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

Abstract

The present application discloses a synchronous self-calibration cable distributed partial discharge detection calibration and positioning device and method, which relates to the technical field of power system cable insulation status detection. The device includes: a host computer and at least two acquisition and detection systems; for any acquisition and detection system: a detection module receives a control signal and outputs a synchronous calibration signal; a pulse calibration unit excites a calibration pulse signal to 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 host computer calibrates adjacent acquisition and detection systems according to the pulse time difference, and performs waveform comparison analysis on the collected data obtained after calibration to obtain analysis results; the analysis results are used to achieve detection and positioning based on waveform delay. The present application aims to achieve synchronous function calibration and partial discharge detection and positioning of cable distributed partial discharge detection.

Description

Technical Field

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

[0002] In power systems, the operating status of power cables is crucial to the stability of power transmission. Partial discharge (PD) location provides clear guidance for cable operation and maintenance. Currently, distributed PD detection and location methods, employing multiple detection and location devices along a single cable line, are commonly used in cable handover testing and live operation monitoring.

[0003] In the prior art, there is no effective detection and calibration method for evaluating the synchronous acquisition performance of multiple detection and positioning devices deployed on cable lines. Although the known technology can detect and evaluate the time synchronization and phase synchronization performance of distributed partial discharge detection systems on high-voltage power cable lines, for long cable lines with numerous intermediate joints, the output signal of the partial discharge calibration source will experience severe attenuation and oscillation as the cable length increases, which will significantly affect the time synchronization calibration of the remote detection devices. Summary of the Invention

[0004] The purpose of this 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 objectives, this application provides the following solutions:

[0006] In a first aspect, the present application provides a synchronous self-calibrating cable distributed partial discharge detection calibration and positioning device, comprising: a host computer and at least two acquisition and detection systems; the host computer is communicatively connected to the acquisition and detection systems;

[0007] 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;

[0008] 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;

[0009] 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;

[0010] For any of the above-mentioned acquisition and detection systems:

[0011] 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 to the cable shield ground wire according to the synchronous calibration signal, and use the obtained excitation pulse signal as a time reference signal;

[0012] 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 the adjacent acquisition detection system;

[0013] The detection module is used to collect the pulse signal, synchronization signal and phase synchronization signal, 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 signal includes: an optical synchronization signal and a Beidou synchronization signal;

[0014] The host computer is used to calibrate adjacent acquisition and detection systems according to the pulse time difference, and perform waveform comparison analysis on the acquisition data obtained after calibration to obtain analysis results; the analysis results are used to achieve detection and positioning based on waveform delay.

[0015] In a second aspect, the present application provides a synchronous self-calibrating cable distributed partial discharge detection calibration and positioning method, which is implemented using a synchronous self-calibrating cable distributed partial discharge detection calibration and positioning device; the synchronous self-calibrating cable distributed partial discharge detection calibration and positioning method comprises:

[0016] The control detection module outputs a synchronous calibration signal based on the control signal sent by the host computer;

[0017] The control pulse calibration unit excites a calibration pulse signal to the cable shield ground wire according to the synchronous calibration signal, and uses the obtained excitation pulse signal as a time reference signal;

[0018] Acquire a pulse signal, a synchronization signal, and a phase synchronization signal, and determine a 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 synchronization signal includes: an optical synchronization signal and a Beidou synchronization signal;

[0019] calibrating adjacent acquisition and detection systems according to the pulse time difference;

[0020] The collected data obtained after calibration is subjected to waveform comparison analysis to obtain analysis results; the analysis results are used to achieve detection and positioning based on waveform delay.

