CN220399613U - Multi-group synchronous detection 10kV high-voltage temporary grounding wire classifying and positioning device - Google Patents

Abstract

The utility model provides a 10kV high-voltage temporary grounding wire classifying and positioning device for multi-group synchronous detection, which mainly comprises a main control board and a bottom board. The main control board consists of a raspberry group module, a storage module, a signal generation module, a filtering module, a communication module and a display module; the bottom plate comprises a battery management module, a current detection module and a voltage detection module. The main control board is connected with the bottom plate, and the bottom plate is connected with the high-voltage line to be detected and the ground. After the synchronization is successful, the short messages are sent among the units, the voltage signals with certain specific frequency in the middle frequency range are respectively injected into the high-voltage line to be detected, then the voltage signals and the current signals are detected, calculated and analyzed, the result is synchronized with the short messages again, whether the temporary grounding wire exists or not is accurately judged, if yes, the type and the geographic position of the temporary grounding wire are pointed out, the power grid accident caused by the closing operation with the grounding wire is prevented, and the workload of line inspection staff is reduced. The utility model has high detection precision and high reliability due to modularized design.

Description

Multi-group synchronous detection 10kV high-voltage temporary grounding wire classifying and positioning device

Technical Field

The utility model discloses electric wire netting earth connection detects the field relates to earth connection type detection and ground connection location detection, is applicable to the earth connection detection under the ten kilovolt electric wire netting power failure state.

Background

Most of the prior art is in on-line detection. Such as application publication number: CN114325476a, application publication date: 2022.04.12A device and method for detecting the state of a grounding wire, which are used for detecting the grounding wire under the condition that the line is always connected and the power grid line can be normally electrified. When the power grid fails, the prior art of online detection fails, and the devices immediately fail and cannot work normally under the condition that the power grid fails.

The existing grounding wire detection technology can detect the grounding type under the power failure state, but cannot accurately detect the grounding point position. Application publication number: CN105137226a, application publication date: 2015.12.09, application number: 2015104694105 the device for detecting and positioning the grounding state of the line can detect the power failure state of the power grid, and the type of the grounding wire is single-phase line grounding, double-phase line grounding, three-phase line grounding or interphase short circuit. The device that can detect under the power failure state has contact resistance in electric wire netting and ground connection in-process, and the device is when being hung in electric wire netting circuit, has the contact resistance of hanging line and electric wire netting circuit, and contact resistance often has 8 ohms to more than 10 ohms, and every 0.4 ohm contact resistance can cause the detection error of about 1 km's earth connection ground connection position. It is these contact resistances that result in the inability of existing detection devices to accurately locate the ground point.

Therefore, a multi-group synchronous detection 10kV high-voltage temporary grounding wire classifying and positioning device is provided, so that the judgment of the state of the grounding wire and the positioning function of the position of the grounding wire are realized; the device is accessed to a detected power grid line through a plurality of contact points, and the devices send out detection signals at the same time to detect the to-be-detected line; the obtained detection signal contains errors due to contact resistances for each contact point, but the signals obtained by signal detection are simultaneously sent out by a plurality of devices, so that the errors due to the contact resistances can be eliminated, and the position of the grounding detection point can be calculated. Therefore, the proposed device can detect not only the type of the ground line of the ground point being single-phase line ground, double-phase line ground, three-phase line ground, or inter-phase short, but also the position of the ground point. The device can solve the problem that the existing device can not detect the positioning of the grounding wire under the condition of power failure. Since the proposed devices need to send out detection signals at the same time, the proposed devices must have a synchronous communication function.

