Synchronous self-calibration cable distributed partial discharge detection, calibration and positioning device and method

Abstract

The invention discloses a synchronous self-calibration cable distributed partial discharge detection calibration positioning device and method, and relates to the technical field of power system cable insulation state detection. The device comprises an upper computer and at least two acquisition and detection systems, for any acquisition and detection system, the detection module receives the control signal and outputs a synchronous calibration signal; the pulse calibration unit excites a calibration pulse signal on the cable shielding grounding wire according to the synchronous calibration signal, and takes the obtained excitation pulse signal as a time reference signal; the detection module determines a pulse time difference based on the time reference signal; the upper computer calibrates the adjacent acquisition and detection systems according to the pulse time difference, and performs waveform comparative analysis on acquired data acquired after calibration to obtain an analysis result; the analysis result is used for realizing detection positioning based on waveform time delay. The invention aims to realize synchronous function calibration and partial discharge detection positioning of cable distributed partial discharge detection.

Description

Technical Field

[0001] The present application relates to the technical field of power system cable insulation state detection, and particularly to a synchronous self-calibration cable distributed partial discharge detection, calibration and positioning device and method. Background Art

[0002] In the power system, the operating state of power cables is related to the stability of power transmission in the power grid. Partial discharge positioning can play a clear guiding role in cable operation and maintenance work. At present, in cable handover tests and on-line monitoring during live operation, a distributed partial discharge detection and positioning method of arranging multiple detection and positioning devices on a single cable line is mostly adopted.

[0003] In the known technology, there is no effective detection and calibration method for evaluating the synchronous acquisition effect of multiple detection and positioning devices arranged on a cable line. Although the known technology can realize the detection and evaluation of the time synchronization performance and phase synchronization performance of a distributed partial discharge detection system for high-voltage power cable lines. However, for long-distance cable lines with many cable joints in the middle, the output signal of the partial discharge calibration source will be severely attenuated and oscillated as the cable length increases, and the time synchronization calibration of long-distance detection devices will be greatly affected. Summary of the Invention

[0004] The purpose of the present application is to provide a synchronous self-calibration cable distributed partial discharge detection, calibration and positioning device and method, which can realize synchronous calibration and positioning of cable distributed partial discharge detection.

[0005] To achieve the above object, the present application provides the following solutions: In a first aspect, the present application provides a synchronous self-calibration cable distributed partial discharge detection, calibration and positioning device, including: a host computer and at least two acquisition and detection systems; the host computer is communicatively connected with the acquisition and detection systems; Each of the acquisition and detection systems includes: a detection unit, a pulse calibration unit, an acquisition unit, and a phase synchronization unit; wherein, the detection unit includes: a detection module and a synchronization module; The acquisition unit and the pulse calibration unit are both arranged on the same shielded ground wire; the pulse calibration unit is located above the acquisition unit; The phase synchronization unit is arranged on the main cable of the cable and is connected to the detection module; the acquisition unit and the pulse calibration unit are both connected to the detection module; the synchronization module is also connected to the detection module; For any one of the acquisition and detection systems: The host computer is used to output a control signal; the detection module is used to receive the control signal and output a synchronous calibration signal; the pulse calibration unit is used to excite a calibration pulse signal on the cable shield ground wire according to the synchronous calibration signal, and use the obtained excitation pulse signal as a time reference signal; The acquisition unit is used to acquire pulse signals; the pulse signals include: the excitation pulse signal and the excitation pulse signal received by the acquisition unit in an adjacent acquisition and detection system; The detection module is used to acquire the pulse signal, the synchronization signal and the phase synchronization signal, and determine the pulse time difference based on the time reference signal; among them, the phase synchronization signal is output by the phase synchronization unit; the synchronization signal is output by the synchronization module; the synchronization signal includes: an optical synchronization signal and a Beidou synchronization signal; The host computer is used to calibrate adjacent acquisition and detection systems according to the pulse time difference, and perform waveform comparison and analysis on the acquired data after calibration to obtain an analysis result; the analysis result is used to realize detection and positioning based on waveform time delay.

[0006] In a second aspect, the present application provides a synchronous self-calibration cable distributed partial discharge detection and calibration positioning method, which is implemented by a synchronous self-calibration cable distributed partial discharge detection and calibration positioning device; the synchronous self-calibration cable distributed partial discharge detection and calibration positioning method includes: Controlling the detection module to output a synchronous calibration signal based on the control signal issued by the host computer; Controlling the pulse calibration unit to excite a calibration pulse signal on the cable shield ground wire according to the synchronous calibration signal, and use the obtained excitation pulse signal as a time reference signal; Acquiring a pulse signal, a synchronization signal and a phase synchronization signal, and determining the pulse time difference based on the time reference signal; the pulse signals include: the excitation pulse signal and the excitation pulse signal received by the acquisition unit in an adjacent acquisition and detection system; the synchronization signal includes: an optical synchronization signal and a Beidou synchronization signal; Calibrating adjacent acquisition and detection systems according to the pulse time difference; Performing waveform comparison and analysis on the acquired data after calibration to obtain an analysis result; the analysis result is used to realize detection and positioning based on waveform time delay.

