Methods and systems for collaboratively improving key performance aspects of dynamic measurement of fiber optic current transformers

Abstract

This invention discloses a method and system for synergistically improving the key performance of dynamic measurement of fiber optic current transformers, including: constructing a first mathematical model of forward channel gain and step response rise time; constructing a second mathematical model of forward channel gain and overshoot; constructing a third mathematical model of common noise and signal-to-noise ratio of the fiber optic current transformer system; based on the first and second mathematical models, with forward channel gain as the independent variable and minimizing overshoot and step response as the objectives, performing dual-objective optimization to determine the optimal forward channel gain, thereby minimizing the dynamic measurement performance (overshoot and step time) of the system; using the forward channel gain value obtained from the optimization as a constraint, improving the third mathematical model with the objective of maximizing it; and guiding the design of fiber optic current transformers based on the optimization results, which can effectively ensure that the fiber optic current transformer has good dynamic measurement performance while having a high signal-to-noise ratio, thus improving the measurement performance of the fiber optic current transformer.

Description

Technical Field

[0001] This invention belongs to the field of fiber optic current transformer technology, specifically relating to a method and system for synergistically improving the key performance of dynamic measurement of fiber optic current transformers. Background Technology

[0002] With the development of power systems towards higher voltage and larger capacity, line relay protection and transformer protection systems based on differential measurement of instantaneous current values ​​place high demands on the dynamic range, frequency response, and signal-to-noise ratio of all-fiber optic current transformers. Traditional electromagnetic current transformers suffer from limitations such as small dynamic range and waveform distortion, leading to serious consequences such as protection maloperation or failure to operate. All-fiber optic current transformers offer advantages such as no magnetic saturation, strong anti-electromagnetic interference capability, no risk of secondary open circuit, simple insulation structure, and no measurement frequency band limitations, enabling them to accurately reflect the dynamic changes of grid current. The measurement method of all-fiber optic current transformers (FOCTs) is non-contact. The inherent insulation characteristics of the sensing fiber ring greatly improve the overall safety of the equipment. Furthermore, since the transformer does not contain electromagnetic induction elements, the transmission of optical signals is not affected by magnetic field interference, providing strong anti-magnetic interference capability and ensuring the measurement accuracy of the transformer even in harsh environments. All-fiber current transformers typically employ closed-loop signal detection technology, which has a large dynamic range and can simultaneously meet the needs of power metering and relay protection. When performing current measurement, the optical fiber is flexibly looped and laid on the object being measured. The optical fiber loop can cover all current channels to ensure accurate measurement. Installation is convenient and reduces the complexity of manual installation.

[0003] However, FOCTs face noise and system oscillation issues in practical applications, primarily due to the influence of numerous factors such as temperature, humidity, electromagnetic interference, optoelectronic device aging, mechanical deformation, and various parasitic effects. Noise affects FOCT performance, consequently impacting measurement accuracy. High signal-to-noise ratio and fast response capability of FOCT data output are crucial for our work. Therefore, we have developed a method and system for synergistically improving key performance aspects of dynamic measurement of all-fiber current transformers. This method significantly enhances the signal-to-noise ratio and step response time of FOCTs, contributing to the advancement of FOCT applications in current sensing. Summary of the Invention

[0004] This invention addresses the problems existing in the prior art by providing a method and system for synergistically improving the key performance of dynamic measurement of fiber optic current transformers. It can solve the technical problem of ensuring high signal-to-noise ratio and fast response capability of the measurement system due to the influence of many factors such as temperature, humidity, electromagnetic interference, aging of optoelectronic devices, mechanical deformation and various parasitic effects on the performance of FOCT.

[0005] To address the above technical problems, this invention provides the following technical solution: a method for synergistically improving key performance aspects of dynamic measurement in all-fiber current transformers, comprising the following steps:

[0006] S1. Obtain the forward channel gain parameters and step response rise time parameters of the fiber optic current transformer, and construct the first mathematical model with the forward channel gain as input and the corresponding step response rise time as output.

