Integrated column switch with traveling wave time extraction function

Abstract

The utility model discloses an integrated column switch with a traveling wave time extraction function, which comprises an integrated switch body and a traveling wave time extraction device, and the traveling wave time extraction device comprises a voltage transformer, a traveling wave head detection module, a clock synchronization module, a communication module and a power supply module. Wherein the voltage transformer is connected to the traveling wave head detection module, the traveling wave head detection module is connected to the clock synchronization module, the clock synchronization module is connected to the communication module, and the power supply module provides a working power supply for the voltage transformer, the traveling wave head detection module, the clock synchronization module and the communication module. According to the utility model, hardware is adopted to capture a fault traveling wave head, an analog signal is converted into a digital signal after passing through the hysteresis comparator circuit, the device has the characteristics of high precision, fast speed, simple structure and the like, and the capability of identifying continuous multiple fault traveling wave signals is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of power distribution network, and in particular relates to an integrated pole-mounted switch with a traveling wave moment extraction function. Background Art

[0002] In recent years, the country has vigorously promoted the construction of smart grids, and improving the automation and intelligence level of distribution networks is the basis for realizing smart grids. With the formation of multi-regional networked power supply, the scale of distribution networks is constantly expanding, and distribution networks are becoming more and more complex, which puts forward higher requirements for the reliability and quality of power supply of distribution networks: once the distribution network fails or operates abnormally, especially after a single-phase grounding fault occurs, the distribution network operator can quickly simulate the fault area, locate the grounding fault point in a timely and accurate manner, and quickly provide a solution, and then quickly operate the fault area to be isolated and the switch to be operated, so as to restore power supply in the shortest time and minimize the losses caused by power outages. Research on post-distribution fault diagnosis and power supply restoration can not only greatly shorten the fault outage time, but also minimize the fault impact area, and minimize the impact and losses caused by power outages on social and economic life. Utility Model Content

[0003] The utility model provides an integrated column switch with a traveling wave time extraction function, which can capture and record the arrival time of the fault traveling wave head.

[0004] In order to achieve the above technical purpose, the utility model adopts the following technical solutions:

[0005] An integrated pole-mounted switch with a traveling wave moment extraction function comprises an integrated switch body and a traveling wave moment extraction device, wherein the traveling wave moment extraction device comprises: a voltage transformer, a traveling wave head detection module, a clock synchronization module, a communication module and a power supply module; wherein the voltage transformer is connected to the traveling wave head detection module, the traveling wave head detection module is connected to the clock synchronization module, the clock synchronization module is connected to the communication module, and the power supply module provides working power for the voltage transformer, the traveling wave head detection module, the clock synchronization module and the communication module.

[0006] Furthermore, the clock synchronization module includes a GPS / Beidou dual-mode satellite clock unit and an STM32 processor; the GPS / Beidou dual-mode satellite clock unit is connected to the STM32 processor to provide second pulses for the STM32 processor; the traveling wave head detection module and the communication module are both connected to the STM32 processor.

[0007] Furthermore, the 1PPS pin of the GPS / Beidou dual-mode satellite clock unit is connected to the STM32 to provide the STM32 with a time with an accuracy of more than one second of the traveling wave moment; the STM32 includes at least two timers, the first timer is used to convert the seconds provided by the GPS / Beidou dual-mode satellite clock unit into a count number, and the second timer is used to stop counting when the traveling wave signal is triggered, and the number recorded at this time is used as the time with an accuracy of less than one second of the traveling wave moment.

[0008] Furthermore, the traveling wave head detection module is used to shape the fault traveling wave collected by the voltage transformer into a square wave to trigger the timer of the STM32 processor; the traveling wave head detection module includes two transient voltage suppression diodes TVS, two hysteresis comparators and one Schmidt inverter; the anode of the first TVS is connected to the voltage transformer, the cathode of the first TVS is connected to the input end of the hysteresis comparator, the output end of the hysteresis comparator is connected to the first input end of the Schmidt inverter, and the first output end of the Schmidt inverter corresponding to the first input end is connected to the STM32 processor; the cathode of the second TVS is connected to the voltage transformer, the anode of the second TVS is connected to the input end of the hysteresis comparator, the output end of the hysteresis comparator is connected to the second input end of the Schmidt inverter, and the second output end of the Schmidt inverter corresponding to the second input end is connected to the STM32 processor.

