An iterative tuning operating point static verification method, electronic device and storage medium

Abstract

This invention discloses an iterative tuning operating point static calibration method, electronic device, and storage medium, belonging to the field of static calibration technology. The iterative tuning operating point static calibration method includes placing an optical electric field sensor and calibration equipment within a Faraday cage; using an AC source connected to a high-voltage transformer to generate a power frequency electric field of known intensity through a pair of parallel electrode plates, with the optical electric field sensor positioned between the two plates; emitting polarized light to the waveguide of the optical electric field sensor and loading the electric field signal to be measured onto the light wave; converting the electric field signal into an analog electrical signal through a photoelectric conversion circuit; and demodulating and calculating the measured electric field value through a digital signal processing circuit. Static operating point calibration is performed in a power frequency electric field environment, and the linear operating point of the sensor is controlled using laser wavelength tuning and an iterative method, improving the stability and accuracy of the optical electric field sensor in a high-voltage electric field environment.

Description

Technical Field

[0001] This invention relates to the field of static verification technology, and in particular to an iteratively tuned operating point static verification method, electronic device, and storage device. Background Technology

[0002] Optical electric field sensors currently have broad application prospects in high-voltage transmission lines, power equipment monitoring, and lightning disaster prevention. With the surge in my country's dual-carbon goals and the demand for new energy grid integration, massive amounts of transmission line information urgently need to be monitored to achieve transparency. Sensing technology for power frequency electric field information of high-voltage equipment can provide crucial assurance for assessing equipment operating status. The massive influx of distributed energy resources and power electronic devices presents challenges to the intelligent and distributed nature of next-generation sensing equipment. Traditional electrical field sensors are mainly discrete active devices with narrow measurement bandwidth, limited to low-frequency and DC electric field measurements. With the construction of new power systems, electric field measurement sensors are required to gradually transform into miniaturized, integrated, high-voltage, and wide-bandwidth optical electric field sensors. For the field of strong electric fields, wide bandwidth, and miniaturized electric field sensors, optical electric field sensors have gradually become the mainstream choice.

[0003] Currently, the main technical approach for optical electric field sensors involves integrating an optical waveguide modulator, a dipole antenna, and a modulation electrode plate onto a crystal surface. The electric field to be measured is then applied between the modulators, utilizing the electro-optic effect of lithium niobate crystals to modulate the light wave propagating in the waveguide. The electric field strength is determined by measuring the output light intensity. However, optical electric field sensors only achieve linear detection at a static operating point. When external physical quantities such as temperature, illuminance, and stress change, this operating point drifts due to interference from the sensor's physical characteristics, leading to measurement errors. In the complex electromagnetic conditions of high-voltage transmission and distribution lines, the linear operating point of the optical electric field sensor is subject to uncertain drift due to environmental electromagnetic fields, temperature, humidity, and illumination. For outdoor high-voltage line environments, there is a lack of a suitable on-site control and calibration scheme for the linear operating point of optical electric field sensors applicable to transmission and distribution lines.

[0004] Optical electric field sensors are based on the electro-optic effect of lithium niobate (LiNbO3) crystals. When an external electric field is applied to the optical electric field sensor, it affects the phase of the light wave, thereby changing the output light intensity. Current optical electric field sensors are widely used in high-voltage power transmission and distribution lines, lightning disaster prevention, and power equipment monitoring. However, in complex electromagnetic environments, external factors such as temperature, humidity, and illumination may cause the sensor's operating point to drift, affecting the measurement accuracy.

[0005] Currently, existing solutions for sensor operating point drift in strong power frequency electric field environments are not ideal. For high-voltage power transmission and distribution line applications, there is a need to develop a real-time adjustable linear operating point control scheme for optical electric field sensors with broad applicability. Summary of the Invention

[0006] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0007] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0008] Therefore, the present invention provides an iterative tuning operating point static calibration method, electronic device and storage device, which can perform static operating point calibration in a power frequency electric field environment, and use laser wavelength tuning and iterative method to control the linear operating point of the sensor, thereby solving the problem of instability of optical electric field sensors in high voltage electric field environments.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0010] In a first aspect, the present invention provides an iterative tuning operating point static verification method, comprising: placing an optical electric field sensor and a verification device inside a Faraday cage; using an AC source connected to a high-voltage transformer to generate a power frequency electric field of known intensity through a pair of parallel electrode plates, with the optical electric field sensor located between the pair of parallel electrode plates; emitting polarized light to the waveguide of the optical electric field sensor and loading the electric field signal to be measured onto the light wave; converting the electric field signal into an analog electrical signal through a photoelectric conversion circuit; and demodulating and calculating the value of the electric field to be measured through a digital signal processing circuit.

