Device and method with accurate fault positioning function

Abstract

The invention belongs to the technical field of distribution network fault diagnosis, and particularly relates to a device and method with a fault accurate positioning function. The main control module is respectively connected with the fault interval judgment module, the traveling wave processing module, the GPS synchronization module and the main station reporting module and establishes a data channel; the fault interval judgment module provides a starting signal and an interval range for the traveling wave processing module and provides a power frequency recording file for the master station reporting module; the traveling wave processing module collects and processes traveling wave current and voltage signals; the GPS synchronization module provides a high-precision pulse signal and is used for recalibrating time; and the master station reporting module carries out fault interval precision and accurate positioning according to the received fault information in combination with the power frequency recording file and the traveling wave recording file. According to the invention, through dual-signal acquisition of traveling wave voltage and current signals, the method adapts to a multi-fault scene, and a current and voltage traveling wave comprehensive research and judgment method is adopted, so that the problem that a blind area exists at a current traveling wave interconnection switch is solved, and the problem of voltage traveling wave length line attenuation is also solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of distribution network fault diagnosis, and in particular relates to a device and method with a function of accurately locating faults. Background Art

[0002] The distribution network has the characteristics of a large number of lines, complex lines, and a large number of users. During operation, it is easily affected by lightning strikes, strong winds, fires, etc., resulting in a large number of instantaneous faults. The fault points are hidden and difficult to find, resulting in a long distribution network fault handling cycle, affecting power supply reliability. Existing distribution network fault location methods can be divided into two categories: one is the distribution network fault section location, and the other is the distribution network fault precise location.

[0003] The fault section location of the distribution network uses the distribution network's automation devices such as primary and secondary fusion and fault indicators to monitor the changes in various network parameters to make fault judgments. The location result is limited to between two automation devices, and the specific fault point still needs other positioning methods or manual line inspections to determine. The precise location of distribution network faults refers to the use of the traveling wave method to accurately locate faults without being limited to the monitoring information of existing automation devices; the current traveling wave method has a blind spot in the normal position of the tie switch and failure problems at the end of the line and the tie switch. The voltage traveling wave has signal attenuation and interference problems in long-distance line transmission, and it is difficult to identify the wave head. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a device and method with the function of accurately locating faults, which adopts the comprehensive analysis method of current and voltage traveling waves, which not only meets the long-distance requirements of the line, but also solves the problem of current traveling wave blind spots when the connecting switch is in normal position.

[0005] The technical solution adopted by the present invention to solve its technical problems is as follows: a device with a function of accurately locating a fault, comprising: a main control module, the main control module is respectively connected to a fault interval judgment module, a traveling wave processing module, a GPS synchronization module and a master station reporting module to establish a two-way data channel; the fault interval judgment module adopts dual-channel 4U4I data to provide a start signal and an interval range for the traveling wave processing module, and provides an industrial frequency recording file for the master station reporting module; the traveling wave processing module collects traveling wave current and voltage signals and processes them to obtain a traveling wave recording file; the GPS synchronization module provides a high-precision pulse signal for recalibrating the time; the master station reporting module: according to the received fault information, the fault interval accuracy and precise positioning are performed in combination with the industrial frequency recording file and the traveling wave recording file.

[0006] Furthermore, the main control module is connected to the field programmable gate array FPGA through a programming interface, and the conditioning circuit of the traveling wave current and voltage signal is connected to the FPGA through an AD converter.

[0007] Furthermore, a Rogowski coil is used to collect current traveling waves, and a capacitive coupler is used to collect voltage traveling waves.

[0008] Furthermore, the conditioning circuit is a dual-channel dual-gain conditioning circuit.

[0009] Furthermore, a random access memory RAM is connected to the FPGA.

[0010] The method for accurately locating a fault, using the above-mentioned device with the function of accurately locating a fault, comprises the following steps:

[0011] S1. Collect the traveling wave current and voltage signals, and transmit them to the AD converter after conditioning by the conditioning circuit. The AD converter converts the traveling wave analog signal into a digital signal and transmits it to the FPGA. The FPGA adds a synchronous time stamp to the collected traveling wave signal, performs threshold sliding window on the traveling wave signal, and analyzes the wave head data within a certain period of time after receiving the power frequency start information to extract the wave head;

[0012] S2, the main control module collects the power frequency 4U4I signal, and performs short circuit and ground fault startup judgment at the same time. When the fault recording is started, the startup signal and fault time are sent to the FPGA, and the fault SOE is reported to the main station reporting module at the same time. After receiving the power frequency startup information, the FPGA analyzes the wave head data within a certain period of time and extracts the wave head;

[0013] S3. Send the wave head signal to the main control module for storage. After the main station reporting module issues the recruitment command, it sends the power frequency and traveling wave information to the main station for comprehensive analysis.