[0007] According to the specific embodiments provided by the present application, the following technical effects are disclosed in the present application: The present application provides a synchronous self-calibration cable distributed partial discharge detection, calibration and positioning device and method. For any acquisition and detection system: the detection module receives a control signal and outputs a synchronous calibration signal; the pulse calibration unit excites a calibration pulse signal on the cable shield grounding wire according to the synchronous calibration signal, and uses the obtained excitation pulse signal as a time reference signal; the detection module determines the pulse time difference based on the time reference signal; the upper computer calibrates adjacent acquisition and detection systems according to the pulse time difference. By arranging multiple acquisition and detection systems distributedly on a cable in the present application, each acquisition and detection system has its own synchronous calibration function, and there is no need to inject pulses at the head end of a long-distance cable line. Moreover, due to the presence of the pulse calibration unit, phase synchronization unit and synchronization module in the present application, the excitation pulse signal will not be severely attenuated and oscillated as the cable length increases, so that the synchronous calibration accuracy is improved. In addition, by performing waveform comparison and analysis on the acquisition data collected after calibration, detection and positioning can be achieved. Thus, the present application can realize synchronous calibration and positioning of cable distributed partial discharge detection. Description of the Drawings

[0008] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0009] Figure 1 It is a structural diagram of a synchronous self-calibration cable distributed partial discharge detection, calibration and positioning device; Figure 2 It is a schematic diagram of the panel of a synchronous self-calibration cable distributed partial discharge detection, calibration and positioning device; Figure 3 It is an application schematic diagram of a synchronous self-calibration cable distributed partial discharge detection, calibration and positioning device based on Beidou synchronous acquisition and 4G wireless network communication; Figure 4 It is an application schematic diagram of a synchronous self-calibration cable distributed partial discharge detection, calibration and positioning device based on optical synchronous acquisition and optical fiber communication; Figure 5 It is a flow chart of a synchronous self-calibration cable distributed partial discharge detection, calibration and positioning method.

[0010] Reference Signs: 1. Partial discharge detection input interface; 2. Synchronous calibration output interface; 3. Optical synchronous signal port; 4. Phase synchronous input port; 5. Fiber optic communication interface; 6. 4G antenna interface; 7. Beidou antenna interface; 8. Host computer; 9. Communication device; 10. First acquisition and detection system; 11. Second acquisition and detection system; 12. First acquisition unit; 13. Second acquisition unit; 14. First pulse calibration unit; 15. Second pulse calibration unit; 16. First phase synchronous unit; 17. Second phase synchronous unit; 18. Cable insulation joint at the head end; 19. Intermediate cable insulation joint. Detailed implementation manners

[0011] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0012] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0013] In an exemplary embodiment, as Figure 1 shown, a synchronous self-calibrating cable distributed partial discharge detection and calibration positioning device is provided. The synchronous self-calibrating cable distributed partial discharge detection and calibration positioning device includes: a host computer and at least two acquisition and detection systems. The host computer is communicatively connected to the acquisition and detection systems.

[0014] Each acquisition and detection system includes: a detection unit, a pulse calibration unit, an acquisition unit, and a phase synchronous unit; wherein, the detection unit includes: a detection module and a synchronous module.

[0015] Both the acquisition unit and the pulse calibration unit are arranged on the same shielded and grounded wire; the pulse calibration unit is located above the acquisition unit.

[0016] The phase synchronous unit is arranged on the main cable of the cable and is connected to the detection module; both the acquisition unit and the pulse calibration unit are connected to the detection module; the synchronous module is also connected to the detection module.

[0017] For any acquisition and detection system: The host computer is used to output a control signal; the detection module is used to receive the control signal and output a synchronous calibration signal; the pulse calibration unit is used to excite a calibration pulse signal on the cable shielded and grounded wire according to the synchronous calibration signal, and use the obtained excitation pulse signal as a time reference signal.

[0018] The acquisition unit is used to obtain pulse signals; the pulse signals include: excitation pulse signals and the excitation pulse signals received by the acquisition units in adjacent acquisition and detection systems.

[0019] The detection module is used to collect pulse signals, synchronization signals, and phase synchronization signals, and determine the pulse time difference based on the time reference signal. Among them, the phase synchronization signal is output by the phase synchronization unit; the synchronization signal is output by the synchronization module; the synchronization signal includes: optical synchronization signal and Beidou synchronization signal.

[0020] The host computer is used to calibrate adjacent acquisition and detection systems according to the pulse time difference, and perform waveform comparison and analysis on the acquired data after calibration to obtain an analysis result; the analysis result is used to realize detection and positioning based on waveform delay.

[0021] Among them, the acquisition data is obtained after synchronously collecting partial discharge signals based on the positioning acquisition instruction issued by the host computer. The partial discharge signal is the pulse signal obtained correspondingly after calibrating adjacent acquisition and detection systems according to the pulse time difference.

[0022] In one embodiment, the device further includes: a communication unit; the communication unit is respectively connected to the host computer and the detection unit.

[0023] Among them, the communication unit includes: a 4G data communication module and an optical fiber communication module.

[0024] The phase synchronization unit uses a current phase synchronization sensor; the pulse calibration unit uses a synchronous pulse calibration sensor.

