 compares the sizes of the second voltage signal and the voltage threshold, and determines the type of the comparison signal according to the comparison result. When the second voltage signal is greater than the voltage threshold, it represents that the real-time current collected at the insulator at this time is greater than the minimum current value of the insulator leakage, and the insulator has a leakage situation. The comparison module 3 outputs the first comparison signal to the processing module 4, and the processing module 4 enters the wake-up state to collect the second voltage signal after receiving the first comparison signal, so as to realize the monitoring of the insulator leakage. When the second voltage signal is lower than or equal to the voltage threshold, it represents that the real-time current collected at the insulator at this time does not exceed the minimum current value of the insulator leakage, and the insulator does not have a leakage situation. The comparison module 3 outputs the second comparison signal to the processing module 4, and the processing module 4 enters the sleep state to not collect the second voltage signal after receiving the second comparison signal, so as to reduce the power consumption of the insulator leakage monitoring device.

[0076] Optionally, Figure 3 is another partial structure schematic diagram of the insulator leakage monitoring device provided by the embodiment of the present application, as shown in Figure 3As shown, the conditioning module further includes an amplification circuit; the amplification circuit includes a fourth resistor R11, a fifth resistor R12, a sixth resistor R13, a seventh resistor R14, an eighth resistor R15, a ninth resistor R16, a tenth resistor R17, a second amplifier A11, a third amplifier A12, and a fourth amplifier A13; the negative output signal of the Rogowski coil 1 is connected to the inverting input terminal of the second amplifier A11, and the positive output signal of the Rogowski coil 1 is connected to the non-inverting input terminal of the third amplifier A12; the non-inverting input terminal of the second amplifier A11 is connected to the first end of the fourth resistor R11 and the first end of the fifth resistor R12 respectively, and the output terminal of the second amplifier A11 is connected to the second end of the fourth resistor R11 and the first end of the seventh resistor R14 respectively; the inverting input terminal of the third amplifier A12 is connected to the second end of the fifth resistor R12 and the first end of the sixth resistor R13 respectively, and the output terminal of the third amplifier A12 is connected to the second end of the sixth resistor R13 and the first end of the eighth resistor R15 respectively; the inverting input terminal of the fourth amplifier A13 is connected to the second end of the seventh resistor R14 and the first end of the ninth resistor R16 respectively, the non-inverting input terminal of the fourth amplifier A13 is connected to the second end of the eighth resistor R15 and the first end of the tenth resistor R17 respectively, and the output terminal of the fourth amplifier A13 is connected to the second end of the ninth resistor R16 and the first end of the first resistor R1 respectively; the second end of the tenth resistor R17 is grounded.

[0077] Specifically, the first voltage signal sensed by the Rogowski coil 1 in relation to the first-order derivative of the real-time current of the insulator is very weak, and direct transmission or processing of such a signal may be disturbed by noise, affecting the accuracy of the measurement result, therefore the output signal negative of the Rogowski coil 1 is connected to the inverting input terminal of the second amplifier A11, and the output signal positive is connected to the non-inverting input terminal of the second amplifier A12, so as to transmit the first voltage signal to the amplification circuit. Through the fourth resistor R11, the fifth resistor R12, the sixth resistor R13, the seventh resistor R14, the eighth resistor R15, the ninth resistor R16, the tenth resistor R17, the second amplifier A11, the third amplifier A12, and the fourth amplifier A13 in the amplification circuit, the signal amplitude of the first voltage signal is amplified, making it easier to be processed by the subsequent differential circuit 211. In addition, since the real-time current of the insulator itself is very small, the first voltage signal sensed by the Rogowski coil 1 according to the real-time current is more susceptible to external electromagnetic interference, and through the processing of the amplification circuit, it helps to suppress noise, thereby improving the signal-to-noise ratio, more accurately restoring the true value of the real-time current of the insulator, and improving the accuracy of the insulator leakage detection.

