CN205139294U - Ground net corrodes situation testing arrangement based on wireless sensor network - Google Patents

Abstract

The utility model relates to a grounding grid corrosion testing device based on a wireless sensor network, comprising: an excitation source module for inputting coded signals to the grounding grid; a test module for collecting electromagnetic wave signals of the grounding grid; a test host for Receive the electromagnetic wave signal collected by the test module, and output the corrosion and on-off status of the grounding grid; the communication between the excitation source module and the test host, and between the test module and the test host are all connected through a wireless network. The utility model has the advantages that the detection process is simple and fast, the ground surface does not need to be dug, and the detection result is accurate.

Description

A grounding grid corrosion testing device based on wireless sensor network

technical field

The utility model relates to a testing device for the corrosion state of a grounding grid based on a wireless sensor network.

Background technique

The grounding grid is an important guarantee for the safe operation of the power system. The quality of its grounding performance is directly related to the personal safety of the workers in the substation and the safe operation of various electrical equipment. Therefore, it has always been highly valued by the power design and production and operation departments.

The conductors that make up the grounding grid are buried underground. Often due to poor welding or missing welding during construction, soil corrosion, and grounding short-circuit current electrodynamic action, etc., as the service life increases, corrosion is prone to occur, which may make the grounding conductor thinner or even broken. , Destroy the original structure of the grounding grid, reduce the electrical connection performance of the grounding grid, and increase the grounding resistance, which will cause the local potential difference of the grounding grid itself or an abnormal increase in the potential of the grounding grid. Once the power system is struck by lightning or a short-circuit fault occurs, it will not only bring danger to the staff, but also easily cause the detection and control equipment to malfunction and expand the impact of the accident. In my country, since the grounding grid material of most substations is ordinary carbon steel, the corrosion problem is relatively prominent. Accidents in the power system caused by corrosion or even fracture of the grounding grid occur from time to time, causing huge economic losses and adverse social impacts.

In recent years, finding the severely corroded section of the grounding grid has become a major anti-accident measure for the power sector. In actual engineering, for the measurement of the fault point of the grounding grid, the corrosion degree of the grounding grid conductor is usually estimated empirically based on the soil corrosion rate in the area , and then sample the surface for inspection. This method has blindness, heavy workload, slow speed, and is also limited by field operating conditions, so it cannot accurately judge the degree of corrosion and the location of the breakpoint.

Utility model content

The purpose of this utility model is to propose a grounding grid corrosion test device based on a wireless sensor network, which has the advantages of simple and fast detection process, no need to dig the ground surface, and accurate detection results.

In order to achieve the above object, the technical scheme adopted by the utility model is as follows: a grounding grid corrosion testing device based on a wireless sensor network, characterized in that it includes:

The excitation source module is used to input the coded signal to the ground grid;

The test module is used to collect electromagnetic wave signals of the grounding grid;

The test host is used to receive the electromagnetic wave signal collected by the test module, and output the corrosion and on-off status of the grounding grid;

Communications between the excitation source module and the test host, and between the test module and the test host are all connected through a wireless network.

According to the above scheme, the test host includes:

The input display unit is used to input instructions and set parameters to the test host, and display test results and working status information;

The FPGA module is used to calculate the corrosion and on-off status of the grounding grid according to the input information;

The input terminal and the output terminal of the input display unit are respectively connected to the output terminal and the input terminal of the FPGA module.

According to the above solution, the test host also includes an environmental parameter sensor connected to the input end of the FPGA module, which is used to collect environmental temperature and humidity, soil temperature and humidity information and send them to the FPGA module.

According to the above scheme, the excitation source module includes:

A coded signal generating circuit, used to generate a coded signal input to the ground grid;

A power amplifying circuit, configured to amplify the power of the coded signal generated by the coded signal generating circuit;

The test terminal is used to input the coded signal after power amplification to the ground grid;

The output end of the encoding signal generating circuit is connected to the input end of the power amplifying circuit, and the input end of the test terminal is connected to the output end of the power amplifying circuit.

According to the above scheme, the test module includes:

The induction coil is used to receive the electromagnetic wave signal with coded signal radiated from the grounding grid;

A signal processing module, configured to process the electromagnetic wave signal received by the induction coil to obtain a coded signal and send it to the test host;

The output end of the induction coil is connected to the input end of the signal processing module.

