Optical voltage transformer and voltage measuring method

Abstract

The invention relates to an optical voltage transformer. Comprising a first electro-optical crystal, a second electro-optical crystal, a laser generator, an optical sensor and a controller, the first electro-optical crystal and the second electro-optical crystal are connected in parallel; the controller is connected with the optical sensor; the laser generator is used for emitting laser, and the laser enters the first electro-optical crystal and the second electro-optical crystal. After the laser passes through the first electro-optical crystal, first output light is output; the laser passes through the second electro-optical crystal and then outputs second output light; the optical sensor is used for respectively detecting first phase delay information of the first output light and second phase delay information of the second output light; and the controller is used for acquiring the first phase delay information and the second phase delay information, performing information analysis based on the first phase delay information and the second phase delay information, and determining voltages applied to the first electro-optical crystal and the second electro-optical crystal. By adopting the optical voltage transformer, the voltage measurement safety can be improved.

Description

Technical Field

[0001] The present application relates to the field of electric power technology, and in particular to an optical voltage transformer and a voltage measurement method. Background Art

[0002] With the development of electric power technology, an electrical device called voltage transformer has emerged, which can measure voltage using electrical components such as resistor dividers or capacitor dividers.

[0003] However, these voltage transformers require the use of insulating oil to improve electrical insulation performance in actual applications, which poses a risk of oil leakage and fire. Especially in high-voltage environments, the use of insulating oil increases equipment maintenance costs and environmental risks, and there is a problem of insufficient safety. Summary of the invention

[0004] Based on this, it is necessary to provide an optical voltage transformer and a voltage measurement method that can improve safety in response to the above technical problems.

[0005] In a first aspect, the present application provides an optical voltage transformer, comprising: a first electro-optical crystal, a second electro-optical crystal, a laser generator, an optical sensor, and a controller; the first electro-optical crystal and the second electro-optical crystal are connected in parallel; the controller is connected to the optical sensor;

[0006] The laser generator is used to emit laser light, and the laser light is respectively emitted into the first electro-optical crystal and the second electro-optical crystal; the laser light outputs a first output light after passing through the first electro-optical crystal; and the laser light outputs a second output light after passing through the second electro-optical crystal;

[0007] The optical sensor is used to detect first phase delay information of the first output light and second phase delay information of the second output light respectively;

[0008] The controller is used to obtain the first phase delay information and the second phase delay information, and perform information analysis based on the first phase delay information and the second phase delay information to determine the voltage applied to the first electro-optical crystal and the second electro-optical crystal.

[0009] In one embodiment, the first electro-optical crystal is a crystal obtained by cutting with the crystal axis as the cutting axis; the second electro-optical crystal is a crystal obtained by cutting with the cutting axis obtained by offsetting the crystal axis by a preset angle.

[0010] In one embodiment, the optical voltage transformer further includes a polarizer, which is used to convert the laser into linearly polarized light so that the linearly polarized light is respectively emitted into the first electro-optical crystal and the second electro-optical crystal.

[0011] In one embodiment, the optical voltage transformer further includes a Faraday rotator, and the Faraday rotator is used to correct the polarization state of the linearly polarized light before the linearly polarized light is respectively incident on the first electro-optical crystal and the second electro-optical crystal.

[0012] In one embodiment, the Faraday rotator is used to rotate the polarization direction of the linearly polarized light according to a first set angle, and to rotate the first output light and the second output light according to a second set angle, so that the updated polarization states corresponding to the rotated updated first output light and the updated second output light are respectively orthogonal to the first polarization state corresponding to the laser.

[0013] In one embodiment, the optical voltage transformer further includes a metal casing; the first electro-optic crystal, the second electro-optic crystal, the laser generator, the optical sensor, and the controller are all disposed in the metal casing.

[0014] In one of the embodiments, the interior of the metal shell is filled with insulating gas.

[0015] In one embodiment, the optical voltage transformer further comprises an optical fiber; the optical fiber is used for optically transmitting the laser, the linearly polarized light, the first output light, and the second output light.

[0016] In one embodiment, the height of the first electro-optical crystal and the second electro-optical crystal are both 200 mm, and the cross-sectional area of ​​the first electro-optical crystal and the second electro-optical crystal are both 100 mm².

[0017] In a second aspect, the present application also provides a voltage measurement method, comprising:

[0018] Acquire first phase delay information obtained by the optical sensor for detecting a first output light, and second phase delay information obtained by the optical sensor for detecting a second output light; the first output light is output light of the laser passing through a first electro-optical crystal; the second output light is output light of the laser passing through a second electro-optical crystal;

[0019] Information analysis is performed based on the first phase delay information and the second phase delay information to determine the voltage applied to the first electro-optical crystal and the second electro-optical crystal.

