CN206470386U - A kind of voltage sensor of suitable substation field measurement - Google Patents

Abstract

A voltage sensor suitable for on-site measurement of a substation includes a voltage equalizing ring, a primary voltage sensing unit, a collection and transmission unit, and a lifting platform. The primary voltage sensing unit adopts parallel plate capacitors to form high-voltage capacitors and low-voltage capacitors, which are filled with air to form a gas capacitor; the high-voltage capacitors are composed of three gas capacitors with three electrode spacings of 1.5m; the low-voltage capacitors It consists of a gas capacitor with a pole spacing of 0.04m; the high-voltage capacitor and the low-voltage capacitor are divided in series. The acquisition and transmission unit is placed under the low-voltage capacitor, and the two are connected through optical fibers. The acquisition and transmission unit is composed of signal processing module, A/D conversion module and FPGA connected in sequence. The signal output by the collection and transmission unit can be transmitted to the subsequent processing terminal through the optical fiber. The utility model can realize the live calibration of the electronic voltage transformer, shorten the calibration cycle, simplify the operation steps, avoid the loss caused by power failure, and improve the accuracy and reliability of the online calibration of the electronic voltage transformer sex.

Description

A voltage sensor suitable for on-site measurement in substations

technical field

The utility model relates to a voltage sensor suitable for on-site measurement of a substation, which relates to the field of power system measurement.

Background technique

With the development of digital substations and smart grids, traditional transformers cannot meet the development requirements of power grids due to their shortcomings such as ferromagnetic resonance, poor insulation, and narrow dynamic range. In order to meet the development needs of high-capacity and high-voltage levels, electronic voltage transformers with the advantages of no magnetic saturation, high measurement accuracy, and wide frequency response have received more and more attention, and have become the main development direction of power system measurement. However, in actual operation, the accuracy of the electronic voltage transformer is more serious, so it is necessary to verify its accuracy. Most of the traditional transformer calibration methods are offline calibration, which is not only complicated in operation and long in the calibration cycle, but also causes power failure losses, which has an adverse effect on the safe and stable operation of the system. Therefore, in order to improve the accuracy of the transformer and ensure the safe, reliable and economical operation of the power grid, it is urgent to study a sensor that can calibrate the electronic voltage transformer when the line is live.

At present, some scholars have carried out relevant research on the online calibration of electronic transformers. Although they have achieved certain success, there are still many problems: Chinese patent "CN102645643A" designed an online calibration system for electronic voltage transformers. However, due to the use of traditional electromagnetic voltage transformers as standard transformers, ferromagnetic resonance may occur when connected to the power grid with electricity, and there are certain safety hazards. When the voltage level is high, the size and weight of the equipment will also change. Large, which is not conducive to the use of online calibration; Chinese patent "CN102401889A" proposes an online calibration method for electronic current transformers, but this method is not suitable for calibration of electronic voltage transformers.

Contents of the invention

Aiming at the deficiencies in the current electronic voltage transformer calibration technology, the utility model provides a voltage sensor suitable for on-site measurement of substations, using parallel plate capacitors as the primary voltage sensing unit, which is small in size, light in weight, and has good anti-interference performance , No ferromagnetic resonance, the capacitor is closed externally as a whole, filled with air inside, forming a gas capacitor. The capacitor includes two parts, the high-voltage capacitor and the low-voltage capacitor, and the primary voltage signal is obtained by detecting the voltage in the low-voltage capacitor. The accuracy verification of the electronic voltage transformer can be realized when the line is not powered off, avoiding the loss and inconvenience caused by power failure, and improving the reliability and economy of the system.

The technical scheme that the utility model takes is:

A voltage sensor suitable for on-site measurement of a substation includes a voltage equalizing ring, a primary voltage sensing unit, a collection and transmission unit, and a lifting platform. The primary voltage sensing unit adopts parallel plate capacitors to form high-voltage capacitors and low-voltage capacitors, which are filled with air to form a gas capacitor; the high-voltage capacitors are composed of three gas capacitors with three electrode spacings of 1.5m; the low-voltage capacitors It is composed of a gas capacitor with a pole spacing of 0.04m; the high-voltage capacitor and the low-voltage capacitor are divided in series.

The acquisition and transmission unit is placed under the low-voltage capacitor, and the two are connected by optical fiber.

The acquisition and transmission unit is composed of signal processing module, A/D conversion module and FPGA connected in sequence.

The signal output by the collection and transmission unit can be transmitted to the subsequent processing terminal through the optical fiber.

The grading ring is used to connect the parallel plate capacitor and the primary wire.

The lifting platform is placed under the primary voltage sensing unit and the collection and transmission unit.

The lifting platform is installed on the trolley.

