CN216696530U

CN216696530U - Accurate positioning device for cable fault

Info

Publication number: CN216696530U
Application number: CN202122989298.1U
Authority: CN
Inventors: 郭洪林; 伊洪全
Original assignee: Beijing Picohood Technology Co ltd
Current assignee: Beijing Picohood Technology Co ltd
Priority date: 2021-12-01
Filing date: 2021-12-01
Publication date: 2022-06-07
Anticipated expiration: 2031-12-01

Abstract

A cable fault pinpointing device, comprising: the system comprises an A phase line traveling wave data monitoring module, a B phase line traveling wave data monitoring module, a C phase line traveling wave data monitoring module, an A phase line power frequency data monitoring module, a B phase line power frequency data monitoring module, a C phase line power frequency data monitoring module, an A phase line grounding loop data monitoring module, a B phase line grounding loop data monitoring module, a C phase line grounding loop data monitoring module, an N grounding line grounding loop data monitoring module, a data acquisition and analysis module and a data uploading module; the two ends of the phase line A are respectively provided with an A phase line traveling wave data monitoring module, the two ends of the phase line B are respectively provided with a B phase line traveling wave data monitoring module, and the two ends of the phase line C are respectively provided with a C phase line traveling wave data monitoring module; and the traveling wave data monitoring signal output end of each A, B, C phase line traveling wave data monitoring module is connected with the corresponding A, B, C phase line traveling wave data monitoring signal input end of the data acquisition and analysis module.

Description

Accurate positioning device for cable fault

Technical Field

The utility model relates to the power industry, in particular to a cable fault accurate positioning device in a power transmission line.

Background

The economy of China is stably and rapidly developed, the national defense and the civil life are increasingly powerful, all walks of life of China are also rapidly developed, and the electric power industry is used for supporting the development of all walks of life of China. With the development of the power industry, power systems in China are becoming more and more large and complex, how to effectively monitor and manage the power systems is increasingly receiving attention of the power department, wherein in order to quickly and efficiently relieve the faults of cables in power transmission lines, the accurate positioning of the cable faults becomes the problem which needs to be solved at present.

The current solution is intrusive, namely, a tested cable can be monitored only by being connected into the testing equipment, the fault type of the cable is monitored singly, most of the fault types are monitored by single functions, and the current solution only adopts some simple fault signal monitoring circuits, is low in reduction degree and accuracy of fault waveforms and comprises amplitude, phase and the like. This also results in a large error in calculating the cable fault point location.

The existing technical scheme has large judgment error on cable fault points, usually more than ten meters, and brings much trouble to the maintenance and repair of cables.

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problem, the utility model provides a cable fault accurate positioning device.

A cable fault pinpointing device, wherein: the method comprises the following steps: the system comprises an A phase line traveling wave data monitoring module, a B phase line traveling wave data monitoring module, a C phase line traveling wave data monitoring module, an A phase line power frequency data monitoring module, a B phase line power frequency data monitoring module, a C phase line power frequency data monitoring module, an A phase line grounding loop data monitoring module, a B phase line grounding loop data monitoring module, a C phase line grounding loop data monitoring module, an N grounding line grounding loop data monitoring module, a data acquisition and analysis module and a data uploading module;

the two ends of the phase line A are respectively provided with an A phase line traveling wave data monitoring module, the two ends of the phase line B are respectively provided with a B phase line traveling wave data monitoring module, and the two ends of the phase line C are respectively provided with a C phase line traveling wave data monitoring module; the traveling wave data monitoring signal output end of each A, B, C phase line traveling wave data monitoring module is connected with the corresponding A, B, C phase line traveling wave data monitoring signal input end of the data acquisition and analysis module;

the two ends of the phase line A are respectively provided with an A phase line power frequency data monitoring module, the two ends of the phase line B are respectively provided with a B phase line power frequency data monitoring module, and the two ends of the phase line C are respectively provided with a C phase line power frequency data monitoring module; the power frequency data monitoring signal output end of each A, B, C phase line power frequency data monitoring module is connected with the corresponding A, B, C phase line power frequency data monitoring signal input end of the data acquisition and analysis module;

the two ends of the phase line A are respectively provided with an A phase line grounding loop data monitoring module, the two ends of the phase line B are respectively provided with a B phase line grounding loop data monitoring module, the two ends of the phase line C are respectively provided with a C phase line grounding loop data monitoring module, and the two ends of the N grounding line are respectively provided with an N grounding line grounding loop data monitoring module; the grounding loop data monitoring signal output end of each A, B, C phase line and N grounding line grounding loop data monitoring module is connected with the grounding loop data monitoring signal input end of the corresponding A, B, C phase line and N grounding line of the data acquisition and analysis module;

the uploading data output end of the data acquisition and analysis module is connected with the uploading data input end of the data uploading module; the data uploading module is used for uploading data.

The cable fault accurate positioning device, wherein: the A phase line traveling wave data monitoring module, the B phase line traveling wave data monitoring module and the C phase line traveling wave data monitoring module have the same structure;

the specific structure of the A phase line traveling wave data monitoring module is as follows: the traveling wave data monitoring module comprises a traveling wave Rogowski coil, a traveling wave data integrating circuit operator, a traveling wave data in-phase proportional operational amplifier, a first-order all-pass filter and a follower which are connected in the next time;

the traveling wave Rogowski coil is sleeved on the corresponding phase line of the power transmission line and is connected with the traveling wave data integrating circuit arithmetic unit through a connector J8;