[0007] S2. Obtain the forward channel gain parameters and overshoot parameters of the fiber optic current transformer, and construct a second mathematical model with the forward channel gain as input and the corresponding overshoot as output.

[0008] S3. Construct a third mathematical model in the fiber optic current sensing system with common noise as input and corresponding signal-to-noise ratio as output;

[0009] S4. Based on the first mathematical model and the second mathematical model, the MOPSO optimization algorithm is used to construct an objective function with the forward channel gain as the independent variable and the overshoot and step response as the objectives. The two objectives are then optimized to obtain the optimal forward channel gain.

[0010] S5. Based on the forward channel gain value of the optimization independent variable in step S4 as a constraint, and combined with the adjustable range of system parameters, PSO optimization is performed with the goal of maximizing the third mathematical model to determine the system design parameters, so as to achieve a high signal-to-noise ratio while maintaining fast step response and low system overshoot in the all-fiber current transformer system.

[0011] Furthermore, in the aforementioned step S1, by changing the detector's received optical power and detector impedance parameters, the value of the forward channel gain is changed, the value of the step response rise time is recorded, and a first mathematical model is constructed using data polynomial fitting with the forward channel gain as input and the corresponding step response rise time as output.

[0012] Furthermore, in step S2 above, by changing the received optical power of the light source and the detector impedance-related parameters, and recording the corresponding forward channel gain and overshoot values, a polynomial of the forward channel gain and overshoot values ​​is fitted, and a second mathematical model is constructed based on the polynomial.

[0013] Furthermore, in step S3 mentioned above, the third mathematical model is as follows:

[0014] ,

[0015] In the formula, SNR is the system signal-to-noise ratio, R is the detector transimpedance, and R D Let P0 be the detector responsivity and P0 be the received optical power of the detector. Here, N is the phase-biased operating point, and V is the number of turns. Dark current, k is the spectral width. B Here, is Boltzmann's constant, T is absolute temperature, e is the charge of the electron, and c is the speed of light. For Faraday phase shift, The current to be measured is... For time, In order to transcend time, The average wavelength of the light source The standard deviation of shot noise, The standard deviation of thermal noise voltage, This represents the standard deviation of the relative intensity noise received by the detector.

[0016] Furthermore, the expression for the aforementioned first mathematical model is:

[0017] ,

[0018] In the formula, y1 is the rise time of the step response, and x is the forward channel gain. This represents the average value of the forward channel gain. A3, A2, A1, and A0 are constants, representing the standard deviation of the forward channel gain.

[0019] Furthermore, the expression for the aforementioned second mathematical model is:

[0020] ,

[0021] In the formula, y2 is the overshoot, and x is the forward channel gain. This represents the average value of the forward channel gain. B3, B2, B1, and B0 are constants, representing the standard deviation of the forward channel gain.

[0022] Furthermore, in step S4 above, in the MOPSO optimization algorithm, the fitness function consists of several objective functions, as shown in the following equation:

[0023] ,

[0024] In the formula, x is the magnitude of the forward channel gain of the decision variable, and y1 and y2 are the objective functions.

[0025] Furthermore, in step S5 above, to achieve the goal of optimizing the system signal-to-noise ratio, the PSO algorithm's constraints are determined using the signal-to-noise ratio as the objective function and the forward channel gain value. First, the position and velocity of each particle are randomly initialized, and each particle's initial position is taken as its individual optimal position. Then, the performance of each particle is evaluated using the objective function, and its objective function value is recorded. In each iteration, the particle's velocity and position are updated according to the following formula:

[0026] ,

[0027] In the formula, v i and x i Let i represent the velocity and position of particle i, respectively. p represents an independent random number, with values ​​uniformly distributed in the range [0, 1]. best,i It is the optimal position for particle i, g best It is the global optimal position. To ensure that the position of the particle is within the effective range, constraints are applied to each dimension.

[0028] In another aspect, the present invention provides an electronic device comprising: at least one processor, and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the method described in any one of the present invention.

[0029] The invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in any one of the invention.