[0025] The amplitude of the synchronous calibration signal is adjustable; the adjustment range of the amplitude is 50 pC - 20 nC; the output frequency of the pulse signal is adjustable; the values of the output frequency include: 50 Hz, 100 Hz, 500 Hz, and 1 kHz.

[0026] When the detection unit adopts the optical fiber cascade method, it adopts optical fiber communication and optical synchronization acquisition; when adopting the wireless method, it adopts wireless communication and Beidou synchronization acquisition.

[0027] The synchronous self-calibration cable distributed partial discharge detection, calibration and positioning device further includes: a partial discharge detection input interface, a synchronous calibration output interface, an optical synchronization signal port, a phase synchronization input port, an optical fiber communication interface, a 4G antenna interface, and a Beidou antenna interface.

[0028] The inside of the partial discharge detection input interface is connected to the acquisition unit; the inside of the synchronous calibration output interface, the optical synchronization signal port, the phase synchronization input port, and the Beidou antenna interface are all connected to the synchronization module.

[0029] The inside of the 4G antenna interface is connected to the 4G data communication module; the inside of the optical fiber communication interface is connected to the optical fiber communication module.

[0030] To address the problems of the prior art, this application can implement partial discharge detection and positioning using optical synchronous acquisition and fiber optic communication, or Beidou synchronous acquisition and 4G wireless network communication, for different cable detection environments. Furthermore, with a synchronous self-calibration function, the device's synchronous acquisition performance can be verified, eliminating the need for additional equipment and methods to verify the performance of the detection, calibration, and positioning device.

[0031] The detection, calibration and positioning device mentioned in this application includes a partial discharge detection input interface, a synchronous calibration output interface, an optical synchronization signal port, a phase synchronization input port, an optical fiber communication interface, a 4G antenna interface and a Beidou antenna interface.

[0032] The synchronization calibration output interface, optical synchronization signal port, phase synchronization input port, and Beidou antenna interface are all internally connected to the synchronization module. The synchronization module provides the acquisition unit with the optical synchronization signal or Beidou synchronization signal required for synchronization acquisition. The phase synchronization input port is externally connected to the current phase synchronization sensor. The synchronization module processes the current signal coupled by the current phase synchronization sensor and provides the phase synchronization signal to the acquisition module. The 4G antenna interface is internally connected to the 4G data communication module, and the fiber optic communication interface is internally connected to the fiber optic communication module. The network port of the acquisition unit is connected to the network ports of the 4G data communication module and the fiber optic communication module, respectively. The 4G data receiving module communicates with the 4G data communication module using the 4G communication method via the 4G wireless network. The fiber optic communication module, through cascading between detection modules, enables data communication between the detection module and the communication device.

[0033] The synchronous data collection method uses Beidou synchronization or optical synchronization, and is connected to the backend via 4G wireless network or optical fiber to upload data. When the site is in an underground closed environment such as a tunnel, the device can use optical synchronous data collection and optical fiber communication to achieve partial discharge detection and positioning. When the site is in an environment where outdoor optical fiber is not convenient to lay, the device can use Beidou synchronous data collection and 4G wireless network communication to achieve partial discharge detection and positioning. In both modes, the device can achieve self-calibration of the detection device's synchronization performance without the need for additional verification devices, providing more accurate and efficient technical support for distributed partial discharge detection and positioning of cables.

[0034] The partial discharge detection input interface is connected to the partial discharge high-frequency sensor (acquisition unit). The partial discharge high-frequency sensor feedthrough is installed on the shielded grounding wire of the cable insulation joint. The partial discharge high-frequency sensor is used to receive the partial discharge signal (pulse signal) inside the cable.

[0035] The synchronous calibration output port connects to a synchronous pulse calibration sensor, which is mounted via a feedthrough on the shield ground wire of the cable's insulated connector. The synchronous pulse calibration sensor generates a calibration pulse signal on the cable's shield ground wire. The synchronous calibration output port also outputs a synchronous calibration signal with an adjustable amplitude range of 50pC to 20nC. The pulse signal output frequency is adjustable: 50Hz, 100Hz, 500Hz, and 1kHz.

[0036] The optical synchronization signal port is divided into two interfaces: an input port and an output port, which are used to connect optical synchronization signals and implement optical synchronization acquisition. The input port of the optical synchronization signal port of the first acquisition and detection system is connected to the input optical synchronization signal fiber, and the output port of the optical synchronization signal port is connected to the input optical synchronization signal port of the next acquisition and detection system. The optical synchronization signal connection method of all acquisition and detection systems is fiber optic cascading.

[0037] The phase synchronization input port is connected to the current phase synchronization sensor, which is mounted on the main cable and senses the running current of the main cable to achieve phase synchronization of the collected signal of the detection device.

[0038] The optical fiber communication interface is cascaded with the background communication device through optical fiber to realize the upload of partial discharge detection and positioning data collected by all detection devices.

[0039] The 4G antenna interface is used to connect an external 4G antenna to receive 4G wireless signals and upload partial discharge detection and positioning data collected by all detection devices. The Beidou antenna interface is used to connect an external Beidou antenna to obtain Beidou synchronization signals and realize Beidou synchronization collection for detection devices.

