Method and apparatus for determining abnormal sampling points in a power system

Abstract

This invention provides a method and apparatus for determining abnormal sampling points in a power system. The method includes: continuously acquiring sampling points of a target quantity in the power system, wherein the curve of the target quantity is a periodic curve when the power system is not disturbed, and the number of sampling points included in each periodic curve is N; determining whether the change amplitude of u(n) satisfies a preset condition; if the determination result is yes, determining the difference a between u(n) and u(n-N); determining the difference b between u(n-1) and u(n-1-N); determining whether the following formula is satisfied: a≥Δu+b or a≤-Δu+b, where Δu is a preset threshold value; if the result is yes, determining the sampling point corresponding to u(n) as an abnormal sampling point.

Description

Technical Field

[0001] This invention relates to the field of power systems, and in particular to a method and apparatus for determining abnormal sampling points in a power system. Background Technology

[0002] If a fault occurs in a power component or the power system itself, the relay protection device can promptly issue an alarm signal or directly send a trip command to the circuit breaker it controls. Therefore, the relay protection device needs to continuously sample the voltage or current of the power system to determine whether a fault has occurred in a power component or the power system itself.

[0003] However, lightning strikes or operational overvoltages can interfere with the sampling of relay protection devices, resulting in incorrect sampling points, i.e., abnormal sampling points. Figure 4 As shown, sampling point 501 is an abnormal sampling point. At this time, the power system is not actually experiencing any fault, but this abnormal sampling point may cause the relay protection device to malfunction. Therefore, it is necessary to identify this abnormal sampling point. Summary of the Invention

[0004] In view of this, the present invention proposes a method for determining abnormal sampling points in a power system, comprising: continuously acquiring sampling points of a target quantity of the power system, wherein the curve of the target quantity is a periodic curve when the power system is not disturbed, and the number of sampling points included in each periodic curve is N;

[0005] The method further includes:

[0006] Determine whether the change in u(n) satisfies a preset condition;

[0007] If the judgment result is yes, then determine the difference a between u(n) and u(nN), where u(n) represents the value of the nth sampling point, u(nN) represents the value of the nNth sampling point, and n is a positive integer;

[0008] Determine the difference b between u(n-1) and u(n-1-N), where u(n-1) represents the value of the (n-1)th sampling point and u(n-1-N) represents the value of the (n-1-N)th sampling point;

[0009] Determine if the following formula is satisfied:

[0010] a≥Δu+b or a≤-Δu+b, where Δu is a preset threshold value;

[0011] If the judgment result is yes, then the sampling point corresponding to u(n) is determined to be an abnormal sampling point.

[0012] According to the method described above, n can optionally be a sampling point at a peak or a sampling point at a trough on the curve.

[0013] Optionally, according to the method described above, the preset condition is one of the following conditions:

[0014] Condition one:

[0015] Determine whether u(n+1)-u(n) is greater than or equal to a first preset threshold, where u(n+1) is the value of the current (n+1)th sampling point;

[0016] Determine whether u(n) - u(n-1) is less than or equal to a second preset threshold;

[0017] If all of the above determination results are yes, then it is determined that the change range of u(n) meets the preset conditions;

[0018] Condition two:

[0019] Determine whether u(n+1)-u(n) is less than or equal to a third preset threshold, where u(n+1) is the value of the current (n+1)th sampling point;

[0020] Determine whether u(n) - u(n-1) is greater than or equal to a fourth preset threshold;

[0021] If all of the above determinations are true, then it is determined that the change range of u(n) meets the preset conditions.

[0022] Optionally, according to the method described above, the first preset threshold is equal to Δu, and the second preset threshold is equal to -Δu; or

[0023] The third preset threshold is equal to -Δu, and the fourth preset threshold is equal to Δu;

[0024] or

[0025] The target quantity is voltage or current.