[0014] Further, collecting the traveling wave current and voltage signal includes: collecting the current traveling wave front end using a Rogowski coil, and the line current signal I collected by the Rogowski coil A-B+C The output is a voltage signal; the voltage traveling wave is collected by a capacitive coupler and then made into a line voltage U according to A-B+C on the primary side. A-B+C .

[0015] Furthermore, in step S1, the wave head information whose amplitude exceeds the threshold is stored in the RAM. When the power frequency start information is received, the FPGA finds the fault wave head 100ms before and after the fault time to perform wave head recognition.

[0016] Furthermore, the synchronization time scale added in step S1 is obtained by processing the 1PPS signal of the high-precision GPS by the main control module and the FPGA, calibrating the crystal oscillator according to the clock deviation twice, and re-calibrating the time.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: through the dual signal collection of traveling wave voltage and current signals, it adapts to multiple fault scenarios and adopts the comprehensive analysis method of current and voltage traveling waves, which not only solves the blind spots at the current traveling wave connecting switch, but also solves the problem of line attenuation of the voltage traveling wave; the voltage and current traveling waves adopt A-B+C line mode dual-channel sampling to reduce the number of traveling wave sampling paths, reduce costs, and increase the traveling wave detection range. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic block diagram of a device with a fault accurate positioning function;

[0019] Figure 2 It is a schematic diagram of collecting current traveling waves and voltage traveling waves in the present invention. DETAILED DESCRIPTION

[0020] In order to facilitate the understanding of the present invention, the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0021] Combination Figure 1 It is understood that a device with the function of accurately locating faults includes: a main control module, which is respectively connected to the fault interval judgment module, the traveling wave processing module, the GPS synchronization module and the main station reporting module to establish a two-way data channel; the fault interval judgment module uses dual-channel 4U4I data to provide a start signal and interval range for the traveling wave processing module, and provides an industrial frequency recording file for the main station reporting module; the traveling wave processing module collects the traveling wave current and voltage signals and processes them to obtain a traveling wave recording file; the GPS synchronization module provides a high-precision pulse signal for recalibrating the time; the main station reporting module: based on the received fault information, combined with the industrial frequency recording file and the traveling wave recording file, the fault interval accuracy and precise positioning are performed.

[0022] In one embodiment, the main control module is connected to a field programmable gate array FPGA via a programming interface, and a conditioning circuit for traveling wave current and voltage signals is connected to the FPGA via an AD converter.

[0023] In one embodiment, a Rogowski coil is used to collect current traveling waves, and a capacitive coupler is used to collect voltage traveling waves.

[0024] In one embodiment, the conditioning circuit is a dual-channel dual-gain conditioning circuit.

[0025] In one embodiment, a random access memory RAM is connected to the FPGA.

[0026] The method for accurately locating a fault, using the above-mentioned device with the function of accurately locating a fault, comprises the following steps:

[0027] S1. Collect the traveling wave current and voltage signals, and transmit them to the AD converter after conditioning by the conditioning circuit. The AD converter converts the traveling wave analog signal into a digital signal and transmits it to the FPGA. The FPGA adds a synchronous time stamp to the collected traveling wave signal, performs threshold sliding window on the traveling wave signal, and analyzes the wave head data within a certain period of time after receiving the power frequency start information to extract the wave head;

[0028] S2, the main control module collects the power frequency 4U4I signal, and performs short circuit and ground fault startup judgment at the same time. When the fault recording is started, the startup signal and fault time are sent to the FPGA, and the fault SOE is reported to the main station reporting module at the same time. After receiving the power frequency startup information, the FPGA analyzes the wave head data within a certain period of time and extracts the wave head;

[0029] S3. Send the wave head signal to the main control module for storage. After the main station reporting module issues the recruitment command, it sends the power frequency and traveling wave information to the main station for comprehensive analysis.

