Integrated optical waveguide electric field sensor processing method and system

Abstract

The invention belongs to the technical field of electrical measurement, and particularly discloses an integrated optical waveguide electric field sensor processing method and system. The method comprises the steps that under the condition that step voltage signals are applied to the two ends of a uniform electric field generator, step response signals of a sensor are measured, and the sensor is located in the center of the uniform electric field generator; preprocessing the obtained step response signal, and estimating a transfer function of the sensor based on the preprocessed step response signal; and calculating an inverse transfer function according to the transfer function, and reconstructing an output signal of the sensor by using the inverse transfer function to realize time domain waveform reconstruction of the sensor. The technical problem of waveform distortion of an integrated optical waveguide electric field sensor is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of electrical measurement, and in particular relates to an integrated optical waveguide electric field sensor processing method and system. Background Art

[0002] For new power systems, the power grid has put forward higher requirements for the depth, breadth and density of information perception, and the demand for sensors has shown explosive growth. To build a new smart grid, an important characteristic state representation quantity that needs to be collected is the real-time information of the voltage / electric field of key nodes and equipment. The frequency coverage of voltage / electric field quantity is very wide. The monitoring of voltage / electric field quantity runs through all aspects of power system generation, transmission, distribution, use and storage. Accurate measurement can effectively reflect the real-time status of the power grid. In the current environment where sensor technology is evolving towards miniaturization, integration, networking and intelligence, the deployment of a new generation of electrical sensors can realize reliable intelligent control based on electrical information, provide support for accurate prediction based on data, and accurately perceive the status of power equipment is the basis for reducing carbon emissions in power grid operation.

[0003] Currently, the existing pulse electric field sensors mainly include D-dot electric field sensors, integrated optical waveguide electric field sensors, optical fiber-waveguide coupler electric field sensors, etc. Among them, the integrated optical waveguide electric field sensor has attracted extensive attention from domestic and foreign researchers and industrial application fields due to its advantages such as small size, wide bandwidth, large dynamic measurement range, strong anti-electromagnetic interference ability, intrinsic insulation, high electrical safety, and suitability for long-distance measurement and signal transmission.

[0004] However, photoelectric sensing also has technical difficulties. Some optical properties of lithium niobate crystals have temperature characteristics, such as the refractive index and electro-optical coefficient, which are related to temperature. Due to the fixed structure and miniaturization of the integrated electric field sensor, it is difficult to add optical temperature compensation elements to reduce the impact of environmental factors such as temperature. In other patents, the method of real-time tracking and feedback of the working point is used to compensate for the impact of temperature by adjusting the laser wavelength.

[0005] Another key point is that the sensitivity coefficients of the integrated optical waveguide electric field sensor device are different under different frequency electric fields. Generally, the sensitivity is high under high-frequency electric fields and low under low-frequency electric fields. Therefore, when measuring the high-frequency signal superimposed on the industrial frequency, or the composite pulse voltage waveform composed of different frequency waveforms, the waveform will be distorted and deformed. Summary of the invention

[0006] The purpose of the present invention is to provide an integrated optical waveguide electric field sensor processing method and system to solve the technical problem of waveform distortion existing in the integrated optical waveguide electric field sensor.

[0007] To achieve the above object, the present invention adopts the following technical solution: A processing method for an integrated optical waveguide electric field sensor comprises: measuring a step response signal of the sensor when a step voltage signal is applied to both ends of a uniform electric field generator, wherein the sensor is located at the center of the uniform electric field generator; preprocessing the acquired step response signal, and estimating a transfer function of the sensor based on the preprocessed step response signal; calculating an inverse transfer function according to the transfer function, and reconstructing an output signal of the sensor using the inverse transfer function to achieve reconstruction of the sensor time domain waveform.

[0008] An integrated optical waveguide electric field sensor processing system comprises: a signal measurement unit, used for measuring a step response signal of a sensor when a step voltage signal is applied to both ends of a uniform electric field generator, wherein the sensor is located at the center of the uniform electric field generator; a processing unit, used for preprocessing the acquired step response signal, and estimating a transfer function of the sensor based on the preprocessed step response signal; and a compensation reconstruction unit, used for calculating an inverse transfer function according to the transfer function, and reconstructing an output signal of the sensor using the inverse transfer function, thereby realizing time domain waveform reconstruction of the sensor.