[0021] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0022] The present application provides a synchronous self-calibrating cable distributed partial discharge detection calibration and positioning device and method. For any acquisition and detection system, the following steps are implemented: a detection module receives a control signal and outputs a synchronous calibration signal; a pulse calibration unit excites a calibration pulse signal onto the cable shield ground wire based on the synchronous calibration signal, and uses the resulting excitation pulse signal as a time reference signal; the detection module determines the pulse time difference based on the time reference signal; and a host computer calibrates adjacent acquisition and detection systems based on the pulse time difference. This application distributes multiple acquisition and detection systems along a cable, each of which has its own synchronous calibration function, eliminating the need for pulse injection at the headend of a long-distance cable line. Furthermore, the presence of the pulse calibration unit, phase synchronization unit, and synchronization module prevents the excitation pulse signal from experiencing severe attenuation and oscillation as the cable length increases, thereby improving the accuracy of synchronous calibration. Furthermore, detection and positioning can be achieved by performing waveform comparison analysis on the acquired data obtained after calibration. Thus, the present application enables synchronous calibration and positioning for distributed cable partial discharge detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 The structural diagram of the calibration and positioning device for synchronous self-calibration cable distributed partial discharge detection;

[0025] Figure 2 Schematic diagram of the panel of the calibration and positioning device for synchronous self-calibration cable distributed partial discharge detection;

[0026] Figure 3 This is an application diagram of a synchronous self-calibration cable distributed partial discharge detection, calibration and positioning device based on Beidou synchronous data acquisition and 4G wireless network communication;

[0027] Figure 4 This is a schematic diagram of the application of a synchronous self-calibration cable distributed partial discharge detection, calibration and positioning device based on optical synchronous acquisition and optical fiber communication;

[0028] Figure 5 The present invention is a flow chart of the calibration and positioning method for synchronous self-calibration cable distributed partial discharge detection.

[0029] Reference numerals:

[0030] 1. Partial discharge detection input interface; 2. Synchronous calibration output interface; 3. Optical synchronization signal port; 4. Phase synchronization 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 synchronization unit; 17. Second phase synchronization unit; 18. Head-end cable insulation joint; 19. Middle cable insulation joint. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0032] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0033] In an exemplary embodiment, Figure 1 As shown, a synchronous self-calibrating cable distributed partial discharge detection calibration and positioning device is provided. The synchronous self-calibrating cable distributed partial discharge detection calibration and positioning device includes: a host computer and at least two acquisition and detection systems. The host computer is in communication with the acquisition and detection system.

[0034] Each acquisition and detection system 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.

[0035] 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.

[0036] 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; and the synchronization module is also connected to the detection module.

[0037] For any acquisition and detection system:

[0038] The host computer is used to output the control signal; the detection module is used to receive the control signal and output the synchronous calibration signal; the pulse calibration unit is used to stimulate the calibration pulse signal to the cable shield grounding wire according to the synchronous calibration signal, and use the obtained excitation pulse signal as the time reference signal.

[0039] The acquisition unit is used to acquire pulse signals; the pulse signals include: excitation pulse signals and excitation pulse signals received by acquisition units in adjacent acquisition and detection systems.

[0040] 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. The phase synchronization signal is output by the phase synchronization unit; the synchronization signal is output by the synchronization module; the synchronization signals include: optical synchronization signal and Beidou synchronization signal.

[0041] The host computer is used to calibrate adjacent acquisition and detection systems according to the pulse time difference, and perform waveform comparison analysis on the acquired data obtained after calibration to obtain analysis results; the analysis results are used to achieve detection and positioning based on waveform delay.

[0042] The collected data is obtained by synchronously collecting partial discharge signals based on the positioning and collection instructions issued by the host computer. The partial discharge signals are the corresponding pulse signals obtained after calibrating adjacent collection and detection systems based on the pulse time difference.

[0043] In one embodiment, the device further includes: a communication unit; the communication unit is connected to the host computer and the detection unit respectively.

[0044] Among them, the communication unit includes: 4G data communication module and optical fiber communication module.

[0045] The phase synchronization unit adopts a current phase synchronization sensor; the pulse calibration unit adopts a synchronous pulse calibration sensor.

[0046] The amplitude of the synchronous calibration signal is adjustable; the adjustment range of the amplitude is 50pC-20nC; the output frequency of the pulse signal is adjustable; the output frequency values ​​include: 50Hz, 100Hz, 500Hz and 1kHz.

[0047] When the detection unit adopts the optical fiber cascade mode, optical fiber communication and optical synchronous acquisition are adopted; when the wireless mode is adopted, wireless communication and Beidou synchronous acquisition are adopted.

