Method and device for determining current based on optical current transformer

Abstract

The invention provides a method and a device for determining current based on an optical current transformer, the optical current transformer is used for sensing real-time current of a target device, the real-time current is alternating current, the optical current transformer corresponds to a light source, the light source is used for providing incident light, and the incident light is incident light. The method comprises the following steps: acquiring the input light intensity of incident light; acquiring real-time output light intensity corresponding to emergent light of the optical current transformer according to a sampling period; determining a real-time angle of a target rotation angle of the optical current transformer according to the input light intensity and the real-time output light intensity; monitoring whether the target rotation angle exceeds a monotonous interval of a sine function according to the real-time angle; determining a final rotation angle according to the monitoring result and the real-time angle of the target rotation angle; and determining the real-time current of the target equipment according to the final rotation angle.

Description

Technical Field

[0001] The present invention relates to the field of transformers, and particularly to a method and device for determining current based on an optical current transformer. Background Art

[0002] For a magneto-optical optical current transformer (OCT), its working principle mainly uses the Faraday magneto-optical effect to calculate the primary-side current. That is, in a magneto-optical material, an externally applied magnetic field can cause the linear polarization plane propagating in the medium along the magnetic field direction to deflect accordingly. The deflected angle is the total rotation angle α. The deflection angle of the incident light is related to the intensity of the magnetic field (through the magnitude of the current) and the length of the interaction between light and the magnetic field in the transparent material and the properties of the material. Usually, the total rotation angle α can be expressed as α = B·V·d, where B is the magnetic induction intensity and is proportional to the magnitude of the current flowing through the target device, V is the Verdet constant related to the material and wavelength of the optical current transformer, and d is the path that the light beam passes through in the optical glass ring of the optical current transformer.

[0003] Generally, the transmission axis of the polarizer is set at a 45° angle to the transmission axis of the analyzer. Then the rotation angle α = θ + 45°, where θ = B·V·d, that is, θ is the deflection angle brought by the magnetic field generated by the current of the target device. According to Malus' law, the relationship between the input and output light intensities is where γ is the light transmission coefficient in the optical glass used in the optical current transformer, E i is the input light intensity, and E o is the output light intensity. Usually, the range of the total rotation angle α is in [0°, 90°]. At this time, by measuring the input light intensity and the output light intensity, the corresponding Faraday rotation angle can be accurately calculated, and then the magnitude of the primary current can be restored.

[0004] Limited by the optical material and the structural parameters of the transformer, when the peak value of the current flowing through the primary-side conductor is greater than a certain critical value, for the rotation angle of the primary-side current, the range will exceed the monotonic interval [-90°, 90°] of the sine function. At this time, the rotation angle that satisfies the relationship between the input light intensity and the output light intensity is no longer unique, resulting in the inability to correctly obtain the primary current by the original calculation method. Therefore, the measurement current range of the optical current transformer is generally small. Summary of the Invention

[0005] In view of this, the present invention proposes a method for determining current based on an optical current transformer. The optical current transformer is used to sense the real-time current of a target device, and the real-time current is an alternating current. The optical current transformer corresponds to a light source, and the light source is used to provide incident light. The method includes:

[0006] Obtain the input optical intensity of the incident light;

[0007] Obtain the real-time output optical intensity corresponding to the outgoing light of the optical current transformer according to a sampling period;

[0008] Determine the real-time angle of a target rotation angle of the optical current transformer based on the input optical intensity and the real-time output optical intensity;

[0009] Monitor whether the target rotation angle exceeds the monotonic interval of the sine function according to the real-time angle;

[0010] Determine a final rotation angle based on the monitoring result and the real-time angle of the target rotation angle;

[0011] Determine the real-time current of the target device according to the final rotation angle.

[0012] According to the method described above, optionally, determining a final rotation angle based on the monitoring result and the real-time angle of the target rotation angle includes:

[0013] If the monitoring result is that the target rotation angle exceeds the monotonic interval of the sine function and the target rotation angle corresponds to the positive half cycle of the current waveform, then use the real-time angle of the complementary angle of the target rotation angle as the final rotation angle; and / or

[0014] If the monitoring result is that the target rotation angle exceeds the monotonic interval of the sine function and the target rotation angle corresponds to the negative half cycle of the current waveform, then use the difference between -π and the real-time angle of the target rotation angle as the final rotation angle.

[0015] According to the method described above, optionally, before monitoring whether the target rotation angle exceeds the monotonic interval of the sine function according to the real-time angle, it further includes:

[0016] Judge whether the product of the current real-time angle and the previous real-time angle of the target rotation angle is less than or equal to 0 and whether the previous real-time angle is less than 0;

[0017] If the judgment results are all yes, trigger the operation of monitoring whether the target rotation angle exceeds the monotonic interval of the sine function according to the real-time angle.

[0018] According to the method described above, optionally, monitoring whether the target rotation angle exceeds the monotonic interval of the sine function according to the real-time angle includes: if it is determined that the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle is in a monotonically increasing state or is in a monotonically increasing state and then in a monotonically decreasing state, the monitoring result is yes;

[0019] Determining a final rotation angle based on the monitoring result and the real-time angle of the target rotation angle includes: using the real-time angle of the complementary angle of the target rotation angle as the final rotation angle.

[0020] According to the method described above, optionally, after determining that the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle is in a monotonically increasing state and then in a monotonically decreasing state, it further includes: if it is determined that the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle are again in a monotonically increasing state, the monitoring result is no;

[0021] Determining a final rotation angle based on the monitoring result and the real-time angle of the target rotation angle includes: using the real-time angle of the target rotation angle as the final rotation angle.

[0022] According to the method described above, optionally, after determining that the target rotation angle returns to the monotonic interval of the sine function, it further includes: if it is determined that the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle are in a monotonically decreasing state or in a monotonically decreasing state and then in a monotonically increasing state, the monitoring result is yes;

[0023] Determining a final rotation angle based on the monitoring result and the real-time angle of the target rotation angle includes: using the difference between -π and the real-time angle of the target rotation angle as the final rotation angle.

[0024] According to the method described above, optionally, after the monitoring result changes from no to yes and before determining a final rotation angle based on the monitoring result and the real-time angle of the target rotation angle, it further includes determining at least one of the following conditions:

[0025] Condition 1: Determine whether the absolute value of the difference between the real-time angle of the target rotation angle and the maximum rotation angle in the same direction is less than or equal to a preset threshold, where the maximum rotation angle is Or

[0026] Condition 2: Determine whether the time difference between the moment when the change trend of the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the corresponding complementary angle reverses and the moment of the peak value in the same direction of the sine wave of the real-time current exceeds a preset time threshold;

[0027] If the judgment result is yes, it is determined that the monitoring result is correct.

