Distribution line fault positioning device

Abstract

The utility model provides a distribution line fault positioning device, which relates to the field of fault positioning and comprises a plurality of data acquisition units, a data collection module and an intelligent fusion terminal. The data collection module is in wireless communication connection with each data acquisition unit through micropower, and the data collection module is connected with the intelligent fusion terminal through a serial port; the data acquisition unit comprises a first data acquisition module, a second data acquisition module and a third data acquisition module; the first data acquisition module, the second data acquisition module and the third data acquisition module are all in wireless communication connection with the data collection module through micropower. According to the utility model, each data acquisition module can be self-powered and complete various detection functions, data of the data acquisition modules are gathered to the data collection module for unified collection and processing, large-area electric wire fault monitoring can be realized, and the electric wire monitoring efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the field of fault locating, in particular to a distribution line fault locating device. Background Art

[0002] With the development of the national economy and society, people are increasingly demanding reliable electricity supply and regulation. This is especially true for the safe operation and timely fault detection of distribution networks, which are closely connected to the public. 10kV-35kV distribution lines generally use a low-current grounding method, with the neutral point ungrounded or grounded via arc suppression coils. Single-phase grounding faults are common in actual operation, especially during rainy seasons, high winds, and other adverse weather conditions. These faults are particularly frequent, severely impacting the safe and economical operation of substation equipment and distribution networks.

[0003] Over the years, new line selection and positioning technologies have emerged one after another, and a variety of more intelligent microcomputer line selection and positioning devices have been developed, but the actual operating effect is not good. Although the powerful primary and secondary fusion switches can effectively collect a variety of line operation data for fault analysis and processing, they are expensive and difficult to install. It is difficult to effectively cover long and multi-branch distribution lines, which makes the monitoring area of existing fault analysis devices small and inefficient. Utility Model Content

[0004] In view of this, the purpose of the present invention is to provide a distribution line fault location device to solve the problem that the existing fault analysis device has a small monitoring area and low efficiency.

[0005] The utility model provides a distribution line fault location device, comprising: a plurality of data acquisition units, a data collection module 2 and an intelligent fusion terminal 3;

[0006] The data collection module 2 is connected to each data acquisition unit through micro-power wireless communication, and the data collection module 2 is connected to the intelligent fusion terminal 3 through a serial port;

[0007] The data acquisition unit includes: a first data acquisition module 1, a second data acquisition module and a third data acquisition module;

[0008] The first data acquisition module 1 , the second data acquisition module and the third data acquisition module are all connected to the data collection module 2 via micropower wireless communication.

[0009] Preferably, the first data acquisition module 1, the second data acquisition module and the third data acquisition module have the same structure;

[0010] The first data acquisition module 1 includes: a power supply module 101, a measurement module 102, an analog-to-digital conversion module 103, a time verification module 104, a wireless communication module 105 and an MCU module 106;

[0011] The MCU module 106 is electrically connected to the power module 101 , the measurement module 102 , the analog-to-digital conversion module 103 , the time synchronization module 104 , and the wireless communication module 105 .

[0012] Preferably, the first data acquisition module 1 is set at phase A of the monitoring point, the second data acquisition module is set at phase B of the monitoring point, and the third data acquisition module is set at phase C of the monitoring point.

[0013] Preferably, the power module 101 includes: a CT power supply module 1011 and an energy storage module 1012;

[0014] The CT power supply module 1011 is electrically connected to the energy storage module 1012 , and the CT power supply module 1011 and the energy storage module 1012 are electrically connected to the MCU module 106 .

[0015] Preferably, the CT power supply module 1011 includes: a protection energy dissipation circuit, a rectifier filter circuit, a voltage stabilization module, an energy management circuit and an output module;

[0016] The protection energy dissipation circuit, the rectification and filtering circuit and the voltage stabilization module are electrically connected in sequence;

[0017] The voltage stabilizing module is electrically connected to the energy management circuit and the output module, and the energy management circuit is electrically connected to the output module.