Disclosure of Invention

The utility model provides a multi-group synchronous detection 10kV high-voltage temporary grounding wire classifying and positioning device, which can judge the grounding state of a power distribution network and position the grounding position according to feedback current values and impedance values,

a multi-group synchronous detection 10kV high-voltage temporary grounding wire classifying and positioning device comprises a main control board and a bottom board;

the base plate, the high-voltage line to be detected, the earth connection voltage unit and the current sampling circuit are respectively connected to the line to be detected;

the main control board comprises a raspberry group module, a storage module, a communication module and a display module;

the base plate comprises a power management module, a signal generation module, a filtering module, a current detection module and a voltage detection module;

the raspberry pie module can perform fast Fourier transform and realize PWM output function;

the memory module comprises two chips and three functions;

the two chips are a RAM and an SD card;

the three functions include: storing data functions required by an operating system and a running process, storing and solidifying a boot program function and storing the data functions in a debugging process;

the raspberry group module can set a PWM mode, a generator range and a frequency divider frequency division through two modes of hardware programming and software programming, so that a PWM output function is realized;

the signal generation module can process the 3.3V PWM signal generated by the raspberry group module, the PWM signal is amplified into 12V, the 12V DC signal output by the battery is converted into a 9V AC signal with specific frequency, namely 200Hz or 400Hz through the inversion switch tube, the signal is filtered through the filtering module, and finally the signal is injected into a 10kV high-voltage circuit;

a filtering module for isolating useful signals from unwanted noise in the circuit;

the communication module is provided with an SIM card slot on board, can be directly inserted into a 1.8V or 3V SIM card, and can ensure stable and effective real-time communication among units;

the display module can display the grounding point state, the geographic position information and the grounding fault types in real time;

the power supply management module is used for providing three direct-current voltage outputs of 5V, 9V and 12V;

the current detection module is used for enabling the injection current of the high-voltage wire to flow back to the ground after passing through the high-voltage resistor; the current passing through the high-voltage resistor is measured through a current transformer arranged in the device; the current signal obtained by the current transformer is filtered and amplified, enters an ADC sampling interface and is input into a raspberry group chip, so that a digital signal of the current is obtained;

the voltage detection module is used for collecting and comparing the voltage signal injected into the high-voltage line with the voltage signal at the output end of the inversion module, and the voltage signal injected into the high-voltage line through the filtering module and the feedback signal for controlling the PWM wave output by the output end of the inversion module are used as conditions for judging whether the temporary grounding wire exists in the line and classifying the temporary grounding wire through the ADC sampling interface;

and after successful synchronization, the devices respectively inject a specific frequency voltage signal of a middle frequency band into a high-voltage line to be detected, then detect, calculate and analyze the voltage and current signals, synchronize the result with the short message again, and accurately judge whether a temporary grounding wire exists or not, and if yes, display the type and the geographic position of the temporary grounding wire.

The prior art can not accomplish 3 functions that this device had simultaneously: (1) can detect in the event of a power outage; (2) The type of the grounding wire capable of detecting the grounding point is single-phase circuit grounding, double-phase circuit grounding, three-phase circuit grounding or interphase short circuit; (3) the position of the ground point can be detected.

Drawings

FIG. 1 is a schematic diagram of a 10kV high-voltage temporary grounding wire classifying and positioning device for multi-group synchronous detection;

FIG. 2 is a schematic diagram of a 10kV high-voltage temporary grounding wire classification and positioning device for multi-group synchronous detection in one embodiment;

fig. 3 is a schematic structural diagram of a 10kV high-voltage temporary ground wire classification and positioning device for multi-group synchronous detection in an application example.

Detailed Description

The utility model provides a specific implementation mode of a multi-group synchronous detection 10kV high-voltage temporary grounding wire classifying and positioning device, which is described in detail below with reference to the accompanying drawings:

fig. 1 is a schematic structural diagram of a 10kV high-voltage temporary grounding wire classifying and positioning device for multi-group synchronous detection, which comprises a main control board and a bottom board. The main control board is connected with the bottom plate; the base plate, the high-voltage line to be detected, the earth connection voltage unit and the current sampling circuit are respectively connected to the line to be detected. The device is used for detecting by the cooperation of a plurality of groups of devices, after the synchronization is successful, the short messages are sent among the groups, voltage signals with certain specific frequency in the middle frequency band are respectively injected into the high-voltage line to be detected, then the voltage signals and the current signals are detected, calculated and analyzed, the result is synchronized with the short messages again, whether a temporary grounding wire exists or not is accurately judged, and if yes, the type and the geographic position of the temporary grounding wire are displayed.