[0009] Furthermore, the communication module adopts GPRS communication to send the traveling wave moment extracted by the STM32 processor to the upper computer positioning system.

[0010] Furthermore, the voltage transformer is an optical voltage transformer.

[0011] Beneficial Effects

[0012] The utility model adopts hardware to capture the fault traveling wave head, and the analog signal is converted into a digital signal after passing through the hysteresis comparator (window comparator) circuit, which has the characteristics of high precision, fast speed, simple structure, etc., and improves the device's ability to identify multiple consecutive fault traveling wave signals. The hysteresis comparator has a certain anti-interference ability.

[0013] The satellite dual-mode model clock unit is based on the complementary characteristics of the satellite clock PPS signal and the Beidou clock PPS signal. The two serve as redundant backups for each other, greatly improving the timing accuracy, and increasing system reliability while also improving system performance.

[0014] Traditional power line carrier communication solutions are easily interfered by fundamental waves during signal transmission, and optical fiber communication is not suitable for large-scale deployment in wild environments. GPRS has almost no cost issues, and the electromagnetic interference generated during operation has a negligible impact on the traveling waves on the transmission line, and will not interfere with the signal collection of the traveling wave sensor. It can ensure the accuracy of fault location, and has the advantages of fast login and real-time online. Its wide access range and flexible access methods enable it to provide reliable data transmission solutions for fault location devices in remote areas and on longer lines. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a block diagram of the composition of the traveling wave time extraction device described in the embodiment of the present application;

[0016] Figure 2 It is a block diagram of the traveling wave head detection module described in the embodiment of the present application;

[0017] Figure 3 is a schematic diagram of a synchronous clock module described in an embodiment of the present application;

[0018] Figure 4 It is a GPRS communication principle diagram described in the embodiment of the present application;

[0019] Figure 5 It is a test installation diagram of the implementation scheme in the embodiment of the present application. DETAILED DESCRIPTION

[0020] The following is a detailed description of an embodiment of the present invention. This embodiment is based on the technical solution of the present invention, and provides a detailed implementation method and a specific operation process to further explain the technical solution of the present invention.

[0021] The present embodiment provides an integrated pole-mounted switch with a traveling wave moment extraction function, which is divided into a primary part (switch body) and a secondary part (distribution switch monitoring terminal FTU) in terms of composition. The primary part is composed of an operating mechanism, an arc extinguishing chamber, a DC motor, etc., and is responsible for collecting the distribution line status and executing FTU control commands; the secondary part is composed of a CPU controller, a safety communication device, a PCB board, etc., and is mainly responsible for operating status analysis and protection control command exports. The present invention adds a traveling wave moment extraction function to the basic functions of the existing integrated intelligent pole-mounted switch, which is used for fault location after fault isolation. It can accurately locate the grounding fault point on the fault section, which is convenient for power grid operators to quickly find and eliminate faults and restore power supply, reduce huge economic losses caused by power outages, and maintain safe and stable operation of the power grid.

[0022] Specifically, in this embodiment, the integrated pole-mounted switch with a traveling wave time extraction function, the integrated switch body and the supporting equipment adopt existing mature software and hardware equipment, which will not be elaborated here. In addition to the integrated switch body, the integrated pole-mounted switch with a traveling wave time extraction function in this embodiment also includes a traveling wave time extraction device, which is as follows: Figure 1 As shown, it includes: an optical voltage transformer, a traveling wave head detection module, a clock synchronization module, a GPRS communication module and a power module. Among them, the clock synchronization module includes a GPS / Beidou dual-mode satellite clock unit and an STM32 processor. The GPS / Beidou dual-mode satellite clock unit is connected to the STM32 processor to provide accurate second pulses for the STM32 processor. The voltage transformer is connected to the traveling wave head detection module, the traveling wave head detection module is connected to the STM32 processor, and the STM32 processor is connected to the GPRS communication module. The power module provides working power for the voltage transformer, the traveling wave head detection module, the clock synchronization module, and the GPRS communication module.