[0011] As a preferred embodiment of the iterative tuning operating point static verification method of the present invention, the Faraday cage is a metal sphere with a uniform and equipotential surface and an internal potential of 0. The Faraday cage is used to shield external electromagnetic fields and to prevent the calibration process from being affected by external environmental electric fields.

[0012] As a preferred embodiment of the iterative tuning operating point static verification method of the present invention, the optical electric field sensor uses lithium niobate as the electro-optic material, the AC source is 220V / 50Hz, the output voltage of the high-voltage transformer is controlled, the size of a pair of parallel electrode plates is 40cm*60cm, and the spacing between the electrode plates is 20cm; when powered on, a power frequency electric field with a frequency of 50Hz and a known voltage intensity is generated between the electrode plates as the calibration electric field; the direction of the dipole antenna on the surface of the optical electric field sensor is parallel to the direction of the electric field between the electrode plates, and when the dipole antenna detects the electric field signal, it generates an electric field between the electrode plates and loads the electric field signal onto the optical signal.

[0013] As a preferred embodiment of the iterative tuning operating point static verification method of the present invention, a tunable laser is used to emit polarized light to generate infrared polarized light with a wavelength between 1500-1600nm and a frequency range of 187.5-200GHz, and the wavelength is adjusted in real time by MCU control; the infrared polarized light is modulated by induced voltage during waveguide transmission, the phase difference changes, and the two polarized beams at the waveguide output end merge and interfere, converting the phase difference into an intensity difference signal.

[0014] As a preferred embodiment of the iterative tuning operating point static verification method of the present invention, the light intensity difference signal output by the optical electric field sensor is transmitted to a 1:9 coupler through a single-mode optical fiber, 90% of the light intensity difference signal is received by the photodetector and converted into an electrical signal for processing, and 10% of the light intensity difference signal is used as a feedback signal to enter the MCU.

[0015] As a preferred embodiment of the iterative tuning operating point static verification method of the present invention, the feedback signal is received by the MCU and subjected to analog-to-digital conversion and calculation processing to control the frequency and wavelength of the laser output light wave, so as to realize the linear operating point adjustment of the sensor.

[0016] As a preferred embodiment of the iterative tuning operating point static verification method of the present invention, the method involves: selecting a set of frequencies and calculating the electrical signal difference between adjacent frequencies to find the frequency range with the largest electrical signal difference, and continuing to refine the scan until the operating frequency is determined.

[0017] As a preferred embodiment of the iterative tuning operating point static verification method of the present invention, the linear operating point wavelength of the optical electric field sensor is determined by frequency scanning of the wavelength emitted by the tunable laser and based on the change of the output signal using an iterative method.

[0018] In a second aspect, the present invention provides an electronic device comprising a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions, wherein the computer-executable instructions, when executed by the processor, implement the steps of the above-described iterative harmonic operating point static verification method.

[0019] Thirdly, the present invention provides a computer-readable storage medium storing computer-executable instructions that, when executed by a processor, implement the steps of the above-described iterative harmonic operating point static verification method.

[0020] The beneficial effects of this invention are: it solves the problem of operating point drift of optical electric field sensors in complex electromagnetic environments, especially in high-voltage power transmission and distribution lines, caused by changes in external physical quantities such as temperature, illumination, and stress. By employing an iterative wavelength tuning method, the operating point of the optical electric field sensor can be adjusted in real time, thereby ensuring that the sensor maintains high-precision linear detection performance. The core innovation of this solution lies in performing static operating point calibration in a power frequency electric field environment and using laser wavelength tuning and an iterative method to control the linear operating point of the sensor, thus improving the stability and accuracy of the optical electric field sensor in high-voltage electric field environments. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0022] Figure 1 The transfer function diagram of the optical electric field sensor for the iterative harmonic operating point static verification method.