[0026] The present invention also provides an apparatus for determining abnormal sampling points in a power system, comprising:

[0027] An acquisition unit is used to continuously acquire sampling points of a target quantity of the power system. When the power system is not disturbed, the curve of the target quantity is a periodic curve, and the number of sampling points included in each period of the curve is N.

[0028] The device further includes:

[0029] A first judgment unit is used to determine whether the change range of u(n) meets a preset condition. If the judgment result is yes, a first determination unit is triggered.

[0030] The first determining unit is used to determine the difference a between u(n) and u(nN), where u(n) represents the value of the nth sampling point, u(nN) represents the value of the nNth sampling point, and n is a positive integer;

[0031] The second determining unit is used to determine the difference b between u(n-1) and u(n-1-N), where u(n-1) represents the value of the (n-1)th sampling point and u(n-1-N) represents the value of the (n-1-N)th sampling point;

[0032] The second judgment unit is used to determine whether the following formula is satisfied:

[0033] a≥Δu+b or a≤-Δu+b, where Δu is a preset threshold value;

[0034] If the judgment result is yes, then a third determination unit is triggered;

[0035] The third determining unit is used to determine that the sampling point corresponding to u(n) is an abnormal sampling point.

[0036] According to the apparatus described above, n can optionally be a sampling point at a peak or a trough on the curve.

[0037] According to the apparatus described above, optionally, the first determining unit is specifically used to determine whether the change range of u(n) satisfies a preset condition based on one of the following conditions:

[0038] Condition one:

[0039] Determine whether u(n+1)-u(n) is greater than or equal to a first preset threshold, where u(n+1) is the value of the current (n+1)th sampling point;

[0040] Determine whether u(n) - u(n-1) is less than or equal to a second preset threshold;

[0041] If all of the above determination results are yes, then it is determined that the change range of u(n) meets the preset conditions;

[0042] Condition two:

[0043] Determine whether u(n+1)-u(n) is less than or equal to a third preset threshold, where u(n+1) is the value of the current (n+1)th sampling point;

[0044] Determine whether u(n) - u(n-1) is greater than or equal to a fourth preset threshold;

[0045] If all of the above determinations are true, then it is determined that the change range of u(n) meets the preset conditions.

[0046] According to the apparatus described above, optionally, the first preset threshold is equal to Δu, and the second preset threshold is equal to -Δu; or

[0047] The third preset threshold is equal to -Δu, and the fourth preset threshold is equal to Δu;

[0048] or

[0049] The target quantity is voltage or current.

[0050] The present invention also provides an apparatus for determining abnormal sampling points in a power system, the apparatus comprising:

[0051] At least one memory for storing instructions;

[0052] At least one processor is configured to execute, according to instructions stored in the memory, a method for determining abnormal sampling points in a power system as described in any one of the above.

[0053] The present invention further provides a readable storage medium storing machine-readable instructions, which, when executed by a machine, perform a method for determining abnormal sampling points in a power system as described in any of the preceding claims.

[0054] As can be seen from the above solution, due to the present invention Attached Figure Description

[0055] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which will make the above and other features and advantages of the present invention more apparent to those skilled in the art. In the drawings:

[0056] Figure 1A This is a flowchart illustrating a method for determining abnormal sampling points in a power system according to an embodiment of the present invention.

[0057] Figure 1B This is a periodic curve of the target quantity according to an embodiment of the present invention.

[0058] Figure 2 This is a flowchart illustrating a method for determining abnormal sampling points in a power system according to another embodiment of the present invention.

[0059] Figure 3 This is a schematic diagram of a device for determining abnormal sampling points in a power system according to an embodiment of the present invention.

[0060] Figure 4 This is a schematic diagram of an abnormal sampling point based on the target quantity. Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of the present invention clearer, the following embodiments are provided to further illustrate the present invention in detail.

[0062] In a power system, a target quantity, when the system is undisturbed, is a periodic signal, meaning the curve representing that target quantity is periodic. This target quantity can be voltage or current. Periodic signals exhibit periodic characteristics, such as being a sine wave, meaning the values ​​at the same sampling point in different periods should be approximately equal. The curve in each period includes N sampling points, where N is a positive integer.