[0030] In one embodiment, collecting the traveling wave current and voltage signal includes: collecting the current traveling wave front end using a Rogowski coil, and the line current signal I collected by the Rogowski coil A-B+C The output is a voltage signal; the voltage traveling wave is collected by a capacitive coupler and then made into a line voltage U according to A-B+C on the primary side. A-B+C .

[0031] In one embodiment, in step S1, the wave head information whose amplitude exceeds the threshold is stored in the RAM. When receiving the power frequency start information, the FPGA finds the fault wave head 100ms before and after the fault time to perform wave head recognition.

[0032] In one embodiment, the synchronization time scale added in step S1 is obtained by processing the 1PPS signal of the high-precision GPS by the main control module and the FPGA, calibrating the crystal oscillator according to the clock deviation twice, and re-calibrating the time.

[0033] Embodiment 1: A device with a fault accurate positioning function, combined with Figure 1 It is understood that it includes: a fault interval judgment module, a traveling wave processing module, a GPS synchronization module, a master station reporting module and a main control module. The fault interval judgment module, the traveling wave processing module, the GPS synchronization module and the master station reporting module respectively establish signal connections with the main control module, and the main control module participates in the data processing of the entire device.

[0034] The fault section judgment module mainly provides start signals and section ranges for traveling waves, including: collection of power frequency phase current, phase voltage, zero-sequence current, and zero-sequence voltage, fault start, and recording. It uses dual-channel to collect 4U4I data and conducts fault judgment.

[0035] The traveling wave processing module includes collection and conditioning of traveling wave current and voltage signals, high-speed AD collection, traveling wave threshold start, and extraction of traveling wave wavefronts; combined with Figure 2 understanding, the front end of the current traveling wave is collected by a Rogowski coil. The line current signal I collected by the Rogowski coil in the A - B + C manner A-B+C The output is the voltage signal U_Rog(A - B + C); specifically, the primary side is I A -I B +I C , and the secondary side output is U_Rog(A - B + C). The "-" end of the A-phase Rogowski coil is connected to the "-" end of the B-phase Rogowski coil, the "+" end of the B-phase Rogowski coil is connected to the "+" end of the C-phase Rogowski coil, and the signal between the "+" end of the A-phase Rogowski coil and the "-" end of the C-phase Rogowski coil is measured, which is U_Rog(A - B + C); the voltage traveling wave is collected by a capacitive coupler. After collection, the line voltage is made in the A - B + C manner on the primary side. The "-" end of the A-phase transformer is connected to the "-" end of the B-phase transformer, the "+" end of the B-phase transformer is connected to the "+" end of the C-phase transformer, and the signal between the "+" end of the A-phase transformer and the "-" end of the C-phase transformer is measured, which is U A-B+C . In Figure 2 two high-voltage capacitors are shown. Using one high-voltage capacitor can achieve the purpose in this application; the current and voltage traveling wave signals enter the high-speed AD collection after passing through the dual-channel and dual-gain conditioning circuit; the traveling wave signals are transmitted to the FPGA for processing after digital-to-analog conversion. The FPGA performs threshold sliding windowing, stores the wavefront information with an amplitude exceeding the threshold in the RAM, and analyzes the wavefront data within 100 ms when receiving the power frequency start information to extract the wavefront.

[0036] GPS synchronization module: The main control chip and the FPGA process the 1PPS signal of the high-precision GPS, calibrate the crystal oscillator according to the clock deviation between two times, and re-perform time calibration.

[0037] Master station reporting module: After a fault occurs, it sends the fault SOE to the master station. The master station returns the power frequency recording file and the traveling wave recording file, and performs fault section accuracy and precise positioning based on the data.