[0009] A computer-readable storage medium stores a computer program, wherein the computer program is configured to execute the above-mentioned integrated optical waveguide electric field sensor processing method when running.

[0010] An electronic device comprises a memory and a processor, wherein the memory stores a computer program, and the processor is configured to execute the integrated optical waveguide electric field sensor processing method through the computer program.

[0011] In the present invention, a step response signal of a sensor is measured when a step voltage signal is applied to both ends of a uniform electric field generator, wherein the sensor is located at the center of the uniform electric field generator; the acquired step response signal is preprocessed, and a transfer function of the sensor is estimated based on the preprocessed step response signal; an inverse transfer function is calculated according to the transfer function, and the output signal of the sensor is reconstructed using the inverse transfer function to achieve reconstruction of the sensor's time domain waveform, thereby determining the transfer function and the inverse transfer function of the sensor based on the measured step response signal of the sensor, compensating the frequency response characteristics of the sensor using the inverse transfer function, restoring the time domain waveform of the original electric field, and achieving reconstruction of the sensor's time domain waveform, solving the technical problem of waveform distortion of an integrated optical waveguide electric field sensor, and achieving the technical effect of reducing waveform distortion of the integrated optical waveguide electric field sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic flow chart of an integrated optical waveguide electric field sensor processing method in an embodiment of the present invention; Figure 2 It is a schematic flow chart of a time domain waveform reconstruction method of an integrated optical waveguide electric field sensor in an embodiment of the present invention; Figure 3 It is a schematic flow chart of an integrated optical waveguide electric field sensor processing method in an embodiment of the present invention; Figure 4 is a schematic diagram of a reconstruction curve of an integrated optical waveguide electric field sensor processing method in an embodiment of the present invention; Figure 5 It is a structural schematic diagram of an integrated optical waveguide electric field sensor processing system in an embodiment of the present invention. DETAILED DESCRIPTION

[0013] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the drawings are all in very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0014] It should be noted that, in order to clearly explain the content of the present invention, the present invention specifically cites multiple embodiments to further illustrate different implementations of the present invention, wherein the multiple embodiments are enumerated rather than exhaustive. In addition, for the sake of brevity of explanation, the contents mentioned in the previous embodiments are often omitted in the subsequent embodiments. Therefore, the contents not mentioned in the subsequent embodiments can refer to the previous embodiments accordingly.

[0015] Example 1 An integrated optical waveguide electric field sensor processing method, such as Figure 1 As shown, the method includes: S102, measuring a step response signal of the sensor when a step voltage signal is applied to both ends of the uniform electric field generator, wherein the sensor is located at the center of the uniform electric field generator; S104, preprocessing the acquired step response signal, and estimating the transfer function of the sensor based on the preprocessed step response signal; S106, calculating an inverse transfer function according to the transfer function, and using the inverse transfer function to compensate the output signal of the sensor to achieve sensor time domain waveform reconstruction.

[0016] The uniform electric field generator is not limited to being composed of two metal plates. A uniform ring is installed around the plates. The diameter of the metal plates is 10 times the distance between the plates. The electric field is the ratio of the output voltage of the standard voltage source to the distance between the plates. The electric field sensor is placed at the center of the two plates. The installation angle is adjusted to make the sensitive axis coincide with the direction of the electric field.

[0017] As an optional implementation, before applying the step voltage signal at both ends of the uniform electric field generator, it also includes: generating the step voltage signal using a square wave voltage source; and measuring the step voltage signal using a high-speed digital oscilloscope to determine whether the step voltage signal reaches preset parameters.

[0018] The specific process of generating the step voltage signal is as follows: a high-stability DC voltage source is used to charge a capacitor. After charging is completed, the capacitor is short-circuited by triggering a relay, and the voltage drops to zero. A standard electric field generator is connected in parallel with the capacitor to generate a step electric field in the center of the paint.

[0019] As an optional implementation, measuring the step response signal of the sensor includes: measuring the step response signal of the sensor multiple times; and taking an average value of the multiple measurements as a measurement result of the step response signal.

