Method for ac zero-crossing compensation of stress-induced birefringence in optical voltage sensors

Abstract

The present application relates to a kind of optical voltage sensor stress line birefringence AC zero-crossing compensation method, the optical voltage sensor includes laser, polarizer, electro-optic crystal, beam expander, crystal wedge and detection polarizer in turn arranged in same optical path, the method includes the following steps: utilize laser to emit optical signal, in turn through polarizer, electro-optic crystal, beam expander, crystal wedge and detection polarizer, under the action of voltage to be measured, output signal is superimposed with the additional phase delay generated by electro-optic phase delay and stress line birefringence, form the displacement of strip light spot of translation;Phase delay superposition amount is measured by the displacement amount of strip light spot positioning by image sensor;The AC zero-crossing point of voltage to be measured is detected, and the phase delay superposition amount measured at zero-crossing point time is regarded as the additional phase delay generated by stress line birefringence;The additional phase delay generated by stress line birefringence is compensated to the output signal of optical voltage sensor by acquisition.

Description

TECHNICAL FIELD

[0001] The application relates to an alternating current zero compensation method for stress line birefringence of an optical voltage sensor and belongs to the technical field of correction of optical voltage sensors. BACKGROUND

[0002] Voltage transformers play a role in transmission, transformation and isolation in power grids. Traditional electromagnetic voltage transformers have gradually exposed their limitations, such as electromagnetic resonance, poor insulation performance, lack of digital interface and the like, and cannot meet the rapid development requirements of power grids. Optical voltage sensors have the advantages of passivity, good insulation performance, wide response frequency band and strong anti-interference capability, effectively overcome the shortcomings of electromagnetic voltage transformers, and have good application prospects.

[0003] The measurement principle of an existing optical voltage sensor is based on a Pockels effect and a polarized light interference measurement mode. Under the modulation of a to-be-measured electric field, linearly polarized light produces an electro-optic phase delay after passing through an electro-optic crystal. It is generally believed that the prior art cannot directly measure the phase delay, and the outgoing light intensity is obtained by means of polarized light interference. The to-be-measured voltage is obtained by nonlinear demodulation of the outgoing light intensity. Influenced by temperature drift and vibration, stress line birefringence is easily generated in the electro-optic crystal and the transmission optical fiber, and is superimposed with the electro-optic phase delay. The polarized light interference measurement mode is difficult to separate the stress line birefringence, thereby affecting the stability and reliability of long-term operation of the optical voltage sensor. SUMMARY

[0004] In order to solve the problems existing in the prior art, the application provides an alternating current zero compensation method for stress line birefringence of an optical voltage sensor.

[0005] The technical scheme of the application is as follows:

[0006] On one hand, the application provides an alternating current zero compensation method for stress line birefringence of an optical voltage sensor. The optical voltage sensor comprises a laser, a polarizer, an electro-optic crystal, a beam expander, a crystal wedge and a polarimeter which are sequentially arranged in the same optical path. The method comprises the following steps:

[0007] The laser emits an optical signal which sequentially passes through the polarizer, the electro-optic crystal, the beam expander, the crystal wedge and the polarimeter. Under the action of a to-be-measured voltage, an output signal is superimposed with an electro-optic phase delay and an additional phase delay generated by stress line birefringence, and a translated bar-shaped light spot is formed.

[0008] The displacement amount of the bar-shaped light spot is positioned by an image sensor to measure the superimposition amount of the phase delay.

[0009] The alternating current zero point of the to-be-measured voltage is detected, and the measured phase delay superimposition amount is obtained as the additional phase delay generated by the stress line birefringence at the zero point.

[0010] The additional phase delay generated by the stress birefringence is used to compensate the output signal of the optical voltage sensor.

