Insulation electric leakage monitoring device

Abstract

The embodiment of the invention discloses an insulation electric leakage monitoring device which 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 the real-time current of the insulator; the input end of the conditioning module is connected with the output end of the Rogowski coil, and the conditioning module is used for carrying out 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 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 is used for acquiring a comparison signal; and the second input end is connected with the output end of the conditioning module and is used for acquiring the second voltage signal according to the comparison signal and determining whether the insulator leaks electricity according to the acquisition result. According to the technical scheme, whether the insulator leaks electricity or not is monitored on line, and meanwhile the detection efficiency and detection accuracy of insulator electricity leakage are improved.

Description

Technical Field

[0001] The invention relates to the technical field of electric energy data monitoring, and in particular to an insulation leakage monitoring device. Background Art

[0002] Insulators of overhead lines and other equipment are exposed to the outside for a long time, and dirt easily accumulates on their surfaces. When it is humid, rainy or snowy, the dirt on the insulation surface increases its conductivity, resulting in an increase in leakage current. This type of leakage current can cause different degrees of harm, such as transmission line tripping, and in severe cases, personal injury.

[0003] For example, monitoring insulation leakage current on overhead lines, the current monitoring method is mainly offline, which cannot monitor instantaneous leakage current and is not easy to install. Once the rain is over, the fault disappears, resulting in the inability to determine the specific fault point of leakage during manual line inspection, and the insulator leakage cannot be monitored online. Summary of the invention

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

[0005] According to one aspect of the present invention, there is provided an insulation leakage monitoring device, 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 to 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 to 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 terminal of the processing module is connected to the output terminal of the comparison module, and is used to obtain the comparison signal;

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

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

[0012] The differential circuit includes 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 to the first end of the first resistor, and the second end of the first resistor is connected to the first end of the first capacitor;

[0014] The inverting input terminal of the first amplifier is connected to the second end of the first capacitor and the first end of the second resistor respectively, the non-inverting input terminal of the first amplifier is connected to the first end of the second capacitor and the first end of the third resistor respectively, and the output terminal of the first amplifier is connected to 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 includes an amplifying circuit;

[0017] The amplifying circuit includes 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 to the inverting input terminal of the second amplifier, and the positive output signal of the Rogowski coil is connected to the non-inverting input terminal of the third amplifier;

[0019] The in-phase input terminal of the second amplifier is respectively connected to the first terminal of the fourth resistor and the first terminal of the fifth resistor, and the output terminal of the second amplifier is respectively connected to the second terminal of the fourth resistor and the first terminal of the seventh resistor;

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

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

[0022] A second terminal of the tenth resistor is grounded.

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

[0024] The input end of the first integration circuit is connected to the output end of the conditioning module, and is used to integrate the second voltage signal and output a third voltage signal;

[0025] The input end of the second integration circuit is connected to the output end of the first integration circuit, and is used to integrate the third voltage signal and output a fourth voltage signal.

[0026] Optionally, the first integration circuit includes 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 to the output end of the conditioning module, and the second end of the eleventh resistor is respectively connected to the inverting input end of the fifth amplifier, the first end of the third capacitor and the first end of the twelfth resistor;

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

[0029] The output end of the fifth amplifier is connected to 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 includes 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 to the first end of the fifteenth resistor, and the second end of the fifteenth resistor is respectively connected to the inverting input end of the sixth amplifier, the first end of the fifth capacitor and the first end of the sixteenth resistor;

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

[0034] The output end of the sixth amplifier is connected to 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] A first end of the sixth capacitor and a first end of the eighteenth resistor are grounded.

[0036] Optionally, the processing module further includes a voltage boost circuit and an analog-to-digital conversion circuit;

[0037] The input end of the voltage boost circuit is connected to the output end of the integration unit, and is used to convert the negative voltage signal in the fourth voltage signal into a positive value, keep the positive voltage signal in the fourth voltage signal unchanged, and output a fifth voltage signal;

[0038] The input end of the analog-to-digital conversion circuit is connected to the output end of the voltage boost circuit, and is used to convert the fifth voltage signal into a digital signal.