[0078] It can be understood that, in order to reduce the power consumption of the amplification circuit, the resistance value in the amplification circuit should be selected to be large, the amplification factor of the amplification circuit is related to the resistance value of the fourth resistor R11 and the fifth resistor R12, the amplification factor of the input and output of the amplification circuit is (1+2*R11 / R12), the amplification factor cannot be too large, otherwise a large zero point error will be introduced; at the same time, in order to improve the accuracy of the amplification factor, the resistance can be selected to be a high-precision and low-temperature-drift type resistance, and the amplifier can be selected to be a high-precision operational amplifier.

[0079] For example, the resistance value of the fourth resistor R11 and the sixth resistor R13 in the amplification circuit can be 50KΩ, the resistance value of the seventh resistor R14, the eighth resistor R15, the ninth resistor R16 and the tenth resistor R17 can be 150KΩ, and the resistance value of the fifth resistor R12 can be 8.2KΩ. The above only exemplarily shows the resistance value in the amplification circuit of the insulation leakage monitoring device, which is not a specific limitation on the embodiments of the present application, and the resistance value can be adjusted according to the actual situation under the condition of meeting the amplification requirement of the insulation leakage monitoring device.

[0080] On the basis of the above embodiment, Figure 4 is another partial structure schematic diagram of the insulation leakage monitoring device provided by the embodiment of the present application, Figure 4 The structure of the processing module in the insulation leakage monitoring device is described. As shown in Figure 4 The processing module 4 further includes an integration unit 5; wherein the integration unit 5 includes a first integration circuit 51 and a second integration circuit 52; the input end of the first integration circuit 51 is connected with the output end of the conditioning module 2, for integrating and processing the second voltage signal and outputting a third voltage signal; the input end of the second integration circuit 52 is connected with the output end of the first integration circuit 51, for integrating and processing the third voltage signal and outputting a fourth voltage signal.

[0081] Specifically, after the second voltage signal which has a second-order derivative relationship with the real-time current of the insulator triggers the comparison module 3 to send a comparison signal for the processing module 4 to collect the second voltage signal, the processing module 4 receives the second voltage signal at this time by connecting the input end of the first integration circuit 51 with the output end of the conditioning module 2, integrates and processes the second voltage signal through the first integration circuit 51 to obtain a third voltage signal which has a first-order derivative relationship with the real-time current of the insulator. The third voltage signal is output from the first integration circuit 51 to the second integration circuit 52 through the connection between the output end of the first integration circuit 51 and the input end of the second integration circuit 52, so that the second integration circuit 52 integrates and processes the third voltage signal to obtain a fourth voltage signal which is proportional to the real-time current of the insulator, thereby realizing the collection of the real-time current of the insulator.

[0082] The second voltage signal processed by the conditioning module is integrated twice by the first integration circuit and the second integration circuit, the signal restoration of the second voltage signal which has a second-order derivative relationship with the real-time current of the insulator is realized, the collection of the real-time current is completed, the noise and interference signal in the second voltage signal are suppressed, and therefore the collection accuracy, stability of the real-time current and the monitoring accuracy of the insulation leakage are improved.