[0020] The optical voltage transformer includes: a laser generator for emitting laser light, the emitted laser light is respectively injected into the first electro-optical crystal and the second electro-optical crystal, the laser light outputs the first output light after passing through the first electro-optical crystal; the laser light outputs the second output light after passing through the second electro-optical crystal, because the electro-optical crystal has an electro-optical effect, applying a voltage to the electro-optical crystal will cause the optical signal passing through the electro-optical crystal to produce a phase delay, therefore, the first phase delay information of the first output light and the second phase delay information of the second output light can be respectively detected by an optical sensor, and the first phase delay information and the second phase delay information can be obtained by a controller, and information analysis is performed based on the first phase delay information and the second phase delay information to determine the voltage applied to the first electro-optical crystal and the second electro-optical crystal. By adopting the optical voltage transformer, the voltage measurement safety can be improved while expanding the measurement voltage range through the electro-optical effect of the first electro-optical crystal and the second electro-optical crystal. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments of the present application or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 is a structural block diagram of an optical voltage transformer in one embodiment;

[0023] Figure 2 A block diagram of an electro-optical crystal design in one embodiment;

[0024] Figure 3 is a structural block diagram of an optical voltage transformer in another embodiment;

[0025] Figure 4 is a structural block diagram of an optical voltage transformer in yet another embodiment;

[0026] Figure 5 A structural block diagram of an optical voltage transformer in yet another embodiment;

[0027] Figure 6 is a structural block diagram of an optical voltage transformer in a practical application scenario in an embodiment;

[0028] Figure 7 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0029] In order to facilitate understanding of the present disclosure, the present disclosure will be described more fully below with reference to the relevant drawings. Embodiments of the present disclosure are given in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thorough and comprehensive.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure.

[0031] It can be understood that the terms "first", "second", etc. used in the present disclosure can be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element.

[0032] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientations shown in the figures, spatially relative terms also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, an element or feature described as "under other elements" or "under it" or "under it" will be oriented as being "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include additional orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0033] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element, or connected to the other element through an intermediate element. In addition, the "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if there is transmission of electrical signals or data between the connected objects.

[0034] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0035] As described in the background technology, traditional voltage transformers use electrical components such as resistor dividers or capacitor dividers to measure voltage. However, these voltage transformers need to use insulating oil to improve electrical insulation performance in practical applications, which may cause oil leakage and fire hazards. Especially in high-voltage environments, the use of insulating oil increases the maintenance cost and environmental risks of the equipment, and there is a problem of insufficient safety. Based on the above reasons, the present invention provides an optical voltage transformer that can solve the above problems to improve safety.

[0036] In one embodiment, an optical voltage transformer is provided, such as Figure 1 As shown, it includes: a first electro-optical crystal 10, a second electro-optical crystal 20, a laser generator 30, an optical sensor 40, and a controller 50; the first electro-optical crystal 10 and the second electro-optical crystal 20 are connected in parallel; the controller 50 is connected to the optical sensor 40; the laser generator 30 is used to emit laser, and the laser is respectively emitted into the first electro-optical crystal 10 and the second electro-optical crystal 20; the laser outputs a first output light after passing through the first electro-optical crystal 10; the laser outputs a second output light after passing through the second electro-optical crystal 20; the optical sensor 40 is used to respectively detect the first phase delay information of the first output light and the second phase delay information of the second output light; the controller 50 is used to obtain the first phase delay information and the second phase delay information, and perform information analysis based on the first phase delay information and the second phase delay information to determine the voltage applied to the first electro-optical crystal 10 and the second electro-optical crystal 20.

[0037] Among them, the electro-optic crystal is a special material with an electro-optic effect, that is, the refractive index of the crystal will change under the action of an external electric field. In this embodiment, the first electro-optic crystal 10 and the second electro-optic crystal 20 are both BGO (bismuth germanate) crystals. Specifically, the Pockels effect is an electro-optic effect, which is mainly reflected in certain non-centrosymmetric crystals (such as BGO crystals). When an external electric field acts on these electro-optic crystals, the refractive index of the electro-optic crystal will change, resulting in a delay in the phase of the light wave passing through the electro-optic crystal. The phase delay is linearly related to the strength (or voltage) of the external electric field. The laser generator 30 refers to a laser generator 30 that is a device that can produce highly focused and powerful excitation energy, and its core function is to generate lasers. The optical sensor 40 user detects the phase delay information of the output light. The controller 50 is a "decision-making body" that issues commands and can coordinate and direct the operation of the entire system or device.

[0038] The first phase delay information refers to the phase delay information generated during the process of laser light being refracted in the first electro-optical crystal 10 , and the second phase delay information refers to the phase delay information generated during the process of laser light being refracted in the second electro-optical crystal 20 .