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

[0040] The storage module is connected to the processing module and is used to store the digital signal.

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

[0042] When the second voltage signal is lower than or equal to the voltage threshold, outputting a second comparison signal;

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

[0044] When the second comparison signal is obtained, the sleep state is entered and the second voltage signal is not collected.

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

[0046] The communication module is connected to the processing module and the terminal, and is used to establish a communication connection between the processing module and the terminal, so that the processing module transmits the leakage information of the insulator to the terminal.

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

[0048] The power supply module is respectively connected to the Rogowski coil, the conditioning module, the comparison module and the processing module, and is used to provide electric energy to the Rogowski coil, the conditioning module, the comparison module and the processing module.

[0049] In this embodiment, a first voltage signal having a first-order derivative relationship with the real-time current of the insulator is sensed and outputted through a Rogowski coil. After the first voltage signal is differentiated by a conditioning module, a second voltage signal having a second-order derivative relationship with the real-time current of the insulator is outputted. The second voltage signal is used as a comparison basis for the comparison module to generate a comparison signal, so that the comparison signal triggers the processing module to collect the second voltage signal, thereby realizing online monitoring of whether the insulator has leakage, and improving the detection efficiency and accuracy of the insulator leakage.

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

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

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

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

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

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

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

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

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

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

[0060] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0061] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0062] In the prior art, the detection of whether the insulator has current leakage is completed based on the 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 the integration link to complete the measurement of the current to be measured. At this time, the magnitude of the current to be measured (excluding the DC component) is equal to the result of the integration of the output voltage of the Rogowski coil over time multiplied by a coefficient. The restored output voltage is used as the judgment condition of the comparator trigger circuit. If the restored output voltage is higher than the set voltage value, it means that the current at the insulator is too large and current leakage occurs, thereby triggering a leakage alarm.

[0063] However, insulation leakage current generally has high-frequency characteristics and is a fast-discharging current. The rising edge of this type of current is very similar to the rising edge of the glitch current, both of which are fast-rising types. The first link of the above-mentioned detection device after collecting the current to be measured is the integration link, which determines whether the current to be measured is a leakage current by the restored voltage. However, this type of circuit will also output a large-amplitude voltage for the collected glitch current. If it is subsequently connected to the comparator trigger circuit, it will easily cause false triggering. In addition, the duration of some leakage currents is short and the rising edge contains more complex current information. If you want to fully record the waveform of the leakage current after judging that the insulator has leakage, and reduce the missed collection of the rising edge current waveform due to judgment, you need to make a faster judgment and trigger the comparator. Therefore, an accurate and efficient detection device is needed to realize leakage monitoring of insulators on overhead lines.