[0018] Preferably, the measurement module 102 is used to monitor the phase current of the line in real time.

[0019] Preferably, the analog-to-digital conversion module 103 is used for mutual conversion between digital voltage signals and analog voltage signals during real-time voltage data sampling.

[0020] Preferably, the time synchronization module 104 is used for wide-area synchronous measurement between each data acquisition module and the data collection module 2 .

[0021] Preferably, the wireless communication module 105 transmits the data collected by each data collection module to the data collection module 2 using a micro-power wireless communication method.

[0022] The utility model has the following beneficial effects:

[0023] The data from the data acquisition units at multiple points are collected into a data collection module. The data collection unit includes three data collection modules that can collect various wire data. Each data collection module can be self-powered and complete various detection functions. The data from each data acquisition module are collected and processed in a unified manner, which can realize wire fault monitoring in a large area and improve the efficiency of wire monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a structural diagram of a distribution line fault location device;

[0025] Figure 2 This is the schematic diagram of the STM32F407VET6 microcontroller;

[0026] Figure 3 This is the schematic diagram of the AD7705AD sampling chip;

[0027] Figure 4 This is the schematic diagram of the CT power module;

[0028] Figure 5 This is the schematic diagram of the rectifier and filter circuit;

[0029] Figure 6 To protect the energy dissipation circuit schematic;

[0030] Figure 7 This is the schematic diagram of the voltage stabilizing module;

[0031] Figure 8 This is the schematic diagram of the energy management circuit;

[0032] Figure 9 This is the schematic diagram of the phase-to-phase transmission module;

[0033] Figure 10 This is the schematic diagram of the Q5604G LTE module;

[0034] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0035] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0036] Reference Figure 1 , the utility model provides a distribution line fault location device, comprising: a plurality of data acquisition units, a data collection module 2 and an intelligent fusion terminal 3;

[0037] The data collection module 2 is connected to each data acquisition unit through micro-power wireless communication, and the data collection module 2 is connected to the intelligent fusion terminal 3 through a serial port;

[0038] The data acquisition unit includes: a first data acquisition module 1, a second data acquisition module and a third data acquisition module;

[0039] The first data acquisition module 1 , the second data acquisition module and the third data acquisition module are all connected to the data collection module 2 via micropower wireless communication.

[0040] Specifically, the data collection module 2 can draw power from the substation distribution cabinet 4, and can simultaneously collect data from the data acquisition module 1 and other monitoring data on the low-voltage side of the substation through micro-power wireless communication. The uploaded data can communicate with the intelligent fusion terminal 3 through the serial port line, and a fault location APP can be installed in the intelligent fusion terminal 3 to perform edge computing analysis procedures.

[0041] Furthermore, the first data acquisition module 1, the second data acquisition module and the third data acquisition module have the same structure;

[0042] The first data acquisition module 1 includes: a power supply module 101, a measurement module 102, an analog-to-digital conversion module 103, a time verification module 104, a wireless communication module 105 and an MCU module 106;

[0043] The MCU module 106 is electrically connected to the power module 101 , the measurement module 102 , the analog-to-digital conversion module 103 , the time synchronization module 104 , and the wireless communication module 105 .

[0044] The first data acquisition module 1 is set at phase A of the monitoring point, the second data acquisition module is set at phase B of the monitoring point, and the third data acquisition module is set at phase C of the monitoring point.

[0045] Specifically, the data acquisition module 1 is installed at each monitoring point of the distribution line, so that the entire line can be evenly monitored in sections. The data collection module 2 is installed in the distribution cabinet 4 at the end of the 10kV line. At the same time, the low-voltage monitoring equipment can also transmit micro-power wirelessly to the data collection module 2, that is, the medium and low voltage share the data collection module 2, which effectively saves the utilization of distribution network resources.