[0039] Specifically, during the operation of the optical voltage transformer, the laser generator 30 first emits a laser, and the emitted laser is respectively incident on the first electro-optical crystal 10 and the second electro-optical crystal 20 for refraction. Since a high voltage is applied to the first electro-optical crystal 10 and the second electro-optical crystal 20, a first output light output from the first electro-optical crystal 10 and a second output light output from the second electro-optical crystal 20 will have a phase delay. It is necessary to detect the first phase delay information of the first output light and the second phase delay information of the second output light respectively by the optical sensor 40. After that, the controller 50 obtains the first phase delay information and the second phase delay information, and performs information analysis based on the first phase delay information and the second phase delay information to determine the voltage applied to the first electro-optical crystal 10 and the second electro-optical crystal 20.

[0040] Exemplarily, a key parameter of the Pockels effect is the "half-wave voltage" Vπ, that is, the voltage value at which the phase delay of light reaches π. The half-wave voltage determines the voltage measurement range of the crystal. When the voltage exceeds the half-wave voltage, the phase delay shows a periodic change, which limits the measurement range of a single crystal. Therefore, the use of two BGO crystals with different half-wave voltages can significantly expand the measurement range and avoid the multi-value problem of a single Pockels crystal. This design allows the voltage to be measured stably and accurately in a high-voltage DC system. It can be understood that in a specific embodiment, a two-dimensional phase mapping table can be pre-constructed to calculate the corresponding voltage value. Since the change period of the two phase delays is different, even at high voltage, the phase difference value can uniquely determine the voltage. Therefore, the above-mentioned first phase delay information and the second phase delay information can be substituted into the above-mentioned two-dimensional phase mapping table to determine the unique corresponding voltage, that is, the voltage applied to the first electro-optical crystal 10 and the second electro-optical crystal 20, avoiding the multi-value problem of a single crystal. In another specific embodiment, a voltage determination model may be established, and the first phase delay information and the second phase delay information may be input into the voltage determination model, and the output obtained is the voltage applied to the first electro-optical crystal 10 and the second electro-optical crystal 20 .

[0041] The optical voltage transformer includes: a laser generator 30 for emitting laser light, the emitted laser light is respectively injected into the first electro-optical crystal 10 and the second electro-optical crystal 20, and the laser light outputs the first output light after passing through the first electro-optical crystal 10; the laser light outputs the second output light after passing through the second electro-optical crystal 20. Since the electro-optical crystal has an electro-optical effect, applying a voltage to the electro-optical crystal will cause a phase delay in the optical signal passing through the electro-optical crystal. Therefore, the first phase delay information of the first output light and the second phase delay information of the second output light can be respectively detected by the optical sensor 40, and the first phase delay information and the second phase delay information can be obtained by the controller 50. Based on the first phase delay information and the second phase delay information, information analysis is performed to determine the voltage applied to the first electro-optical crystal 10 and the second electro-optical crystal 20. By adopting the optical voltage transformer, the voltage measurement safety can be improved while expanding the measurement voltage range through the electro-optical effect of the first electro-optical crystal 10 and the second electro-optical crystal 20.

[0042] In one embodiment, the first electro-optical crystal 10 is a crystal cut with the crystal axis as the cutting axis; the second electro-optical crystal 20 is a crystal cut with the crystal axis offset by a preset angle.

[0043] Among them, the crystal axis is a straight line running through the center of the crystal, which is used to determine the spatial position and direction of the crystal plane.

[0044] Specifically, Figure 2 As shown, the crystal axis is a straight line running through the center of the crystal. For example, in this embodiment, the crystal axis can be understood as the straight line where the z-axis is located. The first electro-optical crystal BGO#1 is a crystal obtained by cutting with the crystal axis as the cutting axis, and the second electro-optical crystal BGO#2 is a crystal obtained by cutting with the cutting axis obtained by offsetting the crystal axis by a preset angle.

[0045] In this embodiment, by cutting in the above manner, the first electro-optical crystal 10 and the second electro-optical crystal 20 can have different half-wave voltages (24.5kV and 25.9kV), respectively, so that the measurement range of the optical voltage transformer is gradually increased from ±50kV to ±400kV, effectively expanding the voltage measurement range of the optical voltage transformer and completely covering the voltage requirements of high-voltage direct current transmission.

[0046] In one embodiment, Figure 3 As shown, the optical voltage transformer further includes a polarizer 60, which is used to convert the laser light into linearly polarized light so that the linearly polarized light is respectively emitted into the first electro-optical crystal 10 and the second electro-optical crystal 20.

[0047] The polarizer 60 is an optical element, and its main function is to convert natural light into polarized light.