[0023] When a fault or other form of disturbance occurs somewhere in the power grid, the high-frequency transient traveling wave signal generated at the fault point or disturbance point propagates to both ends of the line. The voltage transformer extracts the high-frequency transient fault traveling wave signal from the integrated switch, and the fault traveling wave arrival time is extracted by the subsequent traveling wave head detection module, and the communication module uploads the fault traveling wave arrival time. The host computer completes the judgment of the fault traveling wave signal. Specifically: First, the optical voltage transformer collects the fault traveling wave signal of the distribution network; then, the traveling wave head detection module shapes the collected traveling wave signal into a square wave signal; the STM32 processor is responsible for receiving and sending the traveling wave information, and processes the shaped square wave signal to ensure the clock synchronization of the traveling wave moment extraction device of all integrated switch bodies; finally, the GPRS communication module sends the traveling wave moment obtained by the STM32 processor to the host computer.

[0024] Wherein, the traveling wave head detection module is as follows: Figure 2 As shown, it includes 2 transient voltage suppression diodes TVS, 2 hysteresis comparators and 1 Schmidt inverter; the anode of the first TVS is connected to the voltage transformer, the cathode of the first TVS is connected to the input end of the hysteresis comparator, the output end of the hysteresis comparator is connected to the first input end of the Schmidt inverter, and the first output end of the Schmidt inverter corresponding to the first input end is connected to the STM32 processor; the cathode of the second TVS is connected to the voltage transformer, the anode of the second TVS is connected to the input end of the hysteresis comparator, the output end of the hysteresis comparator is connected to the second input end of the Schmidt inverter, and the second output end of the Schmidt inverter corresponding to the second input end is connected to the STM32 processor.

[0025] The hysteresis comparator has two unequal thresholds, and its transfer characteristics have the shape of a "hysteresis" curve, so it has a certain anti-interference ability. When the voltage of the input signal is greater than the threshold, the comparator outputs a high level; when the voltage of the input signal is less than the threshold, the comparator outputs a low level, thereby realizing the conversion of analog signals to digital signals.

[0026] like Figure 3 As shown, the 1PPS pin of the GPS / Beidou dual-mode satellite clock unit is connected to the STM32 to provide the STM32 with time in seconds. In addition, the STM32 includes at least two timers. The first timer is used to convert the seconds provided by the GPS / Beidou dual-mode satellite clock unit into counts, and the second timer is used to stop counting when the traveling wave signal is triggered, and the number recorded at this time is used as the time with an accuracy of less than a second at the traveling wave moment. The STM32 forms a time message with the obtained traveling wave moment, sends it to the GPRS communication module equipped with a SIM card via the parallel port, and sends it to the Alibaba cloud server in the form of a text message. The cloud server performs cloud computing based on the obtained traveling wave time to achieve fault location. Figure 4 shown.

[0027] This embodiment utilizes the GPS / Beidou dual-mode satellite clock unit to upgrade the previously insecure "US timing" to reliable "China timing". Based on the complementary accuracy of the satellite clock pps signal and the Beidou clock pps signal, the timing accuracy is greatly improved.

[0028] In this embodiment, the traveling wave time is sent to the host computer through GPRS communication. GPRS is a wireless mobile communication technology. The establishment and maintenance of all infrastructure are guaranteed by mobile operators, and there is almost no cost problem.

[0029] Implementation plan:

[0030] Through the 10kV real-type laboratory, the distribution network system is simulated, where: Line 1 is II real city line, Line 2 is I real city line, Line 3 is IV real city line, Line 4 is III real city line, Line 5 is II real city line, and Line 6 is I real city line. Various simulated working condition tests of resistance grounding, cable arc grounding and multi-branch line faults are carried out, and the distribution system simulates a capacitive current of 4A to verify the fault location prototype function of the integrated intelligent pole-mounted switch.

[0031] The overall wiring diagram is as follows Figure 5 As shown, each kilometer of overhead line is connected to the next 1 km overhead line through about 30m of cable. Fault point location: Fault point 1 is located at busbar I, fault point 2 is located at busbar II, and fault point 3 is located at column 3-#4. Monitoring point location: Prototype No. 1 is located at column 4-#10, Prototype No. 2 is located at column 3-#4, and Prototype No. 3 is located at column 1-#9.

[0032] Experiment 1: Connect all branches to the experimental line, and compare the changes of traveling waves before and after adding the line under the fault of grounding resistance 5kΩ and arc high resistance grounding.

[0033] Experiment 2: Add a branch line to the overhead branch line where the fault point 1 is located, compare the traveling wave signals before and after adding the branch under the fault of grounding resistance 5kΩ and arc high-resistance grounding, and measure the fault traveling wave signal.