[0046] MCU module 106 is the main control chip of the distribution line fault location device designed in this paper. It is mainly responsible for the collection of A, B, and C three-phase currents, the transmission of data between sensors, the judgment of fault types, and long-distance data transmission. The main control chip used in this system is the STM32F407VET6 microcontroller from STMicroelectronics. This device is a fully integrated mixed-signal system-on-chip MCU module chip. Many analog and digital peripherals are integrated inside it. The analog peripherals include three 12-bit ADCs and two analog comparators, and the digital peripherals include UART ports, SPI ports, timers, programmable counter / timer arrays, etc. The STM32F407VET6 microcontroller is as follows: Figure 2As shown, the chip features five I / O groups (AE), each with 16 I / O ports, for a total of 80 I / O ports, enabling complex system designs. The MCU's PA9 and PA10 ports are connected to the RXD and TXD ports of the precision timing module, respectively, to synchronize time stamps and ensure accurate clock synchronization for the system's current acquisition. The MCU's PA2 and PA3 ports are connected to the RX and TX ports of the Q5604G LTE, respectively, enabling data transmission with the Q5604G LTE networking module. Three SPI-simulated I / O ports and some I / O ports are connected to the NRF24L01, driving it and enabling three-phase command and data transmission. The MCU's PC8-PC12 and PD2 ports serve as control signal ports for TF memory cards.

[0047] The analog-to-digital conversion module 103 uses the more accurate AD7705 16-bit AD sampling chip to measure the output signal of CT. After being processed by the sampling and processing circuit, it is output to the AD7705 AIN1(+) port for analog-to-digital conversion. The temperature sensor DQ port is connected to the AD7705 AIN2(+) port for analog-to-digital conversion. Because the AD conversion accuracy measures the degree of closeness between the actual and ideal outputs, in actual conversion, the accuracy will decrease due to the existence of system errors and quantization errors. Among them, the system error is impossible to eliminate, but the impact of quantization error on accuracy can be reduced by increasing the number of bits of AD conversion. The number of bits of AD converter can be reflected by resolution. The higher the number of bits of AD conversion, the higher the resolution will be, and therefore the conversion accuracy will be higher. Therefore, the system uses the 16-bit AD7705 AD sampling chip to improve sampling accuracy. The three-phase sensors all use the method of writing "0" to CS to start AD sampling conversion. The current acquisition signal is the AC signal on the line, using a single-ended input method. All signal measurements are relative to GND. The reference voltage uses an external reference voltage of 2.5V to improve sampling accuracy. The AD7705 AD sampling chip is as follows: Figure 3 shown.

[0048] Furthermore, the power supply module 101 includes: a CT power supply module 1011 and an energy storage module 1012;

[0049] The CT power supply module 1011 is electrically connected to the energy storage module 1012 , and the CT power supply module 1011 and the energy storage module 1012 are electrically connected to the MCU module 106 .

[0050] refer to Figure 4 , CT power supply module 1011 includes: protection energy dissipation circuit, rectification and filtering circuit, voltage stabilization module, energy management circuit and output module;

[0051] The protection energy dissipation circuit, the rectification and filtering circuit and the voltage stabilization module are electrically connected in sequence;

[0052] The voltage stabilizing module is electrically connected to the energy management circuit and the output module, and the energy management circuit is electrically connected to the output module.

[0053] Specifically, the rectifier filter circuit is as follows: Figure 5 As shown, the voltage sensed by the current transformer from the line is AC, while the voltage required by the subsequent circuit is DC. Therefore, the purpose of rectification and filtering is to convert AC voltage to DC. Currently, two commonly used rectifier circuits are single-phase half-wave rectification and bridge rectification. Bridge rectification offers high output voltage and low ripple voltage, so the rectifier used in this article is the CD-DF410STR-ND bridge rectifier. Common filtering circuits include capacitor filtering and inductor filtering. This article uses capacitor filtering, connecting an electrolytic capacitor after the bridge rectifier and a high-frequency decoupling capacitor in parallel to eliminate high-frequency spikes and smooth ripple.