[0040] The device is battery powered and does not require any external power supply.

[0041] The time usage steps of the device mentioned in this application in actual application are as follows: Step 1: Install the partial discharge high-frequency sensor through-hole card on the shielded grounding wire of the cable insulation joint, and connect the high-frequency sensor output to the partial discharge detection input interface.

[0042] Step 2: Install the synchronous pulse calibration sensor feedthrough card on the same shielded grounding wire as the partial discharge high-frequency sensor. At the same time, the synchronous pulse calibration sensor is located at the upper end of the partial discharge high-frequency sensor, and the synchronous pulse calibration sensor output is connected to the synchronous calibration output interface.

[0043] Step 3: Mount the current phase synchronization sensor on the main cable, and connect the output of the current phase synchronization sensor to the phase synchronization input port.

[0044] Step 4: The host computer controls the first acquisition and detection system to output a synchronous calibration signal. The synchronous pulse calibration sensor connected to the first acquisition and detection system excites a pulse signal on the cable shield ground wire. The partial discharge high-frequency sensor of the first acquisition and detection system receives this excitation pulse signal. At the same time, this excitation pulse signal is used as the time reference signal. The partial discharge high-frequency sensor connected to the partial discharge detection channel of the second acquisition and detection system adjacent to the first acquisition and detection system also receives the excitation pulse signal. The host computer performs waveform comparison and analysis on the data uploaded by the two acquisition and detection systems. Since the cable length between the two acquisition and detection systems is known, the pulse time difference can be calculated by comparing the signals detected by the two acquisition and detection systems. The distance between the first acquisition and detection system and the second acquisition and detection system can be calculated from the pulse time difference and the inherent speed factor, which should be the known cable length. If there is a difference between the calculated distance and the actual cable length, the synchronous acquisition function of the second acquisition and detection system is calibrated by correcting the synchronous time delay of the second acquisition and detection system.

[0045] Step 5: The host computer controls the second acquisition and detection system to output a synchronous calibration signal. The synchronous pulse calibration sensor connected to the second acquisition and detection system excites a pulse signal on the cable shield ground wire. The partial discharge high-frequency sensor of the second acquisition and detection system receives this excitation pulse signal. At the same time, this excitation pulse signal is used as the time reference signal. The partial discharge high-frequency sensor connected to the partial discharge detection channel of the first acquisition and detection system adjacent to the second acquisition and detection system also receives the excitation pulse signal. Since the cable length between the two acquisition and detection systems is known, the pulse time difference can be calculated by comparing the excitation pulse signals detected by the two acquisition and detection systems. The distance between the second acquisition and detection system and the first acquisition and detection system can be calculated from the pulse time difference and the inherent speed factor, which should be the known cable length. If there is a difference between the calculated distance and the actual cable length, the synchronous acquisition function of the first acquisition and detection system is calibrated by correcting the synchronous time delay of the first acquisition and detection system.

[0046] Through the synchronous self-calibration function, the verification of the synchronous acquisition function between the two acquisition and detection systems is completed, and the synchronous time delay parameters have been corrected. In subsequent detections, the host computer issues positioning acquisition instructions to the two acquisition and detection systems. The first acquisition and detection system synchronously acquires the partial discharge signals coupled by the partial discharge high-frequency sensor, and the second acquisition and detection system synchronously acquires the partial discharge signals coupled by the partial discharge high-frequency sensor. At the same time, the detection data of both acquisition and detection systems are uploaded to the host computer. The host computer performs waveform comparison and analysis on the data uploaded by the two acquisition and detection systems, and realizes the detection and positioning function by comparing the waveform time delays detected by the two acquisition and detection systems.

[0047] The present application can stimulate a calibration pulse signal with adjustable amplitude and frequency to the shielded grounding wire of the cable insulation joint. The excitation pulse signal can be used to realize the calibration and detection of the synchronous performance of the distributed partial discharge detection and positioning device arranged on the long-distance cable line. There is no need to add other calibration and detection equipment to detect the synchronization performance of the detection device. This makes up for the deficiency of the detection device in the prior art that the synchronization performance cannot be calibrated by itself, and solves the problem that the pulse injected at the head end of the long-distance cable line will cause signal attenuation and oscillation at a long distance. At the same time, the synchronous acquisition method and communication method can be selected according to the actual on-site detection environment, which greatly improves the on-site compatibility and practicality of the device. It reduces the cost of manpower and material resources in the test and improves the work efficiency of on-site operation and maintenance personnel.

[0048] All acquisition and detection systems can achieve synchronous calibration using their own synchronous calibration functions, thereby ensuring the precision and accuracy of cable partial discharge detection and positioning. This application innovatively utilizes the excitation of calibration pulse signals on the shielded ground wire of high-voltage power cable lines, and then compares and analyzes the pulse signal information detected by two adjacent distributed partial discharge detection devices (acquisition and detection systems). This achieves accurate, reliable, and stable synchronous acquisition at both ends of the distributed partial discharge detection devices on long-distance cables, improving positioning accuracy.