[0023] Figure 2 A schematic diagram of the linear operation of an optical electric field sensor for an iterative harmonic operating point static verification method. Detailed Implementation

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0025] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0026] Secondly, the present invention will be described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure will be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0027] Furthermore, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that mutually excludes other embodiments.

[0028] Example 1

[0029] This is the first embodiment of the present invention, which provides an iterative harmonic operating point static verification method, comprising:

[0030] S100: Place the optical electric field sensor and calibration equipment inside the Faraday cage;

[0031] S200: Uses an AC source connected to a high-voltage transformer to generate a power frequency electric field of known strength through a pair of parallel electrode plates. An optical electric field sensor is located between the pair of parallel electrode plates.

[0032] S300: Transmits polarized light to the waveguide of the optical electric field sensor and loads the electric field signal to be measured onto the light wave;

[0033] S400: Converts electric field signals into analog electrical signals through a photoelectric conversion circuit;

[0034] S500: Demodulates and calculates the measured electric field value through digital signal processing circuitry.

[0035] Example 2

[0036] This embodiment is the second embodiment of the present invention.

[0037] S100: Same as in Example 1, place the optical electric field sensor and calibration equipment inside the Faraday cage;

[0038] S200: Similar to Example 1, an AC source is connected to a high-voltage transformer to generate a power frequency electric field of known strength through a pair of parallel electrode plates, and an optical electric field sensor is located between the pair of parallel electrode plates.

[0039] S300: Same as in Example 1, polarized light is emitted to the waveguide of the optical electric field sensor, and the electric field signal to be measured is loaded onto the light wave;

[0040] S400: Same as in Example 1, the electric field signal is converted into an analog electrical signal through a photoelectric conversion circuit;

[0041] S500: Same as in Example 1, the measured electric field value is demodulated and calculated by digital signal processing circuit;

[0042] S600: Add a signal amplification step to the photoelectric conversion circuit to improve the signal-to-noise ratio and ensure accurate measurement results even under low electric field strength;

[0043] S700: Adds a filtering step to the digital signal processing circuit to remove possible noise and interference, thereby improving the accuracy of electric field numerical calculations.

[0044] Example 3

[0045] See Figure 1 and Figure 2 This is the third embodiment of the present invention, which is based on embodiment 1.

[0046] It is worth noting that the optical electric field sensor system consists of optical waveguide arms, electrode plates, and an antenna. The principle of the optical electric field sensor utilizes the electro-optic effect of lithium niobate (LiNbO3) crystals. When the electric field changes, the refractive index of the lithium niobate crystal changes, and the electric field is inferred by measuring the change in the optical signal. Using an x-cut, y-transfer lithium niobate crystal, two optical waveguide arms with an inherent phase difference are fabricated on its surface. The dipole antenna applies the electric field to be measured as a voltage to the electrode plates, generating an electric field between the plates. The electric field of the electrode plates is applied to one of the waveguide arms, thus modulating the polarized light wave passing through this waveguide arm, while the phase of the polarized light in the other waveguide arm remains unchanged, thereby changing the phase difference between the two polarized beams. After interfering at the output Y-terminus, the output light intensity signal carries the electric field frequency information. This signal is then converted into a current signal by a photodetector module via a single-mode optical fiber.

[0047] Specifically, a Faraday cage is a metal sphere with a uniform surface and equipotential potential, and its internal potential is 0. The Faraday cage is used to shield external electromagnetic fields and prevent the calibration process from being affected by external environmental electric fields. The Faraday cage isolates electromagnetic fields outside the metal sphere, thus acting as a shield. In complex external alternating electric field environments, free electrons can move back and forth on the surface of the metal conductor, canceling out the alternating electric field entering the interior, equivalent to a hollow sphere that can conduct electricity and has an internal potential of 0. By grounding this small-grid, low-resistance mesh-like Faraday cage in a frequency-closed box, with a uniform zero potential on its surface, electromagnetic waves from high-voltage environments are prevented from entering, creating a calibration environment free from external electric field interference.

[0048] Preferably, the AC source is 220V / 50Hz, which controls the output voltage of the high-voltage transformer. The output voltage is connected to a pair of parallel plates with copper wire. The size of the pair of parallel plates is 40cm*60cm, and the distance between the plates is 20cm. When powered on, a power frequency electric field with a frequency of 50Hz and a known voltage intensity is generated between the plates as a calibration electric field.