[0028] According to the method described above, optionally, determining the real-time angle of a target rotation angle of the optical current transformer based on the input light intensity and the real-time output light intensity includes: Among them, E o is the real-time output light intensity corresponding to the outgoing light, and E i is the input light intensity corresponding to the incident light, is the target rotation angle; or

[0029] The real-time current of the target device is determined according to the following formula:

[0030]

[0031] Among them, i(t) represents the real-time current at time t, R represents the distance between the conductor of the target device and the optical glass, represents the final rotation angle, μ represents the magnetic permeability, V represents the Verdet constant, and d represents the path that the light beam passes through in the optical glass ring.

[0032] The present invention also provides a device for determining current based on an optical current transformer. The optical current transformer is used to sense the real-time current of a target device, and the real-time current is an alternating current. The optical current transformer corresponds to a light source, and the light source is used to provide incident light. The device includes:

[0033] A first acquisition unit for acquiring the input light intensity of the incident light;

[0034] A second acquisition unit for acquiring the real-time output light intensity corresponding to the outgoing light of the optical current transformer according to a sampling period;

[0035] A first determination unit for determining the real-time angle of a target rotation angle of the optical current transformer according to the input light intensity and the real-time output light intensity;

[0036] A monitoring unit for monitoring whether the target rotation angle exceeds the monotonic interval of the sine function according to the real-time angle;

[0037] A second determination unit for determining a final rotation angle according to the monitoring result and the real-time angle of the target rotation angle;

[0038] A third determination unit for determining the real-time current of the target device according to the final rotation angle.

[0039] According to the device described above, optionally, it further includes:

[0040] A first judgment unit for judging whether the product of the current real-time angle and the previous real-time angle of the target rotation angle is less than or equal to 0 and whether the previous real-time angle is less than 0. If the judgment results are both yes, the monitoring unit is triggered.

[0041] According to the device described above, optionally, the monitoring unit is specifically configured to: if it is determined that the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle is in a monotonically increasing state or is in a monotonically increasing state and then in a monotonically decreasing state, the monitoring result is yes;

[0042] The second determination unit is specifically configured to: use the real-time angle of the complementary angle of the target rotation angle as the final rotation angle.

[0043] According to the device described above, optionally, the monitoring unit is further specifically configured to: after it is determined that the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle is in a monotonically increasing state and then in a monotonically decreasing state, if it is determined that the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle are again in a monotonically increasing state, the monitoring result is no;

[0044] The second determination unit is further specifically configured to: use the real-time angle of the target rotation angle as the final rotation angle.

[0045] According to the optical current transformer described above, optionally, the monitoring unit is further specifically configured to, after it is determined that the target rotation angle returns to the monotonic interval of the sine function, if it is determined that the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle are in a monotonically decreasing state or are in a monotonically decreasing state and then in a monotonically increasing state, the monitoring result is yes;

[0046] The second determination unit is further specifically configured to: use the difference between -π and the real-time angle of the target rotation angle as the final rotation angle.

[0047] According to the device described above, optionally, it further includes a second judgment unit, configured to, after the monitoring result changes from no to yes and before determining a final rotation angle according to the monitoring result and the real-time angle of the target rotation angle, judge at least one of the following conditions:

[0048] Condition 1: Judge whether the absolute value of the difference between the real-time angle of the target rotation angle and the maximum rotation angle in the same direction is less than or equal to a preset threshold, where the maximum rotation angle is Or

[0049] Condition 2: Judge whether the time difference between the moment when the change trend of the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the corresponding complementary angle is reversed and the moment of the same-direction peak value of the sine wave of the real-time current exceeds a preset time threshold;

[0050] If the judgment result is yes, it is determined that the monitoring result is correct.

[0051] The present invention further provides a device for determining current based on an optical current transformer, including:

[0052] At least one memory for storing instructions;

[0053] At least one processor for executing the method for determining current based on an optical current transformer according to any one of the foregoing based on the instructions stored in the memory.

[0054] The present invention further provides a readable storage medium, in which machine-readable instructions are stored. When the machine-readable instructions are executed by a machine, the machine executes the method for determining current based on an optical current transformer according to any one of the foregoing.

[0055] As can be seen from the above solution, the present invention first monitors whether the target rotation angle exceeds the monotonic interval of the sine function, then determines a final rotation angle according to the monitoring result and the real-time angle of the target rotation angle, and finally can obtain a relatively accurate current of the target device according to the final rotation angle. This method can avoid improving the hardware of the optical current transformer, reduce the manufacturing difficulty, reduce the production cost, and can effectively expand the measurement range of the current of the optical current transformer. Description of the Drawings

[0056] The following will make the above and other features and advantages of the present invention clearer to those of ordinary skill in the art by describing the preferred embodiments of the present invention in detail with reference to the drawings, in which:

[0057] Figure 1A It is a schematic flowchart of a method for determining current based on an optical current transformer according to an embodiment of the present invention.

[0058] Figure 1B An exemplary diagram of an optical current transformer.

[0059] Figure 2 It is a schematic flowchart of a method for determining current based on an optical current transformer according to another embodiment of the present invention.

[0060] Figure 3 It is a schematic structural diagram of a device for determining current based on an optical current transformer according to an embodiment of the present invention.

[0061] Figure 4 It is a schematic structural diagram of a device for determining current based on an optical current transformer according to another embodiment of the present invention. Detailed Embodiments

[0062] To make the objectives, technical solutions and advantages of the present invention clearer, the following embodiments are given to further elaborate on the present invention in detail. In this patent application, nouns and pronouns related to people are not limited to specific genders.

[0063] In order to expand the current measurement range of an optical current transformer, the present invention adopts the following method to determine how to correctly restore the primary-side current when the rotation angle exceeds the monotonic interval of the sine function. The primary-side current can be understood as the current of a target device, and the target device is a primary-side device.

[0064] As Figure 1B shown, for a magneto-optic glass type optical current transformer, the incident light 13 emitted by the LED becomes linearly polarized light after passing through the polarizer 14. After this light beam travels around the primary conductor 11 in the optical glass 12 once, based on the Faraday magneto-optic effect, its polarization plane rotates, and the rotation angle is proportional to the line integral of the magnetic field strength along the path of the polarized light passing through the optical glass.