[0083] Optionally, Figure 5 is another partial structure schematic view of the insulation leakage monitoring device provided by the embodiment of the present application; Figure 6 is another partial structure schematic view of the insulation leakage monitoring device provided by the embodiment of the present application, as shown in Figure 5 and Figure 6 The first integration circuit 51 includes an eleventh resistor R31, a twelfth resistor R32, a thirteenth resistor R33, a fourteenth resistor R34, a third capacitor C31, a fourth capacitor C32 and a fifth amplifier A31; the first end of the eleventh resistor R31 is connected with the output end of the conditioning module 2, the second end of the eleventh resistor R31 is connected with the inverting input end of the fifth amplifier A31, the first end of the third capacitor C31 and the first end of the twelfth resistor R32 respectively; the second end of the twelfth resistor R32 is connected with the first end of the thirteenth resistor R33, the second end of the fourteenth resistor R34 and the second end of the fourth capacitor C32 respectively; the output end of the fifth amplifier A31 is connected with the second end of the third capacitor C31 and the second end of the thirteenth resistor R33 respectively, and the non-inverting input end of the fifth amplifier A31 is grounded; the first end of the fourth capacitor C32 and the first end of the fourteenth resistor R34 are grounded; the second integration circuit includes a fifteenth resistor R41, a sixteenth resistor R42, a seventeenth resistor R43, an eighteenth resistor R44, a fifth capacitor C41, a sixth capacitor C42 and a sixth amplifier A41; the output end of the fifth amplifier A31 is connected with the first end of the fifteenth resistor R41, the second end of the fifteenth resistor R41 is connected with the inverting input end of the sixth amplifier A41, the first end of the fifth capacitor C41 and the first end of the sixteenth resistor R42 respectively; the second end of the sixteenth resistor R42 is connected with the first end of the seventeenth resistor R43, the second end of the eighteenth resistor R44 and the second end of the sixth capacitor C42 respectively; the output end of the sixth amplifier A41 is connected with the second end of the fifth capacitor C41 and the second end of the seventeenth resistor R43 respectively, and the non-inverting input end of the sixth amplifier A41 is grounded; the first end of the sixth capacitor C42 and the first end of the eighteenth resistor R44 are grounded.

[0084] Specifically, the first end of the eleventh resistor R31 is connected with the output end of the conditioning module 2, and receives the second voltage signal output by the conditioning module 2. The third capacitor C31 is an integration capacitor. The time integration processing of the second voltage signal is realized through the eleventh resistor R31, the third capacitor C31 and the fifth amplifier A31, and then the third voltage signal is output at the output end of the fifth amplifier A31. The time constant of the first integration circuit 51 is determined by the eleventh resistor R31 and the third capacitor C31, and the time constant of the first integration circuit 51 is greater than or equal to 10 times the input time width. The cutoff frequency of the integration circuit is determined by the eleventh resistor R31 and the third capacitor C31, and the cutoff frequency is greater than the frequency of the second voltage signal. The twelfth resistor R32, the thirteenth resistor R33 and the fourteenth resistor R34 are feedback resistors. The T-shaped network composed of the three resistors can realize that a small resistance is selected to form a large resistance with high stability, which can not only prevent integration saturation, but also improve the frequency characteristics of the circuit at high frequencies. The fourth capacitor C32 is a feedback capacitor, which helps to stabilize the working state of the fifth amplifier A31 and prevent it from entering the illegal working state of cutoff or saturation.

[0085] The first end of the fifteenth resistor R41 is connected with the output end of the fifth amplifier A31, and receives the third voltage signal output by the first integration circuit 51. The fifth capacitor C41 is an integration capacitor. The time integration processing of the third voltage signal is realized through the fifteenth resistor R41, the fifth capacitor C41 and the sixth amplifier A41, and then the fourth voltage signal is output at the output end of the sixth amplifier A41. The time constant of the second integration circuit 52 is determined by the fifteenth resistor R41 and the fifth capacitor C41, and the time constant of the second integration circuit 52 is greater than or equal to 10 times the input time width. The cutoff frequency of the integration circuit is determined by the fifteenth resistor R41 and the fifth capacitor C41, and the cutoff frequency is greater than the frequency of the third voltage signal. The sixteenth resistor R42, the thirteenth resistor R43 and the fourteenth resistor R44 are feedback resistors. The T-shaped network composed of the three resistors can realize that a small resistance is selected to form a large resistance with high stability, which can not only prevent integration saturation, but also improve the frequency characteristics of the circuit at high frequencies. The sixth capacitor C42 is a feedback capacitor, which helps to stabilize the working state of the sixth amplifier A41 and prevent it from entering the illegal working state of cutoff or saturation.