[0049] An optical electric field sensor is placed in the central region between the electrode plates. The direction of the dipole antenna on the surface of the optical electric field sensor is parallel to the direction of the electric field between the electrode plates. When the dipole antenna detects the electric field signal, it generates an electric field between the electrode plates and loads the electric field signal onto the optical signal.

[0050] Preferably, a tunable laser is used to emit polarized light, which is connected to the waveguide input end of the optical electric field sensor through a polarization-maintaining fiber. Infrared polarized light with a wavelength between 1500-1600nm and a frequency range of 187.5-200GHz is generated and enters the MZI waveguide on the surface of the optical electric field sensor. The wavelength is adjusted in real time by the MCU control. During the transmission of the infrared polarized light in the waveguide, it is modulated by the induced voltage, and the phase difference changes. The two polarized beams at the output end of the waveguide merge and interfere, converting the phase difference into an intensity difference signal.

[0051] Preferably, the light intensity difference signal output by the optical electric field sensor is transmitted to a 1:9 coupler via a single-mode optical fiber. 90% of the light intensity difference signal is received by a photodetector and converted into an electrical signal for processing. The received signal waveform is then transmitted to an oscilloscope via a coaxial cable for observation and comparison. 10% of the light intensity difference signal is used as a feedback signal and input to the MCU. The MCU performs calculations based on the feedback signal and controls the output wavelength of the tunable laser, thereby adjusting the sensor to its linear operating point.

[0052] Preferably, a horn antenna is placed near the electric field sensor to receive the calibration electric field, and the input waveform is input to an oscilloscope for comparison with the waveform of the electric field sensor.

[0053] Furthermore, the feedback signal is received by the MCU and processed through analog-to-digital conversion and calculation. The detected analog quantity is converted into a corresponding digital control signal, and the output wavelength of the harmonic laser is controlled via serial communication. During operating point tuning, the MCU sends commands to control the frequency and wavelength of the laser module's output light wave. The laser frequency is controlled for frequency sweeping, and the waveforms of the feedback voltage and frequency after the sweep are calculated. An iterative method is used to approximate the calculated operating point wavelength, thus achieving linear operating point adjustment of the optical electric field sensor.

[0054] Furthermore, by selecting a set of frequencies and calculating the electrical signal difference between adjacent frequencies, the frequency range with the largest electrical signal difference is found, and the scan is further refined until the working frequency is determined.

[0055] Furthermore, the linear operating point wavelength of the optical electric field sensor is determined by frequency scanning of the wavelength emitted by the tunable laser and based on the changes in the output signal using an iterative method.

[0056] It is worth noting that optical electric field sensors all possess a sinusoidal transfer function, and the input-output characteristics of their measurement system can be expressed as:

[0057]

[0058] Where Vout is the output voltage of the measurement system; A represents the optical power and photoelectric conversion coefficient; b represents the extinction ratio, typically ranging from 0.9 to 1; It is called the static operating point, which is the phase difference between the two arms of the optical waveguide (MZ interference) or the two transmission modes of optical waves (common path interference) when there is no electric field. It can be further expressed as This is called the optical bias point, which is determined by the optical properties of the crystal (waveguide). It is an additional modulation amount mainly caused by temperature changes. The phase modulation caused by the external electric field can be expressed as:

[0059]

[0060] Eπ is called the half-wave electric field, which is the electric field strength when the phase modulation is equal to π. Eπ determines the dynamic range of the optical electric field sensor.

[0061] Let k = π / Eπ, then the expression can be rewritten as:

[0062]

[0063] like Figure 1 As shown, A, b, k and The four parameters determine the transfer function of the measurement system, which can be obtained through calibration experiments. Ideally, At this time, the measurement system has linear input-output characteristics under the action of a small electric field; when When the deviation is significant, such as or The output waveform of the optical electric field sensor will be distorted, leading to the sensor's failure. Therefore, it is hoped that... To stabilize around π / 2, a specific optical bias point is required. Approximately π / 2, with an additional phase difference. Keep it as small as possible.