the traveling wave data integration circuit operator comprises a first resistor R182, a first capacitor C203, a first operational amplifier U24A, a first second resistor R195, a first second capacitor C211, a first third resistor R200, a first third capacitor C197 and a first fourth capacitor C208, wherein the first end of the first resistor R182 is connected with the signal output end of the traveling wave Rogowski coil connector J8, the second end of the first resistor R182 is connected with the non-inverting input end of the first operational amplifier U24A, the grounding end of the traveling wave Rogowski coil connector J8 is grounded, the first end of the first capacitor C203 is connected with the middle joint of the first resistor R182 and the non-inverting input end of the first operational amplifier U24A, the second end of the first capacitor C203 is grounded, and the inverting input end of the first operational amplifier U24A is connected with the first third resistor R200 in series and then grounded; a parallel circuit of a first diode resistor R195 and a first diode capacitor C211 is connected between the inverting input end and the output end of the first operational amplifier U24A in series; one end of a first third capacitor C197 is connected with the middle joint of the positive electrode of the power supply input end of the first operational amplifier U24A and the positive electrode of the direct-current power supply, and the other end of the first third capacitor C197 is grounded; one end of a first four capacitor C208 is connected with the intermediate joint of the negative electrode of the power supply input end of the first operational amplifier U24A and the negative electrode of the direct-current power supply, and the other end of the first four capacitor C208 is grounded;

the travelling wave data in-phase proportional operational amplifier comprises a second operational amplifier U24B, a second resistor R196 and a second resistor R199, the output end of the first operational amplifier U24A is connected with the in-phase input end of the second operational amplifier U24B, the second resistor R196 is connected between the inverting input end and the output end of the second operational amplifier U24B, and the inverting input end of the second operational amplifier U24B is also connected with the second resistor R199 in series and then grounded;

the first-order all-pass filter comprises a third resistor R180, a third capacitor C204, a third resistor R189, a third operational amplifier U25A, a third capacitor C200 and a third capacitor C209, wherein the output end of a second operational amplifier U24B in the in-phase proportional operational amplifier is connected with the non-inverting input end of a third operational amplifier U25A after being connected with the third capacitor C204 in series, the output end of the second operational amplifier U24B is connected with the inverting input end of the third operational amplifier U25A after being connected with the third resistor R189 in series, and the non-inverting input end of the third operational amplifier U25A and the middle joint of the third capacitor C204 are connected with the third resistor R180 in series and then are grounded; the output end of the third operational amplifier is connected with the inverting input end;

one end of a third second capacitor C200 is connected with the middle joint of the positive electrode of the power supply input end of the third operational amplifier U25A and the positive electrode of the direct-current power supply, and the other end of the third second capacitor C200 is grounded; one end of a third capacitor C209 is connected with the intermediate joint of the negative electrode of the power supply input end of the third operational amplifier U25A and the negative electrode of the direct-current power supply, and the other end of the third capacitor C209 is grounded;

the follower comprises a fourth operational amplifier U25B, wherein the non-inverting input terminal of the fourth operational amplifier U25B is connected with the output terminal of the third operational amplifier U25A, the output terminal of the fourth operational amplifier U25B is connected with the inverting input terminal, and the output terminal of the fourth operational amplifier U25B is used for outputting a traveling wave data monitoring signal.

The cable fault accurate positioning device, wherein: the A phase line power frequency data monitoring module, the B phase line power frequency data monitoring module and the C phase line power frequency data monitoring module are identical in structure, and the A phase line power frequency data monitoring module is specifically structured as follows: the power frequency data monitoring module comprises a power frequency Rogowski coil, a power frequency data integrating circuit operator and a power frequency data in-phase proportional operational amplifier which are connected in the second time, the power frequency Rogowski coil is sleeved on a corresponding phase line of the power transmission line, and the power frequency Rogowski coil is connected with the power frequency data integrating circuit operator through a connector J4;

the power frequency data integration circuit operator comprises a sixth resistor R179, a sixth capacitor C199, a sixth operational amplifier U23A, a sixth second resistor R192, a sixth second capacitor C210, a sixth third resistor R198, a sixth third capacitor C196, a sixth fourth capacitor C207, a sixth fourth resistor R199 and a sixth fifth capacitor C199, wherein a first end of the sixth fourth resistor R199 is connected with a signal output end of a power frequency Rogowski coil connector J4, a second end of the sixth resistor R199 is connected with a non-inverting input end of the sixth operational amplifier U23A, an intermediate joint between a second end of the sixth fourth resistor R199 and a non-inverting input end of the sixth operational amplifier U23A is connected with a first end of the sixth fifth capacitor C199, a second end of the sixth capacitor C199 is grounded, and a ground end of the power frequency Rogowski coil connector J4 is grounded; the inverting input end of the sixth operational amplifier U23A is connected in series with the sixth third resistor R198 and then grounded; a parallel circuit formed by a sixth second resistor R192 and a sixth second capacitor C210 is connected between the inverting input end and the output end of the sixth operational amplifier U23A;

one end of a sixth capacitor C196 is connected with the middle joint of the positive electrode of the power supply input end of the sixth operational amplifier U23A and the positive electrode of the direct-current power supply, and the other end of the sixth capacitor C196 is grounded; one end of a sixth fourth capacitor C207 is connected with the intermediate joint of the negative electrode of the power input end of the sixth operational amplifier U23A and the negative electrode of the direct-current power supply, and the other end of the sixth fourth capacitor C207 is grounded;

the power frequency data non-inverting proportional operational amplifier comprises a seventh operational amplifier U23B, a sixth resistor R190 and a sixth resistor R194, wherein the non-inverting input end of the seventh operational amplifier U23B is connected with the output end of the sixth operational amplifier U23A, the sixth resistor R190 is connected between the output end and the inverting input end of the seventh operational amplifier U23B, and the inverting input end of the seventh operational amplifier U23B is grounded after being connected in series with the sixth resistor R194.