[0020] As an optional implementation manner, the acquired step response signal is preprocessed, including: performing differential transformation, data smoothing and cross-correlation processing on the acquired step response signal.

[0021] The specific process of data smoothing is as follows: based on the wavelet transform method, the GC / MS data is decomposed into components of different frequencies, and then the noise components are denoised, and finally the original signal is reconstructed.

[0022] The specific method of cross-correlation processing is as follows: first monitor the input signal and the sensor response signal, then filter and reduce noise on the signal, then calculate the cross-correlation coefficient between the input signal and its sensor response signal, determine the delay between the two signals, and finally eliminate the time delay between the signals.

[0023] Specifically, the above differential transformation is a differential Z-Score transformation, which is not limited to the process of dividing the difference between a number and the mean by the standard deviation. The purpose of this processing is to standardize the data and remove the DC bias carried in the data. Data smoothing processing is not limited to reducing the noise component in the signal through data smoothing technology to make the signal smoother and continuous. Cross-correlation processing is not limited to eliminating the time delay between input and output signals, ensuring the alignment of input and output signals in time, and improving the accuracy of recognition.

[0024] As an optional implementation, estimating the transfer function of the sensor based on the preprocessed step response signal includes: estimating the transfer function of the sensor using a least squares method based on the preprocessed step response signal.

[0025] The specific process of using the least squares method to estimate the transfer function is as follows: (1) exist t = The inverse Laplace transform of time ( i =1, 2, ..., N), can be written in least squares form: (2) in:

[0026] By minimizing and The least squares solution can be obtained by taking the sum of squares of the differences between (3) Calculating the inverse transfer function based on the transfer function is not limited to performing an inverse operation on the transfer function to obtain the inverse transfer function.

[0027] The specific method for solving the inverse transfer function is as follows: (4) in is a matrix The elements in .

[0028] As an optional implementation, the output signal of the sensor is reconstructed using an inverse transfer function, including: reconstructing the frequency response of the output signal of the sensor using an inverse transfer function to restore the true waveform of its input signal, and the restored pulse waveform parameters are obtained by calculation.

[0029] The measurement error calibration method of the restored waveform includes: using a pulse voltage standard generator to apply to both ends of the uniform electric field generator, the pulse waveform characteristic parameters of the standard voltage generator are known, comparing the waveform parameters of the restored pulse waveform with the characteristic parameters of the pulse voltage standard generator, and obtaining the measurement error of the restored waveform parameters. The specific process of frequency response compensation based on the inverse transfer function is as follows: first, the frequency response of the system is obtained through the transfer function, then the frequency characteristic compensation is realized by using the inverse transfer function, and finally the compensation result of the frequency response is verified to ensure the accuracy of the frequency response compensation in the system.

[0030] As an optional implementation method, a standard electric field test platform is established, which includes: a voltage source, a uniform electric field generator, and a data acquisition system. The uniform electric field generator is composed of two metal plates, the diameter of the metal plates is 10 times the distance between the plates, and the sensor is placed at the center of the two metal plates.

[0031] As an optional implementation, the output of the voltage source is changed to generate electric fields of different frequencies in the uniform electric field generator, and the amplitude-frequency characteristics and phase-frequency characteristics at different frequencies are recorded by a data acquisition system.

[0032] As an optional implementation manner, the amplitude-frequency characteristic and the phase-frequency characteristic of the sensor are compensated to obtain an amplitude-frequency compensation curve and a phase-frequency compensation curve.

[0033] Optionally, high-fidelity reconstruction of complex pulse waveforms based on discrete Fourier transform is not limited to being realized based on an integrated optical waveguide electric field sensing device, and the integrated optical waveguide electric field sensing device is not limited to being composed of a sensing probe based on an asymmetric straight waveguide interference effect, a laser power supply, a transmission optical fiber, a photodetector, and an ambient temperature feedback compensation module. The electric field sensing probe is placed in the electric field of the space to be measured, and the electric field to be measured is linearly related to the output light intensity of the probe, so that the measured value of the electric field is obtained through the sensitivity coefficient.

[0034] The calculation formula of the sensitivity coefficient is: (5) Among them, V is the sensor output voltage, E is the measured electric field, K is the sensitivity coefficient, and A is a constant.

