Current determination method and apparatus based on optical current transformer

Abstract

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

Description

Method and device for determining current based on optical current transformer Technical Field

[0001] The present invention relates to the field of mutual inductors, and in particular to a method and device for determining current based on an optical current mutual inductor. Background Art

[0002] The operating principle of a magneto-optical optical current transformer (OCT) is to calculate the primary current using the Faraday magneto-optical effect. This refers to the fact that in magneto-optical materials, an external magnetic field causes the plane of linear polarization propagating along the magnetic field in the medium to deflect accordingly. This deflection is the total rotation angle α. The angle of deflection of the incident light is related to the intensity of the magnetic field (the magnitude of the current passing through it), the length of the interaction between the light and the magnetic field in the transparent material, and the properties of the material. Typically, 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 current flowing through the target device, V is the Verdet constant related to the OCT material and wavelength, and d is the path the light beam travels through the optical glass ring of the OCT.

[0003] Generally, the transmission axis of the polarizer is set at a 45° angle to the transmission axis of the analyzer, and the rotation angle α = θ + 45°, where θ = B·V·d, that is, θ is the deflection angle caused by the magnetic field generated by the current of the target device. According to Malus's law, the relationship between the input and output light intensity is Where γ is the transmission coefficient of light in the optical glass used in the optical current transformer, E i is the input light intensity, E o is the output light intensity. Under normal circumstances, the total rotation angle α is in the range of [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 structure parameters of the transformer, when the peak current flowing through the primary conductor is greater than a certain critical value, the rotation angle of the primary current The range will exceed the monotonic interval of the sine function [-90°, 90°]. 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 original calculation method being unable to correctly obtain the primary current. Therefore, the measurement current range of the optical current transformer is generally small.

[0005] Summary of the Invention

[0006] In view of this, the present invention proposes a method for determining current based on an optical current transformer, wherein the optical current transformer is used to sense the real-time current of a target device, where the real-time current is an AC current. The optical current transformer corresponds to a light source, which is used to provide incident light. The method includes:

[0007] Acquiring the input light intensity of the incident light;

[0008] Acquire the real-time output light intensity corresponding to the output light of the optical current transformer according to a sampling period;

[0009] Determine 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;

[0010] monitoring whether the target rotation angle exceeds the monotonic interval of the sine function according to the real-time angle;

[0011] Determine a final rotation angle according to the monitoring result and the real-time angle of the target rotation angle;

[0012] The real-time current of the target device is determined according to the final rotation angle.

[0013] According to the method described above, optionally, determining a final rotation angle according to the monitoring result and the real-time angle of the target rotation angle includes:

[0014] If the monitoring result shows 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, the real-time angle of the complementary angle of the target rotation angle is used as the final rotation angle; and / or

[0015] If the monitoring result shows 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, the difference between -π and the real-time angle of the target rotation angle is used as the final rotation angle.

[0016] 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, the method further includes:

[0017] 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;

[0018] If the judgment results are all yes, then an operation of monitoring whether the target rotation angle exceeds the monotonic interval of the sine function according to the real-time angle is triggered.

[0019] According to the method as 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, then the monitoring result is yes;

[0020] Determining a final rotation angle according to 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.

[0021] According to the method as 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, the method 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 increasing state again, the monitoring result is no;

[0022] Determining a final rotation angle according to 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.

[0023] According to the method described above, optionally, after determining that the target rotation angle has returned to the monotonic interval of the sine function, the method 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;

[0024] Determining a final rotation angle according to the monitoring result and the real-time angle of the target rotation angle includes: taking the difference between -π and the real-time angle of the target rotation angle as the final rotation angle.

[0025] 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, the method further includes judging at least one of the following conditions:

[0026] 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, the maximum rotation angle is or

[0027] Condition 2: Determine whether the time difference between the moment when 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 when the sine wave of the real-time current reaches the same direction peak exceeds a preset time threshold;

[0028] If the judgment result is yes, it is determined that the monitoring result is correct.

[0029] According to the method described above, optionally, 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 includes: Among them, 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; or

[0030] The real-time current of the target device is determined according to the following formula:

[0031] 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 of the light beam in the optical glass ring.