[0011] As a preferred embodiment, the method for measuring the phase delay superposition amount by locating the displacement amount of the bar-shaped light spot by the image sensor specifically includes:

[0012] locating the initial position of the dark fringe center of the bar-shaped light spot by the image sensor;

[0013] locating the current position of the dark fringe center of the bar-shaped light spot by the image sensor when measuring the to-be-measured voltage, and calculating the light spot displacement amount Δx by the current position and the initial position;

[0014] obtaining the value of the phase delay superposition amount based on the relationship between the light spot displacement amount Δx and the phase delay superposition amount.

[0015] In another aspect, the application also provides an AC zero-crossing compensation system for stress birefringence of an optical voltage sensor, the optical voltage sensor including a laser, a polarizer, an electro-optic crystal, a beam expander, a crystal wedge and a polarimeter arranged in sequence in the same optical path, the system including:

[0016] a starting module for emitting an optical signal by the laser, and sequentially passing through the polarizer, the electro-optic crystal, the beam expander, the crystal wedge and the polarimeter, under the action of a to-be-measured voltage, the output signal superposing an electro-optic phase delay and an additional phase delay generated by stress birefringence, forming a bar-shaped light spot that is translated;

[0017] a measuring module for measuring the phase delay superposition amount by locating the displacement amount of the bar-shaped light spot by the image sensor;

[0018] an AC zero-crossing point detection module for detecting the AC zero-crossing point of the to-be-measured voltage;

[0019] a stress birefringence determination module for obtaining the measured phase delay superposition amount as the additional phase delay generated by stress birefringence at the zero-crossing point;

[0020] a compensation module for compensating the output signal of the optical voltage sensor by the additional phase delay generated by the stress birefringence.

[0021] As a preferred embodiment, the measuring module specifically includes:

[0022] an initial position measuring unit for locating the initial position of the dark fringe center of the bar-shaped light spot by the image sensor;

[0023] A light spot displacement calculation unit calculates a light spot displacement amount Δx by locating a current position of the center of the dark stripe of the bar light spot through the image sensor and calculating the light spot displacement amount Δx through the current position and the initial position when measuring the voltage to be measured;

[0024] A phase delay superposition amount calculation unit obtains a value of the phase delay superposition amount through the relationship between the light spot displacement amount Δx and the phase delay superposition amount.

[0025] In still another aspect, the present application further provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the AC zero-crossing compensation method for stress optic birefringence of an optical voltage sensor as described in any of the embodiments of the present application when executing the program.

[0026] In still another aspect, the present application further provides a computer readable storage medium having a computer program stored thereon, wherein the program is executable on a processor to implement the AC zero-crossing compensation method for stress optic birefringence of an optical voltage sensor as described in any of the embodiments of the present application.

[0027] The present application has the following beneficial effects:

[0028] The present application is an AC zero-crossing compensation method for stress optic birefringence of an optical voltage sensor, which directly converts an electro-optic phase delay angle into a linear translation of a light spot image based on the crystal wedge interference principle, realizes direct linear measurement of a phase delay superposition amount by detecting a displacement amount of a bar light spot, determines a zero-crossing point of a voltage to be measured by using a zero-crossing detection circuit, detects and compensates the stress optic birefringence at this moment, and achieves the purpose of eliminating the stress optic birefringence. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 A method flowchart of the embodiment one of the present application;

[0030] Figure 2 A principle diagram of the AC zero-crossing compensation for stress optic birefringence of the embodiment of the present application;

[0031] Figure 3 An experimental diagram of an output light spot of an optical voltage sensor realized based on a crystal wedge interference in the embodiment of the present application;

[0032] Figure 4 A principle diagram of an AC zero-crossing detection circuit in the embodiment of the present application.

[0033] In the drawings, the reference signs are as follows:

[0034] 1, laser; 2, polarizer; 3, electro-optic crystal; 4, beam expander; 5, crystal wedge; 6, analyzer; 7, bar light spot; 8, AC zero-crossing detection circuit; 9, first bar light spot; 10, second bar light spot. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be apparently and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without any creative effort belong to the protection scope of the present application.