[0048] Specifically, the polarizer 60 can convert the non-polarized light or light with uncertain polarization output by the laser generator 30 into linearly polarized light, ensuring the stability of the polarization characteristics of the output light. This stability is crucial to the power, efficiency and long-term operation stability of the laser generator 30. In addition, by adjusting the parameters of the polarizer 60, the performance of the laser can be further optimized to meet the needs of specific application scenarios.

[0049] In one embodiment, Figure 4 As shown, the optical voltage transformer further includes a Faraday rotator 70, which is used to correct the polarization state of the linear polarized light before the linear polarized light is respectively incident on the first electro-optical crystal 10 and the second electro-optical crystal 20.

[0050] The Faraday rotator 70, also known as a Faraday motor, is an electric motor or optical element that works based on the principle of magnetic field effect and induced electromotive force.

[0051] Specifically, in an optical system, optical fiber propagation may introduce various noises, such as reflection, scattering, and dispersion. These noises may interfere with the polarization state of light, thereby affecting the performance of the optical system. By installing a Faraday rotator 70, the polarization state of the linear polarized light is corrected before the linear polarized light is respectively incident on the first electro-optical crystal 10 and the second electro-optical crystal 20, and these optical noises can be effectively offset.

[0052] In one embodiment, the Faraday rotator 70 is used to rotate the polarization direction of the linearly polarized light according to a first set angle, and to rotate the first output light and the second output light according to a second set angle, so that the updated polarization states corresponding to the rotated updated first output light and the updated second output light are respectively orthogonal to the first polarization state corresponding to the laser.

[0053] In this embodiment, the first setting angle is 45 degrees, and the second setting angle is 90 degrees.

[0054] When the linearly polarized light passes through the Faraday rotator 70 for the first time and rotates 45 degrees, its polarization state is different from the original state. When the linearly polarized light returns and passes through the Faraday rotator 70 again, its polarization direction is rotated 45 degrees again (90 degrees in total), which is equivalent to restoring the polarization state of the light to a position orthogonal to the original state. Since optical noise is usually related to the polarization state of light, by changing the polarization state of light and making it orthogonal to the original state, the influence of noise on the optical system can be effectively reduced.

[0055] In this embodiment, a Faraday rotator 70 is installed under the BGO crystal. The Faraday rotator 70 can rotate the polarization direction of the light by 45 degrees. The light beam rotates 90 degrees when it returns after passing through the crystal. Since optical noise is usually related to the polarization state of light, by changing the polarization state of light and making it orthogonal to the original state, the influence of noise on the optical system can be effectively reduced, thereby effectively offsetting the optical noise caused by optical fiber propagation.

[0056] In one embodiment, Figure 5 As shown, the optical voltage transformer further includes a metal housing 80 ; the first electro-optic crystal 10 , the second electro-optic crystal 20 , the laser generator 30 , the optical sensor 40 , and the controller 50 are all disposed in the metal housing 80 .

[0057] The metal shell 80 refers to a shell made of metal material.

[0058] Specifically, the first electro-optic crystal 10, the second electro-optic crystal 20, the laser generator 30, the optical sensor 40, and the controller 50 are all arranged in the metal housing 80 of the optical voltage transformer, which can protect the above-mentioned devices and crystals.

[0059] In one embodiment, the interior of the metal housing 80 is filled with insulating gas.

[0060] Insulating gas refers to gas that does not easily react with other elements or compounds at normal temperature and pressure. At the same time, these gases also have good insulating properties and can be used as insulating media.

[0061] Specifically, in this embodiment, the insulation design is optimized, SF6 gas pressurization is adopted, and the electric field distribution is calculated by the finite element method (FEM) to ensure the insulation reliability under high voltage. The BGO crystal and the high-voltage electrode are installed in the metal shell 80, and the inside of the shell is filled with pressurized SF6 gas, and the gas pressure is set to 0.4MPa. SF6 gas has excellent insulation properties and can effectively improve the electrical insulation capacity of the equipment to ensure that it can withstand the operating voltage (DC250kV) and abnormal conditions such as lightning strikes and switching impulse voltages (up to 900kV). The electric field distribution around the high-voltage electrode was calculated by the finite element method (FEM), and the results showed that the maximum value of the electric field appeared on the surface of the high-voltage electrode and the edge of the BGO crystal, respectively. In order to prevent gas discharge, this embodiment also considers the effect of the micro-roughness of the electrode surface on the electric field enhancement, and ensures the safe operation of the equipment under high voltage by reasonably designing the electrode structure and gas pressure.

[0062] In one embodiment, the optical voltage transformer further comprises an optical fiber; the optical fiber is used for optically transmitting the laser light, the linearly polarized light, the first output light, and the second output light.

[0063] Among them, optical fiber is the abbreviation of optical fiber, which is a fiber made of glass or plastic that can be used as a light transmission tool.