Fig. 2 is a schematic structural diagram of a 10kV high-voltage temporary ground wire classification and positioning device for multi-group synchronous detection in one embodiment. The main control board comprises a raspberry group module, a storage module, a communication module and a display module. The raspberry pie module can perform fast Fourier transform, has a plurality of input and output interfaces, can run a complete operating system, completes more complex task management and scheduling, supports development of upper-layer application, has output voltages of 3.3V and 5V, has PWM output functions, can set PWM modes, generator ranges and frequency divider frequency division through two modes of hardware programming and software programming, ensures the safety of instruments and circuit boards, and has higher flexibility. The memory module comprises two chips and three functions, wherein the two chips are a RAM and an SD card, and the three functions are respectively a data function required by a memory operating system and running, a memory solidification starting-up bootstrap function and a data function in a memory debugging process. The communication module is provided with an SIM card slot on the board, can be directly inserted into a 1.8V or 3V SIM card, can send Chinese and English short messages, supports 2G/3G/4G network and GNSS global positioning, ensures stable and effective real-time communication between units, and accurately positions a temporary grounding wire, is inserted into a main control board through a USB interface, provides driving suitable for various systems, and is small in size and convenient to carry. The display module, the HDMI high definition touch screen is required to input 5V, is connected with the main control board through an HDMI line, inputs signals through an HD IN interface, and except for a required power supply, only needs a signal line, so that the internal structure of the instrument is simpler and more convenient, meanwhile, the stability of the signals can be ensured, and the grounding point state, the geographic position information and the type of the grounding fault can be displayed IN real time. The bottom plate comprises a power management module, a signal generation module, a filtering module, a current detection module and a voltage detection module. The power management module provides three direct-current voltage outputs of 5V, 9V and 12V, filters the outputs, ensures stable output of the 5V direct-current voltage through the 5V voltage stabilizing chip, isolates the power supply by adopting the direct-current isolation power supply module, and effectively isolates the main control panel 5V power supply in the circuit and the 12V power supply used by the inverter. The 5V voltage stabilizing chip has high and stable precision, ensures the stable operation of the main control chip in the main control board, and simultaneously ensures the stability of output signals, in particular the stability of PWM signals and the stability of dead time control. The signal generation module can process the 3.3V PWM signal generated by the raspberry group module, the PWM signal is amplified into 12V, the 12V DC signal is converted into a 9V AC signal with specific frequency, namely 200Hz or 400Hz, the signal is filtered by the filtering module, and finally the signal is injected into a 10kV high-voltage circuit. The filtering module isolates useful signals from useless noise in the circuit, so that the anti-interference performance and the signal-to-noise ratio of the circuit signals are improved, and the signals are more stable. The current detection module is used for enabling the injection current of the high-voltage wire to flow back to the ground after passing through the high-voltage resistor, so that potential safety hazards can not be left on the instrument. The current passing through the high-voltage resistor is measured through a current transformer arranged in the device, and an external current clamp is not needed. The current signal obtained by the current transformer enters an ADC sampling interface through operations such as filtering and amplifying, and is input into a raspberry group chip, so that a digital signal of the current is obtained. The voltage detection module collects and compares the voltage signal injected into the high-voltage line and the voltage signal at the output end of the inversion module, the voltage signal injected into the high-voltage line through the filtering module and the feedback signal for controlling PWM waves output by the output end of the inversion module are stored in the raspberry pie chip through the ADC sampling interface, the voltage signal injected into the high-voltage line is used as a condition for judging whether a temporary grounding wire exists in the line or not and classifying the temporary grounding wire, and the voltage signal at the output end of the inversion module is used as a feedback control signal for error control. In one embodiment, the chips used in the master board are the Raspberry Pi3B+ chip and the AD7606 chip. The Raspberry Pi 3B+ module can be a minimum system board of the Raspberry Pi3B+, the AD7606 is responsible for collecting and converting analog voltage signals and analog current signals output by the voltage sensor and the current sensor, the main control chip Raspberry Pi3B+ is responsible for analyzing and processing the voltage signals and the current signals output by the AD7606, the analog signals and the digital signals are effectively isolated by the modularized design, stable operation of the control module is ensured, and interference between analog and high-speed digital signals is effectively isolated by adopting two circuit boards. The sampling of the obtained current signal, the isolation of the power supply signal and the voltage signal all need a sampling isolation technology, and the sampling can be realized by sub-packaging an analog signal circuit and a digital signal circuit so as to prevent unnecessary interference between different signals. The ADC analog-to-digital converter has high accuracy and high speed requirements, and even if the processing speed and accuracy are high, the filtering process needs to be performed in the bottom plate, and a second-order band-pass filter formed by an amplifier can be used. The inverter converts the direct current signal into an alternating current signal, filters the signal and finally injects the signal into the high-voltage circuit.

