Overhead line fault indication device

Abstract

The present invention provides a fault indication device for overhead power transmission lines in wind farms, comprising a power module, a charging module, a control module, a line fault indication module, a charging current detection module, a circuit fault indication module and a communication module; the charging current detection module is used to detect the working condition of the charging module, and when it is determined that the charging module has a fault, a warning is issued through the circuit fault indication module, thereby avoiding the problem that the overhead line fault indication device cannot indicate normally due to the fault of the charging module. The communication module is used to communicate with the intelligent terminal. After being connected to the intelligent terminal, the supporting software can be used to check the attenuation of the backup battery, and some information such as geographic location information and inspection date can also be written into the memory of the control module for easy management. The detection data can also be compared through the line fault indication device installed on the same transmission line to check the accuracy of the fault indication device in measuring the current of the transmission line.

Description

Technical Field

[0001] The invention relates to the technical field of wind farm power transmission line fault indication, in particular to a fault indication device applied to wind farm power transmission overhead lines. Background Art

[0002] A fault indicator is an indicator device used to detect and indicate transmission line faults. It is a device used to detect and identify whether a transmission line is faulty. When a transmission line has an overcurrent, short circuit, grounding or other fault, the transmission line fault indicator detects and determines the fault state, determines the fault section, branch and fault point, so that line patrol staff can inspect and maintain it. Transmission lines arranged outdoors are usually erected in an overhead form. The overhead line fault indicator is connected to the cable of the overhead transmission line through the force of a compression spring. The fault indicator detects faults that may occur on the transmission line at any time in real time. Once an abnormal current occurs in the transmission line, the device can choose to flip or emit light to alarm by its own judgment. The maintenance staff can quickly determine the fault section and find the fault point according to the device alarm display, which greatly reduces the labor intensity of the maintenance staff, improves work efficiency, shortens power outage time, and effectively improves the reliability of power transmission.

[0003] The fault indicator relies on the induction of the transmission line to obtain electrical energy. When the current in the transmission line is small or the electrical energy obtained by the induction of the power outage is not enough to support the power module, in order to ensure that the fault indicator can continue to work, it is often powered by a built-in backup battery. The inventor has made a rough statistical analysis of the fault indicators that have been repaired. Most of the faults of the fault indicators are caused by battery attenuation. That is, after several years of outdoor use, the life of the backup battery of the fault indicator is seriously attenuated, which seriously affects the overall reliability, and the attenuation of the backup battery is difficult to detect. In addition, the detection accuracy of the fault indicator should also be calibrated regularly. At present, the means of detecting the functionality of the fault indicator and measuring the accuracy of the current of the transmission line is to use a special test bench for detection, and then reinstall the qualified ones after the inspection and repair. Due to its cumbersome operation, time-consuming and labor-intensive, especially the fault indicators used in overhead lines, they are rarely maintained after installation, and their functionality and reliability cannot be effectively guaranteed. Summary of the invention

[0004] The invention provides an overhead line fault indicating device which is convenient for discovering backup battery faults.

[0005] The present invention adopts the following technical solution:

[0006] An overhead line fault indication device comprises: a power supply module, a charging module, a control module and a line fault indication module, characterized in that it also comprises: a charging current detection module and a circuit fault indication module; the power supply module is used to obtain electric energy from the transmission line to supply power to other power-consuming modules; the charging module comprises a backup battery and a charging circuit, and the backup battery is electrically connected to the charging circuit; the line fault indication module is used to output an indication signal carrying the transmission line fault information provided by the control module; the charging current detection module is used to feed back the charging and discharging current data of the charging module to the control module, and the circuit fault indication module is used to output the charging module fault signal provided by the controller; the charging current detection module, the circuit fault indication module and the line fault indication module are electrically connected to the control module respectively.

[0007] Furthermore, it also includes a communication module, which is used to transmit charging module attenuation data and transmission line detection data to an external intelligent terminal, and the transmission line detection data includes the maximum and minimum currents of the transmission line within a period of time; the transmission line detection data is used to verify the accuracy of the fault indication device detecting the transmission line data, and the communication module is communicatively connected to the control module.