According to the above scheme, the signal processing module includes:

Amplifying and filtering circuit, used for amplifying and band-pass filtering the electromagnetic wave signal received by the induction coil;

A coherent detection circuit for suppressing interference signals;

An analog-to-digital conversion circuit for converting an analog signal into a digital signal;

The input end of the amplification filter circuit is connected to the output end of the induction coil, the input end of the coherent detection circuit is connected to the output end of the amplification filter circuit, and the input end of the analog-to-digital conversion circuit is connected to the The output terminal of the coherent detection circuit.

According to the solution above, there are multiple test modules, and when the ground grid is tested, the multiple test modules are arranged side by side on the ground surface above the ground grid.

According to the above solution, the plurality of test modules are arranged in a square array row by column on the upper ground surface of the ground grid.

The utility model loads the coded signal that can effectively suppress the interference of the power frequency electromagnetic field and its harmonic signals to the grounding network to be tested. If the grounding network is corroded, some branches will break or become thinner obviously and the impedance will increase, resulting in The coded signal injected into the ground grid is distorted; the test module located on the ground surface receives the electromagnetic wave radiated from the ground grid and sends it to the test host; the test host calculates the basic structure of the ground grid and each The corrosion status of the branch, and finally the test results are displayed through the graphical interface. Because different corrosion conditions of the grounding grid will cause different degrees of distortion of the electromagnetic wave, the radiation information received by the test module from the grounding grid to be tested represents the corrosion degree of the corresponding branch of the grounding grid. The corrosion situation of the grounding grid can be obtained without digging the ground surface for inspection, and it is not limited by the on-site inspection conditions. It can accurately judge the corrosion degree of the grounding grid and the location of the breakpoint. It has high accuracy, small workload, and high speed. The advantage of being fast.

Description of drawings

Fig. 1 is a structural representation of the utility model;

Fig. 2 is the structural representation of the test host of the present utility model;

Fig. 3 is the structural representation of the excitation source module of the present utility model;

Fig. 4 is a schematic structural view of the test module of the present invention.

In the figure: 10, excitation source module; 20, test module; 30, test host; 11, coded signal generation circuit; 12, power amplifier circuit; 13, wireless sensor network node II; 21, induction coil; 22, amplification and filtering circuit 23. Coherent detection circuit; 24. Analog-to-digital conversion circuit; 25. Wireless sensor network node III; 31. Input display unit; 32. FPGA module; 33. Environmental parameter sensor; 34. Wireless sensor network node I.

detailed description

The technical scheme of the present utility model is described below in conjunction with accompanying drawing and embodiment.

As shown in Figure 1, a kind of grounding grid corrosion condition testing device based on wireless sensor network described in the utility model comprises: excitation source module 10, is used for inputting coded signal to grounding grid; Test module 20, is used for collecting grounding grid The electromagnetic wave signal of the network; the test host 30 is used to receive the electromagnetic wave signal collected by the test module 20, and output the corrosion and on-off status of the ground grid; between the excitation source module 10 and the test host 30, and test The communication between the module 20 and the test host 30 is through a wireless network connection.

The utility model loads the coded signal that can effectively suppress the interference of the power frequency electromagnetic field and its harmonic signals to the grounding network to be tested. If the grounding network is corroded, some branches will break or become thinner obviously and the impedance will increase, resulting in The encoded signal injected into the ground grid is distorted; the test module 20 located on the ground surface receives the electromagnetic wave radiated from the ground grid and sends it to the test host 30; The corrosion status of the structure and each branch, and finally the test results are displayed through the graphical interface. Because different corrosion conditions of the grounding grid will cause different degrees of distortion of the electromagnetic wave, the radiation information received by the test module 20 from the grounding grid to be tested represents the corrosion degree of the corresponding branch of the grounding grid. The difference in the signal obtained through detection is The corrosion situation of the grounding grid can be obtained without digging the ground surface for inspection, and it is not limited by on-site inspection conditions. It can accurately judge the corrosion degree of the grounding grid and the location of the breakpoint. At the same time, all communication networks use wireless networks for communication , so that the detection construction is convenient and fast, and has the advantages of high accuracy, small workload and fast speed.

Specifically, the test host 30 includes: an input display unit 31, which is used to input instructions and setting parameters to the test host 30, and displays test results and working status information; an FPGA module 32 is used to calculate the corrosion of the ground grid according to the input information. and on-off state; the input end and output end of the input display unit 31 are connected to the output end and the input end of the FPGA module 32 respectively. Further, the test host 30 also includes an environmental parameter sensor 33 connected to the input end of the FPGA module 32 , which is used to collect environmental temperature and humidity, soil temperature and humidity information and send them to the FPGA module 32 .