Fig. 3 is a schematic structural diagram of a 10kV high-voltage temporary ground wire classification and positioning device for multi-group synchronous detection in an application example. The battery 01 can respectively output direct current voltages of 5V, 9V and 12V, can be a chargeable lithium ion battery pack of 12.6V, is provided with an intelligent IC protection board, stabilizes output voltage, prolongs the service life of the battery, has the capacity of 10800mAh, and simultaneously has an electric quantity display lamp to prompt electric quantity so as to prevent low electric quantity from being used. The power management module 02 is internally provided with a direct current isolation power module, a filter and a 5V voltage stabilizing chip, and provides different power supplies for digital signals and analog signals. Because the digital power supply 03 and the analog power supply 04 need different power supply voltages and different stability requirements, the power management module effectively isolates the digital power supply 03 from the analog power supply 04 and provides mutually isolated power supplies for the amplifier 8, the optocoupler 9 and the switching tube 10. The digital power supply 03 is required to provide stable 5V power, and preferably, the digital power supply 03 is separated from the analog power supply 04, and the battery 01 obtains 12V voltage, and the digital power supply is required to provide 5V voltage, so that an unstable output power module cannot be adopted, and a high-precision voltage stabilizing and isolating power supply chip is required, so that the power module of the MONSUN B1205LS-1W and the LM2576-5 power supply chip can be combined, and the 5V voltage is obtained from 12V, and then the stable 5V voltage is obtained, so that the advantages of isolation, voltage stabilizing and high precision are achieved. The power supply provided by the analog power supply 04 is more complex, and the analog power supply 04 provides the working power supply for the amplifier 8, and the power supply has positive and negative power supplies, so that the direct current isolated power supply is selected, and the power supply has positive and negative output. The switching tube 10 and other devices need to be isolated, and the requirements for the power supply are not particularly high. A Jin Sheng positive power module, such as a power module model number MORNSUN a1205S-1W, may be selected to provide isolated power from 12V to plus or minus 5V. A power module of model MONSUN B1205LS-1W was selected to obtain an isolated power supply from 12V to plus 5V. A power module with the model MONSUN B1212LS-1W is selected to obtain an isolated power supply from 12V to positive 12V. And selecting a power module with the model MORNSEN A1212S-1W to obtain an isolated power supply from 12V to plus or minus 12V. The display module 05 needs to meet the conditions of stable control, fewer signal lines, HDMI interface, touch control and compatibility with a main control chip, can select an HDMI 7-inch high-definition capacitive touch screen, is connected with the main control board only through a USB line and an HDMI line, is directly powered by the main control board, has no screen burning phenomenon, has longer service life, can clearly display the operation interface of the device, displays the grounding point state, the geographic position information and the grounding fault types in real time, is sensitive in touch control, and is convenient for human-computer friendly interaction. The raspberry pi module 06 is the core unit of the control, the core unit of the algorithm and the core unit of the signal processing. It should have a PWM wave control module and be able to process the sampled mid-frequency ac signal and perform software filtering and fast fourier decomposition on it. The memory module comprises two chips, namely a RAM and an SD card. The RAM is an LPDDR2 RAM chip of 1GB, and is used as the internal storage of the raspberry group module, the supported working frequency is 100 MHz-533 MHz, the data bit width is 8, 16 and 32, and the data bit width is 2 bits and 4 bits, and is directly supplied by a main control board. The SD card is used to store the operating system, documents, programs, etc. of the rareberry pi3b+. The Raspberry group module 06 can select a Raspberry Pi3B+ chip, is internally provided with 2 paths of independent hardware PWM wave modulation signals, and can realize that 31 gpio ports of the Raspberry group can be controlled by software programming through a pipio library function to generate independent PWM waveforms simultaneously. The raspberry pie chip requires a stable 5V operating voltage, which is too low to cause operation anomalies, while too high voltage can cause irreversible effects on the chip, so the requirements on the digital power supply 03 are high. The communication module 07 has higher requirements, and needs to select a module which has high communication speed, supports short message receiving and sending, is suitable for a Linux operating system and supports GNSS positioning so as to ensure real-time synchronization of a unit and accurate positioning result. The SIM 7600G-H4G DONGLE module may be selected. The module supports communication protocols such as TCP/UDP/FTP/FTPS/HTTP/HTTPS, and the like, and is provided with a USB interface on board, so that the module is convenient