The cable fault accurate positioning device, wherein: the structure of the A phase line grounding loop data monitoring module, the B phase line grounding loop data monitoring module, the C phase line grounding loop data monitoring module and the N grounding line grounding loop data monitoring module is the same;

the A-phase line grounding loop data monitoring module comprises an on-board current transformer CT1, a seventh resistor R314, a seventh diode D13, a seventh diode D14, a seventh resistor R270, a seventh capacitor C302, a seventh third resistor R269, an operational amplifier U40, a seventh second capacitor C309 and a seventh third capacitor C31;

a first transmission pin OUT1 of the on-board current transformer CT1 is connected with a seventh resistor R314 IN series and then is connected with an inverting input end-IN of an operational amplifier U40, a non-inverting input end + IN of the operational amplifier U40 is grounded, a first transmission pin OUT1 of the on-board current transformer CT1 is connected with the anode of a seventh diode D14, the cathode of the seventh diode D14 is connected with a second transmission pin OUT2 of the on-board current transformer CT1, a first transmission pin OUT1 of the on-board current transformer CT1 is connected with the cathode of the seventh diode D13, and the anode of the seventh diode D13 is connected with a second transmission pin OUT2 of the on-board current transformer CT 1; the second transmission pin OUT2 of the on-board current transformer CT1 is also grounded;

a first series circuit formed by connecting the seventh second resistor R270 and the seventh capacitor C302 IN series is connected with the seventh third resistor R269 IN parallel to form a first parallel circuit, and the first parallel circuit is connected between the inverting input end-IN and the output end of the operational amplifier U40;

the middle joint of the positive electrode of the direct-current power supply input end of the operational amplifier U40 and the positive electrode of the direct-current power supply is connected in series with a seventh capacitor C309 and then grounded; the negative electrode of the direct-current power supply input end of the operational amplifier U40 and the intermediate joint of the negative electrode of the direct-current power supply are connected in series with a seventh capacitor C309 and then grounded;

the output end of the operational amplifier U40 is used for outputting the phase line grounding loop data monitoring signal.

The cable fault accurate positioning device, wherein: the data acquisition and analysis module comprises: the system comprises a traveling wave data acquisition and analysis module and a power frequency and grounding loop data acquisition and analysis module, wherein the traveling wave data acquisition and analysis module comprises an A phase line traveling wave data acquisition and analysis module, a B phase line traveling wave data acquisition and analysis module and a C phase line traveling wave data acquisition and analysis module which have the same structure;

the A phase line traveling wave data acquisition and analysis module comprises a high-speed analog-to-digital conversion chip and a Field Programmable Gate Array (FPGA), wherein the input end of the high-speed analog-to-digital conversion chip is connected with the traveling wave data monitoring signal input end of the A phase line traveling wave data monitoring module, the output end of the high-speed analog-to-digital conversion chip is connected with the signal input end of the Field Programmable Gate Array (FPGA), and the signal output end of the Field Programmable Gate Array (FPGA) is connected with the upload data input end of the data upload module;

the power frequency and grounding loop data acquisition and analysis module comprises an AD conversion chip and a field programmable gate array FPGA, wherein the signal input end of an A phase line power frequency data monitoring module, the signal input end of a B phase line power frequency data monitoring module, the signal input end of a C phase line power frequency data monitoring module, the signal input end of an A phase line grounding loop data monitoring module, the signal input end of a B phase line grounding loop data monitoring module, the signal input end of a C phase line grounding loop data monitoring module and the signal input end of an N phase line grounding loop data monitoring module are correspondingly connected with the signal output end of the A phase line power frequency data monitoring module, the signal output end of the B phase line power frequency data monitoring module, the C phase line power frequency data monitoring signal output end of the C phase line power frequency data monitoring module, the A phase line grounding loop data monitoring signal output end of the A phase line grounding loop data monitoring module, the B phase line grounding loop data monitoring module, the signal input end of the C phase line monitoring module, the, The monitoring system comprises a B phase line grounding loop data monitoring signal output end of a B phase line grounding loop data monitoring module, a C phase line grounding loop data monitoring signal output end of a C phase line grounding loop data monitoring module, and an N grounding line grounding loop data monitoring signal output end of an N grounding line grounding loop data monitoring module.

The cable fault accurate positioning device, wherein: the high-speed analog-to-digital conversion chip in the A phase line traveling wave data acquisition and analysis module adopts AD9224, and the field programmable gate array FPGA adopts XC7S 100;

an AD conversion chip in the power frequency and ground loop data acquisition and analysis module adopts ADS8588S, and a field programmable gate array FPGA adopts XC7S 100;

the data uploading module adopts a single chip microcomputer STM 32.