[0064] Figure 1 is a schematic diagram of the structure of an insulation leakage monitoring device provided by an embodiment of the present invention. This embodiment can be applied to monitoring the leakage of insulators on overhead lines, such as Figure 1As shown, the insulation leakage monitoring device 100 includes: 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 to the output end of the Rogowski coil 1, and 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 to the output end of the conditioning module 2, and is used to output a comparison signal according to the second voltage signal; the first input end of the processing module 4 is connected to the output end of the comparison module 3, and is used to obtain a comparison signal; the second input end is connected to the output end of the conditioning module 2, and is used to collect the second voltage signal according to the comparison signal, and determine whether the insulator has leakage 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 performing insulation leakage monitoring, the Rogowski coil 1 is placed around the monitored insulator. Based on Faraday's law of electromagnetic induction and Ampere's loop law, when the real-time current of the insulator passes through the center of the Rogowski coil 1 along the axis, a correspondingly changing magnetic field is generated in the volume surrounded by the annular winding, so that a first voltage signal corresponding to the real-time current is induced at both ends of the Rogowski coil 1 and output, wherein the first voltage signal is proportional to the differential of the real-time current of the insulator with respect to time. The input end of the conditioning module 2 is connected to the output end of the Rogowski coil 1, 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, generates a second voltage signal having a second-order derivative relationship with the real-time current of the insulator, and outputs it. The input end of the comparison module 3 is connected to the output end of the conditioning module 2. The comparison module 3 receives the second voltage signal output by the conditioning module 2 as a judgment unit, judges the situation of the second voltage signal based on a preset rule, and outputs a comparison signal corresponding to the situation of the second voltage signal. The first input end of the processing module 4 is connected to the output end of the comparison module 3, and the second input end is connected to 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 the preset condition, the second voltage signal is collected through the second input end, and the second voltage signal is analyzed after being collected. The characteristics of the real-time current of the insulator are analyzed through the corresponding algorithm, which may include the maximum value, effective value, duration, etc. Finally, the real-time current is determined to be a leakage current through the analysis of the mathematical model. If the characteristics of the real-time current are the same as the characteristics in the leakage current mathematical model, the processing module 4 determines that the insulator has leakage; if the characteristics of the real-time current are different from the characteristics in the leakage current mathematical model, the processing module 4 determines that the insulator has no leakage.

[0066] It is understandable that when an insulator has a leakage fault, the current signal will change significantly in a very short period of time. The second voltage signal, which is in a second-order derivative relationship with the real-time current of the insulator, just reflects the change in the rate of change of the real-time current signal of the insulator. By utilizing the characteristics of the leakage signal, the second voltage signal is used as the judgment basis for the comparison module 3 to generate a comparison signal for the processing module 4 to perform a collection action, which helps to achieve a rapid response between the comparison module 3 and the processing module 4; at the same time, the amplitude of the secondary derivative of the glitch current is small, and the second voltage signal processed by the conditioning module 2 is in 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 a comparison signal for the processing module 4 to perform a collection action caused by the glitch current.

[0067] In this embodiment, a first voltage signal having a first-order derivative relationship with the real-time current of the insulator is sensed and outputted through a Rogowski coil. After the first voltage signal is differentiated by a conditioning module, a second voltage signal having a second-order derivative relationship with the real-time current of the insulator is outputted. The second voltage signal is used as a comparison basis for the comparison module to generate a comparison signal, so that the comparison signal triggers the processing module to collect the second voltage signal, thereby realizing online monitoring of whether the insulator has leakage, and improving the detection efficiency and accuracy of the insulator leakage.

[0068] Based on the above embodiments, Figure 2 is a partial structural diagram of an insulation leakage monitoring device provided by an embodiment of the present invention, Figure 2 The structure of the conditioning module in the insulation leakage monitoring device is described. Figure 2 As shown, 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 to the first end of the first resistor R21, and the second end of the first resistor R21 is connected to the first end of the first capacitor C21; the inverting input end of the first amplifier A21 is respectively connected to the second end of the first capacitor C21 and the first end of the second resistor R22, the non-inverting input end of the first amplifier A21 is respectively connected to the first end of the second capacitor C22 and the first end of the third resistor R23, and the output end of the first amplifier A21 is connected to 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, and the first end of the first resistor R21 is connected to the output end of the Rogowski coil 1, and is used to convert the analog signal (i.e., the first voltage signal) output from the Rogowski coil 1 into a voltage signal, and transmit it to subsequent circuit components through the first resistor R21, so as to ensure that the circuit input end of the differential circuit 211 can work reliably under any conditions, and improve the stability of the differential circuit 211. The first capacitor C21 is an input capacitor, and 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, and is used to couple 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 transmitted 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, and is used to feed 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 that is in 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 in-phase input end of the first amplifier A21, and the second end of the second capacitor C22 and the second end of the third resistor R23 are both grounded. After being connected in parallel, the two are connected between the in-phase input end and the ground end of the first amplifier A21, and are used to improve the stability of the differential circuit 211.