[0064] Specifically, by optically transmitting laser, linearly polarized light, first output light, and second output light through optical fiber, a large amount of information can be transmitted to meet the needs of modern communication and data processing. Moreover, since optical fiber is not affected by electromagnetic interference, it can work stably in harsh electromagnetic environments.

[0065] In one embodiment, the height of the first electro-optical crystal 10 and the second electro-optical crystal 20 are both 200 mm, and the cross-sectional areas of the first electro-optical crystal 10 and the second electro-optical crystal 20 are both 100 mm².

[0066] Specifically, the height of the first electro-optical crystal 10 and the second electro-optical crystal 20 are both 200 mm, and the cross-sectional areas of the first electro-optical crystal 10 and the second electro-optical crystal 20 are both 100 mm², which can ensure the stability of the first electro-optical crystal 10 and the second electro-optical crystal 20.

[0067] In one embodiment, a voltage measurement method is also provided, which is applied to the optical voltage transformer in any of the above embodiments, including: obtaining first phase delay information obtained by the optical sensor 40 for first output light detection, and second phase delay information obtained by the optical sensor 40 for second output light detection; the first output light is the output light of the laser passing through the first electro-optical crystal 10; the second output light is the output light of the laser passing through the second electro-optical crystal 20; based on the first phase delay information and the second phase delay information, information analysis is performed to determine the voltage applied to the first electro-optical crystal 10 and the second electro-optical crystal 20.

[0068] Specifically, the first phase delay information of the first output light detected by the optical sensor 40 and the second phase delay information of the second output light can be obtained, and then information analysis is performed based on the first phase delay information and the second phase delay information to determine the voltage applied to the first electro-optical crystal 10 and the second electro-optical crystal 20.

[0069] Exemplarily, a key parameter of the Pockels effect is the "half-wave voltage" Vπ, that is, the voltage value at which the phase delay of light reaches π. The half-wave voltage determines the voltage measurement range of the crystal. When the voltage exceeds the half-wave voltage, the phase delay shows a periodic change, which limits the measurement range of a single crystal. Therefore, the use of two BGO crystals with different half-wave voltages can significantly expand the measurement range and avoid the multi-value problem of a single Pockels crystal. This design allows the voltage to be measured stably and accurately in a high-voltage DC system. It can be understood that in a specific embodiment, a two-dimensional phase mapping table can be pre-constructed to calculate the corresponding voltage value. Since the change period of the two phase delays is different, even at high voltage, the phase difference value can uniquely determine the voltage. Therefore, the above-mentioned first phase delay information and the second phase delay information can be substituted into the above-mentioned two-dimensional phase mapping table to determine the unique corresponding voltage, that is, the voltage applied to the first electro-optical crystal 10 and the second electro-optical crystal 20, avoiding the multi-value problem of a single crystal. In another specific embodiment, a voltage determination model may be established, and the first phase delay information and the second phase delay information may be input into the voltage determination model, and the output obtained is the voltage applied to the first electro-optical crystal 10 and the second electro-optical crystal 20 .

[0070] In a specific embodiment, Figure 6 As shown, an optical voltage transformer for a specific application scenario is also provided:

[0071] (a) Sensor principle

[0072] (1) The Pockels effect is an electro-optical effect that is mainly manifested in certain non-centrosymmetric crystals (such as BGO crystals). When an external electric field acts on these crystals, the refractive index of the crystal changes, causing a phase delay of the light wave passing through the crystal. This phase delay is linearly related to the strength of the external electric field (or voltage).

[0073] (2) In high-voltage voltage measurement, the Pockels effect reflects the voltage applied to the crystal by measuring the phase delay of light. Specifically, when a voltage V is applied to the Pockels crystal, the electric field changes the birefringence effect of the crystal, thereby affecting the propagation direction and phase of the light. For monochromatic light, the phase delay caused by the applied voltage V is It can be calculated by measuring the light signal.

[0074] (3) A key parameter of the Pockels effect is the “half-wave voltage” Vπ, which is the voltage value at which the phase delay of light reaches π. The half-wave voltage determines the voltage measurement range of the crystal. When the voltage exceeds the half-wave voltage, the phase delay exhibits periodic changes, limiting the measurement range of a single crystal.

[0075] (4) In this embodiment, by using two BGO crystals with different half-wave voltages (the first electro-optical crystal 10 and the second electro-optical crystal 20), the measurement range can be significantly extended, avoiding the multi-value problem of a single Pockels crystal. This design enables stable and accurate voltage measurement in a high-voltage DC system.

[0076] (b) Design of double BGO crystal combination

[0077] In order to break through the limitation of the half-wave voltage of a single Pockels crystal, this embodiment adopts a combination design of two BGO crystals with different half-wave voltages. Specifically, the half-wave voltages of these two BGO crystals are 24.5 kV and 25.9 kV respectively. By combining these two crystals with different optical properties, the range of voltage measurement can be effectively expanded and the multi-value problem can be avoided.