According to the cable fault accurate positioning device provided by the utility model, the traveling wave data detection module adopts a high-frequency Rogowski coil to be sleeved on a cable to be detected, and A, B, C three-phase cables have 3 Rogowski coils in total, so that traveling wave current signals of the cable are differentiated and converted into voltage signals. The voltage signal is subjected to integral conversion through an integrator circuit, the voltage signal is amplified through an amplifying circuit and the phase of the voltage signal is corrected through a phase correcting circuit, then the analog signal is converted into a digital signal through a high-speed analog-to-digital conversion chip and input into a data acquisition and analysis module, and then the digital signal is sent to a data uploading module and uploaded to a background. In the field practical application, two pieces of equipment are respectively arranged at two ends of an underground cable, and the positions of fault points (including lightning stroke, short circuit and other fault positions) of the cable can be accurately calculated by comparing the time difference of traveling wave signals monitored by the two pieces of equipment; the power frequency data monitoring module adopts a power frequency Rogowski coil to be sleeved on a tested cable, and the A, B, C three cables have 3 Rogowski coils in total, so that a power frequency current signal of the cable is differentially converted into a voltage signal. The voltage signal is subjected to integral conversion through an integrator circuit, the voltage signal is amplified through an amplifier circuit, the analog signal is converted into a digital signal through an analog-digital conversion chip, the digital signal is input into a data acquisition and analysis module, and the digital signal is sent to a data uploading module and uploaded to a background. In the field application, faults such as tripping of an underground cable, power frequency current abnormity and the like can be accurately measured by monitoring the power frequency current signal; the grounding loop data monitoring module adopts a CT sensor to be sleeved on a grounding wire of an A, B, C, N cable, a grounding loop signal is input to an onboard current transformer, the current signal is converted into a voltage signal through an operational amplifier circuit, the analog voltage signal is converted into a digital signal through an analog-digital conversion chip, and the digital signal is input to a data acquisition and analysis module and then is sent to a data uploading module to be uploaded to a background. Through the grounding circulation data monitoring module, the grounding circulation data can be accurately judged to be abnormal, and then faults such as whether the cable connection is normal or not, whether the insulation performance of the cable is normal or not and the like can be diagnosed. The technical scheme is that whether the traveling wave fault signal, the power frequency signal or the grounding circulating current signal is monitored, the traveling wave fault signal, the power frequency signal or the grounding circulating current signal is non-intrusive, namely, the traveling wave fault signal, the power frequency signal or the grounding circulating current signal is not in contact with the transmission cable, so that the local work of the cable is not influenced, the integrity of the transmission cable is protected to the maximum extent, and the live-line operation can be realized. At present, most of existing devices with similar schemes are intrusive, namely, the devices are connected into a tested cable, monitoring devices are not completely isolated from the tested cable, and the devices have non-negligible influence on the tested cable.

In addition, the three monitoring modules can work together or independently, and can be freely combined according to the requirements of users to almost monitor all possible faults of the grounding cable. The existing similar scheme has the problems of single function, single fault monitoring point, incapability of diagnosing cable faults in all directions and high cost due to single function.

Moreover, this patent has utilized integrator circuit, amplifier circuit, phase compensation circuit, and the fault signal waveform that has restoreed including waveform amplitude and phase place of high accuracy has observed that not only is directly perceived but also accurate. At present, the similar scheme is simple in processing of fault signals, most of the similar schemes only use a signal amplification circuit, great difference exists in restoring fault signal waveforms, and the purpose of accurately positioning fault points cannot be achieved.

Finally, this patent utilizes the transmission and reflection theory of ripples at the transmission line, and the position of calculating the cable fault point that can be accurate on this hardware basis, the error is within 2 meters.

Drawings

FIG. 1 is a schematic block diagram of a cable fault pinpointing apparatus according to the present invention;

FIG. 2 is a circuit diagram of a traveling wave data monitoring module;

FIG. 3 is a circuit diagram of a power frequency data monitoring module;

FIG. 4 is a circuit diagram of a ground loop data monitoring module;

FIG. 5 is a circuit diagram of the power frequency and ground loop data acquisition and analysis module;

FIG. 6 is a circuit diagram of a traveling wave data acquisition and analysis module;

fig. 7 is a circuit diagram of a data upload module.

Detailed Description

The utility model provides a cable fault accurate positioning device, as shown in fig. 1, comprising: the system comprises an A phase line traveling wave data monitoring module, a B phase line traveling wave data monitoring module, a C phase line traveling wave data monitoring module, an A phase line power frequency data monitoring module, a B phase line power frequency data monitoring module, a C phase line power frequency data monitoring module, an A phase line grounding loop data monitoring module, a B phase line grounding loop data monitoring module, a C phase line grounding loop data monitoring module, an N grounding line grounding loop data monitoring module, a data acquisition and analysis module and a data uploading module;

the two ends of the phase line A are respectively provided with a phase line power frequency data monitoring module A, the two ends of the phase line B are respectively provided with a phase line power frequency data monitoring module B, and the two ends of the phase line C are respectively provided with a phase line power frequency data monitoring module C; the power frequency data monitoring signal output end of each A, B, C phase line power frequency data monitoring module is connected with the corresponding A, B, C phase line power frequency data monitoring signal input end of the data acquisition and analysis module;

The A phase line traveling wave data monitoring module, the B phase line traveling wave data monitoring module and the C phase line traveling wave data monitoring module have the same structure;

as shown in fig. 2, the specific structure of the a-phase line traveling wave data monitoring module is as follows: the traveling wave data monitoring module comprises a traveling wave Rogowski coil, a traveling wave data integrating circuit operator, a traveling wave data in-phase proportional operational amplifier, a first-order all-pass filter and a follower which are connected in the next time;

the travelling wave data in-phase proportional operational amplifier comprises a second operational amplifier U24B, a second resistor R196 and a second resistor R199, wherein the output end of the first operational amplifier U24A is connected with the in-phase input end of the second operational amplifier U24B, the second resistor R196 is connected between the inverting input end and the output end of the second operational amplifier U24B, and the inverting input end of the second operational amplifier U24B is also connected with the second resistor R199 in series and then grounded;

Referring to fig. 2, the present invention includes a three-way traveling wave data monitoring module for monitoring A, B, C traveling wave fault signals of the transmission line cable respectively. The two ends of a transmission cable are respectively provided with the equipment, the accurate fault position point of the cable can be obtained by monitoring the high-precision time difference of the traveling wave signals through the two equipment, and the peak value, the effective value, the rising edge time, the falling edge time, the actual shape of the waveform and the like of the power frequency fault signals can be detected.

