Extra-high voltage direct current magnetic field focusing electricity testing system

Abstract

The invention relates to an extra-high voltage direct current magnetic field focusing electricity testing system which is composed of a magnetic field focusing module and a magnetic field measuring and alarming module. The magnetic field focusing module is made of electromagnetic metamaterials and gathers a magnetic field generated by the ultra-high voltage transmission line. The magnetic field measurement and alarm module comprises a magnetic field measurement sub-module used for measuring a magnetic field signal; the signal processing sub-module is used for collecting magnetic field signals, filtering noise and interference and converting the signals into signals which can be identified by the main control module; the main control sub-module is used for receiving the magnetic field signal, setting an alarm threshold value and controlling sound-light alarm; and the sound-light alarm submodule is used for sending out a sound-light alarm signal. The invention solves the problem of electricity testing of the high-voltage direct-current power transmission line, and provides an electricity testing method for judging the electrified state of the high-voltage direct-current power transmission line. Compared with other electricity testing systems, the electricity testing system has the advantages that the electricity testing system is suitable for a high-voltage direct-current transmission line with a higher voltage level, is less interfered by an external electromagnetic environment, and has the advantages of long non-contact measurement distance, wide measurement range and the like.

Description

Technical Field

[0001] The invention relates to a direct current electricity testing system, in particular to an ultra-high voltage direct current magnetic field focusing electricity testing system. Background Art

[0002] With the development of high-voltage direct current transmission technology, more and more direct current transmission projects have been put into operation. As an important means of detection, maintenance and transformation of transmission and distribution lines, live working on high-voltage transmission lines has played a very important role in the safe and reliable operation of power systems and the improvement of economic benefits. During live working, due to the unconscious movement of operators and errors in distance judgment, the human body exceeds the safe distance and discharges, or the human body directly contacts live equipment, which causes the vast majority of casualties. The high-voltage direct current test device can monitor the voltage and current conditions of the power system in real time, detect abnormal conditions in time and take corresponding measures. This helps to reduce the failure rate of the power system and improve the safety and stability of the system. At the same time, the device can also provide strong data support for the operation and maintenance of the power system, helping staff to better understand the operating status of the system. When conducting maintenance on ultra-high voltage transmission lines, in order to prevent accidents, the live condition of the line must be verified.

[0003] At present, the electric field testers used in the power industry are basically electric field testers based on the electric field principle. Through the electric field, the electric field is measured to timely reflect the electric field strength around the operator. When the electric field strength exceeds the critical electric field threshold of the safe distance or the power frequency electric field exposure limit threshold, the system will issue a warning in time to remind the operator to take corresponding safety protection measures. According to the electric test method, it is mainly divided into two categories: contact testers and non-contact testers. The contact tester is the most widely used tester, that is, the worker holds a retractable insulating protection rod, and the other end of the protection rod is a contact high-voltage probe, which directly contacts the part that needs to be tested. When the part to be tested is energized, the tester will send out an audible and visual alarm signal, indicating that the test result is energized. When it is determined that the part to be tested is not energized, maintenance and other work will be carried out to ensure the personal safety of the staff. Since the contact tester needs to directly touch the high voltage, when the insulation performance decreases, there is a risk of electric shock to personnel. Non-contact electrometers are still in the development stage. There are many non-contact electrometer-related studies based on different principles, including vibration capacitance electric field sensors, field grinding electric field sensors, optical electric field sensors, etc. The conductor of the field grinding sensor induces charges in the electric field. These induced charges are periodically changed by the rotating shielding electrode to obtain current. They are generally used to measure the ground electromagnetic environment. They are prone to failure or measurement errors in strong electric field environments. Optical electric field sensors are expensive and have high operating requirements, and their sensitivity is greatly affected by frequency.