[0065] Based on this, the inventor thought of determining the real-time current value of the device based on the rotation angle of the polarization plane.

[0066] Embodiment 1

[0067] This embodiment provides a method for determining current based on an optical current transformer. The optical current transformer is specifically a magneto-optic type optical current transformer, which is used to sense the real-time current of a target device. The real-time current is an alternating current, and the current waveform is a sine wave. The execution subject of this method is a device for determining current based on an optical current transformer. This device can be integrated into a relay protection device, and the relay protection device can determine current based on the optical current transformer and perform corresponding relay protection operations. The optical current transformer corresponds to a light source, and the light source can provide incident light.

[0068] As shown in Figure 1, it is a method for determining current based on an optical current transformer according to this embodiment. The method for determining current based on an optical current transformer includes:

[0069] Step 100, obtain the input light intensity of the incident light.

[0070] A light source can emit light. The light that enters the optical current transformer is the incident light, and the light that exits the optical current transformer is the outgoing light. After the incident light enters the current transformer, due to the action of the magnetic field generated by the current, such as the action of the magnetic field generated by the primary-side current, the polarization plane deflects, that is, the incident light deflects by a certain angle and then becomes the outgoing light.

[0071] For the incident light, its input light intensity is constant, so it only needs to be obtained once. This obtaining method can be informed by the manufacturer in advance, or it can be approximately obtained indirectly through the sampling value of the outgoing light and software filtering, which will not be elaborated here.

[0072] Step 101: Obtain the real-time output optical intensity corresponding to the outgoing light of the optical current transformer according to a sampling period.

[0073] The sampling period here can be set according to actual needs. For example, sample once every 1 microsecond.

[0074] The real-time output optical intensity corresponding to the outgoing light can be measured by existing technologies, such as the photoelectric effect method, the interference method, the scattering method, etc. This optical intensity can be directly obtained by the device for determining current based on the optical current transformer, or can be indirectly obtained, and no specific limitation is made.

[0075] It should be noted that there is no sequence between Step 101 and Step 100. They can be executed successively or simultaneously. For the convenience of description in this embodiment, Step 100 and Step 101 are used as examples for illustration.

[0076] Step 102: Determine the real-time angle of a target rotation angle of the optical current transformer according to the input optical intensity and the real-time output optical intensity.

[0077] According to the real-time output optical intensity corresponding to the outgoing light and the input optical intensity corresponding to the incident light, a trigonometric function value can be obtained, for example, a sine trigonometric function value. As an exemplary illustration, where E o is the real-time output optical intensity corresponding to the outgoing light, E i is the input optical intensity corresponding to the incident light, is the target rotation angle. In this way,

[0078] Step 103: Monitor whether the target rotation angle exceeds the monotonic interval of the sine function according to the real-time angle.

[0079] Since the output optical intensity is continuously sampled, the real-time angle of the target rotation angle can be continuously obtained.

[0080] For each real-time angle of the target rotation angle, there is a corresponding real-time angle of a complementary angle. As an exemplary illustration, it can be monitored whether the target rotation angle exceeds the monotonic interval of the sine function, that is, [-π / 2, π / 2], by monitoring the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the corresponding complementary angle. For example, start monitoring the change of the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the corresponding complementary angle from the zero crossing point. For example, when the current waveform after the zero crossing point is a sine waveform, judge whether the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle begins to be in the monotonically increasing state of the sine function. If the judgment result is yes, the monitoring result is that the target rotation angle exceeds the monotonic interval of the sine function.

[0081] Specifically, other methods can also be used to determine whether the target rotation angle exceeds the monotonic interval of the sine function, which will not be elaborated here.

[0082] Step 104: Determine a final rotation angle based on the monitoring result and the real-time angle of the target rotation angle.

[0083] The monitoring result here is the monitoring result generated in step 103, and different monitoring results can correspond to different final rotation angles.

[0084] As an exemplary illustration, the final rotation angle can be determined according to whether the real-time current corresponding to the target rotation angle is in the positive half-cycle or the negative half-cycle of the current waveform. For example, if the monitoring result is that the target rotation angle exceeds the monotonic interval of the sine function and the real-time current corresponding to the target rotation angle is in the positive half-cycle of the current waveform, then the real-time angle of the complementary angle of the target rotation angle is used as the final rotation angle, and / or if the monitoring result is that the target rotation angle exceeds the monotonic interval of the sine function and the real-time current corresponding to the target rotation angle is in the negative half-cycle of the current waveform, then the difference between -π and the real-time angle of the target rotation angle is used as the final rotation angle. Here, π is 180 degrees.

[0085] The final rotation angle of this step can reflect the true angle of the rotation angle.

[0086] Step 105: Determine the real-time current of the target device according to the final rotation angle.

[0087] As an exemplary illustration, the real-time current of the target device can be determined according to the following formula:

[0088]

[0089] where i(t) represents the real-time current at time t, R represents the distance between the conductor of the target device and the optical glass, represents the final rotation angle, μ represents the magnetic permeability, V represents the Verdet constant, and d represents the path that the light beam passes through in the optical glass ring. Here, the conductor of the target device is the current carrier, for example, a wire, and a primary-side current flows through it. As Figure 1B shown, the cross-section of the conductor 11 of the target device is circular, R is the distance between the center of the conductor 11 and the optical glass 12, and the optical glass 12 is annular. The incident light 13 enters the optical glass 12 through the polarizer 14 and passes through an annular path in the optical glass 12, and then forms the outgoing light 16 through the analyzer 15.

[0090] In this way, the true real-time current can be obtained according to the final rotation angle.

[0091] According to this embodiment, first, monitor whether the target rotation angle exceeds the monotonic interval of the sine function. Then, based on the monitoring result and the real-time angle of the target rotation angle, determine a final rotation angle. Finally, based on this final rotation angle, a relatively accurate current of the target device can be obtained. This method can avoid improving the hardware of the optical current transformer, reduce the manufacturing difficulty, reduce the production cost, and can effectively expand the measurement range of the current of the optical current transformer.

[0092] Embodiment 2

[0093] This embodiment further supplements and explains the method for determining the current based on the optical current transformer in Embodiment 1.