The signal processing module is used to filter the analog voltage signal output by the low-voltage capacitor to eliminate the interference of the harmonic signal and make the signal smoother; the A/D conversion module is used to convert the analog voltage signal into a digital signal; The FPGA realizes the frame format processing of the signal, so that the final output is a digital signal based on the IEC 61850 protocol.

The subsequent processing terminal is a merging unit, a verification device or a relay protection device.

The parallel plate capacitor includes high and low voltage electrodes and an insulating operating rod, the high and low voltage electrodes are copper electrodes, and the insulating operating rod is made of silicon rubber.

The pressure equalizing ring is made of copper.

An electronic voltage transformer calibration method, the primary voltage sensing unit uses parallel plate capacitors to form high-voltage capacitors and low-voltage capacitors, the primary voltage signal is obtained by detecting the voltage in the low-voltage capacitor; the primary voltage sensing unit is connected to the Or exit the primary wire to realize the online acquisition of the primary voltage signal. The voltage signal output by the primary voltage sensing unit is transmitted to the acquisition and transmission unit through optical fiber. The output of the acquisition and transmission unit is a digital signal based on the IEC 61850 protocol, and its output can be transmitted to the subsequent merging unit, calibration device or relay protection via optical fiber. equipment.

An electronic voltage transformer calibration method, the primary voltage sensing unit and the collection and transmission unit are placed above the lifting platform and the trolley, and during online calibration, the primary voltage sensing unit is connected or exited once by adjusting the height of the lifting platform wire to obtain a primary voltage signal.

The utility model is a voltage sensor suitable for on-site measurement of substations. A gas capacitor is used as a primary sensing unit. With the increase of the voltage level, its volume and weight do not change much, and it has the advantages of small volume, light weight, simple principle and structure, and high measurement accuracy. Advantages, in addition, live calibration of electronic voltage transformers can be realized, the calibration cycle is shortened, the operation steps are simplified, losses caused by power outages are avoided, and the accuracy and accuracy of online calibration of electronic voltage transformers are improved. reliability.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of a voltage sensor suitable for on-site measurement of a substation according to the utility model.

Fig. 2 is a schematic diagram of the pressure equalizing ring of the present invention.

Fig. 3 is a schematic diagram of the primary voltage sensing unit of the utility model.

Fig. 4 is a connection diagram of the collection and transmission unit modules of the utility model.

Fig. 5 is an equivalent circuit diagram of the collection and transmission unit module of the present invention.

detailed description

As shown in Figures 1 to 5, a voltage sensor suitable for on-site measurement in substations includes a voltage equalizing ring 1, a primary voltage sensing unit 2, an acquisition and transmission unit 6, and a lifting platform 7.

The primary voltage sensing unit 2 uses a parallel plate capacitor to form a high-voltage capacitor 4 and a low-voltage capacitor 5, which are filled with air to form a gas capacitor, which has good insulation, and its volume and weight do not change much when the voltage level increases , very suitable for on-site verification. The high-voltage capacitor 4 is composed of three gas capacitors with three pole spacings of 1.5m; the low-voltage capacitor 5 is composed of one gas capacitor with a pole spacing of 0.04m; the high-voltage capacitor 4 and the low-voltage capacitor 5 are divided in series. When the high-voltage transmission circuit is 220kV, the voltage signal U1 generated in the low-voltage capacitor ₅ is about 4V, and the primary voltage signal is obtained by detecting the voltage signal in the low-voltage capacitor 5 . Its structure and principle are simple, small in size and light in weight, which can realize live calibration, avoid losses caused by power failure, and improve the accuracy and economy of electronic voltage transformers.

The parallel plate capacitor is composed of 4 gas capacitors C1~C4 connected in series, which acts as a voltage divider. When the high-voltage electrode of the high-voltage capacitor 4 is excited, a voltage signal will be generated in the low-voltage capacitor 5, and its output will be transmitted to the The acquisition and transmission unit 6 on the low-voltage side performs signal processing in the acquisition and transmission unit 6, and then can be transmitted to the merging unit, calibration platform or other receiving devices via optical fiber for further data analysis and processing, which improves the data transmission rate and accuracy.

The collection and transmission unit 6 is placed under the low-voltage capacitor 5, and the two are connected through an optical fiber;

Acquisition transmission unit 6 is connected successively by three parts of signal processing module, A/D conversion module, FPGA; Said signal processing module is used for filtering the analog voltage signal output by low-voltage capacitor 5, eliminating the interference of harmonic signal, making The signal becomes smoother; the A/D conversion module is used to convert the analog voltage signal into a digital signal. The FPGA realizes the frame format processing of the signal, so that the final output is a digital signal based on the IEC 61850 protocol, which improves the data transmission rate and accuracy.