[0036] It should be understood that the step numbers used herein are only for the convenience of description, and are not limited to the execution sequence of the steps.

[0037] It should be understood that the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification and the appended claims of the present application, the singular forms "a", "an" and "the" are intended to include the plural forms, unless the context clearly indicates otherwise.

[0038] The terms "comprise" and "include" indicate the presence of described features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0039] The term "and / or" means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0040] Embodiment one:

[0041] Referring to Figure 1 and Figure 2 , an AC zero-crossing compensation method for stress linear birefringence of an optical voltage sensor, the optical voltage sensor comprising a laser 1, a polarizer 2, an electro-optic crystal 3, a beam expander 4, a crystal wedge 5 and an analyzer 6 arranged in sequence in the same optical path, the method comprising the following steps:

[0042] S100, a light signal is emitted by the laser 1, and the light signal emitted by the laser 1 becomes linearly polarized light after passing through the polarizer 2. Under the electric field of the voltage to be measured, the electro-optic crystal 3 becomes a biaxial crystal, and the linearly polarized light entering the crystal is decomposed into two linearly polarized lights o and e with orthogonal polarization directions along the induced axis direction and generates an electro-optic phase delay. Temperature drift and vibration produce stress linear birefringence in the electro-optic crystal and the transmission optical fiber, and linearly superimpose on the electro-optic phase delay. The o light and the e light are amplified by the beam expander 4, and after being incident to the crystal wedge 5 and the analyzer 6, an interference image of bright and dark stripes, i.e. a strip-shaped light spot 7, is formed, and the strip-shaped light spot 7 linearly translates with the change of the superimposed amount of the phase delay.

[0043] S200, measure the phase delay superposition amount by locating the displacement amount of the bar-shaped light spot through the image sensor;

[0044] In an embodiment, the method of measuring the phase delay superposition amount by locating the displacement amount of the bar-shaped light spot through the image sensor is specifically:

[0045] S201, locate the initial position of the dark fringe center of the bar-shaped light spot through the image sensor;

[0046] S202, locate the current position of the dark fringe center of the bar-shaped light spot through the image sensor when measuring the to-be-measured voltage, and calculate the light spot displacement amount Δx through the current position and the initial position;

[0047] S203, obtain the value of the phase delay superposition amount based on the relationship between the light spot displacement amount Δx and the phase delay superposition amount.

[0048] S300, according to the Pockels effect, when the to-be-measured alternating voltage is zero, the electro-optical phase delay is also zero, at this time the output signal of the optical voltage sensor is the additional phase delay caused by the stress linear birefringence, therefore, in this embodiment, the alternating zero-crossing point of the to-be-measured voltage is detected through the alternating zero-crossing detection circuit 8, when there is no stress linear birefringence introduced, the first bar-shaped light spot 9 is generated when the electro-optical phase delay is 0° at the zero-crossing point, after the stress linear birefringence is introduced, the second bar-shaped light spot 10 is generated at the zero-crossing point, the light spot displacement amount Δx is obtained by locating the second bar-shaped light spot 10 and the first bar-shaped light spot 9, and the phase delay superposition amount is obtained as the additional phase delay caused by the stress linear birefringence.

[0049] In an embodiment, the principle of the alternating zero-crossing detection circuit 8 adopted is as shown in Figure 4 , in which U2A and U2B are two comparators of LM339, V i is the input signal, V o is the output signal, V2 and V3 are the upper limit value and the lower limit value of the reference voltage of the comparator respectively; 7408N is an integrated double-input four AND gate circuit. Its working principle is: in a period, when V i >V2, V o is low; when V3 i <V2, V o is high; when V i <V3, V o is low. Therefore, by adjusting the values of V2 and V3, the zero-crossing point detection of the alternating voltage can be realized.

[0050] S400, compensate the output signal of the optical voltage sensor by the additional phase delay caused by the stress linear birefringence obtained.