[0094] As Figure 2 shown, it is a schematic flowchart of the method for determining the current based on the optical current transformer according to this embodiment. The method for determining the current based on the optical current transformer includes:

[0095] Step 201, obtain the input light intensity of the incident light.

[0096] A light source can emit light. The light that enters the optical current transformer is the incident light, and the light that exits from the optical current transformer is the outgoing light. After the incident light enters the current transformer, due to the action of the magnetic field generated by the current, such as the magnetic field generated by the primary side current, the polarization plane deflects, that is, the incident light deflects by a certain angle and then becomes the outgoing light.

[0097] For the incident light, its input light intensity is constant, so it only needs to be obtained once. This obtaining method can be informed by the manufacturer in advance, or can be approximately obtained indirectly through the sampling value of the outgoing light and software filtering, which will not be elaborated here.

[0098] Step 202, obtain the real-time output light intensity corresponding to the outgoing light of the optical current transformer according to a sampling period.

[0099] According to the real-time output light intensity corresponding to the outgoing light and the input light intensity corresponding to the incident light, a trigonometric function value can be obtained, such as a sine trigonometric function value. As an exemplary illustration, where E o is the real-time output light intensity corresponding to the outgoing light, E i is the input light intensity corresponding to the incident light, is the target rotation angle. In this way,

[0100] a real-time output light intensity corresponding to the outgoing light is obtained in each sampling period.

[0101] Step 202 has no sequence with step 201 and can be executed successively or simultaneously. For the convenience of description in this embodiment, step 202 and step 201 are taken as examples for illustration.

[0102] Step 203: Determine whether the product of the current real-time angle and the previous real-time angle of the target rotation angle is less than or equal to 0 and whether the previous real-time angle is less than 0. If the judgment result is yes, then execute step 204.

[0103] This step 203 is used to trigger subsequent operations. If the previous real-time angle is less than 0 and the product of the current real-time angle and the previous real-time angle is less than or equal to 0, it means that the real-time angle of the target rotation angle changes from a negative value to 0 or a positive value for the first time, indicating that the current waveform of the corresponding current just passes through zero. Therefore, step 203 is equivalent to a trigger condition.

[0104] Step 204: Monitor whether the target rotation angle exceeds the monotonic interval of the sine function according to the real-time angle, and execute step 205.

[0105] This step specifically includes the following states:

[0106] State 0: The absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle is in a monotonically decreasing state, and the target rotation angle is within the monotonic interval of the sine function;

[0107] State 1: The absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle begins to be in a monotonically increasing state, and the target rotation angle exceeds the monotonic interval of the sine function;

[0108] State 2: The absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle is in a monotonically decreasing state, and the target rotation angle still exceeds the monotonic interval of the sine function;

[0109] State 3: If the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle is in a monotonically increasing state again, then the target rotation angle returns to the monotonic interval of the sine function;

[0110] State 4: The absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle is in a monotonically decreasing state, and the target rotation angle exceeds the monotonic interval of the sine function again;

[0111] State 5: The absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle is in a monotonically increasing state, then the target rotation angle still exceeds the monotonic interval of the sine function;

[0112] Next, if it is determined that the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle is in a state of decreasing monotonically again, that is, it returns to state 0.

[0113] The above several states are sorted in sequence, from state 0 to state 5 and then back to state 0.

[0114] When the target rotation angle is within the monotonic interval of the sine function, the monitoring result is no; when the target rotation angle exceeds the monotonic interval of the sine function, the monitoring result is yes.

[0115] Step 205, determine a final rotation angle according to the monitoring result and the real-time angle of the target rotation angle.

[0116] As an exemplary illustration, it is as follows:

[0117] State 0: The final rotation angle is the real-time angle of the target rotation angle.

[0118] State 1: The final rotation angle is the real-time angle of the complementary angle of the target rotation angle.

[0119] State 2: The final rotation angle is the real-time angle of the complementary angle of the target rotation angle.

[0120] State 3: The final rotation angle is the real-time angle of the target rotation angle.

[0121] State 4: The final rotation angle is -π minus the real-time angle of the target rotation angle.

[0122] State 5: The final rotation angle is -π minus the real-time angle of the target rotation angle.

[0123] It can be seen that different states correspond to different monitoring results, and different monitoring results correspond to different real-time angles.

[0124] Step 206, determine the real-time current of the target device according to the final rotation angle.

[0125] Specifically, the real-time current of the target device can be determined according to the following formula:

[0126]

[0127] Among them, i(t) represents the real-time current at time t, R represents the distance between the primary conductor and the optical glass, represents the final rotation angle, μ represents the magnetic permeability, V represents the Verdet constant, and d represents the path that the light beam passes through in the optical glass ring.

[0128] Optionally, after the monitoring result in step 204 changes from no to yes and before step 205, it further includes judging at least one of the following conditions:

[0129] Condition 1: Determine whether the absolute value of the difference between the target rotation angle and the maximum rotation angle in the same direction is less than or equal to a preset threshold, where the maximum rotation angle is Or

[0130] Condition 2: Determine whether the time difference between the moment when the change trend of the absolute value of the difference between the target rotation angle and the corresponding complementary angle reverses and the moment of the peak value in the same direction of the sine wave of the real-time current exceeds a preset time threshold;

[0131] If the judgment result is yes, then execute step 205. Here, the same direction means either both in the positive half-cycle or both in the negative half-cycle.

[0132] Both Condition 1 and Condition 2 here are for further verification of the monitoring result being yes, that is, for further verification of whether it has truly exceeded the monotonic interval of the sine function.

[0133] For Condition 1, it is used to judge the absolute value range of the difference between the real-time angle of the target rotation angle and the adjacent maximum rotation angle. If the real-time angle of the target rotation angle corresponds to the positive half-cycle of the sine waveform of the real-time current, then judge whether the absolute value of the difference between the target rotation angle and is less than or equal to the preset threshold. If the real-time angle of the target rotation angle corresponds to the negative half-cycle of the sine waveform of the real-time current, then judge whether the absolute value of the difference between the real-time angle of the target rotation angle and is less than or equal to the preset threshold. If the difference between the absolute value and the preset threshold is too large, it means that there is still some time for the current real-time angle of the target rotation angle to reach the maximum rotation angle, and at this time, it is impossible to exceed the monotonic interval of the sine function. Therefore, it can be determined that the previous monitoring result is incorrect.