In fig. 2, a connector J8 is an external connection terminal, and is connected to an external high-frequency rogowski coil, and the rogowski coil outputs a voltage signal. U24A, U24B, U25A and U25B are operational amplifiers TLC072AIDR respectively. R182, C203, U24A, R195, C211, R200 constitute an integrator circuit operator, and since the rogowski coil outputs a voltage signal obtained by differentiating the original traveling wave fault signal, the integrator is used here to perform a first integration operation on the received differentiated signal to restore the traveling wave fault signal. C197 and C208 are power filter capacitors of the operational amplifier U24A, which can filter the noise ripple of the power supply. U24B, R196, R199 constitute the cophase proportion operational amplifier, carry out multiple amplification to the signal, the sampling conversion of the convenient later stage circuit. R180, C204, R189, U25A constitute first-order all-pass filter for the phase place of compensating the travelling wave fault signal gives consideration to amplitude-frequency reminding and phase place characteristic, can be better the reduction travelling wave fault signal, the extremely strong reduction degree that has increased the travelling wave signal waveform. U25B constitutes the follower, and the follower has high input impedance, low output impedance's characteristics, has reduced the distortion of travelling wave fault signal to a great extent.

The A phase line power frequency data monitoring module, the B phase line power frequency data monitoring module and the C phase line power frequency data monitoring module are identical in structure, and the A phase line power frequency data monitoring module is specifically structured as follows: the power frequency data monitoring module comprises a power frequency Rogowski coil, a power frequency data integrating circuit operator and a power frequency data in-phase proportional operational amplifier which are connected in the second time, the power frequency Rogowski coil is sleeved on a corresponding phase line of the power transmission line, and the power frequency Rogowski coil is connected with the power frequency data integrating circuit operator through a connector J4;

as shown in the power frequency data monitoring module circuit diagram of fig. 3, the power frequency data integrator circuit operator includes a sixth resistor R179, a sixth capacitor C199, a sixth operational amplifier U23A, a sixth resistor R192, a sixth capacitor C210, a sixth third resistor R198, a sixth capacitor C196, a sixth fourth capacitor C207, a sixth fourth resistor R199, and a sixth fifth capacitor C199, wherein a first end of the sixth fourth resistor R199 is connected to a signal output end of the power frequency rogowski coil connector J4, a second end of the sixth fourth resistor R199 is connected to a non-inverting input end of the sixth operational amplifier U23A, an intermediate junction between a second end of the sixth fourth resistor R199 and a non-inverting input end of the sixth operational amplifier U23A is connected to a first end of the sixth capacitor C199, a second end of the sixth capacitor C199 is grounded, and a ground end of the rogowski coil connector J4 is grounded; the inverting input end of the sixth operational amplifier U23A is connected in series with the sixth third resistor R198 and then grounded; a parallel circuit formed by a sixth second resistor R192 and a sixth second capacitor C210 is connected between the inverting input end and the output end of the sixth operational amplifier U23A;

As shown in fig. 3, the present invention includes three power frequency data monitoring modules for respectively monitoring A, B, C power frequency data signals of three electric power lines of a power transmission line cable. When any one of the three cables has a power frequency fault signal, the two devices can detect the power frequency fault signal, the high-precision time difference of the power frequency fault signal is detected by the two devices, the power frequency fault position point of the cable can be obtained, and the peak value, the effective value, the rising edge time, the falling edge time, the actual shape of the waveform and the like of the power frequency fault signal can be detected.

In fig. 3, the connector J4 is an external connection terminal, and is connected to an external power frequency rogowski coil, and the rogowski coil outputs a voltage signal. R179, C199, U23A, R192, C210, R198 constitute the arithmetic unit of the integral circuit, because what the Rogowski coil outputs is the voltage signal after the original power frequency signal is made the differentiation, so use the integral circuit here to make the first integral operation to the differential signal received, reduce the power frequency signal. C196 and C207 are filter capacitors of the power supply of the operational amplifier OP2180, which can filter noise ripples of the power supply. R190, R194 and U23B form an in-phase proportional operational amplifier, and the in-phase proportional operational amplifier is used for amplifying signals by multiple times, so that sampling conversion of a later-stage circuit is facilitated.

The structure of the A phase line grounding loop data monitoring module, the B phase line grounding loop data monitoring module, the C phase line grounding loop data monitoring module and the N grounding line grounding loop data monitoring module is the same;

as shown in the circuit diagram of the grounding loop data monitoring module in fig. 4, the structures of the a phase line grounding loop data monitoring module, the B phase line grounding loop data monitoring module, the C phase line grounding loop data monitoring module, and the N grounding line grounding loop data monitoring module are the same;

A circular through hole is formed in the middle of the on-board current transformer CT1, an input signal wire of the grounding circulating current monitoring transformer penetrates through the circular through hole of the on-board current transformer CT1, the on-board current transformer CT1 can induce a current signal, the induced current signal flows OUT from a first transmission pin OUT1 of the on-board current transformer CT1, passes through a circuit formed by a post-stage operational amplifier U40 (the operational amplifier U40 adopts OPA180), and flows back to the on-board current transformer CT1 from a second transmission pin OUT2 to form a complete loop. The sixth pin of the operational amplifier U40(OPA180) outputs a voltage signal to the subsequent stage.

Referring to fig. 4, the present invention includes a four-way ground loop data monitoring module for monitoring the ground loop signals of A, B, C, N four cables of the transmission line cable respectively. When any one of the cables has a grounding circulation fault signal, the two devices can detect the grounding circulation fault signal, the cable power frequency fault position point can be obtained by detecting the high-precision time difference of the grounding circulation fault signal through the two devices, and the peak value, the effective value, the rising edge time, the falling edge time, the actual shape of the waveform and the like of the grounding circulation fault signal can be detected.