[0049] like Figure 2 、 Figure 3 and Figure 4 As shown, in one embodiment of the present application, the devices are respectively arranged at multiple insulation joint positions of the cable line, with the one located at the first end cable insulation joint 18 being the first acquisition and detection system 10, the one located at the middle cable insulation joint 19 adjacent to the first end cable insulation joint being the second acquisition and detection system 11, and so on, and the one located at the terminal cable insulation joint being the acquisition and detection system N.

[0050] In the embodiment of the present application, the sensor connected to the first acquisition and detection system 10, the partial discharge high-frequency sensor 12 is mounted on the shielded grounding wire of the head-end cable insulation joint 18, and its output is connected to the partial discharge detection input interface 1 of the first acquisition and detection system 10; the first pulse calibration unit 14 is mounted on the shielded grounding wire of the head-end cable insulation joint 18 on the same side as the first acquisition unit 12. At the same time, the first pulse calibration unit 14 is located above the first acquisition unit 12, and the output of the first pulse calibration unit 14 is connected to the synchronous calibration output interface 2 of the first acquisition and detection system 10; the first phase synchronization unit 16 is mounted on the main cable, and its output is connected to the phase synchronization input port 4, that is, the phase synchronization input port of the first acquisition and detection system 10.

[0051] The sensors connected to the second acquisition and detection system 11. The second acquisition unit 13 is sleeved through and clamped on the shielding ground wire of the intermediate cable insulating joint 19, and its output is connected to the partial discharge detection input interface 1 of the second acquisition and detection system 11; the second pulse calibration unit 15 is sleeved through and clamped on the shielding ground wire of the intermediate cable insulating joint 19 on the same side as the second acquisition unit 13. At the same time, the second pulse calibration unit 15 is located above the second acquisition unit 13, and the output of the second pulse calibration unit 15 is connected to the synchronous calibration output interface 2 of the second acquisition and detection system 11; the second phase synchronization unit 17 is clamped on the main cable of the cable, and its output is connected to the phase synchronization input port of the second acquisition and detection system 11.

[0052] When the on-site environment is not convenient for laying optical fibers outdoors, such as Figure 3 shown in the application schematic diagram. The 4G antenna interfaces 6 of the first acquisition and detection system 10 and the second acquisition and detection system 11 are externally connected to 4G antennas to receive 4G signals for data communication. The Beidou antenna interfaces 7 are externally connected to Beidou antennas to receive Beidou synchronization signals for Beidou synchronous acquisition of the detection device. At the same time, the communication device 9 (communication unit) is interconnected with N distributed detection devices through the 4G wireless network, and uploads the partial discharge signals collected by the N distributed detection devices to the upper computer 8 through the network cable. The upper computer 8 processes, analyzes, and displays the partial discharge signals collected by the N distributed detection devices.

[0053] When the on-site environment is not convenient for laying optical fibers outdoors, such as Figure 3 shown in the application schematic diagram, the detection device synchronous acquisition method adopts Beidou synchronous signal acquisition. The Beidou antenna interfaces 7 of the first acquisition and detection system 10 and the second acquisition and detection system 11 are externally connected to Beidou antennas to receive Beidou synchronous signals. The inside of the Beidou antenna interface 7 is connected to the synchronization module. The synchronization module processes the received Beidou synchronous signals, and the processed signals are connected to the partial discharge acquisition module to provide the synchronous signals required for synchronous acquisition for the partial discharge acquisition module, and finally realizes Beidou synchronous acquisition of the detection device. The 4G antenna interfaces 6 of the first acquisition and detection system 10 and the second acquisition and detection system 11 are externally connected to 4G antennas to receive 4G wireless signals. The inside of the 4G antenna interface 6 is connected to the 4G data receiving module, and the network port of the 4G data receiving module is connected to the network port of the partial discharge acquisition module. The first acquisition and detection system 10 and the second acquisition and detection system 11 communicate with the communication device 9 through the 4G wireless network, and the communication device 9 is connected to the upper computer 8 through the network cable. The partial discharge signals collected by the partial discharge acquisition modules of the first acquisition and detection system 10 and the second acquisition and detection system 11 communicate with the communication device 9 through the 4G wireless network, and the communication device 9 then uploads the data to the upper computer 8. The upper computer 8 processes, analyzes, and displays the partial discharge signals collected by the detection device.

[0054] In the embodiments of the present application, when the site is in an underground closed environment such as a tunnel shaft, as Figure 4 shown in the application schematic diagram. The inside of the optical fiber communication interface 5 is connected to the optical fiber communication module. Specifically, the optical fiber communication interfaces of the first acquisition and detection system 10 and the second acquisition and detection system 11 are fiber-cascaded with the optical fiber communication interface of the communication device 9. The optical synchronous output of the communication device 9 is connected to the input port in the optical synchronous signal port 3 of the first acquisition and detection system 10 through an optical fiber. The input port inside the optical synchronous signal port 3 of the first acquisition and detection system 10 is connected to the synchronization module. At the same time, the synchronization module is connected to the partial discharge acquisition module. The output port in the optical synchronous signal port 3 of the first acquisition and detection system 10 is connected to the input port in the optical synchronous signal port 3 of the second acquisition and detection system 11. The communication device 9 provides an optical synchronous signal for synchronous acquisition for the first acquisition and detection system 10 and the second acquisition and detection system 11. At the same time, the communication device 9 is interconnected with N distributed detection devices through optical fibers, and uploads the partial discharge signals collected by the N distributed detection devices to the upper computer 8 through a network cable. The upper computer 8 processes, analyzes, and displays the partial discharge signals collected by the N distributed detection devices.