[0134] For Condition 2, it is used to judge whether the position where the change trend of the absolute value of the difference between the real-time angle of the calculated target rotation angle and the real-time angle of the complementary angle has an inflection point is at the midpoint position of the positive half-cycle or the negative half-cycle to distinguish the situation where the rotation angle is at the critical value of the monotonic interval. If the judgment result is yes, it can further indicate that the previous monitoring result is correct; otherwise, it indicates that the monitoring result is incorrect, and at this time, the monotonic interval of the sine function has not been exceeded.

[0135] Therefore, after the monitoring result of step 204 in this embodiment changes from no to yes, it can be combined with Condition 1, or combined with Condition 2, or combined with both Condition 1 and Condition 2, which can be specifically selected according to actual needs, so as to further confirm whether it has truly exceeded the monotonic interval of the sine function.

[0136] For the method of determining current based on an optical current transformer according to this embodiment, it is possible to determine whether it exceeds the monotonic interval of the sine function by the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of its complementary angle. The method is simple and convenient, and the calculation amount is small.

[0137] Embodiment III

[0138] This embodiment gives a specific example of the method for determining current based on an optical current transformer in the signed embodiment.

[0139] In this embodiment, the real-time output light intensity of the outgoing light of the corresponding optical current transformer of the target device is sampled according to a preset period.

[0140] For each sampling value, the corresponding target rotation angle is obtained according to the following formula where E o is the real-time output light intensity corresponding to the outgoing light, and E i is the input light intensity corresponding to the incident light.

[0141] Based on the sampling value of the current real-time output light intensity, the real-time angle of the target rotation angle is obtained. It is judged whether the product of its real-time angle and the previous real-time angle is less than or equal to 0 and whether the previous real-time angle is less than 0. If the judgment result is yes, enter state 0, record the current sampling value as the first sampling value, the current real-time angle of the target rotation angle as the first real-time angle, and obtain the absolute value of the first difference between the first real-time angle and its complementary angle. The current first final rotation angle is the first real-time angle. At this time, the real-time current of the target device determined based on the first final rotation angle is In this formula, t is the sampling time corresponding to the first sampling value, and the final rotation angle is the first real-time angle.

[0142] Next, obtain the second real-time angle, and obtain the absolute value of the second difference between the second real-time angle and its complementary angle. It is recognized that the absolute value of the second difference is less than the absolute value of the first difference. At this time, the second final rotation angle is the second real-time angle. The real-time current of the target device determined based on the second final rotation angle is In this formula, t is the sampling time corresponding to the second sampling value, and the final rotation angle is the second real-time angle.

[0143] Next, obtain the 3rd real-time angle, and obtain the absolute value of the 3rd difference between the 3rd real-time angle and its complementary angle. It is recognized that the absolute value of the 3rd difference is less than the absolute value of the 2nd difference. At this time, the 3rd final rotation angle is the 3rd real-time angle. The real-time current of the target device determined based on the 3rd final rotation angle is In this formula, t is the sampling time corresponding to the 3rd sampling value, and the final rotation angle is the 3rd real-time angle.

[0144] And so on, until it is recognized that the absolute value of the pth difference is greater than the absolute value of the (p - 1)th difference, and the absolute value of the difference between the pth real-time angle and the maximum rotation angle in the positive direction is less than the preset threshold value and the time difference between the sampling moment of the pth difference and the sampling moment of the peak value of the positive half-cycle of the sine wave of the real-time current exceeds the preset time threshold value, then enter state 1. At this time, it is monitored that the target rotation angle exceeds the monotonic interval of the sine function. Of course, in the actual process, it can be monitored that when the absolute values of 3, 4, or more differences are all greater than the absolute value of the previous difference, then it is determined that the monitoring result is that the target rotation angle is in the monotonically increasing state, which can be specifically selected according to actual needs. At this time, the pth final rotation angle is (180° - the pth real-time angle). The real-time current of the target device determined based on the pth final rotation angle is In this formula, t is the sampling time corresponding to the pth sampling value, and the final rotation angle is (180° - the pth real-time angle).

[0145] Next, obtain the (p + 1)th real-time angle, and obtain the absolute value of the (p + 1)th difference between the (p + 1)th real-time angle and its complementary angle. It is recognized that the absolute value of the (p + 1)th difference is greater than the absolute value of the pth difference. At this time, the (p + 1)th final rotation angle is the complementary angle of the (p + 1)th real-time angle. The real-time current of the target device determined based on the (p + 1)th final rotation angle is In this formula, t is the sampling time corresponding to the (p + 1)th sampling value, and the final rotation angle is (180° - the (p + 1)th real-time angle).

[0146] Next, obtain the (p + 2)th real-time angle, and obtain the absolute value of the (p + 2)th difference between the (p + 2)th real-time angle and its complementary angle. It is recognized that the absolute value of the (p + 2)th difference is greater than the absolute value of the (p + 1)th difference. The real-time current of the target device determined based on the (p + 2)th final rotation angle is In this formula, t is the sampling time corresponding to the (p + 2)th sampling value, and the final rotation angle is (180° - the (p + 2)th real-time angle).

[0147] And so on until the absolute value of the j-th difference is recognized to be less than the absolute value of the (j - 1)-th difference, then enter State 2. At this time, it is monitored that the target rotation angle exceeds the monotonic interval of the sine function. Of course, in the actual process, when it is monitored that the absolute values of 3, 4, or more differences are all less than the absolute value of the previous difference, then it is determined that the monitoring result is that the target rotation angle is in a monotonically decreasing state, which can be specifically selected according to actual needs. The real-time current of the target device determined based on the j-th final rotation angle is In this formula, t is the sampling time corresponding to the j-th sampling value, and the final rotation angle is (180° - the j-th real-time angle).

[0148] Next, obtain the (j + 1)-th real-time angle, and obtain the absolute value of the (j + 1)-th difference between the (j + 1)-th real-time angle and its complementary angle. It is recognized that the absolute value of the (j + 1)-th difference is less than the absolute value of the j-th difference. At this time, the (j + 1)-th final rotation angle is the complementary angle of the (j + 1)-th real-time angle. The real-time current of the target device determined based on the j-th final rotation angle is In this formula, t is the sampling time corresponding to the (j + 1)-th sampling value, and the final rotation angle is (180° - the (j + 1)-th real-time angle).