[0030] Compared with the prior art, the beneficial technical effects of the present invention using the above technical solution are as follows:

[0031] This invention explores the mapping relationship between step response rise time and forward channel gain, and overshoot and forward channel gain, constructing a first mathematical model and a second mathematical model. The optimal forward channel gain value can be obtained through the MOPSO optimization algorithm. The signal-to-noise ratio (SNR) of the all-fiber current transformer is studied, and the influence of system parameters on the SNR of the all-fiber current transformer is quantitatively analyzed through mathematical derivation. This facilitates the subsequent development of optimization algorithms targeting the maximum SNR. In this way, the system design parameters can be determined, achieving high SNR and fast response in the all-fiber current transformer. Attached Figure Description

[0032] Figure 1 This is a flowchart of a method for collaboratively improving the key performance of dynamic measurement of fiber optic current transformers according to an embodiment of the present invention.

[0033] Figure 2 This is a structural block diagram of a system for collaboratively improving the key performance of dynamic measurement of fiber optic current transformers according to an embodiment of the present invention.

[0034] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0035] To better understand the technical content of the present invention, specific embodiments are described below in conjunction with the accompanying drawings.

[0036] In this invention, various aspects of the invention are described with reference to the accompanying drawings, in which numerous illustrative embodiments are shown. Embodiments of the invention are not limited to those depicted in the drawings. It should be understood that the invention is implemented through any of the various concepts and embodiments described above, as well as the concepts and embodiments described in detail below, because the concepts and embodiments disclosed herein are not limited to any particular implementation. Furthermore, some aspects of the invention disclosed may be used alone or in any suitable combination with other aspects of the invention disclosed.

[0037] like Figure 1 As shown, this paper illustrates the flowchart of a method for synergistically improving key performance aspects of dynamic measurement in all-fiber current transformers, with the specific steps as follows:

[0038] S1. Obtain the forward channel gain parameters and step response rise time parameters of the fiber optic current transformer, and construct a first mathematical model with the forward channel gain as input and the corresponding step response rise time as output. In this embodiment, by changing the received optical power and detector impedance parameters, the value of the forward channel gain is changed, and the value of the step response rise time is recorded. A first mathematical model with the forward channel gain as input and the corresponding step response rise time as output is constructed using data polynomial fitting, as shown in the following equation:

[0039] ,

[0040] In the formula, y1 is the rise time of the step response, and x is the forward channel gain. This represents the average value of the forward channel gain. A3, A2, A1, and A0 are constants, representing the standard deviation of the forward channel gain.

[0041] S2. Obtain the forward channel gain parameters and overshoot parameters of the fiber optic current transformer, and construct a second mathematical model with the forward channel gain as input and the corresponding overshoot as output. In this embodiment, by changing the received optical power of the light source and the detector impedance-related parameters, and recording the corresponding forward channel gain and overshoot values, a polynomial of the forward channel gain and overshoot magnitude is fitted, and the second mathematical model is constructed based on the polynomial, as follows:

[0042] ,

[0043] In the formula, y2 is the overshoot, and x is the forward channel gain. This represents the average value of the forward channel gain. B3, B2, B1, and B0 are constants, representing the standard deviation of the forward channel gain.

[0044] S3. Construct a third mathematical model for the fiber optic current sensing system, with common noise as input and corresponding signal-to-noise ratio as output, as shown in the following equation:

[0045] ,

[0046] In the formula, SNR is the system signal-to-noise ratio, R is the detector transimpedance, and R D Let P0 be the detector responsivity and P0 be the received optical power of the detector. Here, N is the phase-biased operating point, and V is the number of turns. Dark current, k is the spectral width. B Here, is Boltzmann's constant, T is the absolute temperature, e is the electron charge, and c is the speed of light; For Faraday phase shift, The current to be measured is... For time, In order to transcend time, The average wavelength of the light source The standard deviation of shot noise, The standard deviation of thermal noise voltage, This represents the standard deviation of the relative intensity noise received by the detector. Based on the principle that the signal-to-noise ratio (SNR) is the square of the ratio of sensitivity to noise per unit bandwidth, an SNR correlation model is established. The adjustability of the SNR model and system parameters provides possibilities for optimal SNR design.