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

[0033] a first acquiring unit, configured to acquire the input light intensity of the incident light;

[0034] a second acquiring unit, configured to acquire, according to a sampling period, a real-time output light intensity corresponding to the output light of the optical current transformer;

[0035] a first determining unit, configured to determine 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;

[0036] a monitoring unit, configured to monitor whether the target rotation angle exceeds a monotonic interval of a sine function based on the real-time angle;

[0037] a second determining unit, configured to determine a final rotation angle according to the monitoring result and the real-time angle of the target rotation angle;

[0038] A third determining unit is configured to determine a real-time current of the target device according to the final rotation angle.

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

[0040] A first judging unit is configured 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, and if both judgment results are yes, trigger the monitoring unit.

[0041] According to the device as 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, then the monitoring result is yes;

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

[0043] According to the device as described above, optionally, 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 in a monotonically increasing state again, then the monitoring result is negative;

[0044] The second determining 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 as described above, optionally, the monitoring unit is further specifically configured to, after determining that the target rotation angle has returned to the monotonic interval of the sine function, determine 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, then the monitoring result is yes;

[0046] The second determining 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 above device, optionally, a second judgment unit is further included, which is used to judge at least one of the following conditions 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:

[0048] 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, the maximum rotation angle is or

[0049] Condition 2: Determine whether the time difference between the moment when 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 when the sine wave of the real-time current reaches the same direction peak 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, comprising:

[0052] at least one memory for storing instructions;

[0053] At least one processor is configured to execute any of the aforementioned methods for determining current based on an optical current transformer according to instructions stored in the memory.

[0054] The present invention further provides a readable storage medium, wherein the readable storage medium stores machine-readable instructions. When the machine-readable instructions are executed by a machine, the machine executes the method for determining current based on an optical current transformer as described in any one of the above items.

[0055] As can be seen from the above scheme, the present invention first monitors whether the target rotation angle exceeds the monotonic interval of the sine function. Then, based on the monitoring results and the real-time angle of the target rotation angle, a final rotation angle is determined. Finally, based on this final rotation angle, a relatively accurate current of the target device can be obtained. This method avoids hardware improvements to the optical current transformer, reduces manufacturing difficulty and production costs, and effectively expands the current measurement range of the optical current transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so that those skilled in the art will understand the above and other features and advantages of the present invention more clearly. In the accompanying drawings:

[0057] FIG1A is a schematic flow chart of a method for determining current based on an optical current transformer according to an embodiment of the present invention.

[0058] FIG1B is a diagram showing an example of an optical current transformer.

[0059] FIG2 is a flow chart of a method for determining current based on an optical current transformer according to another embodiment of the present invention.

[0060] FIG3 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] FIG4 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 DESCRIPTION

[0062] To make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail with reference to the following embodiments. Nouns and pronouns related to people in this patent application are not limited to specific genders.

[0063] In order to expand the current measurement range of the 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 the target device, which is the primary side device.

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

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

[0066] Example 1

[0067] This embodiment provides a method for determining current based on an optical current transformer (OCT). Specifically, the OCT is a magneto-optical OCT, which is used to sense the real-time current of a target device. This real-time current is an AC current with a sinusoidal waveform. This method is performed by a device that determines current based on an OCT. This device can be integrated into a relay protection device that determines the current based on the OCT and performs corresponding relay protection operations. The OCT is associated with a light source that provides incident light.

[0068] As shown in FIG1 , a method for determining current based on an optical current transformer according to this embodiment is shown. 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 called incident light, while the light that exits the optical current transformer is called outgoing light. After the incident light enters the current transformer, the magnetic field generated by the current, such as the magnetic field generated by the primary current, causes the polarization plane to deflect. This deflects the incident light by a certain angle and becomes outgoing light.

[0071] For incident light, the input light intensity is constant, so it only needs to be obtained once. This acquisition method can be pre-notified by the manufacturer, or it can be indirectly obtained by sampling the outgoing light and approximating it through software filtering. I will not go into details here.

[0072] Step 101: obtaining the real-time output light intensity corresponding to the output 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, sampling once every 1 microsecond.

[0074] The real-time output light intensity corresponding to the emitted light can be measured by existing technologies, such as photoelectric effect method, interference method, scattering method, etc. The light intensity can be directly obtained by a device that determines the current based on an optical current transformer, or it can be obtained indirectly, without specific limitation.