[0070] It should be noted that the accuracy of the differential processing performed by the differential circuit 211 on the first voltage signal is mainly determined by the differential constant (i.e., R22*C21), the satisfaction degree of the deep negative feedback of the integrated operational amplifier, and the stability of the operational amplifier device. The stability and accuracy of the differential constant can be controlled by selecting high-precision, small temperature coefficient resistors and capacitors; the accuracy and stability of the integrated operational amplifier device can be improved by selecting high-precision, low-drift devices.

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

[0072] It can be understood that the depth of negative feedback of the first amplifier A21 should not only consider the parameter values ​​of the appropriate resistor and capacitor, but also the operating frequency of the circuit. As the operating 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 operating frequency decreases, the open-loop gain of the operational amplifier increases, and the feedback depth increases, which is conducive to improving the operation accuracy.

[0073] This embodiment arranges a differential circuit between the Rogowski coil and the comparison module, performs differential processing on the first voltage signal that is in a first-order derivative relationship with the insulator real-time current, and provides a second voltage signal that is in a second-order derivative relationship with the insulator real-time current as the first-level judgment data of whether the real-time current is a leakage current, thereby improving the detection accuracy of the insulator leakage.

[0074] Optional, continue to refer to Figure 1 The comparison module 3 is used to output a first comparison signal when the second voltage signal is higher than the voltage threshold; and output a second comparison signal when the second voltage signal is lower than or equal to the voltage threshold; the processing module 4 is used to enter a wake-up state when the first comparison signal is obtained and collect the second voltage signal; and enter a sleep state when the second comparison signal is obtained and does not collect the second voltage signal.

[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 value set in advance, wherein the voltage threshold value may be a voltage signal that is in a second-order derivative relationship with the minimum current value of the insulator leakage. The comparison module 3 compares the magnitude of the second voltage signal and the voltage threshold value, and determines the type of the output comparison signal according to the comparison result. When the second voltage signal is greater than the voltage threshold value, it means that the real-time current at the insulator collected at this time is greater than the minimum current value of the insulator leakage, and the insulator has leakage. The comparison module 3 outputs a first comparison signal to the processing module 4. After receiving the first comparison signal, the processing module 4 enters a wake-up state and collects the second voltage signal to realize the monitoring of insulation leakage. When the second voltage signal is lower than or equal to the voltage threshold value, it means that the real-time current at the insulator collected at this time does not exceed the minimum current value of the insulator leakage, and the insulator has not leaked. The comparison module 3 outputs a second comparison signal to the processing module 4. After receiving the second comparison signal, the processing module 4 enters a dormant state and does not collect the second voltage signal, thereby reducing the power consumption of the insulation leakage monitoring device.

[0076] Optional, Figure 3 FIG. 1 is a partial structural diagram of another insulation leakage monitoring device provided by an embodiment of the present invention. Figure 3As shown, the conditioning module also includes an amplifier circuit; the amplifier 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 respectively connected to the first end of the fourth resistor R11 and the first end of the fifth resistor R12, and the output terminal of the second amplifier A11 is respectively connected to the second end of the fourth resistor R11 and the seventh resistor R13. The inverting input terminal of the third amplifier A12 is respectively connected to the second end of the fifth resistor R12 and the first end of the sixth resistor R13, and the output terminal of the third amplifier A12 is respectively connected to the second end of the sixth resistor R13 and the first end of the eighth resistor R15; the inverting input terminal of the fourth amplifier A13 is respectively connected to the second end of the seventh resistor R14 and the first end of the ninth resistor R16, the non-inverting input terminal of the fourth amplifier A13 is respectively connected to the second end of the eighth resistor R15 and the first end of the tenth resistor R17, and the output terminal of the fourth amplifier A13 is respectively connected to the second end of the ninth resistor R16 and the first end of the first resistor; the second end of the tenth resistor R17 is grounded.