[0063] When a power system is disturbed, the target quantity may not follow a periodic curve at certain sampling points; these points are called abnormal sampling points. However, in some cases, the target quantity deviates from its previous periodic pattern due to load changes or other normal reasons. For example... Figure 1B As shown, the periodicity patterns of waveforms E and F are not the same, but the sampling points on waveforms E and F are not actually abnormal sampling points.

[0064] Based on this, the inventors proposed a method for determining abnormal sampling points in a power system.

[0065] Example 1

[0066] This embodiment provides a method for determining abnormal sampling points in a power system. The execution subject of this method is a device for determining abnormal sampling points in a power system, which can be integrated into a relay protection device.

[0067] like Figure 1A The diagram shown is a flowchart illustrating a method for determining abnormal sampling points in a power system according to this embodiment. The method includes:

[0068] Step 100: Continuously acquire sampling points of the target quantity of the power system.

[0069] When a power system is undisturbed, the curve of its target quantity is a periodic curve, such as a sine wave. When the target quantity is disturbed, it will change, for example... Figure 4 The sampling point shown is 501. The number of sampling points included in each period of the curve is N. The curve for this target quantity can be a sine wave. The number of sampling points N included in one period of the curve can be determined according to actual needs, for example, 16.

[0070] It should be noted that although the sampling point 501 has changed, causing the curve for that period to no longer be a complete periodic curve, the number of sampling points corresponding to that curve has not changed. In other words, the sampling period has not changed. After the same sampling period, the position of this sampling point on the curve remains unchanged, but its value may change significantly. Figure 4 For example, if Figure 4 If the curve in the diagram has horizontal and vertical coordinates, then the horizontal coordinate of sampling point 501 does not change, but its vertical coordinate changes significantly.

[0071] Step 101: Determine whether the change range of u(n) meets a preset condition. If the determination result is yes, then proceed to step 102.

[0072] This preset condition can be set according to actual needs. For example, it can be used to judge the change range between the nth sampling point and its two adjacent sampling points. If the change range is too large, it indicates that the nth sampling point may be an abnormal sampling point. This preset condition can be set according to actual needs and is not limited here. However, the condition is not satisfied if only the change range of u(n) is used. For example... Figure 1B When comparing sampling point 22 with its previous sampling point, the variation range is also large, but sampling point 22 is not an abnormal sampling point.

[0073] The nth sampling point here can be any sampling point, and there is no restriction on it.

[0074] Step 102: Determine the difference a between u(n) and u(nN).

[0075] Where u(n) represents the value of the nth sampling point, and u(nN) represents the value of the nNth sampling point, where n and N are both positive integers. The starting point of the first sampling point can be determined according to the actual situation and does not specifically refer to the initial sampling point. u(nN) actually represents the value of the sampling point at the same position in the curve of the previous period of u(n), such as points that are both peaks.

[0076] Step 103: Determine the difference b between u(n-1) and u(n-1-N).

[0077] Where u(n-1) represents the value of the (n-1)th sampling point, and u(n-1-N) represents the value of the (n-1-N)th sampling point. u(n-1) is the value of the sampling point preceding the nth sampling point, and u(n-1-N) represents the value of the sampling point at the same position as the (n-1)th sampling point in the curve of the previous period.

[0078] There is no specific order between steps 102 and 103; this embodiment is merely an example.

[0079] Step 104: Determine whether the following formula is satisfied: a≥Δu+b or a≤-Δu+b. If the result is yes, proceed to step 105.