Specifically, the excitation source module 10 includes: a coded signal generating circuit 11, which is used to generate a coded signal input to the ground grid; a power amplifier circuit 12, which is used to amplify the power of the coded signal generated by the coded signal generating circuit 11. ; The test terminal is used to input the coded signal after power amplification to the ground grid; the output end of the coded signal generating circuit 11 is connected to the input end of the power amplification circuit 12, and the input end of the test terminal is connected to The output end of the power amplifying circuit 12 . The utility model adopts a special encoding method, which can effectively suppress the interference of the power frequency electromagnetic field and its harmonics on the output signal of the excitation source module 10 .

Specifically, the test module 20 includes: an induction coil 21, configured to receive an electromagnetic wave signal with a coded signal radiated from the ground grid; a signal processing module, configured to process the electromagnetic wave signal received by the induction coil 21, The encoded signal is obtained and sent to the test host 30; the output end of the induction coil 21 is connected to the input end of the signal processing module. In addition, the signal processing module includes: an amplification filter circuit 22, which is used to amplify and band-pass filter the electromagnetic wave signal received by the induction coil 21; a coherent detection circuit 23, which is used to suppress interference signals; an analog-to-digital conversion circuit 24 , for converting analog signals into digital signals; the input end of the amplification filter circuit 22 is connected to the output end of the induction coil 21, and the input end of the coherent detection circuit 23 is connected to the output of the amplification filter circuit 22 The input end of the analog-to-digital conversion circuit 24 is connected to the output end of the coherent detection circuit 23 . Using band-pass filtering technology and coherent detection technology, it receives special coded signals injected from the excitation source module 10 through the grounding grid terminal, which further improves the signal-to-noise ratio and anti-interference ability of the system. Further, there are multiple test modules 20, and when testing the ground grid, the multiple test modules 20 are arranged side by side on the ground surface above the ground grid. Preferably, the multiple test modules 20 are arranged in a square array row by column on the upper ground surface of the ground grid.

The utility model is described below through a complete embodiment and its application example.

The basic detection principle of the utility model includes: using a special coded signal to suppress the interference of the power frequency electromagnetic field and its harmonics, collecting the electromagnetic wave signal radiated by the grounding grid to be tested through the multi-point distributed induction coil 21, and using a wireless sensor network to control all After the electromagnetic wave signal measured by the test module 20 is amplified, filtered, detected, and converted from analog to digital, it is sent to the test host 30; the test host 30 synthesizes and calculates the data of all test modules 20 to obtain the basic structural parameters and parameters of the ground grid to be tested. The degree of corrosion and fracture of each branch are displayed on the liquid crystal display.

As shown in Figure 1, the ground grid corrosion condition testing device based on wireless network connection communication includes an excitation source module 10, a test host 30 and several test modules 20; the test host 30 is the core of the ground grid corrosion condition test device , carry out wireless communication with all the test modules 20 of the excitation source module 10 arranged in the area to be tested through the wireless sensor network, and be responsible for system initialization, issuance of control commands, signal synchronization, data collection, data calculation and analysis, and test result output etc.; the excitation source module 10 adopts a unique coding method, injects electromagnetic waves with coded information into the terminals of the grounding grid to be tested through power amplification, and improves the system's ability to suppress power frequency electromagnetic fields and harmonic interference thereof; The test module 20 uses the induction coil 21 to receive electromagnetic waves with coded signals radiated from the ground grid to be tested through the ground surface, and sends them to the test host 30 by wireless communication after amplification and filtering, coherent detection and analog-to-digital conversion. In the utility model, the network nodes of the wireless network connection communication can adopt chips such as CC2530, CC2531, CC2533, JN5148, MC13192, EM260, LINK-23X, and Link-212.

The device provided by the utility model is mainly used for detecting the structure and corrosion condition of the grounding grid. Before the test, according to the specifications and test accuracy of the ground grid to be tested, a certain number of test modules 20, test hosts 30, and excitation source modules 10 are selected to form a test system, and the test hosts 30 and excitation source modules 10 are placed on the ground grid to be tested. Around; the optimal placement method is that the connection between the test host 30 and the excitation source module 10 is parallel to one side of the ground grid to be tested, and the distance is 5 to 10 meters; the test module 20 is placed one by one in the ground grid area to be tested Rows are evenly placed column by column to form a measurement matrix; when the test system is initialized, the test host 30 sends a synchronization signal to the test module 20 and the excitation source module 10, and the clocks of all wireless network connection communication network nodes are synchronized with the starting signal; subsequently, the test The module 20 calculates the position information according to the radio frequency signal characteristic parameters received from the test host 30 and the excitation source module 10, and the position information is sent to the test host 30 through the wireless sensor network node, and the test host 30 obtains all the test nodes in the test by comprehensive information. The location distribution of the area; the test host 30 is sending a test command, and the test module 20 amplifies, filters, detects and converts the received electromagnetic wave signal with code, and sends it to the test host 30 through a wireless sensor network node. The host computer 30 calculates and fits the electromagnetic wave signals of the entire area to be tested according to the data of all the test modules 20, and calculates the impedance distribution of each branch of the grounding network in combination with the position distribution information of the test modules 20, and judges its corrosion status and On-off situation; finally, the test host 30 displays the test results in the form of a three-dimensional simulation diagram.