[0077] Specifically, the first voltage signal induced by the Rogowski coil 1, which is in a first-order derivative relationship with the real-time current of the insulator, is very weak. Direct transmission or processing of such a signal may be interfered by noise, affecting the accuracy of the measurement result. Therefore, the output signal negative electrode of the Rogowski coil 1 is connected to the inverting input terminal of the second amplifier A11, and the output signal positive electrode is connected to the non-inverting input terminal of the second amplifier A12, so that the first voltage signal is transmitted to the amplifier 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 amplifier circuit, the signal amplitude of the first voltage signal is amplified, so that it is 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 induced by the Rogowski coil 1 according to the real-time current is more susceptible to external electromagnetic interference. Through the processing of the amplifier circuit, it is helpful to suppress noise, thereby improving the signal-to-noise ratio, more accurately restore the true value of the real-time current of the insulator, and improve the accuracy of the insulator leakage detection.

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

[0079] Exemplarily, the resistance of the fourth resistor R11 and the sixth resistor R13 in the amplifier circuit can be 50KΩ, the resistance of the seventh resistor R14, the eighth resistor R15, the ninth resistor R16 and the tenth resistor R17 can be 150KΩ, and the resistance of the fifth resistor R12 can be 8.2KΩ. The above only exemplarily shows a value of each resistor in the amplifier circuit that can meet the insulation leakage monitoring device, and is not a specific limitation of the embodiment of the present invention. The value of each resistor can be adjusted according to the actual situation while meeting the amplification requirements of the insulation leakage monitoring device.

[0080] Based on the above embodiments, Figure 4 is a partial structural diagram of another insulation leakage monitoring device provided by an embodiment of the present invention, Figure 4 The structure of the processing module in the insulation leakage monitoring device is described. Figure 4 As shown, the processing module 4 also 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 to the output end of the conditioning module 2, for integrating the second voltage signal and outputting a third voltage signal; the input end of the second integration circuit 52 is connected to the output end of the first integration circuit 51, for integrating the third voltage signal and outputting a fourth voltage signal.

[0081] Specifically, when the second voltage signal that is in a second-order derivative relationship with the real-time current of the insulator triggers the comparison module 3 to send a comparison signal that instructs 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 to the output end of the conditioning module 2, and integrates the second voltage signal through the first integration circuit 51 to obtain a third voltage signal that is in a first-order derivative relationship with the real-time current of the insulator. By connecting the output end of the first integration circuit 51 with the input end of the second integration circuit 52, the third voltage signal is output from the first integration circuit 51 to the second integration circuit 52, so that the second integration circuit 52 integrates the third voltage signal to obtain a fourth voltage signal that is proportional to the real-time current of the insulator, thereby realizing the collection of the real-time current of the insulator.

[0082] This embodiment uses the first integration circuit and the second integration circuit to perform two consecutive integration processes on the second voltage signal processed by the conditioning module, thereby realizing signal restoration of the second voltage signal that is in a second-order derivative relationship with the real-time current of the insulator, completing the collection of the real-time current, and suppressing noise and interference signals in the second voltage signal, thereby improving the collection accuracy and stability of the real-time current and the monitoring accuracy of insulation leakage.