[0004] The charged ions generated by the corona discharge of the UHV DC transmission line form a spatial ion flow under the action of the DC electric field, which will significantly enhance the spatial electric field. The synthetic electric field under the DC transmission line can reach several times the nominal electric field. At present, there is no industry standard and mature test equipment for UHV DC transmission lines in my country. The method of using an insulating rope to suspend metal objects close to the wire or judging whether it is charged by the sound of discharge by maintenance personnel is greatly affected by the outside world and is prone to misjudgment under noisy or strong light conditions. The test device based on the electric field principle is prone to electric field distortion and is easily affected by the surrounding electromagnetic environment due to the large size of the probe, resulting in large measurement errors. Li Shanshan from Wuhan University studied the starting characteristics of the 220kV capacitive high-voltage tester. During the test, there was a false alarm due to the same-direction interference of surrounding equipment when the equipment under test was not charged. Liu Jiaojiao from Donghua University designed a safety alarm device that can be used for large equipment to prevent the equipment from touching the transmission line and causing danger. The sensor design uses multiple electrodes to improve the measurement accuracy. The disadvantage of this electrical inspection system is that it is not suitable for the detection of UHV transmission lines. The electrical inspection device based on the electric field principle is prone to electric field distortion due to the large size of the probe, resulting in large measurement errors. In addition, it often uses a single probe measurement method, which is easily disturbed by human body shaking, resulting in inaccurate measurements. It is very important to develop an UHV DC electrical inspection device with strong adaptability, high measurement accuracy and fast response speed for the UHV DC environment to ensure the stable operation of the electrical inspection device in various complex and changeable power environments. It is necessary to propose a new electrical inspection method suitable for the UHV DC transmission environment. Summary of the invention

[0005] In view of the deficiencies of the above-mentioned prior art, the present invention proposes an ultra-high voltage direct current magnetic field focusing electrical testing system, which judges the charged state of the line by focusing and measuring the magnetic field around the transmission line. It has the advantages of non-contact electrical testing, increased electrical testing distance, and weakening the influence of ultra-high voltage direct current transmission ion flow field, providing strong support for the safe inspection and maintenance of the power system.

[0006] In order to achieve the above-mentioned purpose, the present invention provides an ultra-high voltage direct current magnetic field focusing electrical testing system, which includes the ultra-high voltage direct current magnetic field focusing electrical testing system, including a magnetic field focusing module and a magnetic field measurement and alarm module; the magnetic field focusing module is based on an electromagnetic metamaterial, and the electromagnetic metamaterial is a curved surface structure with a metal conductor pattern and a base plate; the magnetic field measurement and alarm module is composed of a magnetic field measurement submodule, a signal processing submodule, a main control submodule, and an acoustic and light alarm submodule; the magnetic field measurement and alarm module and the magnetic field focusing module transmit data through a wireless communication interface.

[0007] Optionally, the magnetic field focusing module is located between the UHV DC transmission line and the magnetic field measurement module to achieve local focusing of the magnetic field.

[0008] Optionally, the magnetic field focusing module is made of electromagnetic metamaterial.

[0009] Optionally, the magnetic field measurement and alarm module is composed of a magnetic field measurement submodule, a signal processing submodule, a main control submodule, an audible and visual alarm submodule, a switch submodule and a power supply submodule.

[0010] Optionally, the magnetic field measurement submodule is used to collect local focused magnetic field signals generated by the ultra-high voltage direct current transmission line.

[0011] Optionally, the signal processing submodule performs signal amplification, filtering and analog-to-digital conversion on the magnetic field signal measured by the magnetic field measurement module.

[0012] Optionally, the main control submodule receives the magnetic field signal processed by the signal processing module, and determines whether to control the sound and light alarm submodule to send out a sound and light alarm signal according to a set threshold.

[0013] Optionally, the sound and light alarm submodule includes a speaker, a red LED light and a green LED light; when the magnetic field exceeds the alarm threshold, the electroscope sends an alarm signal; when the magnetic field is lower than the alarm threshold, the electroscope does not alarm.