[0078] Since the half-wave voltages of the two crystals are different, their phase delays change differently when the same voltage is applied. Specifically, the half-wave voltage of the first BGO crystal is 24.5 kV, and the half-wave voltage of the second crystal is 25.9 kV. The phase delays of the two show different periodic changes with voltage, allowing the measurement system to uniquely determine the applied voltage by detecting two different phase delays.

[0079] To achieve this goal, this embodiment measures the phase delay of two crystals at the same time and maps the two phase delay values ​​into a two-dimensional phase space. The applied voltage value can be uniquely determined by the phase difference value in the two-dimensional space. Since the half-wave voltages of the two crystals are different, the periodic changes of the phase delay are no longer synchronized, so that the measurement system can still distinguish different voltages even in a range higher than the half-wave voltage of a single crystal.

[0080] Theoretically, the measurable voltage range of the dual BGO crystal combination is approximately the product of the half-wave voltages of the two crystals. Therefore, in the present invention, the combination of the two half-wave voltages of 24.5 kV and 25.9 kV allows the measurement range to be extended to more than ±400 kV, fully covering the voltage requirements of the high-voltage direct current transmission system. This design greatly exceeds the measurement capability of a single Pockels crystal.

[0081] (c) Implementation details

[0082] (1) In order to achieve different half-wave voltages, the two BGO crystals in this embodiment are cut in different ways. One crystal is cut along the crystal axis, and the other is cut at a 10-degree angle. This different cutting method changes the optical properties of the crystal, thereby achieving different half-wave voltages. In addition, the length of the crystal is 200 mm and the cross-sectional area is 10 mm × 10 mm. By rationally designing the size and installation method of the crystal, the measurement accuracy and stability of the system are ensured.

[0083] (2) In the actual measurement process, the system simultaneously collects the phase delay signals of the two BGO crystals through the optical sensor 40. Then, the corresponding voltage value is calculated using the pre-built two-dimensional phase mapping table. Since the change periods of the two phase delays are different, the phase difference value can uniquely determine the voltage even at high voltage, avoiding the multi-value problem existing in a single crystal.

[0084] (3) In the application of traditional Pockels effect, the stability of light intensity directly affects the measurement accuracy. However, due to factors such as unstable laser output, fiber stress and temperature changes, it is extremely challenging to maintain stable light intensity for a long time. In order to eliminate the influence of light intensity fluctuations, the present invention adopts optical modulation technology to replace light intensity measurement with phase measurement. Specifically, the optical modulator applies a triangular wave modulation signal to the input light, so that the input light and the output light present sinusoidal wave characteristics. By comparing the phase difference between the input and output light, the crystal phase delay caused by the applied voltage can be directly calculated, thereby avoiding the influence of unstable light intensity on the measurement accuracy. In the optical measurement system of the present invention, a Faraday rotator 70 is installed under the BGO crystal. The rotator can rotate the polarization direction of the light by 45 degrees, and the light beam rotates 90 degrees when it returns after passing through the crystal, thereby effectively offsetting the optical noise caused by fiber propagation. The introduction of the Faraday rotator 70 significantly improves the anti-interference ability of the system and ensures the long-term stability of the measurement signal.

[0085] (4) In order to ensure that the equipment can operate safely and stably under high voltage environment, this embodiment optimizes the insulation design, adopts SF6 gas pressurization, and calculates the electric field distribution by finite element method (FEM), so as to ensure the insulation reliability under high voltage. The BGO crystal and high voltage electrode are installed in the metal shell 80, and the inside of the shell is filled with pressurized SF6 gas, and the gas pressure is set to 0.4 MPa. SF6 gas has excellent insulation properties and can effectively improve the electrical insulation capacity of the equipment, ensuring that it can withstand the operating voltage (DC 250 kV) and abnormal conditions such as lightning strikes and switching impulse voltage (up to 900 kV). The electric field distribution around the high voltage electrode was calculated by finite element method (FEM), and the results showed that the maximum value of the electric field appeared on the surface of the high voltage electrode and the edge of the BGO crystal respectively. In order to prevent gas discharge, the present invention also considers the influence of the microscopic roughness of the electrode surface on the electric field enhancement, and ensures the safe operation of the equipment under high voltage by reasonably designing the electrode structure and gas pressure.

[0086] (5) In the optical voltage transformer of this embodiment, the BGO crystal directly bears high voltage DC voltage and transient abnormal voltage, so electrode design and electric field distribution control are crucial. The BGO crystal and the high voltage electrode are installed together in the metal housing 80. The electric field distribution is calculated by the finite element method in the design to ensure that the maximum value of the electric field does not exceed the tolerance limit of the material. For example, in the lightning impulse voltage test, the maximum value of the electric field is 21.8 kV / mm, and in the withstand voltage test, the maximum value of the electric field is 26.2 kV / mm, both of which are within the safe range.