[0038] The working principle is as follows: the traveling wave voltage signal collected by the capacitive coupler and the traveling wave current signal collected by the Rogowski coil are conditioned by the conditioning circuit and transmitted to the high-speed AD. The high-speed AD converts the traveling wave analog signal into a digital signal and transmits it to the FPGA. The FPGA adds a synchronous time stamp to the collected traveling wave signal, and the traveling wave signal is thresholded and windowed. When the peak value exceeds the threshold, the 1ms traveling wave data is stored; the main control board collects the power frequency 4U4I signal, and performs short circuit and grounding fault startup judgment at the same time. When the fault recording is started, the startup signal and the fault time are sent to the FPGA for wave head extraction, and the fault SOE is reported to the main station at the same time. The FPGA finds the fault wave head 100ms before and after the fault time for wave head identification; the wave head signal is sent to the main control for storage. After the main station issues the recruitment command, the power frequency and traveling wave information are sent to the main station for comprehensive analysis. The comprehensive analysis mainly considers the signal-level fusion processing of the fault traveling wave and the information-level fusion processing of multiple fault waves at the main station. First, compare the wave head quality evaluation factors in the voltage and current wave head information to determine whether to use voltage or current information. For scenarios with multiple fault traveling waves, use multiple fault traveling waves to perform wave head extraction and analysis to check whether the wave head extraction results satisfy the normal distribution. Multiple syntheses can be used to reduce the extraction error.

[0039] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

Claims

1. A device with a fault accurate positioning function, comprising: The main control module is characterized in that the main control module is respectively connected to the fault interval judgment module, the traveling wave processing module, the GPS synchronization module and the main station reporting module to establish a two-way data channel; the fault interval judgment module adopts dual-channel 4U4I data to provide a start signal and an interval range for the traveling wave processing module, and provides an industrial frequency recording file for the main station reporting module; the traveling wave processing module collects the traveling wave current and voltage signals and processes them to obtain the traveling wave recording file; the GPS synchronization module provides a high-precision pulse signal for recalibrating the time; the main station reporting module: according to the received fault information, the fault interval accuracy and precise positioning are performed in combination with the industrial frequency recording file and the traveling wave recording file.

2. The device with the function of accurately locating faults according to claim 1, characterized in that: The main control module is connected to the field programmable gate array FPGA through a programming interface, and the conditioning circuit of the traveling wave current and voltage signal is connected to the FPGA through an AD converter.

3. The device with the function of accurately locating faults according to claim 2, characterized in that: Rogowski coil is used to collect current traveling wave, and capacitive coupler is used to collect voltage traveling wave.

4. The device with the function of accurately locating faults according to claim 2, characterized in that: The conditioning circuit is a dual-channel dual-gain conditioning circuit.

5. The device with the function of accurately locating faults according to claim 2, characterized in that: The FPGA is connected to a random access memory RAM.

6. A method for accurately locating a fault, characterized in that: The device with the function of accurately locating faults as claimed in claim 2 comprises the following steps: S1. Collect the traveling wave current and voltage signals, and transmit them to the AD converter after conditioning by the conditioning circuit. The AD converter converts the traveling wave analog signal into a digital signal and transmits it to the FPGA. The FPGA adds a synchronous time stamp to the collected traveling wave signal, performs threshold sliding window on the traveling wave signal, and analyzes the wave head data within a certain period of time after receiving the power frequency start information to extract the wave head; S2, the main control module collects the power frequency 4U4I signal, and performs short circuit and ground fault startup judgment at the same time. When the fault recording is started, the startup signal and fault time are sent to the FPGA, and the fault SOE is reported to the main station reporting module at the same time. After receiving the power frequency startup information, the FPGA analyzes the wave head data within a certain period of time and extracts the wave head; S3. Send the wave head signal to the main control module for storage. After the main station reporting module issues the recruitment command, it sends the power frequency and traveling wave information to the main station for comprehensive analysis.

7. The method for accurate fault location according to claim 6, characterized in that: The collection of traveling wave current and voltage signals includes: using a Rogowski coil to collect the current traveling wave front end, and the line current signal I collected by the Rogowski coil A-B+C The output is a voltage signal; the voltage traveling wave is collected by a capacitive coupler and then made into a line voltage U according to A-B+C on the primary side. A-B+C .

8. The method for accurate fault location according to claim 6, characterized in that: In step S1, the wave head information with amplitude exceeding the threshold is stored in the RAM. When the power frequency start information is received, the FPGA finds the fault wave head 100ms before and after the fault time for wave head recognition.

9. The method for accurate fault location according to claim 6, characterized in that: The synchronization time scale added in step S1 is obtained by processing the 1PPS signal of the high-precision GPS by the main control module and FPGA, calibrating the crystal oscillator according to the clock deviation twice, and re-calibrating the time.

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