The data acquisition and analysis module comprises: the system comprises a traveling wave data acquisition and analysis module and a power frequency and grounding loop data acquisition and analysis module, wherein the traveling wave data acquisition and analysis module comprises an A phase line traveling wave data acquisition and analysis module, a B phase line traveling wave data acquisition and analysis module and a C phase line traveling wave data acquisition and analysis module which have the same structure;

a circuit diagram of an a-phase line traveling wave data acquisition and analysis module shown in fig. 6; the A phase line traveling wave data acquisition and analysis module comprises a high-speed analog-to-digital conversion chip and a Field Programmable Gate Array (FPGA), wherein the input end of the high-speed analog-to-digital conversion chip is connected with the traveling wave data monitoring signal input end of the A phase line traveling wave data monitoring module, the output end of the high-speed analog-to-digital conversion chip is connected with the signal input end of the Field Programmable Gate Array (FPGA), and the signal output end of the Field Programmable Gate Array (FPGA) is connected with the upload data input end of the data upload module;

fig. 5 shows a circuit diagram of a power frequency and ground loop data acquisition and analysis module; the power frequency and grounding loop data acquisition and analysis module comprises an AD conversion chip and a field programmable gate array FPGA, wherein the signal input end of an A phase line power frequency data monitoring module, the signal input end of a B phase line power frequency data monitoring module, the signal input end of a C phase line power frequency data monitoring module, the signal input end of an A phase line grounding loop data monitoring module, the signal input end of a B phase line grounding loop data monitoring module, the signal input end of a C phase line grounding loop data monitoring module and the signal input end of an N phase line grounding loop data monitoring module are correspondingly connected with the signal output end of the A phase line power frequency data monitoring module, the signal output end of the B phase line power frequency data monitoring module, the C phase line power frequency data monitoring signal output end of the C phase line power frequency data monitoring module, the A phase line grounding loop data monitoring signal output end of the A phase line grounding loop data monitoring module, the B phase line grounding loop data monitoring module, the signal input end of the C phase line monitoring module, the, The monitoring system comprises a B phase line grounding loop data monitoring signal output end of a B phase line grounding loop data monitoring module, a C phase line grounding loop data monitoring signal output end of a C phase line grounding loop data monitoring module, and an N grounding line grounding loop data monitoring signal output end of an N grounding line grounding loop data monitoring module.

The high-speed analog-to-digital conversion chip in the A phase line traveling wave data acquisition and analysis module adopts AD9224, and the field programmable gate array FPGA adopts XC7S 100;

the circuit diagram of the data uploading module is shown in fig. 7, and the data uploading module adopts a single chip microcomputer STM 32.

As shown in fig. 5, the power frequency and ground loop data acquisition and analysis module is compatible with three-way power frequency and four-way ground loop data acquisition and analysis circuits, and receives analog data of the three-way power frequency data monitoring module and the four-way ground loop data monitoring module at the same time, so that power frequency data of A, B, C cables and ground loop data of A, B, C, N cables can be acquired and analyzed at the same time, as shown in fig. 5, U32 is an ADS8588S digital-to-analog conversion chip combined with a peripheral circuit thereof, performs analog-to-digital conversion on the power frequency data and the ground loop data, converts the analog signal into a digital signal, and facilitates data transmission to a subsequent FPGA for data analysis, thereby satisfying signal level matching, increasing anti-interference of signal transmission, increasing data transmission rate, and meanwhile, U32 has a resolution as high as 16 bits, and has extremely high reduction precision. The U32 adopts 16-bit-wide parallel data to perform data transmission with the FPGA, and the data throughput is high. The U9H is an FPGA field programmable gate array, and meets the requirement of multi-channel multi-data parallel analysis processing. The FPGA can accurately acquire and analyze the received power frequency fault data and the grounding circulation fault data by combining a data analysis software algorithm.

Fig. 6 shows a circuit diagram of a traveling wave data acquisition and analysis module, which employs a high-speed digital-to-analog conversion chip AD9224, see chip U34 in fig. 6, and signal VIN _ HP1 is an output analog signal of a traveling wave data monitoring module, and is used as a receiving signal of the traveling wave data monitoring module. The chip U34 converts the output analog signal of the traveling wave data monitoring module into a parallel digital signal with 12 bit width, and transmits the parallel digital signal to the FPGA as shown in U9D. The design of the chip U34 and the peripheral circuit thereof has the characteristics of high bandwidth, high data conversion rate and high sampling rate, and the data conversion rate is up to 12 bits, so that the acquisition and conversion of high-frequency traveling wave analog signals are met, and high-frequency traveling wave fault signals can be well restored. The converted parallel 12-bit digital signal can be directly transmitted with FPGA, thus realizing perfect compatibility of level, and increasing anti-interference and high data transmission rate of signal transmission. The U9D is an FPGA field programmable gate array, and meets the requirement of multi-channel multi-data parallel analysis processing. The FPGA can accurately acquire and analyze the received three power frequency traveling wave fault signals by combining with a data analysis software algorithm.

As shown in fig. 7, is a data uploading module. The data acquisition and analysis module performs acquisition, analysis, calculation and compression on the data and then sends the data to the data uploading module. The data uploading module adopts an STM32 single-chip microcomputer design, such as U1A in FIG. 7. U1A and FPGA adopt 16 bit parallel data bus transmission, guarantee that data can in time transmit to data upload module. In addition, a 4G wireless transmission circuit is designed in the data uploading module, the U1A single chip microcomputer further compresses and packages the received data, and the data are sent to the background through a 4G wireless network. After the background receives the data, various fault signals can be displayed completely by decompression, and different fault types and fault positions are displayed for different fault signals to trigger alarms at the same time. The staff can know the fault type and the fault position of the cable only by looking up background data.