[0008] Furthermore, the control module is provided with a memory, and the memory is used to store installation geographical location information and inspection date.

[0009] Furthermore, the line fault indication module and the circuit fault indication module are both circuits provided with LED indicator lights.

[0010] Furthermore, the backup battery is a lithium battery.

[0011] The positive effects of the present invention are as follows:

[0012] An overhead line fault indication device is provided with a charging current detection module and a circuit fault indication module. The device can detect the charging current and discharging current of a backup battery during the operation of the charging module, thereby detecting the attenuation of the backup battery. When it is determined that the charging module has a fault, a warning is issued through the circuit fault indication module, eliminating the work of checking the backup battery after disassembly, and also avoiding the problem that the overhead line fault indication device cannot indicate normally due to a charging module fault. Both the line fault indication module and the circuit fault indication module are provided with LED indicator lights, which have a long service life and are energy-saving and power-saving. Each module is equipped with two LED indication circuits with a redundant design. When one is damaged, the other can still play an indicating role. The backup battery adopts a lithium battery, which has a long service life, a light weight, a large capacity, and a long replacement cycle, and is suitable for year-round outdoor use. The overhead line fault indication device is also provided with a communication module, and the control module is provided with a memory. After the communication module is connected to the intelligent terminal, the attenuation of the backup battery can be checked using the software provided with the intelligent terminal. Some information such as geographic location and inspection date can be written into the memory of the control module for easy management. The detection data can also be compared with the fault indication device installed on the same transmission line to check the accuracy of the fault indication device in measuring the current of the transmission line. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a functional block diagram of an embodiment of the present invention;

[0014] Figure 2 This is a schematic diagram of controller pins according to an embodiment of the present invention;

[0015] Figure 3 This is a schematic diagram of the charging module structure according to an embodiment of the present invention;

[0016] Figure 4 A schematic diagram of a charging current sampling circuit according to an embodiment of the present invention;

[0017] Figure 5 A schematic diagram of a discharge current sampling circuit according to an embodiment of the present invention;

[0018] Figure 6 This is a schematic diagram of a backup battery voltage sampling circuit according to an embodiment of the present invention;

[0019] Figure 7 This is a schematic diagram of the structure of a line fault indication module and a circuit fault indication module according to an embodiment of the present invention;

[0020] Figure 8 Schematic diagram of the connection of communication modules according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. 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.

[0022] like Figure 1 As shown, the overhead line fault indication device includes: a power supply module, a charging module, a control module, a line fault indication module, a charging current detection module and a circuit fault indication module;

[0023] The power module is used to obtain electric energy from the wind farm transmission line to supply power to the power consumption module. The charging module, control module, line fault indication module, charging current detection module and circuit fault indication module shown in the figure are all power consumption modules; the line fault indication module is used to indicate when the control module detects a wind farm transmission line fault; the circuit fault indication module is used to indicate when the control module detects a charging module fault through the charging current detection module; the charging module includes a backup battery and a charging circuit. The charging current detection module, the circuit fault indication module and the line fault indication module are electrically connected to the control module respectively.

[0024] The control module includes a wind farm transmission line detection circuit and a controller. The detection circuit relies on a current transformer to obtain the current signal of the wind farm transmission line. The current signal is sent to the controller. After analog-to-digital conversion, the controller digitizes the current signal. The controller compares the digitized current signal with a preset threshold value. When the threshold value is exceeded, a fault indication is given through a line fault indication circuit. The controller is a single-chip microcomputer, such as Figure 2 As shown, this embodiment adopts STM32F103C8T6, and the clock frequency can reach up to 72MHz. The single chip integrates an analog-to-digital converter, a serial communication unit, a general input and output interface and FLASH; the analog-to-digital converter is used to convert analog signals into digital signals for data processing; the serial communication unit is used to communicate with the outside and send and receive serial data; the general input and output interface is used to input level signals or output level signals; the FLASH storage space is 64KB, except for a part used to store program codes, the remaining space can be used as a storage space that is not lost when power is off, and stores acquired data, such as data received by sending and receiving external communications, and data on abnormal transmission lines in wind farms.