The circuit design of the utility model adopts a low power consumption circuit, which is convenient for long-term field measurement and carrying. Fig. 2 shows the structural representation of test host 30, and described test host 30 comprises wireless sensor network node 134, environmental parameter sensor 33, FPGA module 32, input display unit 31 and power supply circuit, and described wireless sensor network node 134 and excitation The source module 10 and the test module 20 form a wireless sensor network, and the wireless sensor network node 134 is the central node of the network, which is used for sending synchronous signals and control signals, collecting data collected by other network sub-nodes, etc.; the environmental parameter sensor 33 mainly It is used to collect parameters such as ambient temperature, humidity, soil temperature and humidity, and to correct the ground grid radiation coded signal data collected by all test modules 20; the FPGA module 32 is mainly used for control, calculation and storage, etc. Out of the part relevant to the present utility model, the FPGA module 32 includes an arithmetic processing unit and a storage unit; the first input and output terminals of the arithmetic processing unit are connected to the wireless sensor network node I34, and transmit synchronous signals and control commands of the testing device, And receive measurement data etc. from the test module 20; The second input and output end of the operation processing unit is connected to the input display unit 31, receives the input information of the touch screen, and displays the status and test analysis results of the system in real time; The operation processing unit also It is directly connected to the storage unit through the internal bus to improve the storage efficiency and speed of data. The input terminal of the power supply circuit is connected to 220V power frequency alternating current, and after step-down, rectification, filtering and voltage stabilizing circuits, it outputs +12V, +5V and +3.3V direct current to supply power for the test host 30 .

In the utility model, the environmental parameter sensor 33 can use DS18B20 to measure the ambient temperature, can use the SH1101 to test the environmental humidity, can use the HA2002 soil temperature sensor to measure the soil temperature, can use the HA2001 soil humidity sensor to measure the soil humidity, and can use an LCD touch screen As the input display unit 31, the FPGA module 32 can be an EP4CE10E22C8N chip.

Fig. 3 is the structural representation of excitation source module 10, and described wireless sensor network node II13 is the control core of excitation source module 10, and the radio frequency transceiver circuit that interior comprises is mainly used for receiving the synchronous signal and the control order from test host 30, according to test The process is to synchronize the signal with the test host 30 to ensure that the triggering time is the same. According to the control command of the test host 30, the wireless sensor network node II13 sends a trigger signal to the coded signal generation circuit 11, outputs a special code, and can pass through the wireless sensor network. The built-in MCU of the node controls the encoding chip to realize adjustable encoding; the input end of the power amplifier circuit 12 is connected to the output end of the encoding signal generation circuit 11, and the control end is connected to the I/O of the built-in MUC of the wireless sensor network node II13. The O port is connected, and the output end of the power amplifier circuit 12 is connected to the connecting terminal of the grounding grid to be tested through the transmitting electrode; the input end of the power circuit is connected to 220V power frequency alternating current, and after step-down, rectification, filtering and voltage stabilizing circuit, Output DC power of +12V, +5V and +3.3V to supply power for the excitation source module 10 . In the present invention, the encoding signal generating circuit 11 can be realized by using EV1527 chip, and the power amplifying circuit 12 can be realized by using MGA43228 chip.