[0083] Optional, Figure 5 It is a partial structural schematic diagram of another insulation leakage monitoring device provided by an embodiment of the present invention; Figure 6 FIG. 1 is a partial structural diagram of another insulation leakage monitoring device provided by an embodiment of the present invention. Figure 5 and Figure 6 As shown, 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 to the output end of the conditioning module 2, and the second end of the eleventh resistor R31 is respectively connected to 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; the second end of the twelfth resistor R32 is respectively connected to 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; the output end of the fifth amplifier A31 is respectively connected to the second end of the third capacitor C31 and the second end of the thirteenth resistor R33, 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 to the first end of the fifteenth resistor R41, and the second end of the fifteenth resistor R41 is respectively connected to 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; the second end of the sixteenth resistor R42 is respectively connected to 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; the output end of the sixth amplifier A41 is respectively connected to the second end of the fifth capacitor C41 and the second end of the seventeenth resistor R43, 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 eleventh resistor R31 in the first integration circuit 51 is an integration resistor, the first end of the eleventh resistor R31 is connected to 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 by 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. Among them, the eleventh resistor R31 and the third capacitor C31 determine the time constant of the first integration circuit 51, and the time constant of the first integration circuit 51 is greater than or equal to 10 times the input time width, and the eleventh resistor R31 and the third capacitor C31 determine the cutoff frequency of the integration circuit, ensuring that 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-type network formed by the three can realize the selection of resistors with smaller resistance values ​​to form a large resistor with high stability, which can not only prevent integral 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 an illegal working state of cutoff or saturation.

[0085] The fifteenth resistor R41 in the second integration circuit 52 is an integration resistor, and the first end of the fifteenth resistor R41 is connected to the output end of the fifth amplifier A31 to receive 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. Among them, the fifteenth resistor R41 and the fifth capacitor C41 determine the time constant of the second integration circuit 52, and the time constant of the second integration circuit 52 must be greater than or equal to 10 times the input time width, and the fifteenth resistor R41 and the fifth capacitor C41 determine the cutoff frequency of the integration circuit to ensure that 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-type network formed by the three can realize the selection of resistors with smaller resistance values ​​to form a large resistor with high stability, which can not only prevent integral 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 an illegal working state of cutoff or saturation.

[0086] Exemplarily, the third capacitor C31 and the fifth capacitor C41 may be 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 composed of the twelfth resistor R32, the thirteenth resistor R33 and the fourteenth resistor R34, and the T-type network structure composed of 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 values ​​of the above two equivalent resistances should be larger. 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 select low bias voltage and high precision types, and the gain bandwidth is at least 10 times the required maximum operating frequency. This embodiment does not make specific limitations on this.

[0087] Optional, continue to refer to Figure 4 The processing module 4 also includes a voltage boosting circuit 6 and an analog-to-digital conversion circuit 7; the input end of the voltage boosting circuit 6 is connected to the output end of the integration unit 5, and is used to convert the negative voltage signal in the fourth voltage signal into a positive value, and keep the positive voltage signal in the fourth voltage signal unchanged, and output a fifth voltage signal; the input end of the analog-to-digital conversion circuit 7 is connected to the output end of the voltage boosting circuit 6, and is used to convert the fifth voltage signal into a digital signal.

[0088] Specifically, the output of the integration unit 5 may contain negative voltage components, which may introduce nonlinear effects or reduce signal quality if not processed. The fourth voltage signal output by the integration unit 5 is processed by the voltage-boosting circuit 6, and the negative voltage signal generated by the integration unit 5 is converted into a positive voltage signal, while the positive voltage signal in the fourth voltage signal is kept unchanged, and a fifth voltage signal containing only positive voltage signals is output, ensuring that all signals are within the effective input range of the analog-to-digital conversion circuit 7, thereby improving the overall quality of the signal and the accuracy of the analog-to-digital conversion circuit 7 in real-time current sampling.

[0089] Optionally, the insulation leakage monitoring device further includes a storage module; the storage module is connected to the processing module 4 and is used to store digital signals.

[0090] Specifically, the processing module 4 stores the collected digital signal about the real-time current of the insulator in the storage module, so that the staff can retrieve the historical data of the insulator leakage, quickly understand the past leakage of the insulator based on the historical data, analyze the trend and pattern of the insulator leakage, and thus predict possible problems in the future, and take preventive measures in advance to avoid unnecessary maintenance work, improve maintenance efficiency, and reduce operation and maintenance costs. Exemplarily, the storage module can be a FLASH chip, which is not specifically limited in this embodiment.