[0048] The synchronous self-calibration cable distributed partial discharge detection, calibration and positioning device also 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.

[0049] The partial discharge detection input interface is internally connected to the acquisition unit; the synchronous calibration output interface, the optical synchronization signal port, the phase synchronization input port and the Beidou antenna interface are all internally connected to the synchronization module.

[0050] The 4G antenna interface is internally connected to the 4G data communication module; the optical fiber communication interface is internally connected to the optical fiber communication module.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] The device is battery powered and does not require any external power supply.

[0062] The time usage steps of the device mentioned in this application in actual application are as follows:

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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 to the cable shield grounding wire. The local discharge high-frequency sensor of the first acquisition and detection system receives the excitation pulse signal. At the same time, the excitation pulse signal is used as the time reference signal. The local 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 pulse time difference and the inherent velocity factor are used to calculate that the distance between the first acquisition and detection system and the second acquisition and detection system should be the known cable length. If the calculated distance is different from the actual cable length, the synchronous acquisition function of the second acquisition and detection system is calibrated by correcting the synchronous delay of the second acquisition and detection system.

[0067] 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 to the cable shield grounding wire. The partial discharge high-frequency sensor of the second acquisition and detection system receives the excitation pulse signal. At the same time, the 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 pulse time difference and the inherent velocity factor are used to calculate that the distance between the second acquisition and detection system and the first acquisition and detection system should be the known cable length. If the calculated distance is different from the actual cable length, the synchronous acquisition function of the first acquisition and detection system is calibrated by correcting the synchronous delay of the first acquisition and detection system.

[0068] The synchronous self-calibration function completes the verification of the synchronous acquisition function between the two acquisition and detection systems, and the synchronization delay parameters are corrected. In subsequent tests, 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 signal coupled to the partial discharge high-frequency sensor, and the second acquisition and detection system synchronously acquires the partial discharge signal coupled to 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 compares the waveform delay detected by the two acquisition and detection systems to realize the detection and positioning function.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] The sensor connected to the second acquisition and detection system 11, the second acquisition unit 13 is mounted on the shielded grounding 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 mounted on the shielded grounding wire of the intermediate cable insulation 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 mounted on the main cable, and its output is connected to the phase synchronization input port of the second acquisition and detection system 11.

[0074] When the site is in an environment where it is inconvenient to lay outdoor optical fiber, such as Figure 3 The application diagram shown in the figure shows that the 4G antenna interface 6 of the first acquisition and detection system 10 and the second acquisition and detection system 11 is connected to an external 4G antenna to receive 4G signals for data communication. The Beidou antenna interface 7 is connected to an external Beidou antenna to receive Beidou synchronization signals for Beidou-synchronized acquisition of the detection devices. Simultaneously, the communication device 9 (communication unit) interconnects with N distributed detection devices via a 4G wireless network and transmits the partial discharge signals collected by these N distributed detection devices via a network cable to the host computer 8. The host computer 8 processes, analyzes, and displays the partial discharge signals collected by the N distributed detection devices.

[0075] When the site is in an environment where it is inconvenient to lay outdoor optical fiber, such as Figure 3 As shown in the application diagram, the detection device uses Beidou synchronization signal acquisition for synchronous acquisition. The Beidou antenna interface 7 of the first acquisition detection system 10 and the second acquisition detection system 11 is externally connected to a Beidou antenna for receiving Beidou synchronization signals. The Beidou antenna interface 7 is internally connected to a synchronization module. The synchronization module processes the received Beidou synchronization signal. The processed signal is connected to the partial discharge acquisition module, providing the partial discharge acquisition module with the synchronization signal required for synchronous acquisition, ultimately achieving Beidou synchronous acquisition of the detection device. The 4G antenna interface 6 of the first acquisition detection system 10 and the second acquisition detection system 11 is externally connected to a 4G antenna for receiving 4G wireless signals. The 4G antenna interface 6 is internally connected to a 4G data receiving module. The network port of the 4G data receiving module is connected to the network port of the partial discharge acquisition module. The first acquisition detection system 10 and the second acquisition detection system 11 communicate with the communication device 9 using a 4G wireless network. The communication device 9 is connected to the host computer 8 via a network cable. The partial discharge signals collected by the partial discharge collection modules of the first collection and detection system 10 and the second collection and detection system 11 communicate with the communication device 9 via the 4G wireless network. The communication device 9 then uploads the data to the host computer 8. The host computer 8 processes, analyzes and displays the partial discharge signals collected by the detection devices.