to directly access a main control board for networking, is provided with a SIM card slot, supports 1.8V and 3V SIM cards, is provided with 3 LED indicator lamps, is convenient to check the running state of the module, and has wide baud rate range for sending and identifying. The amplifier 08 is used for amplifying the signal to have the driving capability of driving the optocoupler 10. The power supply of the power supply is positive and negative 12V power supply. OPA4227 or LM339 may be selected. The amplifier in the two voltage signals, such as amplifier 12, acts to scale down the signal. Such that the voltage signal is within the range of the ADC digital-to-analog converter 15. The current signal obtained from the current transformer 16 is amplified by an amplifier, so that the accuracy of the signal is improved, and the measuring range of the raspberry group module 06 is better adapted. The optocoupler 09 can realize the control of a large signal by a small signal and the control of a large voltage by a small voltage, and the signals are isolated, so that the digital signal and the analog signal are not electrically connected. The high-speed optocoupler is provided with a high-speed optocoupler, and the time for switching on and switching off must be strictly controlled to prevent unsafe factors. The TLP521-1 high speed optocoupler may be selected. The switching tube 10 is an inversion process, converts a 12V direct current signal into a controllable alternating current signal, the amplitude of the alternating current signal and the frequency of the alternating current signal can be controlled, and the alternating current signal can be controlled by setting a PWM output control port of the raspberry group module 06. The control of the switching tube is careful, and the control is slightly bad, which will cause the voltage short circuit, so the requirement on the power management module 02 is higher, and the circuit is designed by adopting the way of isolating the power supply and adding fuse fuses. 2 APs 9971GD may be selected to constitute a full bridge inverter circuit for which drive circuit IR2110 may be employed. IR2110 is a special high-performance full-bridge open-light pipe control chip. The input signal can be amplified by the raspberry group module 06 output through the amplifier LM339. Two switching tubes then require two IR2110 and one LM339 to make up the drive circuit. The 12V direct current detection voltage signal is converted into a 9V alternating current signal after passing through the switching tube 10, the 9V alternating current signal is filtered through the filter 13, the voltage signal is reduced through the amplifier 12, the voltage signal is filtered again through the filter 11, and then is sampled through the ADC (analog-to-digital converter) 15 and then is input into the raspberry group module 06, so that a feedback loop is formed, and a control algorithm can be added into the raspberry group module 06 to regulate the alternating current signal in real time. The alternating current signal output to the line to be detected is more reliable through closed loop control. The filtering module 14 performs filtering processing on the 9V ac signal obtained by the conversion of the switching tube 10, so that the detection signal is more accurate. The ADC analog-to-digital converter 15 is used for converting the analog signal into the digital signal, and because the raspberry group module 06 cannot directly process the analog signal, the ADC analog-to-digital converter 15 is required to convert the detected analog signal into the digital signal, and then input the digital signal into the raspberry group module 06 for processing. The ADC analog-to-digital converter 15 has high precision and speed requirements, even if the processing speed and precision of the ADC analog-to-digital converter are high, in a preferred embodiment, the AD7606 module is selected, the 16-bit resolution and the 8-channel analog input are provided by the raspberry group module 06, the sampling voltage range is positive or negative 5V or positive or negative 10V, the range can be selected by the raspberry group module 06, the maximum sampling frequency is 200Ksps, the 8-stage oversampling setting is supported, and the jitter is effectively reduced. As a preferred embodiment, a method based on the principle of frequency conversion input-sweep detection of earth location is used. After a plurality of intermediate frequency detection signals are injected into a line to be detected by a plurality of devices at a plurality of positions of a line, the devices digitally filter the power frequency signals by using an FIR algorithm, calculate current values corresponding to the plurality of detection signals by using a fast Fourier algorithm, and judge the grounding state and the positioning grounding position of the power distribution network according to feedback current values and impedance values. Meanwhile, the device has the function of real-time communication, can realize the mutual transmission of measurement data among devices at different point positions, synthesizes the data of all the point positions, can comprehensively analyze the topological structure of the power grid, has more accurate measurement results, and the grounding point state, the position geographic information and the grounding fault types are clearly displayed on a display screen.