[0149] And so on until the absolute value of the m-th difference is recognized to be greater than the absolute value of the (m - 1)-th difference, then enter State 3. At this time, the monitoring result is that the target rotation angle returns to the monotonic interval of the sine function. Currently, the m-th final rotation angle is the m-th real-time angle. The real-time current of the target device determined based on the m-th final rotation angle is In this formula, t is the sampling time corresponding to the m-th sampling value, and the final rotation angle is the m-th real-time angle.

[0150] Next, continue to monitor the real-time angle of the target rotation angle until the absolute value of the n-th difference is recognized to be less than the absolute value of the (n - 1)-th difference, but the absolute value of the difference between the n-th real-time angle and the negative maximum rotation angle is greater than the preset threshold, which indicates that it does not exceed the monotonic interval of the sine function at this time. Currently, the n-th final rotation angle is the n-th real-time angle. The real-time current of the target device determined based on the n-th final rotation angle is In this formula, t is the sampling time corresponding to the n-th sampling value, and the final rotation angle is the n-th real-time angle.

[0151] Then, continue to monitor the real-time angle of the target rotation angle, and it is recognized that the absolute value of the (n + 1)-th difference is less than the absolute value of the n-th difference, and the absolute value of the difference between the (n + 1)-th real-time angle and the negative maximum rotation angle The absolute value of the difference between them is less than a preset threshold value, and the time difference between the sampling moment of the n+1th difference and the sampling moment of the peak value of the negative half-cycle of the sine wave of the real-time current exceeds the preset time threshold value, then it enters State 4. At this time, the monitoring result is that the target rotation angle exceeds the monotonic interval of the sine function again. Currently, the n+1th final rotation angle is (-180° - the n+1th real-time angle). The real-time current of the target device determined based on the n+1th final rotation angle is In this formula, t is the sampling time corresponding to the n+1th sampling value, and the final rotation angle is the n+1th real-time angle.

[0152] Next, the absolute value of the n+2th difference is less than the absolute value of the n+1th difference. At this time, the n+2th final rotation angle is (-180° - the n+2th real-time angle). The real-time current of the target device determined based on the n+2th final rotation angle is In this formula, t is the sampling time corresponding to the n+2th sampling value, and the final rotation angle is (-180° - the n+2th real-time angle).

[0153] And so on, until it is monitored that the absolute value of the qth difference is greater than the absolute value of the q-1th difference, then it enters State 5. Currently, the qth final rotation angle is (-180° - the qth real-time angle). The real-time current of the target device determined based on the qth final rotation angle is In this formula, t is the sampling time corresponding to the qth sampling value, and the final rotation angle is (-180° - the qth real-time angle).

[0154] Next, the q+1th difference is greater than the qth difference. At this time, the q+1th final rotation angle is (-180° - the q+1th real-time angle). The real-time current of the target device determined based on the q+1th final rotation angle is In this formula, t is the sampling time corresponding to the q+1th sampling value, and the final rotation angle is (-180° - the q+1th real-time angle).

[0155] And so on, until it is monitored again that the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle is in a monotonically decreasing state, and it re-enters State 0.

[0156] Embodiment 4

[0157] This embodiment provides a device for determining current based on an optical current transformer, which is used to execute the method for determining current based on an optical current transformer in Embodiment 1. This device can be integrated into a relay protection device, or this device can be regarded as the relay protection device itself. The optical current transformer is used to sense the real-time current of a target device. The target device can be a primary-side device, and the real-time current is an alternating current. The optical current transformer corresponds to a light source, and the light source is used to provide incident light.

[0158] As Figure 3 shown, it is a schematic structural diagram of the device for determining current based on an optical current transformer according to this embodiment. The device for determining current based on an optical current transformer includes a first acquisition unit 301, a second acquisition unit 302, a first determination unit 303, a monitoring unit 304, a second determination unit 305, and a third determination unit 306.

[0159] Among them, the first acquisition unit 301 is used to acquire the input light intensity of the incident light; the second acquisition unit 302 is used to acquire the real-time output light intensity corresponding to the outgoing light of the optical current transformer according to a sampling period; the first determination unit 303 is used to determine the real-time angle of a target rotation angle of the optical current transformer according to the input light intensity and the real-time output light intensity; the monitoring unit 304 is used to monitor whether the target rotation angle exceeds the monotonic interval of the sine function according to the real-time angle; the second determination unit 305 is used to determine a final rotation angle according to the monitoring result and the real-time angle of the target rotation angle; the third determination unit 306 is used to determine the real-time current of the target device according to the final rotation angle.

[0160] Optionally, the second determination unit 305 is specifically used for:

[0161] If the monitoring result is that the target rotation angle exceeds the monotonic interval of the sine function and the target rotation angle corresponds to the positive half cycle of the current waveform, then use the real-time angle of the complementary angle of the target rotation angle as the final rotation angle; and / or

[0162] If the monitoring result is that the target rotation angle exceeds the monotonic interval of the sine function and the target rotation angle corresponds to the negative half cycle of the current waveform, then use the difference between -π and the real-time angle of the target rotation angle as the final rotation angle.

[0163] Optionally, the first determination unit 303 is specifically used to determine the real-time angle of the target rotation angle according to the following formula:

[0164] where E o is the real-time output light intensity corresponding to the outgoing light, E i is the input light intensity corresponding to the incident light, is the target rotation angle.

[0165] Optionally, the third determination unit 306 is specifically configured to:

[0166] Determine the real-time current of the target device according to the following formula:

[0167]

[0168] where i(t) represents the real-time current at time t, R represents the distance between the conductor of the target device and the optical glass, represents the final rotation angle, μ represents the magnetic permeability, V represents the Verdet constant, and d represents the path that the light beam passes through in the optical glass ring.

[0169] The working methods of the units in this embodiment are the same as those in the foregoing embodiments, and will not be elaborated here.

[0170] According to this embodiment, first, monitor whether the target rotation angle exceeds the monotonic interval of the sine function, then determine a final rotation angle according to the monitoring result and the real-time angle of the target rotation angle, and finally, a relatively accurate current of the target device can be obtained according to the final rotation angle. This method can avoid improving the hardware of the optical current transformer, reduce the manufacturing difficulty, reduce the production cost, and can effectively expand the measurement range of the current of the optical current transformer.

[0171] Embodiment Five

[0172] This embodiment further supplements and explains the device for determining current based on an optical current transformer in Embodiment Four.