[0076] In the embodiment of the present application, when the site is in an underground closed environment such as a tunnel, Figure 4 The application diagram shown in FIG. The optical fiber communication interface 5 is internally 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 cascaded with the optical fiber communication interface of the communication device 9 via optical fiber. The optical synchronization output of the communication device 9 is connected via optical fiber to the input port of the optical synchronization signal port 3 of the first acquisition and detection system 10. The input port of the optical synchronization signal port 3 of the first acquisition and detection system 10 is internally connected to the synchronization module. Simultaneously, the synchronization module is connected to the partial discharge acquisition module. The output port of the optical synchronization signal port 3 of the first acquisition and detection system 10 is connected to the input port of the optical synchronization signal port 3 of the second acquisition and detection system 11. The communication device 9 provides the first acquisition and detection system 10 and the second acquisition and detection system 11 with an optical synchronization signal for synchronous acquisition. Simultaneously, the communication device 9 interconnects with N distributed detection devices via optical fiber and transmits the partial discharge signals collected by the N distributed detection devices to the host computer 8 via a network cable. The host computer 8 processes, analyzes, and displays the partial discharge signals collected by the N distributed detection devices.

[0077] 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 the high-voltage power cable line. It solves the problem that the partial discharge pulse injection method is used in long-distance cable lines, which produces serious attenuation and oscillation and ultimately affects the calibration synchronization of the device. Its self-calibration working principle and method include: without adding additional calibration equipment, the detection device itself outputs a synchronization calibration signal, and then the synchronous pulse calibration sensor connected to it stimulates a calibration pulse signal to the cable shield grounding wire. The pulse synchronization signal will be captured simultaneously by the partial discharge high-frequency sensors connected to the partial discharge detection channels of the 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 two adjacent devices of all cable distributed detection devices, improve the technical level in the field of cable insulation status detection and evaluation, and has important engineering test application value.

[0078] The calibration pulse signal with synchronous self-calibration function is realized by the detection unit and the synchronous pulse calibration sensor. The detection unit is powered by an internal battery. The synchronous pulse calibration sensor is mounted on the cable shielding grounding wire. The detection module outputs the synchronous calibration signal to the synchronous pulse calibration sensor. The synchronous pulse calibration sensor thereby reversely stimulates a calibration pulse signal. The calibration pulse signal forms a loop with the ground through the shielding grounding wire. The partial discharge high-frequency sensor with the same mounting position as the synchronous pulse calibration sensor captures the calibration pulse signal. At the same time, it is synchronously collected and processed by the detection module. 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.

[0079] The steps for using the device mentioned in this application can be divided into the following steps, taking the first acquisition and detection system 10 and the second acquisition and detection system 11 as examples:

[0080] 1. The first acquisition unit 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 of the first acquisition and detection system 10.

[0081] 2. The second acquisition unit 13 is mounted on the shielded grounding 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 mounted on the shielded grounding wire of the intermediate cable insulation 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 mounted on the main cable, and its output is connected to the phase synchronization input port of the second acquisition and detection system 11.

[0082] 3. Select the corresponding communication and synchronous collection mode on the background monitoring host according to the on-site detection environment. When the site is outdoors and the optical fiber is not convenient to lay, use the following Figure 3 The Beidou synchronous acquisition method and 4G wireless network communication method are used to realize partial discharge detection and positioning. When the site is in an underground closed environment such as a tunnel, the following methods are used: Figure 4 The optical synchronous acquisition method and optical fiber communication method shown in the figure are used to realize the detection and positioning of partial discharge.