[0075] It should be noted that there is no order between step 101 and step 100, and they can be executed one after the other or simultaneously. For the convenience of description, this embodiment uses step 100 and step 101 as examples.

[0076] Step 102: Determine 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.

[0077] 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, such as a sine trigonometric function value, can be obtained. As an example, Among them 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.

[0078] Step 103: Monitor the target rotation angle based on the real-time angle to see if it exceeds the monotonic interval of the sine function.

[0079] Since the output light 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 the complementary angle. As an illustrative explanation, 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 can be monitored to monitor whether the target rotation angle exceeds the monotonic interval of the sine function, that is, [-π / 2, π / 2]. For example, starting from the zero point, the change in 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 monitored. For example, when the current waveform after the zero point is a sine waveform, it is determined 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 a monotonic 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 may be used to determine whether the target rotation angle exceeds the monotonic interval of the sine function, which will not be described in detail 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 may correspond to different final rotation angles.

[0084] As an exemplary illustration, the final rotation angle can be determined based on 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 shows 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, 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 shows 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, 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 is the real angle that can reflect the rotation angle.

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

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

[0088] 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 of the light beam through the optical glass ring. Here, the conductor of the target device is a current carrier, such as a wire through which a primary current flows. As shown in Figure 1B, the cross-section of the target device's conductor 11 is circular, and R is the distance between the center of the conductor 11 and the optical glass 12, which is annular in shape. Incident light 13 enters optical glass 12 through polarizer 14, travels a circular path within optical glass 12, and then passes through analyzer 15 to form output light 16.

[0089] In this way, the real real-time current can be obtained according to the final rotation angle.

[0090] According to this embodiment, the target rotation angle is first monitored to see if it exceeds the monotonic interval of the sine function. A final rotation angle is then determined based on the monitoring result and the real-time angle of the target rotation angle. Finally, a relatively accurate current measurement of the target device is obtained based on this final rotation angle. This method avoids hardware improvements to the optical current transformer, reduces manufacturing complexity and production costs, and effectively expands the current measurement range of the optical current transformer.

[0091] Example 2

[0092] This embodiment further supplements the method for determining current based on an optical current transformer in the first embodiment.

[0093] As shown in FIG2 , it is a flow chart of 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:

[0094] Step 201: Obtain the input light intensity of the incident light.

[0095] A light source can emit light. The light that enters the optical current transformer is called the incident light, while the light that exits the optical current transformer is called the outgoing light. After the incident light enters the current transformer, the magnetic field generated by the current, such as the magnetic field generated by the primary current, causes the polarization plane to deflect. This deflects the incident light by a certain angle and becomes the outgoing light.

[0096] For incident light, the input light intensity is constant, so it only needs to be obtained once. This acquisition method can be pre-notified by the manufacturer, or it can be indirectly obtained by sampling the outgoing light and approximating it through software filtering. I will not go into details here.

[0097] Step 202: obtaining the real-time output light intensity corresponding to the output light of the optical current transformer according to a sampling period.

[0098] 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, such as a sine trigonometric function value, can be obtained. As an example, Among them 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.

[0099] The real-time output light intensity corresponding to an outgoing light is obtained in each sampling period.

[0100] There is no order between step 202 and step 201 , and they can be performed one after the other or simultaneously. For the convenience of description, this embodiment uses step 202 and step 201 as examples.

[0101] Step 203 , determining 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 determination result is yes, executing step 204 .

[0102] 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 indicates that the real-time angle of the target rotation angle has changed from a negative value to 0 or a positive value for the first time. This indicates that the current waveform of the corresponding current has just passed zero. Therefore, step 203 acts as a trigger condition.

[0103] Step 204 : Monitor the target rotation angle based on the real-time angle to see whether it exceeds the monotonic interval of the sine function, and then execute step 205 .

[0104] This step specifically includes the following states:

[0105] 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;

[0106] 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;

[0107] 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;

[0108] State 3: 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, and the target rotation angle is restored to the monotonic interval of the sine function;

[0109] 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;

[0110] 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, and the target rotation angle still exceeds the monotonic interval of the sine function;

[0111] 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 monotonically decreasing state again, the state is restored to 0.

[0112] The above states are sorted in sequence, from state 0 to state 5 and then restored to state 0.