[0025] The power module relies on current transformers to obtain electrical energy from the wind farm transmission line. Its output is divided into two paths and sent to each power module for power consumption. Figure 1The charging module, control module, line fault indication module, charging current detection module and circuit fault indication module shown in the figure are all power-consuming modules; because the current of the wind farm transmission line will fluctuate due to the influence of load size, when the current is too small to drive the power-consuming module to consume electricity, it will switch to the charging module for power supply; diodes are provided at the output ends of the charging module and the power module, and the cathode connection point of the two diodes serves as the power supply output point.

[0026] The charging module includes a charging circuit and a backup battery, and the backup battery is a lithium battery, such as Figure 3 As shown in the figure, the charging circuit uses the TP4056 chip as the core to control the charging process of the backup battery. The TP4056 is a constant current / constant voltage linear charger for lithium batteries. It uses a PMOSFET structure internally and has a thermal feedback function. It can automatically adjust the charging current and limit the chip temperature under high-power operation or high-temperature ambient temperature conditions. The charging voltage is constant at 4.2V, and the charging current can be set through programming resistors. After reaching the final charging voltage, the charging current drops to one-tenth of the set value, and the TP4056 will automatically terminate the charging cycle; when there is no input voltage, the TP4056 automatically enters a low current state to reduce the battery leakage current to less than 2uA. The TP4056 can also be placed in shutdown mode when there is power, reducing the supply current to 55uA.

[0027] In this embodiment, U4 is TP4056, and the CE pin of U4 is a strobe pin, which is enabled when the high level is high, so it is connected to the POWER+ of the power module; TEMP is a temperature measurement pin. Since the battery temperature is not sampled in this embodiment, the functions of the charging indication NCHRG pin and the charging fault indication NSTDBY pin are not used in this embodiment, so the TEMP pin, NCHRG pin, and NSTDBY pin are all connected to the power ground GND; one end of the insurance resistor R7 is connected to the Power+ of the power module, and the other end is connected to the power input pin Vcc of U4; the Gnd pin of U4 is connected to the power ground GND and the negative electrode B- of the backup battery; R12 is a charging current sampling resistor, one end of which is connected to the BAT pin of U4, and the other end is connected to the positive electrode B+ of the backup battery; the resistor R9 is a programming resistor, one end of which is connected to the PROG pin of TP4056, and the other end is connected to the Gnd pin of TP4056; the charging current of TP4056 is controlled by the programming resistor, and its formula is as follows:

[0028] IBAT=VPROG / R9×1200

[0029] IBAT is the charging current, VPROG is the programming voltage, which is 1V during charging, and R9 is the programming resistor. A 2500mAh lithium battery is used as the backup battery in this embodiment. Considering the battery capacity and charging speed, a 1.2kΩ resistor is selected.

[0030] As an improvement of the existing technology, a charging current detection module is newly added, including: a charging current sampling circuit, a discharging current sampling circuit, and a backup battery voltage sampling circuit. Figure 4 The figure shows a schematic diagram of a charging current sampling circuit. The positive input terminal of the operational amplifier U2 is connected to the BAT pin of U4, the reverse input terminal is connected to the positive electrode B+ of the backup battery, the first terminal of the resistor R7 and the first terminal of the resistor R14, the output terminal is respectively connected to the second terminal of the resistor R14 and the input terminal of the controller analog-to-digital converter, and the second terminal of the resistor R7 is connected to the power ground GND. This circuit constitutes a proportional operational amplifier circuit, which amplifies the charging current signal obtained from the charging current sampling resistor R12 to reach a voltage range that the controller can recognize.

[0031] Figure 5 This is a schematic diagram of a discharge current sampling circuit. The positive input terminal of the operational amplifier U3 is connected to the positive electrode B+ of the backup battery, the reverse input terminal is connected to the second terminal BPOWER+ of the discharge current sampling resistor R13, the first terminal of the resistor R15 and the first terminal of the resistor R8, the output terminal is connected to the second terminal of the resistor R15 and the input terminal of the controller analog-to-digital converter, and the second terminal of the resistor R8 is connected to the power ground GND. This circuit constitutes a proportional operational amplifier circuit, which amplifies the signal obtained from the discharge current sampling resistor R13 to reach a voltage range that the controller can recognize.