[0047] S4. Based on the first and second mathematical models, using the MOPSO optimization algorithm, with the forward channel gain as the independent variable and the minimum of the overshoot and step response as the objectives, an objective function is constructed, and the optimization of these two objectives is carried out to obtain the optimal forward channel gain. Through the MOPSO optimization algorithm, the optimization of the first and second mathematical models is achieved, determining the value of the forward channel gain and providing constraints for the subsequent optimization of the third mathematical model. The fitness function consists of several objective functions, as shown in the following equation:

[0048] ,

[0049] In the formula, x is the magnitude of the forward channel gain of the decision variable, and y1 and y2 are the objective functions.

[0050] S5. Based on the forward channel gain value of the optimization independent variable in step S4 as a constraint, and combined with the adjustable range of system parameters, PSO optimization is performed with the goal of maximizing the third mathematical model to determine the system design parameters. This enables the all-fiber current transformer system to maintain a fast step response, low system overshoot, and high signal-to-noise ratio.

[0051] To achieve the optimal system signal-to-noise ratio (SNR), the PSO algorithm is constrained using the SNR as the objective function and the forward channel gain value. First, the position and velocity of each particle are randomly initialized, and each particle's initial position is taken as its individual best position (pbest). Then, the performance of each particle is evaluated using the objective function, and its value is recorded. In each iteration, the particle's velocity and position are updated according to the following formula:

[0052] ,

[0053] In the formula, v i and xi Let p represent the velocity and position of particle i, respectively. best,i It is the optimal position for particle i, g best It is the global optimal position. To ensure that the position of the particle is within the effective range, constraints are applied to each dimension.

[0054] In summary, the method of this application explores the mapping relationship between step response rise time and forward channel gain, and overshoot and forward channel gain, constructs a first mathematical model and a second mathematical model, and obtains the optimal forward channel gain value through the MOPSO optimization algorithm. It studies the signal-to-noise ratio (SNR) of the all-fiber current transformer and quantitatively analyzes the influence of system parameters on the SNR of the all-fiber current transformer through mathematical derivation. This facilitates the subsequent development of optimization algorithms with the maximum SNR as the objective. In this way, the system design parameters can be determined to achieve high SNR and fast response of the all-fiber current transformer.

[0055] Please see Figure 2 The diagram shows a structural block diagram of a system for collaboratively improving the key performance of dynamic measurement of all-fiber current transformers according to this application.

[0056] like Figure 2 As shown, the system 200 for the collaborative improvement of key performance of dynamic measurement of all-fiber current transformers includes a first construction module 210, a second construction module 220, and a determination module 230.

[0057] The first construction module 210 is configured to construct a first mathematical model relating the step response time to the forward channel gain.

[0058] The second construction module 220 is configured to construct a second mathematical model of the overshoot magnitude and the forward channel gain magnitude, and to perform MOPSO optimization algorithm optimization based on the first mathematical model and the second mathematical model.

[0059] Module 230 is configured to determine the optimal forward channel gain value.

[0060] like Figure 3 As shown in the schematic diagram of the structure of the electronic device provided in the embodiment of the present invention, the electronic device includes: at least one processor 310, and a memory 320, an input device 330, and an output device 340 communicatively connected to the at least one processor. The input device 330 receives instructions and stores them in the memory 320. The instructions are executed by the at least one processor 310 to enable the at least one processor 310 to execute the method described in any one of the embodiments of the present invention, and output through the output device 340.