[0173] As Figure 4 shown, the device for determining current based on an optical current transformer in this embodiment further includes a first judgment unit 401 in addition to the foregoing first acquisition unit 301, second acquisition unit 302, first determination unit 303, monitoring unit 304, second determination unit 305, and third determination unit 306. The first judgment unit 401 is used to judge whether the product of the current real-time angle and the previous real-time angle of the target rotation angle is less than or equal to 0 and whether the previous real-time angle is less than 0. If the judgment results are both yes, the monitoring unit 304 is triggered.

[0174] Optionally, the monitoring unit 304 is specifically configured to: if it is judged that the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle is in a monotonically increasing state or is in a monotonically decreasing state after being in a monotonically increasing state, the monitoring result is yes; correspondingly, the second determination unit 305 is specifically configured to: use the real-time angle of the complementary angle of the target rotation angle as the final rotation angle.

[0175] Optionally, the monitoring unit 304 is further specifically configured to: after determining that the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle is in a monotonically increasing state and then in a monotonically decreasing state, if it is determined that the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle are in a monotonically increasing state again, the monitoring result is negative; the second determination unit 305 is further specifically configured to: use the real-time angle of the target rotation angle as the final rotation angle.

[0176] Optionally, the monitoring unit 304 is further specifically configured to, after determining that the target rotation angle returns to the monotonic interval of the sine function, if it is determined that the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle are in a monotonically decreasing state or are in a monotonically decreasing state and then in a monotonically increasing state, the monitoring result is positive; the second determination unit 305 is further specifically configured to: use the difference between -π and the real-time angle of the target rotation angle as the final rotation angle.

[0177] Optionally, the device for determining current based on an optical current transformer in this embodiment further includes a second determination unit 402, and the second determination unit 402 is configured to determine at least one of the following conditions after the monitoring result of the monitoring unit 304 changes from negative to positive and before determining a final rotation angle according to the monitoring result and the real-time angle of the target rotation angle:

[0178] Condition 1: Determine whether the absolute value of the difference between the real-time angle of the target rotation angle and the maximum rotation angle in the same direction is less than or equal to a preset threshold, and the maximum rotation angle is Or

[0179] Condition 2: Determine whether the time difference between the moment when the change trend of the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the corresponding complementary angle is reversed and the moment of the peak value in the same direction of the sine wave of the real-time current exceeds a preset time threshold value;

[0180] If the determination result is positive, it is determined that the monitoring result is correct.

[0181] The working methods of the units in this embodiment are the same as those in the foregoing embodiments and will not be elaborated here.

[0182] According to the device for determining current based on an optical current transformer in this embodiment, it is possible to determine whether it exceeds the monotonic interval through the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of its complementary angle. The method is simple and convenient, and the calculation amount is small.

[0183] The present invention also provides a device for determining current based on an optical current transformer, including at least one memory and at least one processor. Among them, the memory is used to store instructions. The processor is used to execute the method for determining current based on the optical current transformer described in any of the foregoing embodiments according to the instructions stored in the memory. The device for determining current based on the optical current transformer can be regarded as a part of the relay protection device or the relay protection device itself.

[0184] An embodiment of the present invention also provides a readable storage medium. Machine-readable instructions are stored in the readable storage medium, and when the machine-readable instructions are executed by a machine, the machine executes the method for determining current based on the optical current transformer described in any of the foregoing embodiments.

[0185] Machine-readable instructions are stored on the readable medium, and when the machine-readable instructions are executed by a processor, the processor executes any of the foregoing methods. Specifically, a system or device equipped with a readable storage medium can be provided, and software program codes for implementing the functions of any one of the above embodiments are stored on the readable storage medium, and the computer or processor of the system or device is made to read and execute the machine-readable instructions stored in the readable storage medium.

[0186] In this case, the program code read from the readable medium itself can implement the functions of any one of the above embodiments. Therefore, the machine-readable code and the readable storage medium storing the machine-readable code constitute a part of the present invention.

[0187] Embodiments of the readable storage medium include floppy disks, hard disks, magneto-optical disks, optical disks (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), magnetic tapes, non-volatile memory cards, and ROMs. Optionally, the program code can be downloaded from a server computer or a cloud via a communication network.

[0188] Those skilled in the art should understand that various deformations and modifications can be made to the above-disclosed embodiments without departing from the essence of the invention. Therefore, the protection scope of the present invention should be defined by the appended claims.

[0189] It should be noted that not all steps and units in the above-mentioned processes and system structure diagrams are necessary, and some steps or units can be ignored according to actual needs. The execution order of each step is not fixed and can be adjusted according to needs. The device structures described in the above embodiments can be physical structures or logical structures. That is, some units may be implemented by the same physical entity, or some units may be implemented by multiple physical entities respectively, or some components in multiple independent devices may be jointly implemented.

[0190] In the above embodiments, the hardware unit may be implemented mechanically or electrically. For example, a hardware unit or a processor may include permanent dedicated circuits or logic (such as a dedicated processor, FPGA or ASIC) to perform corresponding operations. The hardware unit or the processor may also include programmable logic or circuits (such as a general-purpose processor or other programmable processors), which can be temporarily set by software to perform corresponding operations. The specific implementation method (mechanical method, or dedicated permanent circuit, or temporarily set circuit) can be determined based on cost and time considerations.

[0191] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for determining current based on an optical current transformer, where the optical current transformer is used to sense the real-time current of a target device, the real-time current being an alternating current, and the optical current transformer corresponds to a light source for providing incident light. The method includes: Obtaining the input light intensity of the incident light; Obtaining the real-time output light intensity corresponding to the outgoing light of the optical current transformer according to a sampling period; Determining the real-time angle of a target rotation angle of the optical current transformer based on the input light intensity and the real-time output light intensity; Monitoring whether the target rotation angle exceeds the monotonic interval of the sine function according to the real-time angle; Determining a final rotation angle based on the monitoring result and the real-time angle of the target rotation angle; Determining the real-time current of the target device based on the final rotation angle.

2. The method according to claim 1, wherein Determining a final rotation angle based on the monitoring result and the real-time angle of the target rotation angle includes: If the monitoring result is that the target rotation angle exceeds the monotonic interval of the sine function and the target rotation angle corresponds to the positive half-cycle of the current waveform, then taking the real-time angle of the complementary angle of the target rotation angle as the final rotation angle; and / or If the monitoring result is that the target rotation angle exceeds the monotonic interval of the sine function and the target rotation angle corresponds to the negative half-cycle of the current waveform, then taking the difference between -π and the real-time angle of the target rotation angle as the final rotation angle.