[0014] A method for ultra-high voltage direct current magnetic field focusing electrical testing is implemented based on the ultra-high voltage direct current magnetic field focusing electrical testing system. The method comprises the following steps: a magnetic field measurement submodule included in a magnetic field measurement and alarm module receives a magnetic field signal by means of the electromagnetic induction principle; a signal processing submodule amplifies, filters and performs analog-to-digital conversion processing on the signal; the signal processing submodule transmits the processed magnetic field signal to a main control submodule; a main controller of the main control submodule determines the magnetic field value and compares it with the alarm threshold set in the main controller; and determines whether to control the sound and light alarm submodule to send out an sound and light alarm signal according to the comparison result.

[0015] The beneficial effects provided by the present invention are: The present invention achieves the effect of increasing the non-contact electrical detection distance by applying a magnetic field focusing module. When the magnetic field received by the magnetic field measurement submodule is greater than the alarm threshold, the sound and light alarm submodule effectively alarms, and when the magnetic field received by the magnetic field measurement submodule is less than the alarm threshold, the sound and light alarm submodule does not alarm. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of ultra-high voltage direct current magnetic field focusing electrical testing of the present invention; Figure 2 A schematic diagram of the structure of the magnetic field focusing module of the present invention; Figure 3 The magnetic field measurement and alarm module structure diagram of the present invention; Figure 4Functional program flowchart of ultra-high voltage direct current magnetic field focusing electrical testing of the present invention.

[0017] In the figure: magnetic field focusing module 1, magnetic field measurement and electrical testing module 2, magnetic field measurement submodule 2-1, signal processing submodule 2-2, main control submodule 2-3, sound and light alarm submodule 2-4, switch submodule 2-5, power supply submodule 2-6. DETAILED DESCRIPTION

[0018] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0019] Before formally describing the present invention, the scheme of the present invention is first generally described for easy understanding.

[0020] Please refer to Figure 1 , Figure 1 It is a schematic diagram of the ultra-high voltage direct current magnetic field focusing electrical testing of the present invention.

[0021] The present invention discloses an ultra-high voltage direct current magnetic field focusing electrical testing system, which includes a magnetic field focusing module and a magnetic field measurement and alarm module; the magnetic field focusing module is based on an electromagnetic metamaterial, and the electromagnetic metamaterial is a curved surface structure with a metal conductor pattern and a bottom plate; the magnetic field measurement and alarm module is composed of a magnetic field measurement submodule, a signal processing submodule, a main control submodule, and an acousto-optic alarm submodule; the magnetic field measurement and alarm module and the magnetic field focusing module perform data transmission via a wireless communication interface.

[0022] Optionally, the magnetic field focusing module is located between the UHV DC transmission line and the magnetic field measurement module to achieve local focusing of the magnetic field.

[0023] Optionally, the magnetic field focusing module is made of electromagnetic metamaterial.

[0024] Optionally, the magnetic field measurement and alarm module is composed of a magnetic field measurement submodule, a signal processing submodule, a main control submodule, an audible and visual alarm submodule, a switch submodule and a power supply submodule.

[0025] Optionally, the magnetic field measurement submodule is used to collect local focused magnetic field signals generated by the ultra-high voltage direct current transmission line.

[0026] Optionally, the signal processing submodule performs signal amplification, filtering and analog-to-digital conversion on the magnetic field signal measured by the magnetic field measurement module.

[0027] Optionally, the main control submodule receives the magnetic field signal processed by the signal processing module, and determines whether to control the sound and light alarm submodule to send out a sound and light alarm signal according to a set threshold.

[0028] Optionally, the sound and light alarm submodule includes a speaker, a red LED light and a green LED light; when the magnetic field exceeds the alarm threshold, the electroscope sends an alarm signal; when the magnetic field is lower than the alarm threshold, the electroscope does not alarm.