[0087] This embodiment creates a new type of high-voltage direct current optical voltage transformer by adopting a double BGO crystal combination and an electro-optical Pockels effect, which has significant advantages. First, by using the different half-wave voltages of the double BGO crystals, the voltage measurement range is successfully expanded, overcoming the problem of limited measurement range of a single Pockels crystal, so that the measurement range can reach more than ±400 kV, fully meeting the needs of the high-voltage direct current transmission system. Secondly, the present invention realizes voltage measurement through the phase delay measurement of light, avoids the common electromagnetic interference problem in traditional electrical transformers, has extremely high anti-interference ability, and is particularly suitable for use in complex high-voltage environments. In addition, the optical measurement method makes the entire system structure more compact, reduces the complexity of mechanical components, reduces the maintenance cost of equipment, and improves the stability of long-term operation. Through the application of Faraday rotator 70 and optical modulation technology, the stability and measurement accuracy of the system are further improved, ensuring the high reliability and low error of the system in long-term operation. In short, the present invention not only solves many technical bottlenecks in the prior art, but also shows great advantages in measurement range, accuracy, anti-interference ability and system stability.

[0088] The specific implementation of this embodiment verifies the effectiveness of the dual BGO crystal combination in high voltage DC voltage measurement through experiments. The following is a detailed process and result analysis of the experiment, and the experimental steps are explained in conjunction with relevant drawings.

[0089] 1. Experimental equipment and preparation:

[0090] (1) The experiment used a prototype device of an optical voltage transformer with a dual BGO crystal combination. The device includes two BGO crystals with different half-wave voltages (24.5 kV and 25.9 kV), and collects phase delay signals through an optical sensor 40. In order to ensure the accuracy of the optical signal, a Faraday rotator 70 is also introduced into the system to eliminate the optical noise generated during the optical fiber transmission process. The BGO crystal and the high-voltage electrode are installed in a metal shell 80 filled with SF6_66 gas, and the gas pressure is set to 0.4 MPa to ensure good insulation performance under high-voltage environment.

[0091] (2) Before the experiment, the system was debugged to ensure that the optical sensor 40 could stably collect the phase delay signals of the two BGO crystals, and a two-dimensional mapping table of phase delay and voltage was pre-constructed for voltage calculation in subsequent experiments.

[0092] 2. Performance test:

[0093] (1) In order to verify the voltage measurement accuracy and range of the dual BGO crystal combination, the experiment was gradually increased from low voltage to high voltage, simulating the working environment of the high-voltage direct current transmission system.

[0094] (2) Apply different voltages in the test system, gradually increasing from low voltage to high voltage, and record the phase delay changes of the two BGO crystals at each voltage.

[0095] (3) The optical sensor 40 is used to simultaneously collect the phase delay signals of the two crystals, and the phase delay is converted into a voltage value using a pre-constructed two-dimensional phase mapping table.

[0096] (4) Compare the voltage value measured by the system with the actual applied voltage, calculate the measurement error, and verify whether the dual BGO crystal combination can accurately measure voltages higher than the single half-wave voltage range.

[0097] (5) In this experiment, the measurement range was gradually increased from ±50 kV to ±400 kV, which fully covered the voltage requirements of high-voltage direct current transmission. By comparing the measurement results with the actual applied voltage, the measurement error of the system was controlled within ±1%. The experiment showed that the dual BGO crystal combination can effectively expand the voltage measurement range and avoid the multi-value problem of a single Pockels crystal.

[0098] 3. Withstand voltage test:

[0099] (1) In order to verify the stability and safety of the system under high-voltage shock conditions, a withstand voltage test was also carried out.

[0100] (2) Apply transient impulse voltages up to 900 kV to the test system to simulate voltage fluctuations under abnormal conditions such as lightning strikes and switching operations.

[0101] (3) Record the phase delay and voltage measurement results of the system under the impulse voltage to observe whether the system fails or the measurement error increases.

[0102] (4) The electric field distribution around the high-voltage electrode is calculated using the finite element method (FEM) to verify whether the system's insulation performance under high electric field conditions and the maximum electric field value are within a safe range.

[0103] (5) The experimental results show that the system can still work stably when an impulse voltage of up to 900 kV is applied, and the measurement error does not increase significantly. The maximum electric field strength is 26.2 kV / mm, and no breakdown or discharge occurs, which proves the reliability and voltage resistance of the system.

[0104] 4. Experimental results analysis:

[0105] (1) Experimental results show that the dual BGO crystal combined optical voltage transformer of the present invention has good performance and broad application prospects in high voltage DC voltage measurement.