[0091] Based on the above embodiments, Figure 7 is a structural schematic diagram of another insulation leakage monitoring device provided by an embodiment of the present invention, Figure 7 The communication module in the insulation leakage monitoring device is explained. Figure 7 As shown, the insulation leakage monitoring device also includes a communication module 8; the communication module 8 connects the processing module 4 and the 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 terminal, analyzes the second voltage signal after collecting it, analyzes the characteristics of the real-time current of the insulator through the corresponding algorithm, which may include the maximum value, effective value, 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 the characteristics in the leakage current mathematical model, the processing module 4 determines that the insulator has leakage, and sends the information of the insulator leakage to the terminal 9 through the communication module 8. Exemplarily, the communication module 8 can be a narrowband Internet of Things (NB-IoT) module or a Bluetooth communication module, which is not specifically limited in this embodiment.

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

[0094] Based on the above embodiments, Figure 8 is a structural schematic diagram of another insulation leakage monitoring device provided by an embodiment of the present invention, Figure 8 The power module in the insulation leakage monitoring device is described. Figure 8 As shown, the insulation leakage monitoring device also includes a power supply module 10; the power supply module 10 is respectively connected to the Rogowski coil 1, the conditioning module 2, the comparison module 3 and the processing module 4, and is used to provide power to 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 to ensure the safety of the battery and the stability of the power supply of the insulating 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 insulating leakage device. At this time, the photovoltaic panel directly supplies power to the insulating leakage device. However, once the power demand of the insulating leakage device increases, the photovoltaic panel cannot maintain a stable voltage output, and the power management chip will mobilize the lithium battery to provide power in coordination to ensure the continuous and stable operation of the insulating leakage device. In addition, when the power of the lithium battery is lower than the safety threshold, the photovoltaic panel will automatically switch to charging mode to replenish power for the lithium battery. In the face of thunderstorms or night time, the power generation efficiency of the photovoltaic panel drops significantly and cannot meet the voltage requirements of the insulating leakage device. At this time, the lithium battery assumes the main power supply responsibility to ensure the uninterrupted operation of the insulating leakage device.

[0096] In this embodiment, the power module supplies power to each module of the insulation leakage device, thereby improving the stability and flexibility of the operation of the insulation leakage device.

[0097] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An insulation leakage monitoring device, characterized in that: include: Rogowski coil, conditioning module, comparison module and processing module; The Rogowski coil is used to output a first voltage signal according to the real-time current of the insulator; The input end of the conditioning module is connected to 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; The input end of the comparison module is connected to the output end of the conditioning module, and is used to output a comparison signal according to the second voltage signal; The first input terminal of the processing module is connected to the output terminal of the comparison module, and is used to obtain the comparison signal; The second input terminal is connected to the output terminal of the conditioning module, and is used to collect the second voltage signal according to the comparison signal, and determine whether the insulator has leakage according to the collection result.

2. The insulation leakage monitoring device according to claim 1, characterized in that: The conditioning module includes a differential circuit; The differential circuit includes a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor and a first amplifier; The output end of the Rogowski coil is connected to the first end of the first resistor, and the second end of the first resistor is connected to the first end of the first capacitor; The inverting input terminal of the first amplifier is connected to the second end of the first capacitor and the first end of the second resistor respectively, the non-inverting input terminal of the first amplifier is connected to the first end of the second capacitor and the first end of the third resistor respectively, and the output terminal of the first amplifier is connected to the second end of the second resistor; The second end of the second capacitor and the second end of the third resistor are grounded.