[0051] Based on the above embodiment, the method has the characteristics that the optical voltage sensor is based on linear measurement mode, and the stress linear birefringence can be extracted and compensated when the alternating voltage is zero. The optical voltage sensor converts the electro-optic phase delay angle into linear translation of the spot image based on the crystal wedge interference principle, and realizes the direct and linear measurement of the electro-optic phase delay by detecting the displacement of the spot. The temperature drift and vibration produce stress linear birefringence in the electro-optic crystal and transmission optical fiber, and the additional phase delay introduced has a harmful extinction effect on the electro-optic phase delay. Based on the above linear measurement mode, the output of the optical voltage sensor is the linear superposition of the electro-optic phase delay and the stress linear birefringence. When the alternating voltage to be measured is zero, the electric field is zero, and the electro-optic phase delay is also zero. At this time, the output signal of the optical voltage sensor is the stress linear birefringence. Then, the zero-crossing detection circuit is used to determine the zero-crossing point of the alternating voltage to be measured, and the stress linear birefringence can be detected and compensated at this moment, so as to realize the purpose of eliminating the stress linear birefringence.

[0052] The implementation principle of the embodiment is as follows:

[0053] As shown in Figure 2 , the fast and slow axis directions of the crystal wedge are defined as the x and y axes of the entire optical path, and the laser direction is the z axis. The laser 1 emits an optical signal to be incident on the polarizer 2 to obtain linearly polarized light, and the angles between the linearly polarized light and the x and y axes are both 45°, which is represented by the Jones matrix E1 as follows:

[0054]

[0055] Wherein A represents the input light intensity.

[0056] The linearly polarized light passes through the electro-optic crystal 3, and under the electric field modulation of the voltage to be measured, the linearly polarized light is decomposed into two orthogonal linearly polarized lights: o light and e light. Because the refractive indexes of the two polarization directions are different, the o light and the e light produce an electro-optic phase delay δ after propagating a certain distance in the crystal, and the transmission matrix J1 can be represented as:

[0057]

[0058] Affected by the temperature drift and vibration, stress linear birefringence is produced in the electro-optic crystal and the transmission optical fiber, and the additional phase delay introduced is θ. At this time, J1 can be rewritten as:

[0059]

[0060] After the spot size is enlarged by the beam expander 4, it is incident on the surface of the crystal wedge 5. The additional phase delay produced by the crystal wedge 5 is

[0061]

[0062] Wherein

[0063]

[0064] where x λ is the full wave path of the exit light spot, x is the distance between the linearly polarized light incident point and the split tip.

[0065] After passing through the crystal split 5, o light and e light are again through the optical axis direction and parallel to the polarizer 2 polarizer 6, forming a coherent light, the Jones matrix of the polarizer 6 is:

[0066]

[0067] The light vector E2 emitted by the polarizer 6 is:

[0068]

[0069] The exit light intensity distribution is:

[0070]

[0071] Based on the Matlab simulation output light intensity as shown in the attached Figure 3 , with the change of , the light spot fringe occurs linear translation. Therefore, by positioning the displacement of the light spot, the direct and linear measurement of can be realized.

[0072] where satisfies:

[0073]

[0074] Therefore, the measurement result of the optical voltage sensor is the linear superposition of δ and According to the Pockels electro-optic effect, the measured voltage U and satisfy:

[0075] δ = πU / U π (9)

[0076] where U π is the half-wave voltage of the crystal. Therefore, when U = 0, δ = 0, and when the alternating voltage is zero, the output signal of the optical voltage sensor is At this moment, the can be detected and compensated.