[0080] Where Δu is a preset threshold value, which can be determined based on actual conditions, and will not be elaborated here. The reason for using the above formula is that the interference factor of the braking quantity b has been removed. For example, if the voltage or load of the power system changes, causing a sudden increase or decrease in the sampled value, the periodicity characteristic will temporarily not be satisfied. Figure 1B As shown, waveform E is the periodic curve before the target quantity changes, and waveform F is the periodic curve after the target quantity changes. The periodicity characteristic between waveform E and waveform F is not satisfied; the values ​​of sampling points at the same location differ significantly. However, none of the sampling points detected in waveform F should be considered outliers. Therefore, a braking amount b is needed to counteract the changes in normal sampling values. Figure 1B The figure shows the nth sampling point 11 located at the peak of waveform E and the nth sampling point 12 located at the peak of waveform F, with a difference between them. It also shows the n-1-Nth sampling point 21 located at the peak of waveform E and the n-1th sampling point 22 located at the peak of waveform F, with a difference between them.

[0081] Furthermore, if u(n-1) represents the value of the origin of the periodic curve, then n+1 can be used to replace n, and the process returns to step 102. This is because the braking amount at the same position of the origin in different periods is 0, which cannot truly detect the magnitude of the braking amount; the next sampling point needs to be used for detection.

[0082] Step 105: Determine the sampling point corresponding to u(n) as an abnormal sampling point.

[0083] Once the nth sampling point is determined to be an abnormal sampling point, it can be removed to avoid affecting the judgment of the relay protection device.

[0084] If the result of step 104 is negative, it means that the nth sampling point is a normal sampling point. For example, a sudden increase in voltage may cause two adjacent voltage curves to no longer exhibit periodicity, but the sampling point on the subsequent voltage curve should not actually be considered an abnormal sampling point. Replace n with the value of n+1 and return to step 101. In this way, sampling and judging whether abnormal sampling points have occurred simultaneously is efficient and timely.

[0085] Optionally, in this embodiment, n can be a sampling point at a peak or a trough on the curve, because the values ​​of these two sampling points best reflect the characteristics of the curve within a period, especially the characteristics of a periodic curve. It should be noted that the peak or trough refers to the position of the sampling point within the periodic curve. If the value of the sampling point changes significantly, making it no longer a true peak or trough of the curve, it is still considered a sampling point at a peak or trough of the curve.

[0086] According to this embodiment, the characteristic of periodic change of target quantity in power system is utilized. The difference between sampling points at the same position of curves in different periods should be less than or equal to a preset threshold value. Furthermore, this embodiment uses braking amount b to offset the change of normal sampling value, thereby accurately identifying abnormal sampling points.

[0087] Example 2

[0088] This embodiment further supplements the method for determining abnormal sampling points in a power system described in Embodiment 1.

[0089] like Figure 2 The diagram shown is a flowchart illustrating a method for determining abnormal sampling points in a power system according to this embodiment. The method includes:

[0090] Step 200: Continuously acquire sampling points of the target quantity of the power system.

[0091] When the power system is undisturbed, the curve of the target quantity is a periodic curve, and the number of sampling points included in each period of the curve is N. The specific content of this step is the same as that of step 100, and will not be repeated here.

[0092] Step 201: Determine whether condition one or condition two is met. If the result is met, proceed to step 203; otherwise, proceed to step 207.

[0093] Condition 1: Determine whether u(n+1)-u(n) is greater than or equal to a first preset threshold, and determine whether u(n)-u(n-1) is less than or equal to a second preset threshold. If both are true, the determination result is satisfied.

[0094] Condition 2: Determine whether u(n+1)-u(n) is less than or equal to a third preset threshold, and determine whether u(n)-u(n-1) is greater than or equal to a fourth preset threshold. If both are true, the result is considered satisfied.

[0095] Where u(n+1) is the value of the (n+1)th sampling point, which can be the current sampling point. Then, the judgment after step 201 is executed immediately, so as to quickly determine whether u(n) is an abnormal sampling point. The first and second preset thresholds can be set according to the actual situation. For example, the first preset threshold is Δu, and the second preset threshold is -Δu. Optionally, the third preset threshold is equal to -Δu, and the fourth preset threshold is equal to Δu. Such preset threshold values ​​can make the overall judgment criteria consistent.