[0113] If the target rotation angle is within the monotonic interval of the sine function, the monitoring result is no; if the target rotation angle exceeds the monotonic interval of the sine function, the monitoring result is yes.

[0114] Step 205: Determine a final rotation angle based on the monitoring result and the real-time angle of the target rotation angle.

[0115] As an example, the following is an example:

[0116] State 0: The final rotation angle is the real-time angle of the target rotation angle.

[0117] State 1: The final rotation angle is the real-time angle of the complementary angle of the target rotation angle.

[0118] State 2: The final rotation angle is the real-time angle of the complementary angle of the target rotation angle.

[0119] State 3: The final rotation angle is the real-time angle of the target rotation angle.

[0120] State 4: The final rotation angle is -π minus the target rotation angle.

[0121] State 5: The final rotation angle is -π minus the target rotation angle.

[0122] It can be seen that different states correspond to different monitoring results, and different monitoring results correspond to different real-time angles.

[0123] Step 206 : Determine the real-time current of the target device according to the final rotation angle.

[0124] Specifically, the real-time current of the target device can be determined according to the following formula:

[0125] Where 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 of the light beam in the optical glass ring.

[0126] Optionally, after the monitoring result of step 204 changes from no to yes and before step 205, the process further includes determining at least one of the following conditions:

[0127] 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. The maximum rotation angle is or

[0128] Condition 2: Determine whether the time difference between the moment when the absolute value of the difference between the target rotation angle and the corresponding complementary angle reverses and the moment when the sine wave of the real-time current reaches the same direction peak exceeds a preset time threshold;

[0129] If the judgment result is yes, then step 205 is executed. The same direction here means being in the same positive half cycle or the same negative half cycle.

[0130] Conditions 1 and 2 here are both for further verification of the monitoring result being yes, that is, to further verify whether it has actually exceeded the monotonic interval of the sine function.

[0131] 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 sinusoidal waveform of the real-time current, then the target rotation angle is judged to be If the absolute value of the difference between the target rotation angle and the real-time current is less than or equal to the preset threshold, then the real-time target rotation angle is determined to be equal to the real-time current. Is the absolute value of the difference between the two values ​​less than or equal to the preset threshold? If the absolute value of the difference is too different from the preset threshold, it means that the current real-time angle of the target rotation angle is still some distance away from the maximum rotation angle, and it is impossible to exceed the monotonic interval of the sine function at this time. Therefore, it can be determined that the previous monitoring result is incorrect.

[0132] For condition 2, it is used to determine the target rotation angle The absolute value of the difference between the real-time angle and the complementary angle is determined by checking whether the inflection point is at the midpoint of the positive or negative half-cycle to distinguish when the rotation angle is within the critical value of the monotonic interval. If the judgment result is yes, it can be further confirmed that the previous monitoring results are correct. Otherwise, the monitoring results are incorrect and the monotonic interval of the sine function has not yet been exceeded.

[0133] Therefore, in this embodiment, after the monitoring result of step 204 changes from no to yes, it can be combined with condition one, or combined with condition two, or combined with condition one and condition two. The specific selection can be made according to actual needs, so as to further confirm whether it is actually beyond the monotonic interval of the sine function.

[0134] According to the method for determining current based on an optical current transformer in this embodiment, 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 can be used to determine whether it exceeds the monotonic interval of the sine function. The method is simple and convenient, and the calculation amount is small.

[0135] Example 3

[0136] This embodiment specifically illustrates the method for determining current based on an optical current transformer according to the embodiment.

[0137] In this embodiment, the real-time output light intensity of the output light of the optical current transformer corresponding to the target device is sampled according to a preset period.

[0138] For each sampling value, the corresponding target rotation angle is obtained according to the following formula Real-time perspective: Among them, 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.

[0139] The target rotation angle obtained based on the current real-time output light intensity sampling value The real-time angle of the target rotation angle is determined by multiplying the real-time angle by the last real-time angle to determine whether the product of the real-time angle and the last real-time angle is less than or equal to 0 and whether the last real-time angle is less than 0. If the result is yes, the system enters state 0 and records the current sampling value as the first sampling value. The real-time angle of the current target rotation angle is the first real-time angle. The absolute value of the first difference between the first real-time angle and its complementary angle is obtained. 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.