[0035] The electric field sensing device has excellent high frequency response characteristics, and the measurement bandwidth reaches 10 GHz. The specific implementation steps of the time domain waveform reconstruction of the integrated optical waveguide electric field sensor based on the electric field sensing device are not limited to the following: Figure 2 As shown, including: (1) Establish a standard electric field test platform, including: an AC standard voltage source or a pulse voltage standard source, a uniform electric field generator, and a calibrated high-speed data acquisition system. The uniform electric field generator consists of two metal plates with a uniform ring installed around the plates. The diameter of the metal plates is 10 times the distance between the plates. The electric field is the ratio of the output voltage of the standard voltage source to the distance between the plates. The electric field sensor is placed at the center of the two plates, and the installation angle is adjusted to make the sensitive axis coincide with the electric field.

[0036] (2) Perform discrete Fourier transform on the voltage of the pulse voltage standard source to obtain the amplitude of the measured electric field waveform A ( f i ) curve and phase P ( f i ) curve to obtain the proportion of different frequency components of the pulse electric field waveform.

[0037] (3) By changing the amplitude of the AC standard voltage source at a single frequency and obtaining at least five electric field points and the effective value of the output voltage, the constant A and the sensitivity coefficient K in formula (5) are obtained according to the fitting curve.

[0038] (4) Change the output voltage frequency of the AC standard voltage source to generate electric fields of different frequencies in the uniform field generator, and record the amplitude-frequency characteristics of the sensor at different frequencies within the range of 50 Hz to 1 MHz through the data acquisition system.M ( f i ), and use a phase meter to measure the phase-frequency characteristics of the input and output waveforms N ( f i ).

[0039] (5) Frequency segmentation method: not limited to the logarithmic segmentation method. For example, the frequency interval of 100Hz~1kHz is 100Hz, and the frequency interval of 1kHz~10kHz is 1kHz. The frequency interval in the range of 10kHz~100kHz is 10kHz... and so on from 10Hz~1MHz, the number of frequency points is 46. Obtain the amplitude-frequency characteristic curve based on the measurement results and calculate the working bandwidth. The frequency segmentation method with equal spacing can also be used, but the number of measurement frequency points is not less than 1200.

[0040] (6) Compensate the amplitude-frequency characteristics and phase-frequency characteristics of the sensor to obtain the amplitude-frequency compensation curve and the phase-frequency compensation curve.

[0041] (7) Perform inverse Fourier transform on the compensated amplitude-frequency characteristic and phase-frequency characteristic to reconstruct the time domain waveform.

[0042] The above method is not limited to being used to process wide dynamic electric field signals, perform fast discrete Fourier analysis, obtain the amplitude ratio of fundamental signals and high-order and ultra-high-order harmonics, and thus calculate the measurement error of characteristic values ​​such as frequency and period of the wide dynamic electric field / voltage of the concentrated optical waveguide electric field sensor.

[0043] Specifically, the implementation process of the above integrated optical waveguide electric field sensor processing method is not limited to the following: Figure 3 As shown, including: (1) A square wave voltage source applies a step voltage signal to both ends of the uniform electric field generator. The step voltage signal is measured by a high-speed digital oscilloscope to generate a measured step electric field waveform. (2) The sensor device is placed at the center of the uniform electric field generator, generating a constant step response measurement waveform, and measuring the step response signal of the sensor device. This is not limited to taking the average value of 10 repeated tests.

[0044] (3) After obtaining the step response measurement waveform, preprocessing is performed to improve the accuracy of the subsequent system identification process. Preprocessing includes: ① Differential Z-Score transformation: the process of dividing the difference between a number and the mean by the standard deviation. This step is mainly to standardize the data and remove the DC bias carried in the data. ② Data smoothing: reduce the noise component in the signal through data smoothing technology, making the signal smoother and more continuous. ③ Cross-correlation method: used to eliminate the time delay between the input and output signals, ensure the alignment of the input and output signals in time, and improve the accuracy of identification.