[0055] The present application can solve the deficiency in the prior art that there is no detection and evaluation method for the synchronization performance of the distributed partial discharge detection system of high-voltage power cable lines. It solves the problem that for long-distance cable lines, the use of the partial discharge pulse injection method causes serious attenuation and oscillation, ultimately affecting the calibration synchronization of the device. Its self-calibration working principle method includes: without adding additional calibration equipment, by detecting the self-output synchronization calibration signal of the detection device, and then enabling the synchronization pulse calibration sensor connected thereto to excite a calibration pulse signal on the cable shield grounding wire. This pulse synchronization signal will be simultaneously captured by the partial discharge high-frequency sensors connected to the partial discharge detection channels of two adjacent detection devices. Since the cable length between the two detection devices is known, the synchronization acquisition function of the device can be calibrated by comparing the time difference of the pulse signals detected by the two detection devices. The present application can realize the calibration of the synchronization acquisition performance between adjacent two devices of all cable distributed detection devices, improving the technical level in the field of cable insulation state detection and evaluation, and having important engineering test application value.

[0056] The calibration pulse signal with synchronous self-calibration function is realized by a detection unit and a synchronous pulse calibration sensor. The detection unit is powered by an internal battery. The synchronous pulse calibration sensor is clamped on the cable shielding ground wire. The detection module outputs a synchronous calibration signal to the synchronous pulse calibration sensor, and the synchronous pulse calibration sensor then reversely excites a calibration pulse signal. This calibration pulse signal forms a loop with the ground through the shielding ground wire. The partial discharge high-frequency sensor at the same clamping position as the synchronous pulse calibration sensor captures this calibration pulse signal. At the same time, it is synchronously collected and processed by the detection module, and the synchronous acquisition function of the acquisition and detection system is calibrated by comparing the time difference of the pulse signals detected by the two acquisition and detection systems.

[0057] The usage steps of the device mentioned in this application, taking the first acquisition and detection system 10 and the second acquisition and detection system 11 as examples, can be divided into the following steps: 1. The first acquisition unit 12 is clamped through the shielded ground wire of the first cable insulation joint 18 at the head end, and its output is connected to the partial discharge detection input interface 1 of the first acquisition and detection system 10; the first pulse calibration unit 14 is clamped through the shielded ground wire of the first cable insulation joint 18 at the same side as the first acquisition unit 12. At the same time, the first pulse calibration unit 14 is located above the first acquisition unit 12, and the output of the first pulse calibration unit 14 is connected to the synchronous calibration output interface 2 of the first acquisition and detection system 10; the first phase synchronization unit 16 is clamped on the main cable of the cable, and its output is connected to the phase synchronization input port of the first acquisition and detection system 10.

[0058] 2. The second acquisition unit 13 is clamped through the shielded ground wire of the intermediate cable insulation joint 19, and its output is connected to the partial discharge detection input interface 1 of the second acquisition and detection system 11; the second pulse calibration unit 15 is clamped through the shielded ground wire of the intermediate cable insulation joint 19 at the same side as the second acquisition unit 13. At the same time, the second pulse calibration unit 15 is located above the second acquisition unit 13, and the output of the second pulse calibration unit 15 is connected to the synchronous calibration output interface 2 of the second acquisition and detection system 11; the second phase synchronization unit 17 is clamped on the main cable of the cable, and its output is connected to the phase synchronization input port of the second acquisition and detection system 11.

[0059] 3. Select the corresponding communication and synchronous acquisition methods on the background monitoring host according to the on-site detection environment. When the site is outdoors and it is not convenient to lay optical fibers, adopt the Beidou synchronous acquisition method and 4G wireless network communication method as shown in the Figure 3 application schematic to realize partial discharge detection and positioning. When the site is in an underground closed environment such as a tunnel shaft, adopt the optical synchronous acquisition method and optical fiber communication method as shown in the Figure 4 application schematic to realize partial discharge detection and positioning.

[0060] 4. Open the calibration control option of the host computer 8 to control the first acquisition and detection system 10 to output a synchronous calibration signal. The amplitude adjustment range of the synchronous calibration signal is 50 pC - 20 nC, and the output frequency adjustment range of the discharge pulse (pulse signal) is 50 Hz, 100 Hz, 500 Hz, and 1 kHz. According to the on-site environmental noise interference, a synchronous calibration signal with a larger amplitude and a frequency avoiding the interference signal can be output.