[0106] (2) Through the combination of dual BGO crystals, the system's measurement range has been successfully expanded to over ±400 kV, far exceeding the measurement capability of a single Pockels crystal and able to meet the voltage measurement requirements of high-voltage direct current transmission systems.

[0107] (3) Within the entire voltage range, the measurement error of the system is controlled within ±1%. In particular, within the voltage range higher than the half-wave voltage of a single crystal, the dual crystal combination can still accurately distinguish the voltage value through the difference in phase delay.

[0108] (4) Through the voltage withstand test, the system remained stable under a transient impulse voltage of up to 900 kV, and the maximum electric field strength did not exceed the safety limit of the material, verifying the system's voltage withstand capability and anti-interference performance.

[0109] (5) Through optical modulation technology, the experiment successfully eliminated the impact of light intensity fluctuations on measurement accuracy, further improving the stability and long-term reliability of the system.

[0110] In an exemplary embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as shown in FIG. Figure 7As shown. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, near field communication (NFC) or other technologies. When the computer program is executed by the processor, a voltage measurement method is implemented. The display unit of the computer device is used to form a visually visible picture, which can be a display screen, a projection device or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the computer device shell, or an external keyboard, touchpad or mouse.

[0111] Those skilled in the art will understand that Figure 7 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0112] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps of the above method when executing the computer program.

[0113] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0114] In one embodiment, a computer program product is provided, comprising a computer program, which implements the steps of the above method when executed by a processor.

[0115] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0116] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0117] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0118] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. An optical voltage transformer, characterized in that: include: A first electro-optic crystal, a second electro-optic crystal, a laser generator, an optical sensor, and a controller; the first electro-optic crystal and the second electro-optic crystal are connected in parallel; The controller is connected to the optical sensor; The laser generator is used to emit laser light, and the laser light is respectively emitted into the first electro-optical crystal and the second electro-optical crystal; the laser light outputs a first output light after passing through the first electro-optical crystal; and the laser light outputs a second output light after passing through the second electro-optical crystal; The optical sensor is used to detect first phase delay information of the first output light and second phase delay information of the second output light respectively; The controller is used to obtain the first phase delay information and the second phase delay information, and perform information analysis based on the first phase delay information and the second phase delay information to determine the voltage applied to the first electro-optical crystal and the second electro-optical crystal.

2. The optical voltage transformer according to claim 1, characterized in that: The first electro-optical crystal is a crystal obtained by cutting with the crystal axis as the cutting axis; the second electro-optical crystal is a crystal obtained by cutting with the cutting axis obtained by offsetting the crystal axis by a preset angle.

3. The optical voltage transformer according to claim 1, characterized in that: The optical voltage transformer further includes a polarizer, which is used to convert the laser into linearly polarized light so that the linearly polarized light is incident on the first electro-optical crystal and the second electro-optical crystal respectively.

4. The optical voltage transformer according to claim 3, characterized in that: The optical voltage transformer further includes a Faraday rotator, and the Faraday rotator is used to correct the polarization state of the linearly polarized light before the linearly polarized light is respectively incident on the first electro-optical crystal and the second electro-optical crystal.

5. The optical voltage transformer according to claim 4, characterized in that: The Faraday rotator is used to rotate the polarization direction of the linearly polarized light according to a first set angle, and to rotate the first output light and the second output light according to a second set angle, so that the updated polarization states corresponding to the rotated updated first output light and the updated second output light are respectively orthogonal to the first polarization state corresponding to the laser.

6. The optical voltage transformer according to claim 1, characterized in that: The optical voltage transformer also includes a metal shell; the first electro-optical crystal, the second electro-optical crystal, the laser generator, the optical sensor, and the controller are all arranged in the metal shell.

7. The optical voltage transformer according to claim 6, characterized in that: The interior of the metal shell is filled with insulating gas.

8. The optical voltage transformer according to any one of claims 1 to 7, characterized in that: The optical voltage transformer further includes an optical fiber; the optical fiber is used for optically transmitting the laser, the linearly polarized light, the first output light, and the second output light.

9. The optical voltage transformer according to claim 1, characterized in that: The height of the first electro-optical crystal and the second electro-optical crystal are both 200 mm, and the cross-sectional area of ​​the first electro-optical crystal and the second electro-optical crystal are both 100 mm².

10. A voltage measurement method, characterized in that: Applied to the optical voltage transformer according to any one of claims 1 to 9, the method comprises: Acquire first phase delay information obtained by the optical sensor for detecting a first output light, and second phase delay information obtained by the optical sensor for detecting a second output light; the first output light is output light of the laser passing through a first electro-optical crystal; the second output light is output light of the laser passing through a second electro-optical crystal; Information analysis is performed based on the first phase delay information and the second phase delay information to determine the voltage applied to the first electro-optical crystal and the second electro-optical crystal.

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