[0029] A method for ultra-high voltage direct current magnetic field focusing electrical testing is implemented based on the ultra-high voltage direct current magnetic field focusing electrical testing system. The method comprises the following steps: a magnetic field measurement submodule included in a magnetic field measurement and alarm module receives a magnetic field signal by means of the electromagnetic induction principle; a signal processing submodule amplifies, filters and performs analog-to-digital conversion processing on the signal; the signal processing submodule transmits the processed magnetic field signal to a main control submodule; a main controller of the main control submodule determines the magnetic field value and compares it with the alarm threshold set in the main controller; and determines whether to control the sound and light alarm submodule to send out an sound and light alarm signal according to the comparison result.

[0030] As an example, Figure 1 In order to achieve the purpose of magnetic field focusing and electrical testing, the UHV DC magnetic field focusing and electrical testing system of the present invention is composed of a magnetic field focusing module 1 and a magnetic field measurement and alarm module 2. The magnetic field focusing module is located between the UHV DC transmission line and the magnetic field measurement module 2, and is used to achieve local magnetic field focusing.

[0031] The magnetic field focusing module 1 is composed of electromagnetic metamaterials, such as Figure 2 As shown, it is used to focus the local magnetic field generated by the ultra-high voltage direct current transmission line to the magnetic field measurement module. The electromagnetic metamaterial is a curved structure with a metal wire pattern and a bottom plate; the bottom plate is located at the bottom of the electromagnetic metamaterial, the metal wire pattern is fixed on the bottom plate, and the cross-sectional size and shape of the metal wire pattern are the same; the electromagnetic metamaterial terminals are respectively located on the two long sides; the pattern curved surface is perpendicular to the incident direction of the magnetic field.

[0032] The magnetic field measurement and alarm module of the present invention is as follows Figure 3 The magnetic field measurement and alarm module 2 comprises a magnetic field measurement module 2-1, a signal processing module 2-2, a main control module 2-3, an acoustic and optical alarm module 2-4, a switch module 2-5, and a power supply module 2-6.

[0033] The magnetic field measurement submodule 2-1 is used to collect the local focused magnetic field signal generated by the ultra-high voltage direct current transmission line. The signal processing submodule 2-2 performs signal amplification, filtering and analog-to-digital conversion on the magnetic field signal collected by the magnetic field measurement submodule 2-1, and then transmits the data to the main control submodule 2-3 using a communication protocol.

[0034] The main control submodule 2-3 receives the magnetic field signal processed by the signal processing module 2-2, and judges the live condition of the transmission line by comparing the measured value with the set threshold value, and judges whether to control the sound and light alarm submodule 2-4 to send out a sound and light alarm signal. The STM32F407 single-chip microcomputer is selected as the core of the main control submodule 2-3, and the CPU operating frequency is as high as 168MHz; including up to 6 USARTs, USBs, FSMCs, 3 high-speed SPIs, etc.; with 2 12-bit DACs, 3 high-speed 12-bit ADCs; with 512KB~1MB Flash and 192KB data storage. STM32F407 has the advantages of small size, light weight, low cost, high performance, low voltage, low power consumption, simple and easy to use, etc., and a variety of peripheral interfaces enable the chip to realize more abundant functions and more reliable control requirements.

[0035] The switch submodule 2-5 is used to turn on or off the power supply of the ultra-high voltage direct current magnetic field focusing electrical testing system.

[0036] The power supply submodule 2-6 is used to supply power to the magnetic field measurement submodule 2-1, the signal processing submodule 2-2, the main control submodule 2-3 and the sound and light alarm submodule 2-4.

[0037] The sound and light alarm submodule 2-4 includes a speaker, a red LED light and a green LED light. When the magnetic field exceeds the alarm threshold, the red LED light is on, the speaker sounds, and the electrometer sends an alarm signal; when the magnetic field is lower than the alarm threshold, the green LED light is on, the speaker does not sound, and the electrometer does not alarm.