[0140] Next, the second real-time angle is obtained, and the absolute value of the second difference between the second real-time angle and its complementary angle is obtained. It is identified 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.

[0141] Next, the third real-time angle is obtained, and the absolute value of the third difference between the third real-time angle and its complementary angle is obtained. It is identified that the absolute value of the third difference is less than the absolute value of the second difference. At this point, the third final rotation angle is the third real-time angle. The real-time current of the target device determined based on the third final rotation angle is In this formula, t is the sampling time corresponding to the third sampling value, and the final rotation angle is the third real-time angle.

[0142] This process is repeated until the absolute value of the pth difference is greater than the absolute value of the p-1th difference, and the pth real-time angle is equal to the maximum rotation angle in the positive direction. The absolute value of the difference between the two 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, and enters 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 the absolute values ​​of 3, 4 or more differences are greater than the absolute value of the previous difference, and then the monitoring result is determined to be that the target rotation angle is in a monotonically increasing state. The specific selection can be made 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 p-th sampling value, and the final rotation angle is (180°-the p-th real-time angle).

[0143] Next, the p+1th real-time angle is obtained, and the absolute value of the p+1th difference between the p+1th real-time angle and the complementary angle is obtained. It is identified that the absolute value of the p+1th difference is greater than the absolute value of the pth difference. At this time, the p+1th final rotation angle is the complementary angle of the p+1th real-time angle. The real-time current of the target device determined based on the p+1th final rotation angle is In this formula, t is the sampling time corresponding to the p+1th sampling value, and the final rotation angle is (180°-p+1th real-time angle).

[0144] Next, the p+2th real-time angle is obtained, and the absolute value of the p+2th difference between the p+2th real-time angle and the complementary angle is obtained. It is identified that the absolute value of the p+2th difference is greater than the absolute value of the p+1th difference. The real-time current of the target device determined based on the p+2th final rotation angle is In this formula, t is the sampling time corresponding to the p+2th sampling value, and the final rotation angle is (180°-p+2th real-time angle).

[0145] And so on, until it is identified that the absolute value of the j-th difference is less than the absolute value of the j-1-th difference, and enters 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, it can be monitored that the absolute values ​​of 3, 4 or more differences are all less than the absolute value of the previous difference, and then the monitoring result is determined to be that the target rotation angle is in a monotonically decreasing state. The specific selection can be made 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°-j-th real-time angle).

[0146] Next, the j+1th real-time angle is obtained, and the absolute value of the j+1th difference between the j+1th real-time angle and the complementary angle is obtained. It is identified that the absolute value of the j+1th difference is less than the absolute value of the jth difference. At this point, the j+1th final rotation angle is the complementary angle of the j+1th real-time angle. The real-time current of the target device determined based on the jth final rotation angle is In this formula, t is the sampling time corresponding to the j+1th sampling value, and the final rotation angle is (180°-j+1th real-time angle).

[0147] This process is repeated until the absolute value of the mth difference is found to be greater than the absolute value of the m-1th difference, and the process enters state 3. The monitoring result at this time is that the target rotation angle returns to the monotonic interval of the sine function. Currently, the mth final rotation angle is the mth real-time angle. The real-time current of the target device determined based on the mth final rotation angle is In this formula, t is the sampling time corresponding to the mth sampling value, and the final rotation angle is the mth real-time angle.

[0148] Next, continue to monitor the real-time angle of the target rotation angle until it is identified that the absolute value of the nth difference is less than the absolute value of the n-1th difference, but the nth real-time angle is greater than the maximum negative rotation angle. If the absolute value of the difference between is greater than the preset threshold, it means that the monotonic interval of the sine function has not been exceeded. At present, the nth final rotation angle is the nth real-time angle. The real-time current of the target device determined based on the nth final rotation angle is In this formula, t is the sampling time corresponding to the nth sampling value, and the final rotation angle is the nth real-time angle.

[0149] Then, continue to monitor the real-time angle of the target rotation angle, identify that the absolute value of the n+1th difference is less than the absolute value of the nth difference, and the n+1th real-time angle is equal to the maximum rotation angle in the negative direction. The absolute value of the difference between the two values ​​is less than the preset threshold value, and the time difference between the sampling time of the n+1th difference and the sampling time of the peak value of the negative half cycle of the sine wave of the real-time current exceeds the preset time threshold value, and the state 4 is entered. The monitoring result at this time is that the target rotation angle exceeds the monotonic interval of the sine function again. At present, the n+1th final rotation angle is (-180°-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.