[0096] Step 201 can be considered a basic judgment step, that is, determining whether the nth sampling point has a sudden change by using three adjacent sampling points. However, this condition can only make a preliminary judgment and is not precise. For example, it may lead to misjudgment for sampling values ​​with harmonics, or when the amplitude of the target quantity is very large, the sampling points at the peaks or troughs may easily satisfy one of the two conditions in step 201.

[0097] Step 202: Determine the difference a between u(n) and u(nN).

[0098] Where u(n) represents the value of the nth sampling point, u(nN) represents the value of the nNth sampling point, and n is a positive integer.

[0099] In this step, a=u(n)-u(nN).

[0100] Step 203: Determine the difference b between u(n-1) and u(n-1-N).

[0101] Where u(n-1) represents the value of the (n-1)th sampling point, and u(n-1-N) represents the value of the (n-1-N)th sampling points. In this step, b = u(n-1) - u(n-1-N).

[0102] This step is to obtain the braking amount b.

[0103] Step 204: Determine whether the following formula is satisfied: a≥Δu+b or a≤-Δu+b. If the result is yes, proceed to step 205; otherwise, proceed to step 206.

[0104] This step is the same as step 104, and will not be repeated here.

[0105] Step 205: Determine the sampling point corresponding to u(n) as an abnormal sampling point.

[0106] After identifying u(n) as an outlier, the outlier sampling point is removed to avoid it affecting the judgment of other devices, such as preventing misjudgments by relay protection devices.

[0107] Step 206: Update n to n+1 and return to execute step 201.

[0108] Step 206 is the operation of determining whether the nth sampling point corresponding to u(n) is an abnormal sampling point, and then determining whether the (n+1)th sampling point is an abnormal sampling point.

[0109] In this embodiment, the nth sampling point is first initially judged to be an abnormal sampling point by using two sampling points adjacent to the nth sampling point. Then, the sampling point in the previous period at the same position as the nth sampling point is used to further judge whether the nth sampling point is an abnormal sampling point. This dual judgment makes the judgment result more accurate.

[0110] Example 3

[0111] This embodiment provides an apparatus for determining abnormal sampling points in a power system, used to execute the method for determining abnormal sampling points in a power system described in the foregoing embodiment.

[0112] like Figure 3 The diagram shown is a structural schematic of a device for determining abnormal sampling points in a power system according to this embodiment. The device includes an acquisition unit 301, a first judgment unit 302, a first determination unit 303, a second determination unit 304, a second judgment unit 305, and a third determination unit 306.

[0113] The acquisition unit 301 is used to continuously acquire sampling points of the target quantity of the power system. When the power system is not disturbed, the curve of the target quantity is a periodic curve, and the number of sampling points included in each period of the curve is N. The first judgment unit 302 is used to judge whether the change amplitude of u(n) meets a preset condition. If the judgment result is yes, a first determination unit 303 is triggered. The second determination unit 304 is used to determine the difference b between u(n-1) and u(n-1-N), where u(n-1) represents the value of the (n-1)th sampling point and u(n-1-N) represents the value of the (n-1-N)th sampling point. The second judgment unit 305 is used to judge whether the following formula is satisfied: a≥Δu+b or a≤-Δu+b, where Δu is a preset threshold value. If the judgment result is yes, a third determination unit 306 is triggered. The third determination unit 306 determines that the sampling point corresponding to u(n) is an abnormal sampling point, that is, the nth sampling point is an abnormal sampling point.

[0114] Optionally, n represents the sampling point at the peak or trough of the curve.