[0086] Exemplarily, the third capacitor C31 and the fifth capacitor C41 can be selected as C0G or NP0 type capacitors, which are characterized by high precision and good temperature stability, so as to improve the stability of the first integration circuit 51 and the second integration circuit 52 and the accuracy of the integration processing. The T-type network structure formed by the twelfth resistor R32, the thirteenth resistor R33 and the fourteenth resistor R34, and the T-type network structure formed by the sixteenth resistor R42, the thirteenth resistor R43 and the fourteenth resistor R44 have equivalent resistances of (R32+R33+R32*R33 / R34) and (R42+R43+R42*R43 / R44) respectively. In order to achieve a better integration effect, the above two equivalent resistances should take a larger value, and therefore the resistance values of the eleventh resistor R31, the twelfth resistor R32, the thirteenth resistor R33, the sixteenth resistor R42, the thirteenth resistor R43 and the fourteenth resistor R44 can all be 10MΩ. The fifth amplifier A31 and the sixth amplifier A41 can be selected as low-bias voltage and high-precision types, and the gain bandwidth is at least 10 times the maximum working frequency required. The present embodiment does not make specific limitations on this.

[0087] Optionally, continuing to refer to Figure 4 , the processing module 4 further comprises a voltage lifting circuit 6 and an analog-digital conversion circuit 7. The input end of the voltage lifting circuit 6 is connected with the output end of the integration unit 5, for converting the negative voltage signal in the fourth voltage signal into a positive value and keeping the positive voltage signal in the fourth voltage signal unchanged, and outputting a fifth voltage signal. The input end of the analog-digital conversion circuit 7 is connected with the output end of the voltage lifting circuit 6, for converting the fifth voltage signal into a digital signal.

[0088] Specifically, the output of the integration unit 5 can contain negative voltage components, which can introduce nonlinear effects or reduce signal quality without processing. The voltage lifting circuit 6 processes the fourth voltage signal output by the integration unit 5, converts the negative voltage signal generated by the integration unit 5 into a positive voltage signal, keeps the positive voltage signal in the fourth voltage signal unchanged, and outputs a fifth voltage signal containing only positive voltage signals, ensuring that all signals are within the effective input range of the analog-digital conversion circuit 7, improving the overall quality of the signals and the accuracy of the real-time current sampling of the analog-digital conversion circuit 7.

[0089] Optionally, the insulation leakage monitoring device further comprises a storage module; the storage module is connected with the processing module 4, for storing the digital signal.

[0090] Specifically, the processing module 4 stores the collected digital signal of the real-time current of the insulator in the storage module, so that the staff can retrieve the historical data of the leakage of the insulator, quickly understand the past leakage of the insulator according to the historical data, analyze the trend and mode of the leakage of the insulator, thereby predicting possible future problems and taking preventive measures in advance, avoiding unnecessary maintenance work, improving maintenance efficiency, and reducing operation and maintenance cost. The storage module can be a FLASH chip, which is not limited in the embodiment.

[0091] On the basis of the above embodiment, Figure 7 is a structural schematic diagram of another insulator leakage monitoring device provided by the embodiment of the application, Figure 7 The communication module in the insulator leakage monitoring device is described. Figure 7 As shown in the figure, the insulator leakage monitoring device further comprises a communication module 8; the communication module 8 is connected with the processing module 4 and a terminal 9, and is used to establish a communication connection between the processing module 4 and the terminal 9, so that the processing module 4 transmits the leakage information of the insulator to the terminal 9.

[0092] Specifically, the processing module 4 collects the second voltage signal through the second input end, analyzes the second voltage signal after collecting it, analyzes the characteristics of the real-time current of the insulator through a corresponding algorithm, which can include the maximum value, the effective value, the duration, etc., and finally determines whether the real-time current is a leakage current through the analysis of the mathematical model. If the characteristics of the real-time current are the same as those in the mathematical model of the leakage current, the processing module 4 determines that the insulator has a leakage, and sends the information of the leakage of the insulator to the terminal 9 through the communication module 8. The communication module 8 can be a Narrow Band Internet of Things (NB-IoT) module or a Bluetooth communication module, which is not limited in the embodiment.

[0093] The embodiment realizes the information interaction between the insulator leakage monitoring device and the terminal through the communication module, so that the staff can obtain the alarm information of the leakage of the insulator in time, repair the faulty insulator, and improve the monitoring efficiency of the insulator and the operation and maintenance cost.