3. The method according to claim 1, characterized in that Before monitoring whether the target rotation angle exceeds the monotonic interval of the sine function according to the real-time angle, it further includes: Judging whether the product of the current real-time angle and the previous real-time angle of the target rotation angle is less than or equal to 0 and whether the previous real-time angle is less than 0; If the judgment results are all yes, then triggering the operation of monitoring whether the target rotation angle exceeds the monotonic interval of the sine function according to the real-time angle.

4. The method according to claim 3, wherein Monitoring whether the target rotation angle exceeds the monotonic interval of the sine function according to the real-time angle includes: if it is judged that the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle is in a monotonically increasing state or in a monotonically increasing state and then in a monotonically decreasing state, then the monitoring result is yes; Determining a final rotation angle based on the monitoring result and the real-time angle of the target rotation angle includes: taking the real-time angle of the complementary angle of the target rotation angle as the final rotation angle.

5. The method according to claim 4, wherein After it is judged that the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle is in a monotonically increasing state and then in a monotonically decreasing state, it further includes: if it is judged that the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle are in a monotonically increasing state again, then the monitoring result is no; Determining a final rotation angle based on the monitoring result and the real-time angle of the target rotation angle includes: taking the real-time angle of the target rotation angle as the final rotation angle.

6. The method according to claim 5, wherein After it is determined that the target rotation angle returns to the monotonic interval of the sine function, it further includes: if it is determined that the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle are in a monotonically decreasing state or are in a monotonically decreasing state and then in a monotonically increasing state, the monitoring result is yes; Determining a final rotation angle according to the monitoring result and the real-time angle of the target rotation angle includes: using the difference between -π and the real-time angle of the target rotation angle as the final rotation angle.

7. The method according to claim 1, wherein After the monitoring result changes from no to yes and before determining a final rotation angle according to the monitoring result and the real-time angle of the target rotation angle, it further includes judging at least one of the following conditions: Condition 1: Determine whether the absolute value of the difference between the real-time angle of the target rotation angle and the maximum rotation angle in the same direction is less than or equal to a preset threshold, where the maximum rotation angle is or Condition 2: Judging whether the time difference between the moment when the change trend of the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the corresponding complementary angle is reversed and the co-directional peak moment of the sine wave of the real-time current exceeds a preset time threshold; If the judgment result is yes, it is determined that the monitoring result is correct.

8. The method according to claim 1, characterized in that, Determining the real-time angle of a target rotation angle of the optical current transformer based on the input optical intensity and the real-time output optical intensity includes: wherein, E o is the real-time output optical intensity corresponding to the outgoing light, and E i is the input optical intensity corresponding to the incident light, is the target rotation angle; or Determine the real-time current of the target device according to the following formula: Among them, i(t) represents the real-time current at time t, and R represents the distance between the conductor of the target device and the optical glass. represents the final rotation angle, μ represents the magnetic permeability, V represents the Verdet constant, and d represents the path that the light beam passes through in the optical glass ring.

9. A device for determining current based on an optical current transformer, the optical current transformer is used to sense the real-time current of a target device, the real-time current is an alternating current, the optical current transformer corresponds to a light source, and the light source is used to provide incident light. The device includes: A first acquisition unit for acquiring the input light intensity of the incident light; A second acquisition unit for acquiring the real-time output light intensity corresponding to the outgoing light of the optical current transformer according to a sampling period; A first determination unit for determining the real-time angle of a target rotation angle of the optical current transformer according to the input light intensity and the real-time output light intensity; A monitoring unit for monitoring whether the target rotation angle exceeds the monotonic interval of the sine function according to the real-time angle; A second determination unit for determining a final rotation angle according to the monitoring result and the real-time angle of the target rotation angle; A third determination unit for determining the real-time current of the target device according to the final rotation angle.

10. The device according to claim 9, characterized in that, It further includes: A first judgment unit for judging whether the product of the current real-time angle and the previous real-time angle of the target rotation angle is less than or equal to 0 and whether the previous real-time angle is less than 0. If the judgment results are both yes, the monitoring unit is triggered.

11. The device according to claim 10, characterized in that, The monitoring unit is specifically used for: if it is determined that the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle is in a monotonically increasing state or is in a monotonically increasing state and then in a monotonically decreasing state, the monitoring result is yes; The second determination unit is specifically used for: using the real-time angle of the complementary angle of the target rotation angle as the final rotation angle.

12. The device according to claim 11, wherein The monitoring unit is further specifically configured to: after determining that the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle is in a monotonically increasing state and then in a monotonically decreasing state, if it is determined that the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle are again in a monotonically increasing state, the monitoring result is negative; The second determination unit is further specifically configured to: use the real-time angle of the target rotation angle as the final rotation angle.

13. The device according to claim 12, characterized in that, The monitoring unit is further specifically configured to, after determining that the target rotation angle returns to the monotonic interval of the sine function, if it is determined that the real-time angle of the target rotation angle and the real-time angle of the complementary angle of the target rotation angle are in a monotonically decreasing state or in a monotonically decreasing state and then in a monotonically increasing state, the monitoring result is positive; The second determination unit is further specifically configured to: use the difference between -π and the real-time angle of the target rotation angle as the final rotation angle.

14. The device according to any one of claims 9 - 13, characterized in that, It further includes a second judgment unit, configured to, after the monitoring result changes from negative to positive and before determining a final rotation angle according to the monitoring result and the real-time angle of the target rotation angle, judge at least one of the following conditions: Condition 1: Determine whether the absolute value of the difference between the real-time angle of the target rotation angle and the maximum rotation angle in the same direction is less than or equal to a preset threshold, where the maximum rotation angle is Or Condition 2: Judge whether the time difference between the moment when the change trend of the absolute value of the difference between the real-time angle of the target rotation angle and the real-time angle of the corresponding complementary angle is reversed and the moment of the same-direction peak value of the sine wave of the real-time current exceeds a preset time threshold; If the judgment result is positive, it is determined that the monitoring result is correct.

15. Device for determining current based on an optical current transformer, characterized in that, Comprising: At least one memory for storing instructions; At least one processor for executing the method for determining current based on an optical current transformer according to any one of claims 1-8 according to the instructions stored in the memory.

16. A readable storage medium, characterized in that, Machine-readable instructions are stored in the readable storage medium, and when the machine-readable instructions are executed by a machine, the machine executes the method for determining current based on an optical current transformer according to any one of claims 1-8.

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