The signal output by the collection and transmission unit 6 can be transmitted to the subsequent processing terminal 11 through the optical fiber 10 . The subsequent processing terminal 11 is a merging unit, a verification device or a relay protection device.

The equalizing ring 1 is used to connect the parallel plate capacitor and the primary wire;

The lifting platform 7 is placed under the primary voltage sensing unit 2 and the collection and transmission unit 6 . The online calibration can be realized by adjusting the height of the lifting platform 7 according to the different heights of the on-site lines, so it is suitable for online calibration of various voltage levels. The lifting platform 7 is installed on a trolley 8 .

The parallel plate capacitor includes three parts: high-voltage electrode 3, low-voltage electrode and insulating operating rod 9. The high-voltage and low-voltage electrodes are copper electrodes, which have good conductivity and corrosion resistance. The insulating operating rod 9 is made of silicone rubber and is light in weight. And the insulation performance is good, which ensures the anti-interference performance of the capacitor as a whole.

The grading ring 1 is a copper grading ring with good conductivity and is used to connect the capacitor and the primary wire. In addition, it is used to improve the electric field distribution around the capacitor, make the electric field distribution more uniform, and prevent the tip discharge from affecting the test results. Interference, improve the accuracy of measurement.

An electronic voltage transformer calibration method, the primary voltage sensing unit 2 uses parallel plate capacitors to form a high-voltage capacitor 4 and a low-voltage capacitor 5, and obtains a primary voltage signal by detecting the voltage in the low-voltage capacitor 5; the primary voltage sensing unit 2 passes Controlling the lifting platform 7 to connect or withdraw from the primary wire realizes the online acquisition of the primary voltage signal. The voltage signal output by the primary voltage sensing unit 2 is transmitted to the acquisition and transmission unit 6 through an optical fiber. The output of the acquisition and transmission unit 6 is a digital signal based on the IEC61850 protocol, and its output can be transmitted to a subsequent merging unit, calibration device or Relay protection equipment for the next step of data analysis and processing.

An electronic voltage transformer calibration method, the primary voltage sensing unit 2 and the collection and transmission unit 6 are placed above the lifting platform 7 and the trolley 8, and the primary voltage sensing unit is realized by adjusting the height of the lifting platform 7 during online calibration. 2 Insert or exit the primary wire to obtain the primary voltage signal. It is easy to operate and can realize online calibration of electronic voltage transformers of various voltage levels.

Claims (6)

1. A voltage sensor suitable for on-site measurement of substations, including a voltage equalizing ring (1), a primary voltage sensing unit (2), an acquisition and transmission unit (6), and a lifting platform (7); it is characterized in that: the primary voltage The sensing unit (2) uses a parallel plate capacitor to form a high-voltage capacitor (4) and a low-voltage capacitor (5), which are filled with air to form a gas capacitor; the high-voltage capacitor (4) is composed of three gas capacitors; The low-voltage capacitor (5) is composed of a gas capacitor; the high-voltage capacitor (4) and the low-voltage capacitor (5) are divided in series; the acquisition and transmission unit (6) is placed under the low-voltage capacitor (5), and the two are connected through an optical fiber; The transmission unit (6) is composed of a signal processing module, an A/D conversion module, and an FPGA connected in sequence; the signal output by the acquisition and transmission unit (6) can be transmitted to the subsequent processing terminal (11) through the optical fiber (10); The ring (1) is used to connect the parallel plate capacitor and the primary wire; the lifting platform (7) is placed under the primary voltage sensing unit (2) and the acquisition and transmission unit (6). 2. A voltage sensor suitable for on-site measurement in substations according to claim 1, characterized in that: the lifting platform (7) is installed on a trolley (8). 3. A voltage sensor suitable for on-site measurement of substations according to claim 1, characterized in that: the signal processing module is used to filter the analog voltage signal output by the low-voltage capacitor (5) to eliminate the interference of harmonic signals, Make the signal smoother; the A/D conversion module is used to convert the analog voltage signal into a digital signal; the FPGA realizes the frame format processing of the signal, so that the final output is a digital signal based on the IEC 61850 protocol. 4. A voltage sensor suitable for on-site measurement in substations according to claim 1, characterized in that: the subsequent processing terminal (11) is a merging unit, a verification device or a relay protection device. 5. A voltage sensor suitable for on-site measurement in substations according to claim 1, characterized in that: the parallel plate capacitor includes high and low voltage electrodes and an insulating operating rod (9), the high and low voltage electrodes are copper electrodes, and the insulating operation The rod (9) is made of silicone rubber. 6. A voltage sensor suitable for on-site measurement in substations according to claim 1, characterized in that: the voltage equalizing ring (1) is a copper voltage equalizing ring.