[0083] 4. Turn on 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 50pC-20nC, and the output frequency adjustment range of the discharge pulse (pulse signal) is 50Hz, 100Hz, 500Hz and 1kHz. According to the noise interference of the on-site environment, a synchronous calibration signal with a larger amplitude and a frequency that avoids interference signals can be output.

[0084] 5. The first pulse calibration unit 14 stimulates a pulse signal onto the cable shield ground wire. This 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 acquires and processes the signal captured by the first acquisition unit 12, and the second acquisition and detection system 11 acquires and processes the signal captured by the second acquisition unit 13. The processed data information is uploaded to the host computer 8 via the communication device 9. The host computer 8 compares and analyzes the pulse signal delays collected by the first acquisition and detection system 10 and the second acquisition and detection system 11, calculates the time difference of the collected pulse signals, and further calculates the distance between the pulse signal source and the second acquisition unit 13 by combining the inherent speed factor. 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 the calculated distance differs from the actual cable length, the synchronization delay of the second acquisition and detection system 11 is corrected to calibrate the synchronization acquisition function of the second acquisition and detection system 11.

[0085] 6. The second pulse calibration unit 15 excites a pulse signal onto the cable shield ground wire. This 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 acquires and processes the signal captured by the second acquisition unit 13, and the first acquisition and detection system 10 acquires and processes the signal captured by the first acquisition unit 12. The processed data information is uploaded to the host computer 8 via the communication device 9. The host computer 8 compares and analyzes the pulse signal delays collected by the first acquisition and detection system 10 and the second acquisition and detection system 11, calculates the time difference of the collected pulse signals, and further calculates the distance between the pulse signal source and the first acquisition unit 12 by combining the inherent speed factor. 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 the calculated distance differs from the actual cable length, the synchronization delay of the first acquisition and detection system 10 is corrected to calibrate the synchronization acquisition function of the first acquisition and detection system 10.

[0086] This application solves the current problem of a single synchronous acquisition and communication method in distributed detection systems. Furthermore, long-distance cables are typically around 5 km long, with intermediate connectors installed every 500 meters. Simply injecting a partial discharge pulse signal from the cable head is clearly insufficient for verifying the synchronization performance of partial discharge detection over long cables. This application, by stimulating a calibration signal on the cable shield ground wire, enables the detection and evaluation of the synchronization performance of distributed partial discharge detection devices over long cable lines, demonstrating significant engineering utility.

[0087] In an exemplary embodiment, a synchronous self-calibration cable distributed partial discharge detection calibration positioning method is provided, which is implemented using a synchronous self-calibration cable distributed partial discharge detection calibration positioning device. Figure 5 As shown, the synchronous self-calibration cable distributed partial discharge detection calibration and positioning method includes:

[0088] Step 100: The control detection module outputs a synchronous calibration signal based on the control signal sent by the host computer.

[0089] Step 200: Control the pulse calibration unit to excite a calibration pulse signal to the cable shield ground wire according to the synchronous calibration signal, and use the obtained excitation pulse signal as a time reference signal.

[0090] Step 300: Acquire pulse signals, synchronization signals, and phase synchronization signals, and determine the pulse time difference based on the time reference signal. The pulse signals include: excitation pulse signals and excitation pulse signals received by acquisition units in adjacent acquisition and detection systems; the synchronization signals include: optical synchronization signals and Beidou synchronization signals.

[0091] Step 400: Calibrate adjacent acquisition and detection systems according to the pulse time difference.

[0092] Step 500: Perform waveform comparison analysis on the collected data obtained after calibration to obtain analysis results. The analysis results are used to implement detection and positioning based on waveform delay. The collected data is obtained by synchronously collecting partial discharge signals based on positioning acquisition instructions issued by the host computer. The partial discharge signals are pulse signals obtained after calibrating adjacent acquisition and detection systems based on pulse time differences.

[0093] As an optional implementation, calibrating adjacent acquisition and detection systems based on the pulse time difference specifically includes:

[0094] The cable length between the acquisition and detection system and the adjacent acquisition and detection system is determined based on the pulse time difference and the inherent speed factor.

[0095] The calculated cable length is compared with the known cable length. If the values ​​are different, the adjacent acquisition and detection systems are synchronized and calibrated for delay correction.