[0064] Once the output Vout of the measurement system is obtained, the electric field to be measured can be deduced:

[0065]

[0066] The working principle and method of using an iterative method to approximate the operating point wavelength by frequency sweeping are as follows. First, the wavelength range λ of the coordinateable laser is set to 1500nm to 1600nm, corresponding to a frequency range f of 187.5GHz to 200GHz. Polarized light passes through an optical electric field sensor waveguide of length L. After electric field modulation, the output light intensity has a cosine function relationship with the incident polarized light frequency f:

[0067]

[0068] in, Let be the phase difference generated after light passes through the waveguide, and its expression is:

[0069]

[0070] In the formula, c is the speed of light, λ is the operating wavelength of the sensor, and n eff ΔL is the effective refractive index of the optical waveguide, and ΔL is the inherent difference in arm length between the two waveguides. The inherent phase difference of an optical waveguide changes with variations in the external environment; this inherent phase difference is also known as the unknown operating point drift of an optical electric field sensor. Therefore, the phase difference generated by the modulation of the optical signal in the waveguide by the electric field is determined by two factors: the electric field itself and environmental influences. The half-wave electric field E is defined as... π Given the electric field value to be measured by the sensor when the phase difference is π, the expression for the output light intensity can be modified as follows:

[0071]

[0072] If and only if When m is an odd number, within the sensor's measurement range The sensor output light intensity can be approximately reduced to:

[0073]

[0074] At this point, the light intensity signal output by the optical electric field sensor has a linear relationship with the measured electric field, and the sensor's detection sensitivity is highest under linear operating conditions. However, in high-voltage line environments, unpredictable environmental variables can cause inherent phase differences. The change in frequency f causes the optical electric field sensor to deviate from its linear operating point. The amount of change in the light phase caused by the electric field is adjusted by controlling the frequency f. This maintains the optical phase difference at π / 2, thus controlling the sensor to operate within its linear region. The laser frequency f0 is used to ensure the optical electric field sensor operates within this linear region. This is to accommodate environmental variables. Under unknown conditions, determine the operating point wavelength λ0 and frequency f0, and use an iterative method to perform frequency sweep approximation on the sensor.

[0075] Select a set of m frequencies f with a frequency interval of Δf1. i (i = 1, 2, 3, ..., m), (m = 2π / Δf), output and record the corresponding frequency f. i The sensor outputs an electrical signal E i Calculate the electrical signal difference ΔE between adjacent frequencies. i-1 =(E i -E i-1 This yields the difference ΔE between the output electrical signals of a set of m-1 sensors. i-1 =(E i -E i-1 (i = 1, 2, 3, ..., m-1), (m = 2π / Δf). The MCU calculates and compares the maximum electrical signal difference ΔE. k1 =ΔE i-1(max) For ΔE k1 The frequency range (f) k -f k-1 Then perform frequency sweep sampling.

[0076] Repeat the above steps to select the frequency range (f k -f k-1 A set of frequencies with intervals of Δf2 = (f k -f k-1 The m frequencies f of ) / m i (i = 1, 2, 3, ..., m), (m = 2π / Δf²), output and record the selected frequency f of the optical electric field sensor again. i Output electrical signal E i Calculate the electrical signal difference ΔE between m-1 adjacent frequencies. i-1 And the maximum electrical signal difference ΔE is obtained by comparison. k2 =ΔE i-1(max) For ΔE k2 The frequency range (f) k '-f k-1 ') Select the frequency interval again as A set of m frequencies.

[0077] Repeat the above steps until Δf < 3 GHz, and record the frequency range (f) at this point. k-1 ,f k ) and corresponding electrical signal (E) i-1 E i ), take the average value of the electrical signal Corresponding frequency f iThe target operating frequency is f0, which is the frequency that provides a linear operating point, and the corresponding wavelength λ0 is the wavelength that provides a linear operating point. The tunable laser (DBR) is controlled by the MCU to output polarized light with a frequency of f0, thereby controlling the optical electric field sensor to operate within its static operating point.

[0078] See Figure 2 This demonstrates the waveform of the output signal versus frequency f when the sensor is frequency-sweeped using an MCU. The operating point frequency f0 is determined using an approximation method, at which point the sensor operates at... Figure 2 (b) At point a, the output signal has the maximum rate of change relative to frequency f, and the optical phase is... This point corresponds to the target operating frequency f0 when the sensor is operating in its linear operating region. The target operating frequency and operating wavelength can be expressed as follows:

[0079]

[0080] This embodiment also provides a computing device suitable for static verification of iterative harmonic operating points, including: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement the static verification method of iterative harmonic operating points proposed in the above embodiment.