[0115] Optionally, the first judgment unit 302 is specifically used to determine whether the change range of u(n) satisfies a preset condition based on one of the following conditions:

[0116] Condition one:

[0117] Determine whether u(n+1)-u(n) is greater than or equal to a first preset threshold, where u(n+1) is the value of the current (n+1)th sampling point;

[0118] Determine whether u(n) - u(n-1) is less than or equal to a second preset threshold;

[0119] If all of the above determination results are yes, then it is determined that the change range of u(n) meets the preset conditions;

[0120] Condition two:

[0121] Determine whether u(n+1)-u(n) is less than or equal to a third preset threshold, where u(n+1) is the value of the current (n+1)th sampling point;

[0122] Determine whether u(n) - u(n-1) is greater than or equal to a fourth preset threshold;

[0123] If all of the above determinations are true, then it is determined that the change range of u(n) meets the preset conditions.

[0124] Optionally, the first preset threshold is equal to Δu, and the second preset threshold is equal to -Δu; or

[0125] The third preset threshold is equal to -Δu, and the fourth preset threshold is equal to Δu.

[0126] Optionally, the target quantity is voltage or current.

[0127] According to this embodiment, the characteristic of periodic change of target quantity in power system is utilized. The difference between sampling points at the same position of curves in different periods should be less than or equal to a preset threshold value. Furthermore, this embodiment uses braking amount b to offset the change of normal sampling value, thereby accurately identifying abnormal sampling points.

[0128] The present invention also provides an apparatus for determining abnormal sampling points in a power system. The apparatus includes at least one memory and at least one processor, wherein the memory is used to store instructions; and the processor is used to execute, according to the instructions stored in the memory, the method for determining abnormal sampling points in a power system as described in any of the foregoing embodiments.

[0129] Embodiments of the present invention also provide a readable storage medium. This readable storage medium stores machine-readable instructions, which, when executed by a machine, perform the method for determining abnormal sampling points in a power system as described in any of the foregoing embodiments.

[0130] 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 apparatus equipped with a readable storage medium storing software program code that implements the functions of any of the embodiments described above, and causing the computer or processor of the system or apparatus to read and execute the machine-readable instructions stored in the readable storage medium.

[0131] In this case, the program code itself, which can be read from a readable medium, can perform the functions of any 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.

[0132] Examples of readable storage media 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. Alternatively, program code can be downloaded from a server computer or the cloud via a communication network.

[0133] Those skilled in the art will understand that the various embodiments disclosed above can be modified and varied without departing from the spirit of the invention. Therefore, the scope of protection of this invention should be defined by the appended claims.

[0134] It should be noted that not all steps and units in the above process and system structure diagrams are mandatory; some steps or units can be omitted as needed. The execution order of each step is not fixed and can be adjusted as required. 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 they may be jointly implemented by certain components in multiple independent devices.

[0135] In the above embodiments, the hardware units can be implemented mechanically or electrically. For example, a hardware unit or processor may include permanent dedicated circuitry or logic (such as a dedicated processor, FPGA, or ASIC) to perform the corresponding operations. The hardware unit or processor may also include programmable logic or circuitry (such as a general-purpose processor or other programmable processor), which can be temporarily configured by software to perform the corresponding operations. The specific implementation method (mechanical, dedicated permanent circuitry, or temporarily configured circuitry) can be determined based on cost and time considerations.

[0136] The above are merely preferred embodiments of the present invention and are 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 within the protection scope of the present invention.