[0094] On the basis of the above embodiment, Figure 8 is a structural schematic diagram of another insulator leakage monitoring device provided by the embodiment of the application, Figure 8 The power module in the insulator leakage monitoring device is described. Figure 8 As shown in the figure, the insulator leakage monitoring device further comprises a power module 10; the power module 10 is connected with the Rogowski coil 1, the conditioning module 2, the comparison module 3 and the processing module 4 respectively, and is used to provide power for the Rogowski coil 1, the conditioning module 2, the comparison module 3 and the processing module 4.

[0095] Specifically, the power module 10 can be composed of a lithium battery, a solar photovoltaic panel and a power management chip. The power management chip is responsible for monitoring, controlling and protecting the lithium battery, ensuring the safety of the battery and the stability of the power supply of the insulation leakage device. In the case of abundant sunlight, the power generation efficiency of the photovoltaic panel is sufficient to meet the daily power demand of the insulation leakage device. At this time, the photovoltaic panel directly supplies power to the insulation leakage device. However, once the power demand of the insulation leakage device increases, the photovoltaic panel cannot maintain stable voltage output, and the power management chip will mobilize the lithium battery to cooperate in power supply to ensure the continuous and stable operation of the insulation leakage device. In addition, when the lithium battery power is lower than the safety threshold, the photovoltaic panel will automatically switch to charging mode to supplement the power of the lithium battery. In the face of thunderstorm weather or night period, the power generation efficiency of the photovoltaic panel decreases significantly, and it cannot meet the voltage requirement of the insulation leakage device. At this time, the lithium battery takes on the main responsibility of power supply to ensure the uninterrupted operation of the insulation leakage device.

[0096] The embodiment improves the stability and flexibility of the operation of the insulation leakage device by supplying power to each module of the insulation leakage device through the power module.

[0097] The above specific embodiments do not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An insulation leakage monitoring device, characterized by, The application relates to a leakage current detection device. The device comprises a Rogowski coil, a conditioning module, a comparison module and a processing module. The Rogowski coil is used for outputting a first voltage signal according to a real-time current of an insulator; An input end of the conditioning module is connected with an output end of the Rogowski coil, and the conditioning module is used for performing differential processing on the first voltage signal and outputting a second voltage signal in a second-order derivative relationship with the real-time current of the insulator, the second voltage signal being used as first-level judgment data of whether the real-time current is a leakage current; An input end of the comparison module is connected with an output end of the conditioning module, and the comparison module is used for outputting a comparison signal according to the second voltage signal; A first input end of the processing module is connected with an output end of the comparison module, and the processing module is used for acquiring the comparison signal; The processing module is triggered by the comparison signal to collect the second voltage signal; The processing module further comprises an integration unit, wherein the integration unit comprises a first integration circuit and a second integration circuit; An input end of the first integration circuit is connected with an output end of the conditioning module, and the first integration circuit is used for performing integration processing on the second voltage signal and outputting a third voltage signal; An input end of the second integration circuit is connected with an output end of the first integration circuit, and the second integration circuit is used for performing integration processing on the third voltage signal and outputting a fourth voltage signal, so as to realize collection of the real-time current of the insulator.

2. The insulation leakage monitoring device of claim 1, wherein, The conditioning module comprises a differential circuit; The differential circuit comprises a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor and a first amplifier; An output end of the Rogowski coil is connected with a first end of the first resistor, and a second end of the first resistor is connected with a first end of the first capacitor; An inverting input end of the first amplifier is connected with a second end of the first capacitor and a first end of the second resistor respectively, a non-inverting input end of the first amplifier is connected with a first end of the second capacitor and a first end of the third resistor respectively, and an output end of the first amplifier is connected with a second end of the second resistor; A second end of the second capacitor and a second end of the third resistor are grounded.