[0081] This embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements the iterative tuning operating point static verification method as proposed in the above embodiments.

[0082] The storage medium proposed in this embodiment and the iterative tuning operating point static verification method proposed in the above embodiments belong to the same inventive concept. Technical details not described in detail in this embodiment can be found in the above embodiments, and this embodiment has the same beneficial effects as the above embodiments.

[0083] Based on the above, the advantages of the present invention are: by controlling the laser wavelength λ using an iterative laser tuning method, the inherent phase drift of the optical electric field sensor caused by unknown environmental changes is compensated, thereby achieving control of the operating point of the optical electric field sensor.

[0084] Based on the above description of the implementation methods, those skilled in the art will clearly understand that the present invention can be implemented using software and necessary general-purpose hardware, and of course, it can also be implemented using hardware. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of the various embodiments of the present invention.

[0085] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A static verification method for iterative harmonic operating point, characterized in that, include: The optical electric field sensor and calibration equipment are placed inside a Faraday cage; An AC source is connected to a high-voltage transformer to generate a power frequency electric field of known strength through a pair of parallel electrode plates. An optical electric field sensor is located between the pair of parallel electrode plates. A tunable laser emits polarized light into the waveguide of an optical electric field sensor, and loads the electric field signal to be measured onto the light wave. The electric field signal is converted into an analog electrical signal through a photoelectric conversion circuit; The measured electric field value is demodulated and calculated using digital signal processing circuitry. Among them, the light intensity difference signal output by the optical electric field sensor is transmitted to the 1:9 coupler through a single-mode optical fiber. 90% of the light intensity difference signal is received by the photodetector and converted into an electrical signal for processing. 10% of the light intensity difference signal is used as a feedback signal to enter the MCU. The feedback signal is received by the MCU and subjected to analog-to-digital conversion and calculation processing. The optical electric field sensor is approximated by frequency sweep using an iterative method to determine the frequency f0 corresponding to the linear operating point wavelength of the optical electric field sensor. The MCU controls the tunable laser to output polarized light with frequency f0, thereby controlling the optical electric field sensor to work within the static operating point. The frequency sweep approximation specifically includes: selecting a set of frequencies and calculating the electrical signal difference between adjacent frequencies, finding the frequency range with the largest electrical signal difference, and continuing to refine the scan until the operating point frequency f0 is determined.

2. The iterative harmonic operating point static verification method as described in claim 1, characterized in that, A Faraday cage is a metal sphere with a uniform surface and equipotential, and its internal potential is 0. Faraday cages are used to shield external electromagnetic fields and to prevent the calibration process from being affected by the electric field of the external environment.

3. The iterative harmonic operating point static verification method as described in claim 1 or 2, characterized in that, The optical electric field sensor uses lithium niobate as the electro-optic material, the AC source is 220V / 50Hz, the output voltage of the high voltage transformer is controlled, and the size of a pair of parallel electrode plates is 40cm*60cm, with a spacing of 20cm between the electrode plates. When powered on, a power frequency electric field with a known voltage intensity and a frequency of 50Hz is generated between the electrode plates, which serves as the calibration electric field. The direction of the dipole antenna on the surface of the optical electric field sensor is parallel to the direction of the electric field between the electrode plates. When the dipole antenna detects the electric field signal, it generates an electric field between the electrode plates and loads the electric field signal onto the optical signal.

4. The iterative harmonic operating point static verification method as described in claim 3, characterized in that, A tunable laser is used to emit polarized light, generating infrared polarized light with a wavelength between 1500-1600nm and a frequency range of 187.5-200GHz, and the wavelength is adjusted in real time by MCU control. Infrared polarized light is modulated by an induced voltage during its transmission through the waveguide, causing a change in phase difference. The two polarized beams at the waveguide output end then converge and interfere, converting the phase difference into an intensity difference signal.

5. An electronic device, characterized in that, include: Memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, they implement the steps of the iterative harmonic operating point static verification method according to any one of claims 1 to 4.

6. A computer-readable storage medium, characterized in that, It stores computer-executable instructions that, when executed by a processor, implement the steps of the iterative harmonic operating point static verification method according to any one of claims 1 to 4.

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