[0038] refer to Figure 4 , the control system software is written in C language, and the STM32F407 single-chip microcomputer is selected to realize the functions of hardware control, circuit self-test, output signal communication, data processing, and control of the output of sound and light alarm signals. In order to ensure the safety of personnel and prevent the failure of the electroscope from causing danger, after the electroscope is turned on, the circuit self-test is first performed under the control of the single-chip microcomputer, the ADC, serial port, and other parts are initialized, and the switch status is read to complete the function detection of the magnetic field measurement sensor and the single-chip microcomputer program of the electroscope, and the electroscope is judged to be in normal electroscope mode. After the detection is completed, the single-chip microcomputer controls the buzzer to send a signal to remind the user that the electroscope function is normal. The single-chip microcomputer enters an interrupt when it detects the received data, takes out the data and puts it into an array, and enters the data processing part after detecting the received data. The magnetic field threshold is selected as 100uT, and the measured magnetic field value is compared with the threshold. When it is greater than the threshold, an sound and light alarm signal is issued.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A UHV DC magnetic field focusing electrical testing system, characterized in that: The UHV DC magnetic field focusing electrical testing system includes a magnetic field focusing module and a magnetic field measurement and alarm module; the magnetic field focusing module is based on electromagnetic metamaterials, and the electromagnetic metamaterials are curved structures with metal wire patterns and base plates; the magnetic field measurement and alarm module is composed of a magnetic field measurement submodule, a signal processing submodule, a main control submodule, and an acoustic and optical alarm submodule; the magnetic field measurement and alarm module and the magnetic field focusing module transmit data through a wireless communication interface.

2. The UHV DC magnetic field focusing electrical testing system according to claim 1, characterized in that: The magnetic field focusing module is located between the UHV DC transmission line and the magnetic field measuring module to achieve local focusing of the magnetic field.

3. The UHV DC magnetic field focusing electrical testing system according to claim 1, characterized in that: The magnetic field focusing module is composed of electromagnetic metamaterials.

4. The UHV DC magnetic field focusing electrical testing system according to claim 1, characterized in that: The magnetic field measurement and alarm module is composed of a magnetic field measurement submodule, a signal processing submodule, a main control submodule, an audible and visual alarm submodule, a switch submodule and a power supply submodule.

5. The UHV DC magnetic field focusing electrical testing system according to claim 4, characterized in that: The magnetic field measurement submodule is used to collect the local focused magnetic field signal generated by the ultra-high voltage direct current transmission line.

6. The UHV DC magnetic field focusing electrical testing system according to claim 4, characterized in that: The signal processing submodule performs signal amplification, filtering and analog-to-digital conversion processing on the magnetic field signal measured by the magnetic field measurement module.

7. The UHV DC magnetic field focusing electrical testing system according to claim 4, characterized in that: The main control submodule receives the magnetic field signal processed by the signal processing module, and determines whether to control the sound and light alarm submodule to send out a sound and light alarm signal according to a set threshold value.

8. The UHV DC magnetic field focusing electrical testing system according to claim 4, characterized in that: The sound and light alarm submodule comprises a loudspeaker, a red LED light and a green LED light; when the magnetic field exceeds the alarm threshold, the electroscope sends out an alarm signal; when the magnetic field is lower than the alarm threshold, the electroscope does not alarm.

9. A method for ultra-high voltage direct current magnetic field focusing electrical testing, characterized in that: The method is implemented based on the ultra-high voltage direct current magnetic field focusing electrical testing system described in any one of claims 1 to 9, and includes the following: the magnetic field measurement submodule included in the magnetic field measurement and alarm module receives the magnetic field signal by means of the electromagnetic induction principle, the signal processing submodule amplifies, filters and performs analog-to-digital conversion processing on the signal, the signal processing submodule transmits the processed magnetic field signal to the main control submodule, the main controller of the main control submodule determines the magnetic field value and compares it with the alarm threshold set in the main controller, and determines whether to control the sound and light alarm submodule to send out the sound and light alarm signal according to the comparison result.

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