[0150] Next, the absolute value of the n+2th difference is less than the absolute value of the n+1th difference. At this point, the n+2th final rotation angle is (-180°-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°-n+2th real-time angle).

[0151] This process continues until the absolute value of the qth difference is greater than the absolute value of the q-1th difference, and the process enters state 5. Currently, the qth final rotation angle is (-180°-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°-qth real-time angle).

[0152] Next, the q+1th difference is greater than the qth difference. At this point, the q+1th final rotation angle is (-180°-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°-q+1th real-time angle).

[0153] This process is deduced in this way until 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 again monitored to be in a monotonically decreasing state, and the state 0 is re-entered.

[0154] Example 4

[0155] This embodiment provides a device for determining current based on an optical current transformer, which is used to implement the method for determining current based on an optical current transformer described in Example 1. This device can be integrated into a relay protection device, or it can be considered the relay protection device itself. The optical current transformer is used to sense the real-time current of a target device, which can be a primary-side device. The real-time current is AC current. The optical current transformer corresponds to a light source, which is used to provide incident light.

[0156] FIG3 is a schematic diagram of the structure of a 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.

[0157] Among them, the first acquisition unit 301 is used to obtain the input light intensity of the incident light; the second acquisition unit 302 is used to obtain the real-time output light intensity corresponding to the output 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 based on 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 based on the real-time angle; the second determination unit 305 is used to determine a final rotation angle based on the monitoring results 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 based on the final rotation angle.

[0158] Optionally, the second determining unit 305 is specifically configured to:

[0159] If the monitoring result shows 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, the real-time angle of the complementary angle of the target rotation angle is used as the final rotation angle; and / or

[0160] If the monitoring result shows 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, the difference between -π and the real-time angle of the target rotation angle is taken as the final rotation angle.

[0161] Optionally, the first determining unit 303 is specifically configured to determine the real-time angle of the target rotation angle according to the following formula:

[0162] Among them, 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.

[0163] Optionally, the third determining unit 306 is specifically configured to:

[0164] The real-time current of the target device is determined according to the following formula:

[0165] 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 of the light beam in the optical glass ring.

[0166] The working methods of the various units in this embodiment are the same as those in the previous embodiment and will not be described again here.

[0167] According to this embodiment, the target rotation angle is first monitored to see if it exceeds the monotonic interval of the sine function. A final rotation angle is then determined based on the monitoring result and the real-time angle of the target rotation angle. Finally, a relatively accurate current measurement of the target device is obtained based on this final rotation angle. This method avoids hardware improvements to the optical current transformer, reduces manufacturing complexity and production costs, and effectively expands the current measurement range of the optical current transformer.

[0168] Example 5

[0169] This embodiment further supplements the device for determining current based on an optical current transformer in the fourth embodiment.

[0170] As shown in Figure 4, the device for determining current based on an optical current transformer in this embodiment, in addition to the aforementioned first acquisition unit 301, second acquisition unit 302, first determination unit 303, monitoring unit 304, second determination unit 305 and third determination unit 306, also includes a first judgment unit 401, which is used to judge whether the product of the current real-time angle of the target rotation 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 results are all yes, the monitoring unit 304 is triggered.

[0171] Optionally, the monitoring unit 304 is specifically used 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; accordingly, the second determination unit 305 is specifically used to: use the real-time angle of the complementary angle of the target rotation angle as the final rotation angle.

[0172] Optionally, the monitoring unit 304 is also specifically used 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 no; the second determination unit 305 is also specifically used to: use the real-time angle of the target rotation angle as the final rotation angle.

[0173] Optionally, the monitoring unit 304 is also specifically used to, after determining that the target rotation angle has returned 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, then the monitoring result is yes; the second determination unit 305 is also specifically used to: take the difference between -π and the real-time angle of the target rotation angle as the final rotation angle.