In summary, the technical scheme comprises 5 components: the system comprises a traveling wave data monitoring module, a power frequency data monitoring module, a grounding loop data monitoring module, a data acquisition and analysis module and a data uploading module.

1. Traveling wave data monitoring module: after functions of integral amplification phase compensation, number conversion and the like of the traveling wave fault signal are achieved, data are sent to the data acquisition and analysis module.

2. Power frequency data monitoring module: after the functions of integral amplification operation, analog-to-digital conversion and the like of the power frequency fault signal are realized, the data are sent to the data acquisition and analysis module.

3. Ground loop flow data monitoring module: after the functions of converting the current of the grounding circulation fault signal into voltage, performing analog-to-digital conversion and the like are realized, the data are sent to the data acquisition and analysis module.

4. The data acquisition and analysis module: and receiving data of the traveling wave, power frequency and grounding loop data monitoring module, performing synchronous analysis calculation processing, and sending the processed data to the data uploading module.

5. The data uploading module: and receiving the data of the data acquisition and analysis module, and uploading the data to a server or a background.

The design circuit of the utility model is in loop-to-loop connection, each step is vital and none, each step of data processing plays a role after the beginning, and has consistent importance, and the function of the utility model can not be realized if one step is lacked.

In addition, the utility model comprises a traveling wave fault detection module, a power frequency fault detection module and a grounding circulation fault detection module, wherein the three modules work independently and can be combined at will, one or two modules are lacked, and other modules can work normally, so that fault monitoring can be combined freely according to user requirements.

The FPGA is adopted to realize uninterrupted synchronous acquisition and analysis of various faults, when the faults of different types and different channels are triggered simultaneously, the faults can be acquired without delay and conflict, and if a competitor wants to realize the purpose, the competitor has to adopt the mode of the competitor.

The most difficult of them is to judge the exact position of the fault point of the traveling wave, which is also insurmountable in the prior art, and the realization of this function requires two devices of the present invention to be installed at both ends of the cable. Besides the traveling wave data monitoring module which ensures high-precision and high-quality restoration of fault signal waveforms, the GPS module is adopted for continuously receiving second pulses of the satellites and sending the second pulses to the FPGA, and the FPGA of each device takes the time as a reference. The method is characterized in that the transmission and reflection theory of waves on a transmission line is utilized to analyze the time difference of the catastrophe points of the fault waveforms sampled by each device, so that the purpose of accurately positioning the cable fault is achieved.

The utility model relates to a non-invasive sensor, such as a high-frequency Rogowski coil, a power-frequency Rogowski coil and a current transformer. The sensors are added to realize non-invasion, namely complete isolation, of a circuit to be tested, and meanwhile, the field construction and later maintenance and repair are facilitated.

The utility model adopts an integrator circuit and a phase compensation circuit aiming at a traveling wave fault monitoring module and a power frequency fault monitoring module. Not only can accurate reduction measured signal but also can accurate compensation phase place, realize the accurate measurement of signal.

According to the utility model, an on-board current transformer is added for the grounding circulation monitoring module, the measuring range of fault current is enlarged, and simultaneously, the physical isolation between an on-board circuit and an external current transformer is realized, because the current induced by the external current transformer cannot flow into the board card, the working stability of the circuit is improved.

The utility model adds a GPS module in a data uploading module for receiving the second pulse of the satellite to carry out time correction and calibration. Therefore, the accuracy of fault signal detection is greatly improved, and accurate positioning of various fault positions is guaranteed to a great extent.

In the data acquisition and analysis module, the FPGA parallel simultaneous acquisition and analysis design is added, and the acquisition and analysis design of a single chip microcomputer is replaced. The design realizes the parallel real-time acquisition and analysis of various fault signals without mutual influence.

For example, a substation outputs electricity to a factory or an enterprise through a cable, and it is known that the substation is far away from the factory in the city, usually over several tens of kilometers, and the cable includes an overhead line and an underground transmission cable, and usually the two ways are combined, and the whole transmission cable is formed by connecting several sections of cables. The equipment of the patent is installed at each section of the ground-entering cable and the ground-exiting cable, when a cable fault occurs, such as the cable is dug to be broken by a construction unit, lightning stroke and faults of insulation fault, leakage fault, short circuit and open circuit of the cable and the like caused by aging and corrosion of the cable, fault waveforms are transmitted to two ends along the cable, the fault data can be monitored by two equipment and uploaded to a background upper computer of a transformer substation, the background receives the fault data of the two equipment, the fault type can be obtained, and fault points can be accurately calculated. And the maintenance personnel directly go to the fault position point to remove the cable maintenance fault, so that the power supply can be recovered.

For power plants, transformer substations and other places, firstly, the existing invention aims at single fault type, and can mostly monitor only one signal fault, so that a plurality of different devices are required to be installed for monitoring different types of faults, thereby not only wasting resources and manpower and occupying the field, but also having complex line laying. The utility model perfectly solves the problem, can monitor three major faults of traveling wave fault, power frequency fault and grounding circulation, can include specific fault types of various types, saves manpower, material resources and financial resources, and is convenient to install and route simply; secondly, the fault position positioning deviation of the prior invention is large, the error can reach dozens of meters, and the existing invention is very troublesome when the maintenance is needed for both overhead lines and buried lines, and the maintenance personnel can be very labourious because the accurate fault point can not be found. The utility model develops a high-precision hardware circuit and then cooperates with a precise algorithm, so that precise fault positioning can be carried out, and reliable support is provided for the maintenance, overhaul and fault removal of the cable; at present, the cable is connected in an intrusive mode, namely, the cable needs to be connected into the equipment, the cable is influenced, meanwhile, the equipment to be tested is influenced, and power-off operation is needed when the equipment is installed. The utility model develops a non-invasive wiring method, only the Rogowski coil and the detection CT are required to be sleeved on the cable during installation, the complete physical isolation of the detected cable and the detection equipment is realized, the detected cable is not influenced, the independent operation of the monitoring equipment is also ensured, and the uninterrupted operation of the cable is also realized. Finally, the existing invention has insufficient intellectualization, the data transmitted to the background is incomplete, and needs manual operation and judgment, for example, when a certain section of cable has a fault, the monitoring equipment only sends a fault signal to the background, and the background can only receive one message, namely the cable has a fault. The utility model perfectly optimizes the problem, and when monitoring the fault signal, the monitoring equipment can send the fault waveform, the fault type and the fault position point to the background, so that background personnel can clearly see the waveform diagram, the fault type and the precise position of the fault signal, and inform the information to the maintenance personnel to carry out maintenance.