3. The insulation leakage monitoring device according to claim 2, characterized in that: The conditioning module also includes an amplifying circuit; The amplifying circuit includes 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; The negative output signal of the Rogowski coil is connected to the inverting input terminal of the second amplifier, and the positive output signal of the Rogowski coil is connected to the non-inverting input terminal of the third amplifier; The in-phase input terminal of the second amplifier is respectively connected to the first terminal of the fourth resistor and the first terminal of the fifth resistor, and the output terminal of the second amplifier is respectively connected to the second terminal of the fourth resistor and the first terminal of the seventh resistor; The inverting input terminal of the third amplifier is respectively connected to the second end of the fifth resistor and the first end of the sixth resistor, and the output terminal of the third amplifier is respectively connected to the second end of the sixth resistor and the first end of the eighth resistor; The inverting input terminal of the fourth amplifier is respectively connected to the second end of the seventh resistor and the first end of the ninth resistor, the non-inverting input terminal of the fourth amplifier is respectively connected to the second end of the eighth resistor and the first end of the tenth resistor, and the output terminal of the fourth amplifier is respectively connected to the second end of the ninth resistor and the first end of the first resistor; A second terminal of the tenth resistor is grounded.

4. The insulation leakage monitoring device according to claim 1, characterized in that: The processing module further comprises an integration unit; wherein the integration unit comprises a first integration circuit and a second integration circuit; The input end of the first integration circuit is connected to the output end of the conditioning module, and is used to integrate the second voltage signal and output a third voltage signal; The input end of the second integration circuit is connected to the output end of the first integration circuit, and is used to integrate the third voltage signal and output a fourth voltage signal.

5. The insulation leakage monitoring device according to claim 4, characterized in that: The first integration circuit includes 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 to the output end of the conditioning module, and the second end of the eleventh resistor is respectively connected to the inverting input end of the fifth amplifier, the first end of the third capacitor and the first end of the twelfth resistor; The second end of the twelfth resistor is respectively connected to the first end of the thirteenth resistor, the second end of the fourteenth resistor and the second end of the fourth capacitor; The output end of the fifth amplifier is connected to 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; The first end of the fourth capacitor and the first end of the fourteenth resistor are grounded; The second integration circuit includes 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 to the first end of the fifteenth resistor, and the second end of the fifteenth resistor is respectively connected to the inverting input end of the sixth amplifier, the first end of the fifth capacitor and the first end of the sixteenth resistor; The second end of the sixteenth resistor is respectively connected to the first end of the seventeenth resistor, the second end of the eighteenth resistor and the second end of the sixth capacitor; The output end of the sixth amplifier is connected to 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; A first end of the sixth capacitor and a first end of the eighteenth resistor are grounded.

6. The insulation leakage monitoring device according to claim 4, characterized in that: The processing module also includes a voltage boost circuit and an analog-to-digital conversion circuit; The input end of the voltage boost circuit is connected to the output end of the integration unit, and is used to convert the negative voltage signal in the fourth voltage signal into a positive value, keep the positive voltage signal in the fourth voltage signal unchanged, and output a fifth voltage signal; The input end of the analog-to-digital conversion circuit is connected to the output end of the voltage boost circuit, and is used to convert the fifth voltage signal into a digital signal.

7. The insulation leakage monitoring device according to claim 6, characterized in that: The insulation leakage monitoring device also includes a storage module; The storage module is connected to the processing module and is used to store the digital signal.

8. The insulation leakage monitoring device according to claim 1, characterized in that: The comparison module is used for outputting a first comparison signal when the second voltage signal is higher than a voltage threshold; When the second voltage signal is lower than or equal to the voltage threshold, outputting a second comparison signal; The processing module is used to enter a wake-up state and collect the second voltage signal when the first comparison signal is obtained; When the second comparison signal is obtained, the sleep state is entered and the second voltage signal is not collected.

9. The insulation leakage monitoring device according to claim 1, characterized in that: The insulation leakage monitoring device also includes a communication module; The communication module is connected to the processing module and the terminal, and is used to establish a communication connection between the processing module and the terminal, so that the processing module transmits the leakage information of the insulator to the terminal.

10. The insulation leakage monitoring device according to claim 1, characterized in that: The insulation leakage monitoring device also includes a power supply module; The power supply module is respectively connected to the Rogowski coil, the conditioning module, the comparison module and the processing module, and is used to provide electric energy to the Rogowski coil, the conditioning module, the comparison module and the processing module.

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