Claims

1. A method for determining abnormal sampling points in a power system, including: The sampling points of the target quantity of the power system are continuously acquired. When the power system is not disturbed, the curve of the target quantity is a periodic curve, and the number of sampling points included in each period of the curve is N. The method is characterized in that it further includes: Determine whether the magnitude of change of u(n) satisfies a preset condition; If the judgment result is yes, then determine the difference a between u(n) and u(nN), where u(n) represents the value of the nth sampling point, u(nN) represents the value of the nNth sampling point, and n is a positive integer; Determine the difference b between u(n-1) and u(n-1-N), where u(n-1) represents the value of the (n-1)th sampling point and u(n-1-N) represents the value of the (n-1-N)th sampling point; Determine if the following formula is satisfied: a≥Δu+b or a≤-Δu+b, where Δu is a preset threshold value; If the judgment result is yes, then the sampling point corresponding to u(n) is determined to be an abnormal sampling point; The preset condition is one of the following conditions: Condition one: Determine whether u(n+1) - u(n) is greater than or equal to a first preset threshold, where u(n+1) is the value of the current (n+1)th sampling point; Determine whether u(n) - u(n-1) is less than or equal to a second preset threshold; If all of the above determination results are yes, then it is determined that the change range of u(n) meets the preset conditions; Condition two: Determine whether u(n+1) - u(n) is less than or equal to a third preset threshold, where u(n+1) is the value of the current (n+1)th sampling point; Determine whether u(n) - u(n-1) is greater than or equal to a fourth preset threshold; If all of the above determinations are true, then it is determined that the change range of u(n) meets the preset conditions.

2. The method according to claim 1, characterized in that, n represents the sampling point at the peak or trough of the curve.

3. The method according to claim 1, characterized in that, The first preset threshold is equal to Δu, and the second preset threshold is equal to -Δu; or The third preset threshold is equal to -Δu, and the fourth preset threshold is equal to Δu; or The target quantity is voltage or current.

4. A device for determining abnormal sampling points in a power system, comprising: An acquisition unit is used to continuously acquire sampling points of a target quantity of the power system. When the power system is not disturbed, the curve of the target quantity is a periodic curve, and the number of sampling points included in each period of the curve is N. The device is characterized in that it further includes: A first judgment unit is used to determine whether the change range of u(n) meets a preset condition. If the judgment result is yes, a first determination unit is triggered. The first determining unit is used to determine the difference a between u(n) and u(nN), where u(n) represents the value of the nth sampling point, u(nN) represents the value of the nNth sampling point, and n is a positive integer; The second determining unit is used to determine the difference b between u(n-1) and u(n-1-N), where u(n-1) represents the value of the (n-1)th sampling point and u(n-1-N) represents the value of the (n-1-N)th sampling point; The second judgment unit is used to determine whether the following formula is satisfied: a≥Δu+b or a≤-Δu+b, where Δu is a preset threshold value; If the judgment result is yes, then a third determination unit is triggered; The third determining unit is used to determine that the sampling point corresponding to u(n) is an abnormal sampling point; The first judgment unit is specifically used to determine whether the change range of u(n) meets a preset condition based on one of the following conditions: Condition one: Determine whether u(n+1) - u(n) is greater than or equal to a first preset threshold, where u(n+1) is the value of the current (n+1)th sampling point; Determine whether u(n) - u(n-1) is less than or equal to a second preset threshold; If all of the above determination results are yes, then it is determined that the change range of u(n) meets the preset conditions; Condition two: Determine whether u(n+1) - u(n) is less than or equal to a third preset threshold, where u(n+1) is the value of the current (n+1)th sampling point; Determine whether u(n) - u(n-1) is greater than or equal to a fourth preset threshold; If all of the above determinations are true, then it is determined that the change range of u(n) meets the preset conditions.

5. The apparatus according to claim 4, characterized in that, n represents the sampling point at the peak or trough of the curve.

6. The apparatus according to claim 4, characterized in that, The first preset threshold is equal to Δu, and the second preset threshold is equal to -Δu; or The third preset threshold is equal to -Δu, and the fourth preset threshold is equal to Δu; or The target quantity is voltage or current.

7. An apparatus for determining abnormal sampling points in a power system, characterized in that, The device includes: At least one memory for storing instructions; At least one processor is configured to execute, according to instructions stored in the memory, a method for determining abnormal sampling points in a power system as described in any one of claims 1-3.

8. A readable storage medium, characterized in that, The readable storage medium stores machine-readable instructions, which, when executed by a machine, perform a method for determining abnormal sampling points in a power system according to any one of claims 1-3.

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