[0096] In addition, the synchronous self-calibration cable distributed partial discharge detection calibration and positioning method also includes: using 4G signals and optical fibers for data transmission.

[0097] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, 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, they should be considered to be within the scope of this specification.

[0098] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only intended to help understand the device, method, and core concept of this application. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of this application. In summary, the contents of this specification should not be construed as limiting this application.

Claims

1. A synchronous self-calibration cable distributed partial discharge detection calibration and positioning device, characterized in that: include: Host computer and at least two acquisition and detection systems; The host computer is communicatively connected with the acquisition and detection system; 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 of the above-mentioned 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 to 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 the adjacent acquisition detection system; The detection module is used to collect the pulse signal, synchronization signal and phase synchronization signal, 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 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 analysis on the acquired data obtained after calibration to obtain analysis results; the analysis results are used to achieve detection and positioning based on waveform delay; When the detection unit adopts the optical fiber cascade mode, optical fiber communication and optical synchronous acquisition are adopted; when the wireless mode is adopted, wireless communication and Beidou synchronous acquisition are adopted; Calibrate adjacent acquisition and detection systems based on pulse time differences, including: Determine 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; The calculated cable length is compared with the known cable length. If the values ​​are different, the adjacent acquisition and detection systems are synchronized and calibrated for delay correction.

2. The synchronous self-calibration cable distributed partial discharge detection calibration and positioning device according to claim 1, characterized in that: Also includes: Communication unit; The communication unit is connected to the host computer and the detection unit respectively; 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 synchronization 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 synchronous calibration signal is adjustable; the adjustment range of the amplitude is 50pC-20nC; the output frequency of the pulse signal is adjustable; The output frequency values ​​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 2, characterized in that: The synchronous self-calibration cable distributed partial discharge detection, calibration and positioning device also 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; The partial discharge detection input interface is internally connected to the acquisition unit; the synchronization calibration output interface, the optical synchronization signal port, the phase synchronization input port and the Beidou antenna interface are all internally connected to the synchronization module; The 4G antenna interface is internally connected to the 4G data communication module; the optical fiber communication interface is internally connected to the optical fiber communication module.

6. A synchronous self-calibration cable distributed partial discharge detection calibration and positioning method, characterized in that: The method is implemented by using the synchronous self-calibration cable distributed partial discharge detection calibration and positioning device according to any one of claims 1 to 5; The synchronous self-calibration cable distributed partial discharge detection calibration and positioning method comprises: The control detection module outputs a synchronous calibration signal based on the control signal sent by the host computer; The control pulse calibration unit excites a calibration pulse signal to the cable shield ground wire according to the synchronous calibration signal, and uses the obtained excitation pulse signal as a time reference signal; Acquire a pulse signal, a synchronization signal, and a phase synchronization signal, and determine a 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 synchronization signal includes: an optical synchronization signal and a Beidou synchronization signal; calibrating adjacent acquisition and detection systems according to the pulse time difference; The collected data obtained after calibration is subjected to waveform comparison analysis to obtain analysis results; the analysis results are used to achieve detection and positioning based on waveform delay.

7. The synchronous self-calibration cable distributed partial discharge detection calibration and positioning method according to claim 6, characterized in that: The collected data is obtained by synchronously collecting partial discharge signals based on the positioning collection instructions issued by the host computer; the partial discharge signals are pulse signals correspondingly obtained after calibrating adjacent collection and detection systems according to the pulse time difference.

8. The synchronous self-calibration cable distributed partial discharge detection calibration and positioning method according to claim 6, characterized in that: Calibrate adjacent acquisition and detection systems according to the pulse time difference, specifically including: Determining the cable length between the acquisition and detection system and an adjacent acquisition and detection system based on the pulse time difference and the inherent speed factor; The calculated cable length is compared with the known cable length. If the values ​​are different, synchronization delay correction and calibration are performed on adjacent acquisition and detection systems.

9. The synchronous self-calibration cable distributed partial discharge detection calibration and positioning method according to claim 6, characterized in that: 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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