[0034] Experiment 3: Add 2km of cable after the first branch, and compare the traveling wave signals when the branch line length changes under the fault of 5kΩ grounding resistance and arc high-resistance grounding.

[0035] Based on the above experimental analysis: connect the output signal of the traveling wave generator to the traveling wave ranging module, inject the traveling wave signal directly into the cable line through the traveling wave generator, and send a heartbeat to the computer once a second. For example, the first segment of the first line represents the hour, minute, second, day, month, and year, the second segment represents the number of crystal oscillator beats within one second when the traveling wave arrives, and the third segment represents the total number of crystal oscillator beats within one second. The first segment represents the hour, minute, second, day, month, and year data, which will be updated once a second, and the second and third segments will only be updated when the traveling wave arrives. Repeat each experiment six times, collect serial port data, and analyze the positioning effect.

[0036] After repeating the experiment six times, the data is organized into a table as shown in the table. It is known that the traveling wave velocity v = 3.8×10 8 m / s. The time when the traveling wave reaches the head end is t1, and the time when it reaches the end is t2. Therefore, the length of the experimental distance measurement line can be calculated according to the time when the traveling wave reaches both ends, and compared with the actual given line length to verify the fault location effect of the integrated intelligent pole-mounted switch.

[0037]

[0038] By comparing the experimental data tested on the dynamic model experimental platform of the 10km cable line distribution network and the real-type experiment, the maximum positioning error was within 150 meters, and the experimental results met the requirements.

[0039] The above embodiments are preferred embodiments of the present application. Ordinary technicians in this field can also make various changes or improvements on this basis. Without departing from the overall concept of the present application, these changes or improvements should fall within the scope of protection required by the present application.

Claims

1. An integrated pole-mounted switch with a traveling wave time extraction function, comprising an integrated switch body, characterized in that: It also includes a traveling wave moment extraction device, which includes: a voltage transformer, a traveling wave head detection module, a clock synchronization module, a communication module and a power supply module; wherein the voltage transformer is connected to the traveling wave head detection module, the traveling wave head detection module is connected to the clock synchronization module, the clock synchronization module is connected to the communication module, and the power supply module provides working power for the voltage transformer, the traveling wave head detection module, the clock synchronization module and the communication module; The traveling wave head detection module is used to shape the fault traveling wave collected by the voltage transformer into a square wave to trigger the timer of the STM32 processor; the traveling wave head detection module includes two transient voltage suppression diodes TVS, two hysteresis comparators and one Schmidt inverter; the anode of the first TVS is connected to the voltage transformer, the cathode of the first TVS is connected to the input end of the hysteresis comparator, the output end of the hysteresis comparator is connected to the first input end of the Schmidt inverter, and the first output end of the Schmidt inverter corresponding to the first input end is connected to the STM32 processor; the cathode of the second TVS is connected to the voltage transformer, the anode of the second TVS is connected to the input end of the hysteresis comparator, the output end of the hysteresis comparator is connected to the second input end of the Schmidt inverter, and the second output end of the Schmidt inverter corresponding to the second input end is connected to the STM32 processor.

2. The integrated column switch with traveling wave time extraction function according to claim 1 is characterized in that: The clock synchronization module includes a GPS / Beidou dual-mode satellite clock unit and an STM32 processor; the GPS / Beidou dual-mode satellite clock unit is connected to the STM32 processor to provide second pulses for the STM32 processor; the traveling wave head detection module and the communication module are both connected to the STM32 processor.

3. The integrated column switch with traveling wave time extraction function according to claim 2 is characterized in that: The 1PPS pin of the GPS / Beidou dual-mode satellite clock unit is connected to the STM32 to provide the STM32 with a time with an accuracy of more than one second of the traveling wave moment; the STM32 includes at least two timers, the first timer is used to convert the seconds provided by the GPS / Beidou dual-mode satellite clock unit into a count number, and the second timer is used to stop counting when the traveling wave signal is triggered, and the number recorded at this time is used as the time with an accuracy of less than one second of the traveling wave moment.

4. The integrated column switch with traveling wave time extraction function according to claim 1, characterized in that: The communication module adopts GPRS communication to send the traveling wave moment extracted by the STM32 processor to the upper computer positioning system.

5. The integrated column switch with traveling wave time extraction function according to claim 1, characterized in that: The voltage transformer is an optical voltage transformer.

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