4 is a schematic structural diagram of the test module 20, which mainly includes an induction coil 21, an amplification filter circuit 22, a coherent detection circuit 23, an analog-to-digital conversion circuit 24, a wireless sensor network node III 25 and a point source circuit. The induction coil 21 is used to couple the electromagnetic wave signal from the ground grid to be tested, and the output end of the induction coil 21 is connected to the amplification filter circuit 22, and the amplification filter circuit 22 amplifies the weak signal sensed, and passes the bandpass filter The input end of the coherent detection circuit 23 is connected to the output end of the amplification filter circuit 22, and the coded signal is extracted through multiple iterations of the coherent detection technology; the input end of the analog-to-digital conversion circuit 24 is connected to the coherent detection The output terminal of the circuit 23 converts the analog signal into a digital signal, which is convenient for calculation, storage and transmission; the input terminal of the wireless sensor network node III25 is connected to the analog-to-digital conversion circuit 24, and the measured electromagnetic wave signal with encoded information It is sent to the test host 30 through wireless communication; the power supply circuit is implemented by a rechargeable lithium ion electric field, and the stable voltage output of +5V and +3.3V is realized through a DC-DC conversion circuit to supply power for the entire test module 20. In the present utility model, the induction coil 21 can be wound with enameled wire, and the amplification and filter circuit 22 can be designed by using the instrument operational amplifier AD620 to design the amplification circuit, INA333 to design the band-pass filter, the CA3070 to design the coherent detection circuit, and the AD7878 to design Analog-to-digital conversion circuit 24.

It has been proved that the utility model can effectively detect the corrosion status of the grounding grid with a buried depth less than 2.0 meters, and display the structure of the grounding grid and the corrosion status of each branch by testing the input display unit 31 of the host computer 30, and has strong anti-interference ability , accurate measurement, simple structure, good versatility, easy operation and so on.

Claims (8)

1. A grounding grid corrosion condition testing device based on wireless sensor network, it is characterized in that, comprising: The excitation source module (10) is used to input the coded signal to the ground grid; A test module (20), used for collecting electromagnetic wave signals of the grounding grid; A test host (30), configured to receive the electromagnetic wave signal collected by the test module (20), and output the corrosion and on-off status of the grounding grid; Communications between the excitation source module (10) and the test host (30), and between the test module (20) and the test host (30) are all connected through a wireless network. 2. a kind of ground grid corrosion condition testing device based on wireless sensor network according to claim 1, is characterized in that, described test host computer (30) comprises: The input display unit (31) is used for inputting instructions and setting parameters to the test host (30), and displaying test results and working status information; The FPGA module (32) is used to calculate the corrosion and on-off state of the ground grid according to the input information; The input terminal and the output terminal of the input display unit (31) are respectively connected to the output terminal and the input terminal of the FPGA module (32). 3. a kind of ground grid corrosion condition testing device based on wireless sensor network according to claim 2, is characterized in that, described test host computer (30) also comprises the environment parameter that is connected to the input end of described FPGA module (32) A sensor (33), which is used to collect ambient temperature and humidity, soil temperature and humidity information and send it to the FPGA module (32). 4. a kind of ground grid corrosion condition testing device based on wireless sensor network according to claim 1, is characterized in that, described excitation source module (10) comprises: A coded signal generating circuit (11), used to generate a coded signal input to the ground grid; A power amplification circuit (12), configured to amplify the power of the coded signal generated by the coded signal generation circuit (11); The test terminal is used to input the coded signal after power amplification to the ground grid; The output end of the encoding signal generating circuit (11) is connected to the input end of the power amplifying circuit (12), and the input end of the test terminal is connected to the output end of the power amplifying circuit (12). 5. a kind of ground grid corrosion condition testing device based on wireless sensor network according to claim 1, is characterized in that, described test module (20) comprises: The induction coil (21) is used to receive the electromagnetic wave signal with the coded signal radiated from the grounding grid; A signal processing module, configured to process the electromagnetic wave signal received by the induction coil (21), to obtain a coded signal and send it to the test host (20); The output end of the induction coil (21) is connected to the input end of the signal processing module. 6. a kind of grounding grid corrosion condition testing device based on wireless sensor network according to claim 5, is characterized in that, described signal processing module comprises: Amplifying and filtering circuit (22), used for amplifying and band-pass filtering the electromagnetic wave signal received by the induction coil (21); A coherent detection circuit (23), used for suppressing interference signals; An analog-to-digital conversion circuit (24), used for converting analog signals into digital signals; The input end of the amplification filter circuit (22) is connected to the output end of the induction coil (21), and the input end of the coherent detection circuit (23) is connected to the output end of the amplification filter circuit (22), so The input end of the analog-to-digital conversion circuit (24) is connected to the output end of the coherent detection circuit (23). 7. a kind of ground grid corrosion condition testing device based on wireless sensor network according to claim 1, is characterized in that, described test module (20) has multiple, when ground grid is tested, described multiple The test modules (20) are respectively arranged side by side on the upper ground surface of the ground grid. 8. A kind of grounding grid corrosion condition testing device based on wireless sensor network according to claim 7, it is characterized in that, described a plurality of test modules (20) are arranged row by column in square array on described grounding grid of the ground surface above.