3. The insulation leakage monitoring device of claim 2, wherein, The conditioning module further comprises an amplification circuit; The amplification circuit comprises a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a second amplifier, a third amplifier and a fourth amplifier; A negative output signal of the Rogowski coil is connected with an inverting input end of the second amplifier, and a positive output signal of the Rogowski coil is connected with a non-inverting input end of the third amplifier; A non-inverting input end of the second amplifier is connected with a first end of the fourth resistor and a first end of the fifth resistor respectively, and an output end of the second amplifier is connected with a second end of the fourth resistor and a first end of the seventh resistor respectively; An inverting input end of the third amplifier is connected with a second end of the fifth resistor and a first end of the sixth resistor respectively, and an output end of the third amplifier is connected with a second end of the sixth resistor and a first end of the eighth resistor respectively; The non-inverting input end of the fourth amplifier is connected with the second end of the seventh resistor and the first end of the ninth resistor respectively, the inverting input end of the fourth amplifier is connected with the second end of the eighth resistor and the first end of the tenth resistor respectively, and the output end of the fourth amplifier is connected with the second end of the ninth resistor and the first end of the first resistor respectively; The second end of the tenth resistor is grounded.

4. The insulation leakage monitoring device of claim 3, wherein, The first integration circuit comprises an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a third capacitor, a fourth capacitor and a fifth amplifier; The first end of the eleventh resistor is connected with the output end of the conditioning module, and the second end of the eleventh resistor is connected with the non-inverting input end of the fifth amplifier, the first end of the third capacitor and the first end of the twelfth resistor respectively; The second end of the twelfth resistor is connected with the first end of the thirteenth resistor, the second end of the fourteenth resistor and the second end of the fourth capacitor respectively; The output end of the fifth amplifier is connected with the second end of the third capacitor and the second end of the thirteenth resistor respectively, and the inverting input end of the fifth amplifier is grounded; The first end of the fourth capacitor and the first end of the fourteenth resistor are grounded. The second integration circuit comprises a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a fifth capacitor, a sixth capacitor and a sixth amplifier; The output end of the fifth amplifier is connected with the first end of the fifteenth resistor, and the second end of the fifteenth resistor is connected with the non-inverting input end of the sixth amplifier, the first end of the fifth capacitor and the first end of the sixteenth resistor respectively; The second end of the sixteenth resistor is connected with the first end of the seventeenth resistor, the second end of the eighteenth resistor and the second end of the sixth capacitor respectively; The output end of the sixth amplifier is connected with the second end of the fifth capacitor and the second end of the seventeenth resistor respectively, and the inverting input end of the sixth amplifier is grounded; The first end of the sixth capacitor and the first end of the eighteenth resistor are grounded.

5. The insulation leakage monitoring device of claim 3, wherein, The processing module further comprises a pressure lifting circuit and an analog-to-digital conversion circuit; The input end of the pressure lifting circuit is connected with the output end of the integration unit, for converting the negative voltage signal in the fourth voltage signal into a positive value, keeping the positive voltage signal in the fourth voltage signal unchanged, and outputting a fifth voltage signal; The input end of the analog-to-digital conversion circuit is connected with the output end of the pressure lifting circuit, for converting the fifth voltage signal into a digital signal.

6. The insulation leakage monitoring device of claim 5, wherein, The insulation leakage monitoring device further comprises a storage module; The storage module is connected with the processing module, for storing the digital signal.

7. The insulation leakage monitoring device of claim 1, wherein, The comparison module is configured to output a first comparison signal when the second voltage signal is higher than a voltage threshold value; output a second comparison signal when the second voltage signal is lower than or equal to the voltage threshold value; The processing module is configured to enter a wake-up state to collect the second voltage signal when the first comparison signal is acquired; enter a sleep state to not collect the second voltage signal when the second comparison signal is acquired.

8. The insulation leakage monitoring device of claim 1, wherein, The insulation leakage monitoring device further comprises a communication module; The communication module connects the processing module and a terminal, and is used for establishing a communication connection between the processing module and the terminal, so that the processing module transmits the electric leakage information of the insulator to the terminal.

9. The insulation leakage monitoring device of claim 1, wherein, The insulator electric leakage monitoring device further comprises a power module. The power module is connected with the Rogowski coil, the conditioning module, the comparison module and the processing module respectively, and is used for providing electric energy for the Rogowski coil, the conditioning module, the comparison module and the processing module.

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