[0174] Optionally, the apparatus for determining current based on an optical current transformer in this embodiment further includes a second judgment unit 402, configured to judge 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 based on the monitoring result and the real-time angle of the target rotation angle:

[0175] 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. The maximum rotation angle is or

[0176] Condition 2: Determine whether the time difference between the moment when 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 when the sine wave of the real-time current reaches the same direction peak exceeds a preset time threshold;

[0177] If the judgment result is yes, it is determined that the monitoring result is correct.

[0178] The working methods of the various units in this embodiment are the same as those in the previous embodiment and will not be described again here.

[0179] According to the device for determining current based on an optical current transformer of this embodiment, whether the monotonic interval is exceeded can be determined 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.

[0180] The present invention also provides a device for determining current based on an optical current transformer, comprising at least one memory and at least one processor. The memory is configured to store instructions. The processor is configured to execute the method for determining current based on an optical current transformer described in any of the aforementioned embodiments according to the instructions stored in the memory. The device for determining current based on an optical current transformer can be considered part of a relay protection device or the relay protection device itself.

[0181] An embodiment of the present invention further provides a readable storage medium having machine-readable instructions stored therein, wherein when the machine-readable instructions are executed by a machine, the machine executes the method for determining current based on an optical current transformer as described in any of the aforementioned embodiments.

[0182] The readable medium stores machine-readable instructions that, when executed by a processor, cause the processor to perform any of the aforementioned methods. Specifically, a system or device equipped with a readable storage medium may be provided, wherein the readable storage medium stores software program code that implements the functions of any of the aforementioned embodiments, and causes a computer or processor of the system or device to read and execute the machine-readable instructions stored in the readable storage medium.

[0183] In this case, the program code itself read from the machine-readable medium can realize the function of any one of the above embodiments, and thus the machine-readable code and the machine-readable storage medium storing the machine-readable code constitute part of the present invention.

[0184] Examples of readable storage media include floppy disks, hard disks, magneto-optical disks, optical disks (e.g., CD-ROMs, CD-Rs, CD-RWs, DVD-ROMs, DVD-RAMs, DVD-RWs, DVD+RWs), magnetic tapes, non-volatile memory cards, and ROMs. Alternatively, the program code may be downloaded from a server computer or a cloud via a communication network.

[0185] Those skilled in the art will appreciate that the various embodiments disclosed above may be modified and altered in various ways without departing from the essence of the invention. Therefore, the scope of protection of the present invention shall be defined by the appended claims.

[0186] It should be noted that not all steps and units in the above processes and system structure diagrams are required, and certain steps or units can be omitted according to actual needs. The execution order of each step is not fixed and can be adjusted as needed. The device structure described in the above embodiments can be a physical structure or a logical structure, that is, some units may be implemented by the same physical entity, or some units may be implemented by multiple physical entities, or may be implemented by certain components in multiple independent devices.

[0187] In the above embodiments, the hardware unit can be realized by mechanical means or electrical means. For example, a hardware unit or a processor can include a permanent dedicated circuit or logic (such as a special processor, FPGA or ASIC) to complete the corresponding operation. The hardware unit or the processor can also include programmable logic or circuit (such as a general-purpose processor or other programmable processors), which can be temporarily set up by software to complete the corresponding operation. Concrete implementation (mechanical means or dedicated permanent circuit or temporarily set circuit) can be determined based on the consideration in cost and time.

[0188] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for determining current based on an optical current transformer, the optical current transformer being used to sense the real-time current of a target device, the real-time current being an alternating current, the optical current transformer corresponding to a light source for providing incident light, the method comprising: 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 according to 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 according to the monitoring result and the real-time angle of the target rotation angle; Determining the real-time current of the target device according to the final rotation angle.

2. The method according to claim 1, wherein Determining a final rotation angle according to 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, 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 is in a monotonically increasing state and then in a monotonically decreasing 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: 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, characterized in that, After judging 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, the monitoring result is no; Determining a final rotation angle according to 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, the following is further included: 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, the following is further included: 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 reverses 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 yes, it is determined that the monitoring result is correct.

8. The method according to claim 1, wherein Determining 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 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: Where, 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 in a monotonically increasing state again, the monitoring result is negative; The second determining 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 are in a monotonically decreasing state and then in a monotonically increasing state, the monitoring result is positive; The second determining 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 judging unit, configured to judge at least one of the following conditions 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: 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 reverses 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.

Images