[0054] Protect the energy dissipation circuit such as Figure 6 As shown in the figure, even when a transmission line is operating normally without a phase-to-phase short circuit, it may still operate at high current for extended periods. Therefore, the protective energy-drain circuit is primarily intended to protect the voltage-regulated input of subsequent circuits. When the output voltage of the rectifier bridge exceeds the voltage drop of the Zener diode, the diode conducts, and the voltage comparator outputs a high level, turning on the G5LE relay. At this point, the positive and negative terminals of the CT are conductive through a 100Ω energy-drain resistor, effectively protecting the subsequent circuits.

[0055] Voltage regulator module such as Figure 7 As shown, the voltage regulator module stabilizes the voltage of rectified and filtered DC power at 5V for subsequent circuitry. This article uses the LM2596-ADJ switching power supply regulator, which provides all the functions of a step-down switching regulator and provides a stable 5V output over a wide input voltage range. This series of regulators is a monolithic integrated circuit with a load drive capability of up to 3A. It also features built-in overcurrent and thermal protection circuits, ensuring excellent heat dissipation.

[0056] Energy management circuits such as Figure 8 As shown in the figure, the power provided by the CT inductive power supply depends on the current level of the transmission line. When the transmission line is lightly loaded or there is a power outage, the power provided by the current transformer cannot guarantee the normal operation of the monitoring terminal circuit. Therefore, it is necessary to cooperate with the energy management circuit to power the monitoring terminal. The main chip of the energy management circuit is the BQ24072 produced by TI. The BQ24072 can charge single-cell lithium-ion batteries with constant current and constant voltage.

[0057] Furthermore, the measurement module 102 is used to monitor the phase current of the line in real time.

[0058] The analog-to-digital conversion module 103 is used for mutual conversion between digital voltage signals and analog voltage signals during real-time voltage data sampling.

[0059] The time verification module 104 is used for wide-area synchronous measurement between each data acquisition module and the data collection module 2 .

[0060] The wireless communication module 105 transmits the data collected by each data collection module to the data collection module 2 using micro-power wireless communication.

[0061] Specifically, the wireless communication module 105 includes: an inter-phase transmission module and a long-distance data transmission module;

[0062] The distance between the three phases A, B, and C of the 10kV overhead line of the distribution network is relatively large, so the three sensors A, B, and C can only be logically connected through wireless communication to achieve mutual instruction transmission and data transmission. In this paper, the wireless communication between the three phases A, B, and C is called inter-phase data communication. The inter-phase transmission module in the fault location system designed in this paper adopts the short-range wireless communication module NRF24L01. The inter-phase transmission module is as follows: Figure 9 As shown, it consists of the NRF24L01 chip combined with simple peripheral devices, with small size and power consumption. NRF24L01 is a single-chip RF transceiver device. It operates in the 2.4GHz~2.5GHz ISM band, with a maximum transmission rate of more than 1Mbit / S. It has built-in frequency synthesizer, power amplifier, crystal oscillator, modulator and other functional modules, and integrates enhanced ShockBurst technology. Its transmission power and operating frequency can be configured through the program. Each chip can be set to a maximum of 40-bit address through software, and data will only be output when the local address is received, which makes programming very convenient. NRF24L01 has four working modes: transceiver mode, configuration mode, idle mode and shutdown mode. The working mode of NRF24L01 is determined by the three pins PWR_UP, CE, and CS.

[0063] The long-distance data transmission module is used to realize the communication between the sensor and the central station. The A-phase sensor realizes this function. The long-distance data transmission part of the fault location system introduced in this article adopts the Q5604G LTE module of Chengdu Yixuntong Technology Co., Ltd. The Q5604G LTE module is a low-power distributed wireless mobile ad hoc network module that supports 7 modes and 15 frequencies. The maximum transmission power is 100mW (20dbm), the average transmission current is 60-100mA, the average current in online standby mode is 15-20mA, the average current in idle offline mode is 10-20mA, the operating voltage range is 5-24V, and the serial port baud rate is 1200-921600bits / s. The Q5604G LTE module is as follows: Figure 10 shown.