[0032] Figure 6 This is a schematic diagram of the backup battery voltage sampling circuit. One end of R21 is connected to the backup battery positive electrode B+, and the other end is connected to the first end of R22. The second end of R22 is connected to the power ground. The first end of R22 is connected to the converter of the controller as a battery voltage sampling signal.

[0033] like Figure 7As shown in the figure, the line fault indication module and the circuit fault indication module are both based on ULN2803A. ULN2803 is an octal NPN Darlington connection transistor array series, which is particularly suitable for the interface between low logic level digital circuits (such as TTL, CMOS or PMOS / NMOS) and higher current / voltage requirements. It is widely used in computers, industrial and consumer products, lamps, relays, printing hammers or other similar loads. All devices have open collector outputs and freewheeling clamping diodes to suppress jumps. The design of ULN2803 is compatible with the standard TTL series. Pins 1 to 8 of the chip are input pins, namely 1B-8B, and pins 18 to 11 are output pins, namely 1C-8C. The input pins and output pins form a one-to-one correspondence, and the logic is a non-gate. For example, when the 1B input is low, the transistor inside 1C is saturated and turned on; the chip can carry a maximum load capacity of 500mA, which is enough to meet the needs of use. In this embodiment, the 4B pin of the chip is connected to the IO port PA1 of the single-chip microcomputer, the 5B pin is connected to the IO port PA2 of the single-chip microcomputer, the 6B pin of the chip is connected to the IO port PA3 of the single-chip microcomputer, and the 7B pin is connected to the IO port PA4 of the single-chip microcomputer; there are two indicator lights of the line fault indication module: LED1 and LED2, the anode of LED1 is connected to the 4C pin of U1, one end of the current limiting resistor R3 is connected to the cathode of LED1, and the other end is connected to the power supply VCC; the anode of LED2 is connected to the 5C pin of U1, one end of the current limiting resistor R4 is connected to the cathode of LED1, and the other end is connected to the power supply VCC; there are two circuit fault indicator lights: LED3 and LED4, the anode of LED3 is connected to the 6C pin of U1, one end of the current limiting resistor R5 is connected to the cathode of LED3, and the other end is connected to the power supply VCC; the anode of LED4 is connected to the 7C pin of U1, one end of the current limiting resistor R6 is connected to the cathode of LED4, and the other end is connected to the power supply VCC. The line fault indication module and the circuit fault indication module both have two indicator lights, which are designed for redundancy. Damage to one does not affect the function of the other. When one is damaged, the other can still serve as an indication.

[0034] During use, when the backup battery is discharging, the controller detects the discharge current and battery voltage once every time segment, such as 20 milliseconds, through the charging current detection module. After a period of discharge, the battery voltage drops, such as from 4.1V to 4.0V. The total output power for this period of time is counted, and the total output power is compared with the backup battery attenuation threshold set in advance. When it is lower than the backup battery attenuation threshold, the controller records it; the total output power is calculated by multiplying the discharge current collected each time by the time segment as the time segment power of the time segment. The accumulation of all time segment power is the total output power corresponding to the backup battery voltage dropping from 4.1V to 4.0V as mentioned above; there is another situation, which is to refer to the situation during charging, the controller At every time segment, such as 20 milliseconds, the charging current and the backup battery voltage are detected once through the charging current detection module. After a period of charging, the backup battery voltage rises, such as from 3.8V to 3.9V. The total input power for this period of time is counted, and the total input power is compared with the backup battery attenuation threshold set in advance. When it is lower than the backup battery attenuation threshold, it is recorded; the total input power is calculated by multiplying the charging current collected each time by the time segment as the time segment power of the time segment. The accumulation of all time segment power is the total input power corresponding to the backup battery voltage rise, such as the above-mentioned 3.8V to 3.9F; when the attenuation record number reaches the record number threshold, such as 10 times, the controller control circuit fault indicator light flashes.