[0061] 5. The first pulse calibration unit 14 excites a pulse signal on the cable shield ground wire. The pulse signal forms a loop with the ground through the shield ground wire. The first acquisition unit 12 and the second acquisition unit 13 simultaneously capture the pulse signal. The first acquisition and detection system 10 collects and processes the signal captured by the first acquisition unit 12, and the second acquisition and detection system 11 collects and processes the signal captured by the second acquisition unit 13. The processed data information is uploaded to the host computer 8 through the communication device 9. By comparing and analyzing the time delays of the pulse signals collected by the first acquisition and detection system 10 and the second acquisition and detection system 11 on the host computer 8, the time difference of the collected pulse signals is calculated. Combining with the inherent speed factor, the distance between the pulse signal source and the second acquisition unit 13 is further calculated. This distance should be the known cable length between the first acquisition and detection system 10 and the second acquisition and detection system 11. If there is a difference between the calculated distance and the actual cable length, the synchronous acquisition function of the second acquisition and detection system 11 is calibrated by correcting the synchronous time delay of the second acquisition and detection system 11.

[0062] 6. The second pulse calibration unit 15 excites a pulse signal on the cable shield ground wire. The pulse signal forms a loop with the ground through the shield ground wire. The second acquisition unit 13 and the first acquisition unit 12 simultaneously capture the pulse signal. The second acquisition and detection system 11 collects and processes the signal captured by the second acquisition unit 13, and the first acquisition and detection system 10 collects and processes the signal captured by the first acquisition unit 12. The processed data information is uploaded to the host computer 8 through the communication device 9. By comparing and analyzing the time delays of the pulse signals collected by the first acquisition and detection system 10 and the second acquisition and detection system 11 on the host computer 8, the time difference of the collected pulse signals is calculated. Combining with the inherent speed factor, the distance between the pulse signal source and the first acquisition unit 12 is further calculated. This distance should be the known cable length between the first acquisition and detection system 10 and the second acquisition and detection system 11. If there is a difference between the calculated distance and the actual cable length, the synchronous acquisition function of the first acquisition and detection system 10 is calibrated by correcting the synchronous time delay of the first acquisition and detection system 10.

[0063] This application solves the problem of the singularity of the synchronous acquisition and communication methods in current distributed detection systems. At the same time, the length of general long-distance cables is about 5 km, and an intermediate joint is set every 500 meters. Obviously, the method of simply injecting partial discharge pulse signals from the cable head end can no longer meet the calibration of the synchronous performance of long-distance cable partial discharge detection. This application can realize the detection and evaluation of the synchronous performance of distributed partial discharge detection devices for long-distance cable lines by exciting calibration signals on the cable shielding ground wire, which has important engineering practical value.

[0064] In an exemplary embodiment, a synchronous self-calibration cable distributed partial discharge detection and calibration positioning method is provided, which is implemented by using a synchronous self-calibration cable distributed partial discharge detection and calibration positioning device. As Figure 5 shown, the synchronous self-calibration cable distributed partial discharge detection and calibration positioning method includes: Step 100: Control the detection module to output a synchronous calibration signal based on the control signal issued by the upper computer.

[0065] Step 200: Control the pulse calibration unit to excite a calibration pulse signal on the cable shielding ground wire according to the synchronous calibration signal, and use the obtained excitation pulse signal as the time reference signal.

[0066] Step 300: Obtain the pulse signal, synchronous signal, and phase synchronous signal, and determine the pulse time difference based on the time reference signal. The pulse signal includes: the excitation pulse signal and the excitation pulse signal received by the acquisition unit in the adjacent acquisition detection system; the synchronous signal includes: the optical synchronous signal and the Beidou synchronous signal.

[0067] Step 400: Calibrate the adjacent acquisition detection systems according to the pulse time difference.

[0068] Step 500: Perform waveform comparison and analysis on the acquired data after calibration to obtain the analysis result. The analysis result is used to realize detection and positioning based on waveform time delay. Among them, the acquired data is obtained after synchronous acquisition of partial discharge signals based on the positioning acquisition instruction issued by the upper computer. And the partial discharge signal is the pulse signal obtained correspondingly after calibrating the adjacent acquisition detection systems according to the pulse time difference.

[0069] As an optional implementation manner, calibrating the adjacent acquisition detection systems according to the pulse time difference specifically includes: Based on the pulse time difference and the inherent speed factor, determine the cable length between the acquisition detection system and the adjacent acquisition detection system.

[0070] Compare the calculated cable length with the known cable length. If the values are different, perform synchronous time delay correction and calibration on the adjacent acquisition detection systems.

[0071] In addition, the synchronous self-calibration cable distributed partial discharge detection calibration and positioning method further includes: using 4G signals and optical fibers for data transmission.