The utility model can simultaneously monitor various cable faults including lightning stroke, short circuit, wiring error, cable aging, cable insulation layer damage, damage of external force (such as branches, birds, manual cable cutting and the like) to the cable transmission electric energy, and can accurately judge the position of a fault point.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions, and shall be covered by the scope of the present invention.

Claims

1. The utility model provides a cable fault accurate positioning device which characterized in that: the method comprises the following steps: the system comprises an A phase line traveling wave data monitoring module, a B phase line traveling wave data monitoring module, a C phase line traveling wave data monitoring module, an A phase line power frequency data monitoring module, a B phase line power frequency data monitoring module, a C phase line power frequency data monitoring module, an A phase line grounding loop data monitoring module, a B phase line grounding loop data monitoring module, a C phase line grounding loop data monitoring module, an N grounding line grounding loop data monitoring module, a data acquisition and analysis module and a data uploading module;

2. The cable fault pinpoint device of claim 1, wherein: the A phase line traveling wave data monitoring module, the B phase line traveling wave data monitoring module and the C phase line traveling wave data monitoring module have the same structure;

3. The cable fault pinpoint device of claim 2, wherein: the A phase line power frequency data monitoring module, the B phase line power frequency data monitoring module and the C phase line power frequency data monitoring module are identical in structure, and the A phase line power frequency data monitoring module is specifically structured as follows: the power frequency data monitoring module comprises a power frequency Rogowski coil, a power frequency data integrating circuit operator and a power frequency data in-phase proportional operational amplifier which are connected in the second time, the power frequency Rogowski coil is sleeved on a corresponding phase line of the power transmission line, and the power frequency Rogowski coil is connected with the power frequency data integrating circuit operator through a connector J4;

4. The cable fault pinpoint device of claim 3, wherein: the structure of the A phase line grounding loop data monitoring module, the B phase line grounding loop data monitoring module, the C phase line grounding loop data monitoring module and the N grounding line grounding loop data monitoring module is the same;

a first transmission pin OUT1 of the on-board current transformer CT1 is connected with a seventh resistor R314 IN series and then is connected with an inverting input end-IN of an operational amplifier U40, a non-inverting input end + IN of the operational amplifier U40 is grounded, a first transmission pin OUT1 of the on-board current transformer CT1 is connected with the anode of a seventh diode D14, the cathode of the seventh diode D14 is connected with a second transmission pin OUT2 of the current transformer CT1, a first transmission pin OUT1 of the on-board current transformer CT1 is connected with the cathode of a seventh diode D13, and the anode of the seventh diode D13 is connected with a second transmission pin OUT2 of the current transformer CT 1; the second transmission pin OUT2 of the on-board current transformer CT1 is also grounded;

5. The cable fault pinpoint device of claim 4, wherein: the data acquisition and analysis module comprises: the system comprises a traveling wave data acquisition and analysis module and a power frequency and grounding loop data acquisition and analysis module, wherein the traveling wave data acquisition and analysis module comprises an A phase line traveling wave data acquisition and analysis module, a B phase line traveling wave data acquisition and analysis module and a C phase line traveling wave data acquisition and analysis module which have the same structure;

the power frequency and ground loop data acquisition and analysis module comprises an AD conversion chip, a field programmable gate array FPGA, an A phase line power frequency data monitoring module signal input end, a B phase line power frequency data monitoring module signal input end, a C phase line power frequency data monitoring module signal input end, an A phase line ground loop data monitoring module signal input end, a B phase line ground loop data monitoring module signal input end, a C phase line ground loop data monitoring module signal input end and an N phase line ground loop data monitoring module signal input end which are correspondingly connected with an A phase line power frequency data monitoring signal output end of the A phase line power frequency data monitoring module, a B phase line power frequency data monitoring signal output end of the B phase line power frequency data monitoring module, a C phase line power frequency data monitoring signal output end of the C phase line power frequency data monitoring module, an A phase line ground loop data monitoring signal output end of the A phase line ground loop data monitoring module, a phase line power loop data monitoring signal output end of the A phase line power loop data monitoring module, a phase line power monitoring signal output end of the A phase line power loop data monitoring module, a phase line power loop data monitoring signal input end of the A phase line monitoring module, a phase line monitoring module, a phase line monitoring module, a phase line monitoring module, a phase monitoring module, a phase, The monitoring system comprises a B phase line grounding loop data monitoring signal output end of a B phase line grounding loop data monitoring module, a C phase line grounding loop data monitoring signal output end of a C phase line grounding loop data monitoring module, and an N grounding line grounding loop data monitoring signal output end of an N grounding line grounding loop data monitoring module.

6. The cable fault pinpoint device of claim 5, wherein: the high-speed analog-to-digital conversion chip in the A phase line traveling wave data acquisition and analysis module adopts AD9224, and the field programmable gate array FPGA adopts XC7S 100;

the data uploading module adopts a single chip microcomputer STM 32.