[0061] While the present invention has been described above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A method for synergistically improving the key performance of dynamic measurement of an all-fiber current transformer, characterized in that, The method comprises the following steps: S1, acquiring the forward channel gain parameter and the step response rise time parameter of the optical fiber current transformer, and constructing a first mathematical model with the forward channel gain as input and the corresponding step response rise time as output; specifically, by changing the received light power of the detector, the detector impedance parameter, the value of the forward channel gain is changed, and the value of the step response rise time is recorded, and a first mathematical model with the forward channel gain as input and the corresponding step response rise time as output is constructed by using data polynomial fitting; S2, acquiring the forward channel gain parameter and the overshoot parameter of the optical fiber current transformer, and constructing a second mathematical model with the forward channel gain as input and the corresponding overshoot as output; specifically, by changing the received light power of the light source, the detector impedance related parameter, and recording the corresponding value of the forward channel gain and the value of the overshoot, fitting the polynomial of the forward channel gain and the overshoot, and constructing the second mathematical model according to the fitted polynomial; S3, constructing a third mathematical model with common noise in the optical fiber current sensing system as input and corresponding signal-to-noise ratio as output; S4, according to the first mathematical model and the second mathematical model, using MOPSO optimization algorithm, taking the forward channel gain as the independent variable, and taking the minimum of the two parameters of overshoot and step response as the target, constructing a target function, and carrying out optimization of the two targets to obtain the optimal forward channel gain; S5, according to the optimization of the independent variable forward channel gain value in step S4, combining the adjustable range of the system parameters, and taking the maximum of the third mathematical model as the target, the PSO optimization is carried out to determine the design parameters of the system, so that the all-optical fiber current transformer system can maintain fast step response, low system overshoot and high signal-to-noise ratio at the same time.

2. The method for synergistically improving the dynamic measurement key performance of an all-fiber current transformer according to claim 1, characterized in that, In step S3, the third mathematical model is as follows: ， where SNR is the system signal-to-noise ratio, R is the detector transimpedance, R D is the detector responsivity, P0 is the received optical power of the detector, is the phase bias operating point, N is the number of turns, V is the is the dark current, is the spectral width, k B is the Boltzmann constant, T is the absolute temperature, e is the electron charge, c is the speed of light, is the Faraday phase shift, is the current to be measured, is time, is the transit time, is the average wavelength of the light source, is the standard deviation of the shot noise, is the standard deviation of the thermal noise voltage, is the standard deviation of the relative intensity noise received by the detector.

3. The method for synergistically improving the dynamic measurement key performance of an all-fiber current transformer according to claim 2, characterized in that, The expression of the first mathematical model is: ， In the formula, y1 is the size of the step response rise time, x is the size of the forward channel gain, is the size of the average value of the forward channel gain, is the size of the standard deviation of the forward channel gain, A3, A2, A1 and A0 are constants.

4. The method for synergistically improving the dynamic measurement key performance of an all-fiber current transformer according to claim 3, characterized in that, The expression of the second mathematical model is: ， where y2 is the overshoot, x is the magnitude of the forward path gain, is the average magnitude of the forward path gain, is the standard deviation of the forward path gain, and B3, B2, B1 and B0 are constants.

5. The method for synergistically improving the dynamic measurement key performance of an all-fiber current transformer according to claim 1, characterized in that, In step S4, in the MOPSO optimization algorithm, the fitness function is composed of several objective functions, and the objective function is as follows: , In the formula, x is the size of the decision variable forward channel gain, y1 and y2 are objective functions.

6. The method for synergistically improving the dynamic measurement key performance of an all-fiber current transformer according to claim 1, characterized in that, In step S5, the target of realizing the optimal signal-to-noise ratio of the system is to take the signal-to-noise ratio as the objective function, and to take the forward channel gain value as the constraint condition of the PSO algorithm. First, the position and speed of each particle are randomly initialized, and the initial position of each particle is taken as its personal best position. Then, the performance of each particle is evaluated by the objective function, and the objective function value is recorded. In each iteration, the speed and position of the particle are updated according to the following formula: ， where v i and x i denote the velocity and position of particle i, respectively, denote an independent random number uniformly distributed in the range [0, 1], p best,i is the personal best position of particle i, g best is the global best position. To ensure that the position of the particle is within the effective range, a constraint processing is performed for each dimension.

7. An electronic device, comprising: It comprises: At least one processor, and a memory connected in communication with the at least one processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method of any one of claims 1 to 6.

8. A computer-readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to implement the method of any one of claims 1 to 6.

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