[0045] (4) After preprocessing, the transfer function of the sensor is estimated using the least squares method. The transfer function is a mathematical expression that describes the relationship between the output and input of a system and indicates the dynamic characteristics of the system. By establishing an input-output data matrix and applying the least squares method to fit the parameters, the transfer function of the sensor is obtained. The frequency response characteristics of the sensor, especially the low-frequency response, are accurately described by the transfer function.

[0046] (5) After obtaining the transfer function, the inverse transfer function is further calculated. The measured waveform output by the sensor is compensated based on the inverse transfer function to achieve sensor time domain waveform reconstruction. The inverse transfer function compensates for the frequency response characteristics of the sensor, and the output signal of the sensor is processed through the inverse transfer function to restore the true waveform of the input signal.

[0047] For the integrated optical waveguide electric field sensor, the measured pulse electric field waveform and the measured waveform before and after reconstruction are as follows: Figure 4 As shown, it can be clearly known that the reconstructed measurement waveform is closer to the measured pulse electric field waveform, which verifies the effectiveness of the above-mentioned integrated optical waveguide electric field sensor time domain waveform reconstruction method.

[0048] In the embodiment of the present application, the transfer function and inverse transfer function of the sensor are determined based on the step response signal of the measurement sensor, and the inverse transfer function is used to compensate for the frequency response characteristics of the sensor, and the time domain waveform of the original electric field is restored, thereby realizing reconstruction of the sensor time domain waveform, solving the technical problem of waveform distortion existing in the integrated optical waveguide electric field sensor, and achieving the technical effect of reducing the waveform distortion of the integrated optical waveguide electric field sensor.

[0049] Example 2 An integrated optical waveguide electric field sensor time domain waveform reconstruction system, such as Figure 5 As shown, the system includes: A signal measuring unit 502, configured to measure a step response signal of the sensor when a step voltage signal is applied to both ends of the uniform electric field generator, wherein the sensor is located at the center of the uniform electric field generator; A processing unit 504, configured to preprocess the acquired step response signal, and estimate a transfer function of the sensor based on the preprocessed step response signal; The compensation reconstruction unit 506 is used to calculate the inverse transfer function according to the transfer function, and reconstruct the output signal of the sensor using the inverse transfer function to achieve sensor time domain waveform reconstruction.

[0050] Optionally, before the signal measuring unit 502 applies the step voltage signal to both ends of the uniform electric field generator, it further includes: generating the step voltage signal by using a square wave voltage source; and measuring the step voltage signal by using a high-speed digital oscilloscope.

[0051] Optionally, the signal measuring unit 502 measures the step response signal of the sensor, including: measuring the step response signal of the sensor multiple times; and taking an average value of the multiple measurements as a measurement result of the step response signal.

[0052] Optionally, the processing unit 504 pre-processes the acquired step response signal, including: performing differential transformation, data smoothing and cross-correlation processing on the acquired step response signal.

[0053] Optionally, the processing unit 504 estimates the transfer function of the sensor based on the preprocessed step response signal, including: estimating the transfer function of the sensor using a least square method based on the preprocessed step response signal.

[0054] Optionally, the compensation reconstruction unit 506 calculates the inverse transfer function according to the transfer function, including: performing an inverse operation on the transfer function to obtain the inverse transfer function.

[0055] Optionally, the compensation reconstruction unit 506 reconstructs the output signal of the sensor using an inverse transfer function, including: performing frequency response compensation on the output signal of the sensor using an inverse transfer function.

[0056] In the present invention, a step response signal of a sensor is measured when a step voltage signal is applied to both ends of a uniform electric field generator, wherein the sensor is located at the center of the uniform electric field generator; the acquired step response signal is preprocessed, and a transfer function of the sensor is estimated based on the preprocessed step response signal; an inverse transfer function is calculated according to the transfer function, and the output signal of the sensor is reconstructed using the inverse transfer function to achieve reconstruction of the sensor's time domain waveform, thereby determining the transfer function and the inverse transfer function of the sensor based on the measured step response signal of the sensor, compensating the frequency response characteristics of the sensor using the inverse transfer function, restoring the time domain waveform of the original electric field, and achieving reconstruction of the sensor's time domain waveform, solving the technical problem of waveform distortion of an integrated optical waveguide electric field sensor, and achieving the technical effect of reducing waveform distortion of the integrated optical waveguide electric field sensor.