The foregoing description is only of the preferred embodiments of the present utility model and is not intended to limit the scope of the utility model, and all equivalent structures or equivalent processes using the descriptions and drawings of the present utility model or directly or indirectly applied to other related technical fields are included in the scope of the utility model. Accordingly, the scope of protection of the present utility model is to be determined by the appended claims.

Claims (1)

1. The 10kV high-voltage temporary grounding wire classifying and positioning device for multi-group synchronous detection is characterized by comprising a main control board and a bottom board;

the main control board is connected with the bottom plate;

the base plate, the high-voltage line to be detected, the earth connection voltage unit and the current sampling circuit are respectively connected to the line to be detected;

the main control board comprises a raspberry group module, a storage module, a communication module and a display module;

the base plate comprises a power management module, a signal generation module, a filtering module, a current detection module and a voltage detection module;

the raspberry pie module can perform fast Fourier transform and realize PWM output function;

the memory module comprises two chips and three functions;

the two chips are a RAM and an SD card;

the three functions include: storing data functions required by an operating system and a running process, storing and solidifying a boot program function and storing the data functions in a debugging process;

the raspberry group module can set a PWM mode, a generator range and a frequency divider frequency division through two modes of hardware programming and software programming, so that a PWM output function is realized;

the signal generation module can process the 3.3V PWM signal generated by the raspberry group module, the PWM signal is amplified into 12V, the 12V DC signal output by the battery is converted into a 9V AC signal with specific frequency, namely 200Hz or 400Hz through the inversion switch tube, the signal is filtered through the filtering module, and finally the signal is injected into a 10kV high-voltage circuit;

a filtering module for isolating useful signals from unwanted noise in the circuit;

the communication module is provided with an SIM card slot on board, can be directly inserted into a 1.8V or 3V SIM card, and can ensure stable and effective real-time communication among units;

the display module can display the grounding point state, the geographic position information and the grounding fault types in real time;

the power supply management module is used for providing three direct-current voltage outputs of 5V, 9V and 12V;

the current detection module is used for enabling the injection current of the high-voltage wire to flow back to the ground after passing through the high-voltage resistor; the current passing through the high-voltage resistor is measured through a current transformer arranged in the device; the current signal obtained by the current transformer is filtered and amplified, enters an ADC sampling interface and is input into a raspberry group chip, so that a digital signal of the current is obtained;

the voltage detection module is used for collecting and comparing the voltage signal injected into the high-voltage line with the voltage signal at the output end of the inversion module, and the voltage signal injected into the high-voltage line through the filtering module and the feedback signal for controlling the PWM wave output by the output end of the inversion module are used as conditions for judging whether the temporary grounding wire exists in the line and classifying the temporary grounding wire through the ADC sampling interface;

after the synchronization of the devices is successful, a certain specific frequency voltage signal of a middle frequency band is respectively injected into the high-voltage line to be detected, and then the voltage and current signals are detected, so that whether the temporary grounding wire exists, the type and the geographic position are accurately judged.