[0077] ​In the embodiment, the laser 1 is a Distributed Bragg Reflector (DBR) with a wavelength of 980 nm; the electro-optic crystal used is an LN crystal with a half-wave voltage of 743 V; the crystal wedge used has a wedge angle of 2° and a full-wave path of 3.118 mm; the polarizer and the analyzer used are Glan-Taylor prisms; the image sensor used is an MV-1300UM area array CCD camera; the zero-crossing detection circuit is as shown in FIG. 2. Figure 4 ;

[0078] In order to verify the effectiveness of the method proposed in the embodiment, a high-low temperature alternating damp heat test box is used to provide different temperature environments, and the temperature range is -40℃ to 85℃, and the temperature fluctuation is ±0.5℃. In the example, the optical path of the optical voltage sensor is placed in the inner tank of the temperature box, and the temperature cycle experiment is carried out in the range of -40℃ to 85℃. The zero-crossing detection circuit is used to detect the zero-crossing point, and the stress line birefringence introduced in each cycle is determined and compensated. Finally, the basic accuracy of the optical voltage sensor is recorded by the calibration instrument, as shown in Table 1. The optical voltage sensor can meet the 0.5-level accuracy requirement under the temperature cycle condition.

[0079] Table 1 Basic accuracy experimental data

[0080]

[0081] Embodiment two:

[0082] The application also provides an alternating current zero-crossing compensation system for stress line birefringence of an optical voltage sensor, the optical voltage sensor comprising a laser, a polarizer, an electro-optic crystal, a beam expander, a crystal wedge and an analyzer arranged in sequence on the same optical path, and the system comprising:

[0083] A starting module is configured to emit an optical signal by using the laser, and the optical signal sequentially passes through the polarizer, the electro-optic crystal, the beam expander, the crystal wedge and the analyzer, and under the action of the voltage to be measured, the output signal is superimposed with an additional phase delay caused by the electro-optic phase delay and the stress line birefringence, and a translated strip-shaped light spot is formed. The module is used to realize the function of step S100 in embodiment one, and will not be described here.

[0084] A measurement module is configured to measure the phase delay superposition amount by positioning the displacement amount of the strip-shaped light spot by using the image sensor. The module is used to realize the function of step S200 in embodiment one, and will not be described here.

[0085] An alternating current zero-crossing point detection module is configured to detect the alternating current zero-crossing point of the voltage to be measured.

[0086] The stress line birefringence determination module is configured to obtain the measured phase delay superposition amount as an additional phase delay caused by the stress line birefringence at the zero-crossing moment; the AC zero-crossing detection module and the stress line birefringence determination module jointly realize the function of step S300 in Embodiment One, and thus no further description is provided herein.

[0087] The compensation module is configured to compensate the output signal of the optical voltage sensor by the additional phase delay caused by the stress line birefringence; the compensation module is configured to realize the function of step S400 in Embodiment One, and thus no further description is provided herein.

[0088] As a preferred embodiment of the present embodiment, the measurement module specifically comprises:

[0089] The initial position measurement unit is configured to locate the initial position of the dark fringe center of the bar-shaped light spot by the image sensor;

[0090] The light spot displacement calculation unit is configured to locate the current position of the dark fringe center of the bar-shaped light spot by the image sensor when measuring the to-be-measured voltage, and to calculate the light spot displacement amount Δx by the current position and the initial position;

[0091] The phase delay superposition amount calculation unit is configured to obtain the value of the phase delay superposition amount by the relationship between the light spot displacement amount Δx and the phase delay superposition amount.

[0092] Embodiment Three:

[0093] The present embodiment provides an electronic device, which comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor realizes the AC zero-crossing compensation method for stress line birefringence of an optical voltage sensor according to any one of the embodiments of the present application when executing the program.

[0094] Embodiment Four:

[0095] The present embodiment provides a computer readable storage medium, which stores a computer program, and the program is executable on a processor to realize the AC zero-crossing compensation method for stress line birefringence of an optical voltage sensor according to any one of the embodiments of the present application.

[0096] In the embodiments of the present application, "at least one" means one or more, and "multiple" means two or more. The "and / or" describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent the cases of A alone, A and B together, and B alone. Wherein A and B can be singular or plural. The character " / " generally represents an "or" relationship between the front and rear associated objects. "At least one of the following" and the like means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b and c can represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0097] Those of ordinary skill in the art can realize that the units and algorithm steps described in the embodiments disclosed herein can be realized in electronic hardware, computer software, and a combination of electronic hardware and computer software. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0098] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be described here.