[0035] The overhead line fault indication device equipped with a charging current detection module and a circuit fault indication module can detect the charging current and discharging current of the backup battery during the operation of the charging module, thereby detecting the attenuation of the backup battery. When it is determined that the charging module has a fault, a warning is issued through the circuit fault indication module, eliminating the work of checking the backup battery after disassembly, and also avoiding the problem that the overhead line fault indication device cannot indicate normally due to a charging module fault. Both the line fault indication module and the circuit fault indication module are equipped with LED indicator lights, which have a long life and are energy-saving and power-saving. Each module is equipped with two LED indication circuits with a redundant design. When one is damaged, the other can still play an indicating role; the backup battery uses a lithium battery, which has a long life, light weight, large capacity, and a long replacement cycle, and is suitable for year-round outdoor use.

[0036] Furthermore, a communication module for communicating with the intelligent terminal is also provided; the module is a WiFi communication circuit with ESP8266 as the core chip, such as Figure 8 The communication module U7 shown is electrically connected to the single-chip microcomputer through the serial port, the USART1_RX pin (pin 31) of the single-chip microcomputer is connected to the TXD pin of U7, and the USART1_TXD pin (pin 30) of the controller is connected to the RXD pin of U7.

[0037] When in use, a smart terminal such as a mobile phone searches for the WiFi signal of the device, enters the password to complete the connection between the smart terminal and the device, and the smart terminal opens the matching APP. Through the APP, the current backup battery attenuation can be read, and the maximum current and minimum current of the wind farm transmission line in the recent period can be read. Some information such as the longitude and latitude data of the geographical location information of the installation location and the date of this inspection can be written into the memory of the control module for the next query. A pre-calibrated line fault indication device can also be installed on the same wind farm transmission line to obtain the maximum current and minimum current of the wind farm transmission line in a period of time, and then compared with the maximum current and minimum current obtained by this device in the same period. If the deviation is large, it needs to be removed for repair or replacement.

[0038] After the overhead line fault indication device equipped with a communication module is connected to the smart terminal, the backup battery attenuation can be checked using the software supporting the smart terminal. Some information such as geographic location and inspection date can also be written into the memory of the control module for easy management. The detection data can also be compared with the line fault indication device installed on the transmission line of the same wind farm to check the accuracy of the fault indication device in measuring the current of the wind farm transmission line.

[0039] The above-described embodiments are only preferred embodiments of the present invention, and are not exhaustive of the feasible implementations of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.

Claims

1. An overhead line fault indication device, comprising: The power supply module, charging module, control module and line fault indication module are characterized in that they also include: a charging current detection module and a circuit fault indication module; the control module includes a wind farm transmission line detection circuit and a controller, The power supply module is used to obtain electric energy from the transmission line to supply power to other power-consuming modules; the charging module includes a backup battery and a charging circuit, and the backup battery is electrically connected to the charging circuit; the line fault indication module is used to output an indication signal carrying the transmission line fault information provided by the control module; the charging current detection module is used to feed back the charging and discharging current data of the charging module to the control module, and the circuit fault indication module is used to output the charging module fault signal provided by the controller; The charging current detection module, the circuit fault indication module and the line fault indication module are electrically connected to the control module respectively; The detection circuit relies on the current transformer to obtain the current signal of the wind farm transmission line. The current signal is sent to the controller. After analog-to-digital conversion, the controller digitizes the current signal. The controller compares the digitized current signal with the preset threshold. When the threshold is exceeded, a fault indication is given through the line fault indication circuit.

2. The overhead line fault indication device according to claim 1, characterized in that: It also includes a communication module, which is used to transmit charging module attenuation data and transmission line detection data to an external intelligent terminal, and the transmission line detection data includes the maximum and minimum currents of the transmission line within a period of time; the communication module is communicatively connected with the control module.

3. The overhead line fault indication device according to claim 2, characterized in that: The control module is provided with a memory, and the memory is used to store installation geographical location information and inspection date.

4. The overhead line fault indication device according to claim 3, characterized in that: The line fault indication module and the circuit fault indication module are both circuits provided with LED indicator lights.

5. The overhead line fault indication device according to claim 4, characterized in that: The backup battery is a lithium battery.

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