[0072] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0073] Specific examples are used in this article to elaborate on the principles and implementation manners of the present application. The descriptions of the above embodiments are only used to help understand the device, method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A synchronous self-calibration cable distributed partial discharge detection calibration and positioning device, characterized in that: Including: A host computer and at least two acquisition and detection systems; The host computer is communicatively connected to the acquisition and detection systems; Each of the acquisition and detection systems includes: a detection unit, a pulse calibration unit, an acquisition unit, and a phase synchronization unit; wherein, the detection unit includes: a detection module and a synchronization module; The acquisition unit and the pulse calibration unit are both arranged on the same shielded grounding wire; the pulse calibration unit is located above the acquisition unit; The phase synchronization unit is arranged on the main cable and is connected to the detection module; the acquisition unit and the pulse calibration unit are both connected to the detection module; the synchronization module is also connected to the detection module; For any one of the acquisition and detection systems: The host computer is used to output a control signal; the detection module is used to receive the control signal and output a synchronization calibration signal; the pulse calibration unit is used to excite a calibration pulse signal on the cable shielded grounding wire according to the synchronization calibration signal and use the obtained excitation pulse signal as a time reference signal; The acquisition unit is used to acquire pulse signals; the pulse signals include: the excitation pulse signal and the excitation pulse signal received by the acquisition unit in an adjacent acquisition and detection system; The detection module is used to acquire the pulse signals, synchronization signals, and phase synchronization signals and determine the pulse time difference based on the time reference signal; wherein, the phase synchronization signal is output by the phase synchronization unit; the synchronization signal is output by the synchronization module; the synchronization signals include: an optical synchronization signal and a Beidou synchronization signal; The host computer is used to calibrate adjacent acquisition and detection systems according to the pulse time difference and perform waveform comparison and analysis on the acquired data after calibration to obtain an analysis result; the analysis result is used to realize detection and positioning based on waveform time delay.

2. The synchronous self-calibration cable distributed partial discharge detection calibration and positioning device according to claim 1, characterized in that: It further includes: A communication unit; The communication unit is respectively connected to the host computer and the detection unit; Wherein, the communication unit includes: a 4G data communication module and an optical fiber communication module.

3. The synchronous self-calibration cable distributed partial discharge detection calibration and positioning device according to claim 1, characterized in that: The phase synchronization unit adopts a current phase synchronization sensor; the pulse calibration unit adopts a synchronous pulse calibration sensor.

4. The synchronous self-calibration cable distributed partial discharge detection, calibration and positioning device according to claim 1, characterized in that, The amplitude of the synchronization calibration signal is adjustable; the adjustment range of the amplitude is 50 pC - 20 nC; the output frequency of the pulse signal is adjustable; The values of the output frequency include: 50 Hz, 100 Hz, 500 Hz, and 1 kHz.

5. The synchronous self-calibration cable distributed partial discharge detection calibration and positioning device according to claim 1, characterized in that: When the detection unit adopts a fiber optic cascade method, it adopts fiber optic communication and optical synchronization acquisition; when adopting a wireless method, it adopts wireless communication and Beidou synchronization acquisition.

6. The synchronous self-calibration cable distributed partial discharge detection, calibration and positioning device according to claim 2, characterized in that, The synchronous self-calibration cable distributed partial discharge detection, calibration, and positioning device further includes: a partial discharge detection input interface, a synchronization calibration output interface, an optical synchronization signal port, a phase synchronization input port, an optical fiber communication interface, a 4G antenna interface, and a Beidou antenna interface; The inside of the partial discharge detection input interface is connected to the acquisition unit; the inside of the synchronization calibration output interface, the optical synchronization signal port, the phase synchronization input port, and the Beidou antenna interface are all connected to the synchronization module; The interior of the 4G antenna interface is connected to the 4G data communication module; the interior of the optical fiber communication interface is connected to the optical fiber communication module.

7. A synchronous self - calibration cable distributed partial discharge detection, calibration and positioning method, characterized in that, It is realized by using the synchronous self-calibration cable distributed partial discharge detection, calibration and positioning device according to any one of claims 1-6; The synchronous self-calibration cable distributed partial discharge detection, calibration and positioning method includes: Controlling the detection module to output a synchronous calibration signal based on the control signal issued by the host computer; Controlling the pulse calibration unit to excite a calibration pulse signal on the cable shield ground wire according to the synchronous calibration signal, and using the obtained excitation pulse signal as the time reference signal; Obtaining the pulse signal, the synchronous signal and the phase synchronous signal, and determining the pulse time difference based on the time reference signal; the pulse signal includes: the excitation pulse signal and the excitation pulse signal received by the acquisition unit in the adjacent acquisition and detection system; the synchronous signal includes: the optical synchronous signal and the Beidou synchronous signal; Calibrating the adjacent acquisition and detection systems according to the pulse time difference; Performing waveform comparison and analysis on the acquired data after calibration to obtain an analysis result; the analysis result is used for detection and positioning based on the waveform time delay.

8. The synchronous self-calibration cable distributed partial discharge detection, calibration and positioning method according to claim 7, characterized in that, The acquired data is obtained after synchronously acquiring the partial discharge signal based on the positioning acquisition instruction issued by the host computer; the partial discharge signal is the pulse signal corresponding to the adjacent acquisition and detection systems after calibration according to the pulse time difference.

9. The synchronous self-calibration cable distributed partial discharge detection calibration and positioning method according to claim 7, characterized in that, Calibrating the adjacent acquisition and detection systems according to the pulse time difference specifically includes: Determining the cable length between the acquisition and detection system and the adjacent acquisition and detection system based on the pulse time difference and the inherent speed factor; Comparing the calculated cable length with the known cable length, and if the values are different, performing synchronous time delay correction and calibration on the adjacent acquisition and detection systems.

10. The synchronous self-calibration cable distributed partial discharge detection calibration and positioning method according to claim 7, wherein The synchronous self-calibration cable distributed partial discharge detection, calibration and positioning method further includes: using 4G signals and optical fibers for data transmission.

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