[0064] Furthermore, the working principle of the distribution line fault location device is as follows:

[0065] The data acquisition module 1 of the distribution line fault locating device is installed at each monitoring point of the distribution line, one for each phase, so that the entire line can be evenly monitored in sections. The data collection module 2 is installed in the distribution cabinet 4 at the end of the 10kV line. The data acquisition module 1 obtains power by induction on the line through the power supply module 101, monitors the line phase current through the measurement module 102, performs signal conversion through the analog-to-digital conversion module 103 and synchronizes with the time verification module 104, and then collects the data to the data collection module 2 through the wireless communication module 105. The data collection module 2 uploads the data to the intelligent fusion terminal 3 through the serial port line. The fault location APP installed in the intelligent fusion terminal 3 can synthesize the line phase current into the zero-sequence current for fault judgment, and the result can be uploaded to the distribution automation master station through the intelligent fusion terminal 3.

[0066] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or system. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or system comprising the element.

[0067] The serial numbers of the embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. In a unit claim that lists several means, several of these means may be embodied by the same item of hardware. The use of the terms first, second, and third, etc., does not indicate any order; these terms should be interpreted as identifiers.

[0068] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A distribution line fault location device, characterized in that: include: A plurality of data collection units, a data collection module (2) and an intelligent fusion terminal (3); The data collection module (2) is connected to each data collection unit through micro-power wireless communication, and the data collection module (2) is connected to the intelligent fusion terminal (3) through a serial port; The data acquisition unit comprises: a first data acquisition module (1), a second data acquisition module and a third data acquisition module; The first data acquisition module (1), the second data acquisition module and the third data acquisition module are all connected to the data collection module (2) through micro-power wireless communication.

2. The power distribution line fault location device according to claim 1, characterized in that: The first data acquisition module (1), the second data acquisition module and the third data acquisition module have the same structure; The first data acquisition module (1) comprises: a power supply module (101), a measurement module (102), an analog-to-digital conversion module (103), a time verification module (104), a wireless communication module (105) and an MCU module (106); The MCU module (106) is electrically connected to the power module (101), the measurement module (102), the analog-to-digital conversion module (103), the time synchronization module (104) and the wireless communication module (105).

3. The power distribution line fault location device according to claim 1, characterized in that: The first data acquisition module (1) is arranged at phase A of the monitoring point, the second data acquisition module is arranged at phase B of the monitoring point, and the third data acquisition module is arranged at phase C of the monitoring point.

4. The distribution line fault location device according to claim 2, characterized in that: The power supply module (101) comprises: a CT power supply module (1011) and an energy storage module (1012); The CT power supply module (1011) is electrically connected to the energy storage module (1012), and the CT power supply module (1011) and the energy storage module (1012) are electrically connected to the MCU module (106).

5. The power distribution line fault location device according to claim 4, characterized in that: The CT power supply module (1011) comprises: a protection energy dissipation circuit, a rectifier filter circuit, a voltage stabilization module, an energy management circuit and an output module; The protection energy dissipation circuit, the rectification and filtering circuit and the voltage stabilization module are electrically connected in sequence; The voltage stabilizing module is electrically connected to the energy management circuit and the output module, and the energy management circuit is electrically connected to the output module.

6. The power distribution line fault location device according to claim 2, characterized in that: The measurement module (102) is used to monitor the phase current of the line in real time.

7. The power distribution line fault location device according to claim 2, characterized in that: The analog-to-digital conversion module (103) is used for mutual conversion between digital voltage signals and analog voltage signals during real-time voltage data sampling.

8. The power distribution line fault location device according to claim 2, characterized in that: The time verification module (104) is used for wide-area synchronous measurement between each data acquisition module and the data collection module (2).

9. The power distribution line fault location device according to claim 2, characterized in that: The wireless communication module (105) transmits the data collected by each data collection module to the data collection module (2) using a micro-power wireless communication method.

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