[0057] Example 3 Another aspect of the embodiments of the present invention further provides an electronic device for implementing the above-mentioned integrated optical waveguide electric field sensor time domain waveform reconstruction method, and the electronic device is not limited to being a terminal device or a server in the system. The electronic device is not limited to including a memory and a processor, the memory stores a computer program, and the processor is configured to execute the steps in any of the above-mentioned method embodiments through the computer program.

[0058] Example 4 Another aspect of the embodiments of the present invention provides a computer program product or a computer program, which includes computer instructions stored in a computer-readable storage medium. The processor of the computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the method provided in various optional embodiments of the above-mentioned integrated optical waveguide electric field sensor time domain waveform reconstruction method. The computer program is configured to execute the steps of any of the above-mentioned method embodiments when running.

Claims

1. A method for processing an integrated optical waveguide electric field sensor, characterized in that: include: When a step voltage signal is applied to both ends of a uniform electric field generator, measuring a step response signal of a sensor, wherein the sensor is located at the center of the uniform electric field generator; Preprocessing the acquired step response signal, and estimating the transfer function of the sensor based on the preprocessed step response signal; The inverse transfer function is calculated according to the transfer function, and the output signal of the sensor is reconstructed using the inverse transfer function to achieve sensor time domain waveform reconstruction.

2. The integrated optical waveguide electric field sensor processing method according to claim 1, characterized in that: Before applying a step voltage signal to both ends of the uniform electric field generator, the method further includes: A step voltage signal is generated by using a square wave voltage source; The step voltage signal is measured using a high-speed digital oscilloscope to determine whether the step voltage signal reaches a preset parameter.

3. The integrated optical waveguide electric field sensor processing method according to claim 1, characterized in that: Measure the sensor's step response signal, including: Measure the step response signal of the sensor multiple times; The average value of multiple measurements is taken as the measurement result of the step response signal.

4. The integrated optical waveguide electric field sensor processing method according to claim 1, characterized in that: The acquired step response signal is preprocessed, including: The acquired step response signal is subjected to differential transformation, data smoothing and cross-correlation processing.

5. The integrated optical waveguide electric field sensor processing method according to claim 1, characterized in that: Estimate the transfer function of the sensor based on the preprocessed step response signal, including: Based on the preprocessed step response signal, the transfer function of the sensor is estimated using the least squares method.

6. The integrated optical waveguide electric field sensor processing method according to claim 1, characterized in that: The output signal of the sensor is reconstructed using the inverse transfer function, including: The inverse transfer function is used to reconstruct the frequency response of the sensor's output signal to restore the true waveform of its input signal. The parameters of the restored pulse waveform are obtained by calculation.

7. The integrated optical waveguide electric field sensor processing method according to claim 1, characterized in that: Also includes: A standard electric field test platform is established, which includes: a voltage source, a uniform electric field generator, and a data acquisition system, wherein the uniform electric field generator is composed of two metal plates, the diameter of the metal plates is 10 times the distance between the plates, and the sensor is placed at the center of the two metal plates.

8. The integrated optical waveguide electric field sensor processing method according to claim 7, characterized in that: Also includes: The output of the voltage source is changed to generate electric fields of different frequencies in the uniform electric field generator, and the amplitude-frequency characteristics and phase-frequency characteristics at different frequencies are recorded by a data acquisition system.

9. The integrated optical waveguide electric field sensor processing method according to claim 8, characterized in that: Also includes: The amplitude-frequency characteristic and the phase-frequency characteristic of the sensor are compensated to obtain an amplitude-frequency compensation curve and a phase-frequency compensation curve.

10. An integrated optical waveguide electric field sensor processing system, characterized in that: include: A signal measuring unit, used to measure a step response signal of a sensor when a step voltage signal is applied to both ends of a uniform electric field generator, wherein the sensor is located at the center of the uniform electric field generator; a processing unit, configured to preprocess the acquired step response signal and estimate a transfer function of the sensor based on the preprocessed step response signal; The compensation reconstruction unit is used to calculate the inverse transfer function according to the transfer function, and reconstruct the output signal of the sensor using the inverse transfer function to achieve sensor time domain waveform reconstruction.

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