[0099] In several embodiments provided in the present application, any function realized in the form of a software function unit and sold or used as an independent product can be stored in a computer-readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the parts that make contributions to the prior art or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (Read-Only Memory; hereinafter referred to as: ROM), a random access memory (Random Access Memory; hereinafter referred to as: RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0100] The above only describes the embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation based on the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An AC zero-crossing compensation method for stress-birefringence in an optical voltage sensor, characterized in that, The optical voltage sensor comprises a laser, a polarizer, an electro-optic crystal, a beam expander, a crystal wedge and a polarimeter arranged in sequence in the same optical path, and the method comprises the following steps: The laser emits an optical signal which passes through the polarizer, the electro-optic crystal, the beam expander, the crystal wedge and the polarimeter in sequence, and under the action of the voltage to be measured, the output signal is superimposed with an additional phase delay caused by electro-optic phase delay and stress-induced birefringence, forming a translated bar-shaped light spot; The displacement of the bar-shaped light spot is located by the image sensor to measure the phase delay superposition amount; The AC zero-crossing point of the voltage to be measured is detected, and the measured phase delay superposition amount is obtained at the zero-crossing point as the additional phase delay caused by stress-induced birefringence; The output signal of the optical voltage sensor is compensated by the obtained additional phase delay caused by stress-induced birefringence; The method for measuring the phase delay superposition amount by locating the displacement of the bar-shaped light spot by the image sensor is specifically: The initial position of the dark stripe center of the bar-shaped light spot is located by the image sensor; In measuring the voltage to be measured, the current position of the center of the dark stripe of the bar-shaped light spot is located by the image sensor, and the displacement amount Δ of the light spot is calculated from the current position and the initial position x ; Based on the spot displacement amount Δ x The value of the phase delay superposition amount is acquired in relation to the phase delay superposition amount.

2. An AC zero-crossing compensation system for stress-induced birefringence in an optical voltage sensor, characterized by, The optical voltage sensor comprises a laser, a polarizer, an electro-optic crystal, a beam expander, a crystal wedge and a polarimeter arranged in sequence in the same optical path, and the system comprises: A starting module for emitting an optical signal by the laser, which passes through the polarizer, the electro-optic crystal, the beam expander, the crystal wedge and the polarimeter in sequence, and under the action of the voltage to be measured, the output signal is superimposed with an additional phase delay caused by electro-optic phase delay and stress-induced birefringence, forming a translated bar-shaped light spot; A measurement module for measuring the phase delay superposition amount by locating the displacement of the bar-shaped light spot by the image sensor; An AC zero-crossing point detection module for detecting the AC zero-crossing point of the voltage to be measured; A stress-induced birefringence determination module for obtaining the measured phase delay superposition amount at the zero-crossing point as the additional phase delay caused by stress-induced birefringence; A compensation module for compensating the output signal of the optical voltage sensor by the obtained additional phase delay caused by stress-induced birefringence; The measurement module specifically comprises: An initial position measurement unit for locating the initial position of the dark stripe center of the bar-shaped light spot by the image sensor; A light spot displacement calculation unit calculates the light spot displacement amount Δ by locating the current position of the center of the dark stripe of the bar-shaped light spot by the image sensor and by the current position and the initial position when measuring the voltage to be measured x ; a phase delay superposition amount calculation unit configured to calculate a phase delay superposition amount Δφ by a spot displacement amount Δx x acquire a value of the phase delay superposition amount in relation to the phase delay superposition amount.

3. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the program to realize the AC zero-crossing compensation method for stress-induced birefringence of the optical voltage sensor according to claim 1.

4. A computer-readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to realize the AC zero-crossing compensation method for stress-induced birefringence of the optical voltage sensor according to claim 1.

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