Transient quantity protection starting method and device, readable storage medium and electronic equipment

Abstract

The application discloses a transient quantity protection starting method and device, a readable storage medium and an electronic equipment. The transient quantity protection starting method comprises the following steps: acquiring sampling data, wherein the sampling data is obtained by performing high-pass filtering and high-frequency sampling processing on a transient quantity in a protected power system; calculating a first starting quantity average value change quantity sequence and a second starting quantity variance sequence based on the sampling data; determining that any first starting quantity average value change quantity in the first starting quantity average value change quantity sequence is greater than a first threshold value; determining that a second starting quantity variance before a preset time of the first starting quantity average value change quantity is less than a second threshold value; and starting the transient quantity protection.

Description

Technical Field

[0001] This application relates to the field of power system relay protection, and more specifically, to a transient quantity protection initiation method and apparatus, a readable storage medium, and an electronic device. Background Technology

[0002] A "transient state" refers to the transition process when a circuit changes its state from a stable state under certain conditions (such as a fault in the power grid circuit) and enters another stable state through a transition process.

[0003] "Transient quantity" refers to a data reference quantity that changes during a transient process, such as current transient quantity and voltage transient quantity. When a fault occurs in the power grid, the protection that determines the location of the fault based on the changing characteristics of the transient quantity during the fault and isolates the faulty component is called "transient quantity protection".

[0004] Transient quantity protection has the advantages of rapid protection action and low susceptibility to interference from power electronic equipment strategies. It has promising applications in the field of relay protection for power systems with electronic power systems.

[0005] The activation of transient quantity protection relies on an activation algorithm based on current transients and / or voltage transients. The transient quantity protection is activated when the current transients and / or voltage transients meet certain preset activation algorithm requirements.

[0006] An effective transient protection startup algorithm should be able to reliably start when a grid fault occurs, avoid starting transient protection as much as possible when transient changes are caused by non-grid faults, and ensure timeliness when starting transient protection.

[0007] However, the inventors of this application have discovered the following problems with the current transient quantity protection startup algorithm.

[0008] 1. Current transient protection startup algorithms cannot effectively distinguish between interference and fault transients, which can easily lead to false startup of transient protection.

[0009] 2. Current transient protection startup algorithms set a certain blocking time after starting transient protection, which cannot adapt to scenarios where transient protection needs to be started multiple times when a transitional fault occurs in a short period of time. Summary of the Invention

[0010] At least one embodiment of this disclosure provides a transient quantity protection start-up method, a transient quantity protection start-up device, a readable access medium, and an electronic device.

[0011] According to a first aspect of this application, a transient quantity protection initiation method is provided. The method includes: acquiring sampled data, wherein the sampled data is obtained by high-pass filtering and high-frequency sampling processing of transient quantities in the protected power system; based on the sampled data, calculating a first initiation quantity average value change sequence and a second initiation quantity variance sequence; determining that any first initiation quantity average value change in the first initiation quantity average value change sequence is greater than a first threshold; determining that the second initiation quantity variance before a preset time of the first initiation quantity average value change is less than a second threshold; and initiating transient quantity protection.

[0012] For example, in some embodiments of the first aspect of this disclosure, the transient quantity includes a current transient quantity and / or a voltage transient quantity; calculating the first starting quantity average value change sequence and the second starting quantity variance sequence based on the sampled data includes: calculating the first starting quantity sequence according to the sampled data; wherein, when the transient quantity is a current transient quantity, the first starting quantity sequence is a first current starting quantity sequence; when the transient quantity is a voltage transient quantity, the first starting quantity sequence is a first voltage starting quantity sequence; when the transient quantity is both a current transient quantity and a voltage transient quantity, the first starting quantity sequence is a first current starting quantity sequence and a first voltage starting quantity sequence; and calculating the first starting quantity average value change sequence and the second starting quantity variance sequence according to the first starting quantity sequence.

[0013] For example, in some embodiments of the first aspect of this disclosure, the first current initiation sequence is: M I ={q1(1), q1(2), q1(3), ..., q1(k), ..., q1(L)}, where M I Let L be the first current initiation quantity sequence; L be the length of the first current initiation quantity sequence; q1(k) be the kth value of the first current initiation quantity sequence; the time corresponding to the kth value is t; the formula for calculating the kth value of the first current initiation quantity sequence is: q1(k) = |i a (t)|+|i b (t)|+|i c (t)|, the first voltage initiation sequence is: M U ={q1(1), q1(2), q1(3)...q1(k)...q1(L)}, where M U Let L be the first voltage initiation quantity sequence; L be the length of the first voltage initiation quantity sequence; q1(k) be the kth value of the first voltage initiation quantity sequence; the time corresponding to the kth value is t; the formula for calculating the kth value of the first voltage initiation quantity sequence is: q1(k) = |U a (t)|+|U b (t)|+|U c (t)|, where k is a non-zero natural number.

[0014] For example, in some embodiments of the first aspect of this disclosure, the first current initiation sequence is: M I ={q1(1), q1(2), q1(3), ..., q1(k), ..., q1(L)}, where M I Let L be the first current initiation quantity sequence; L be the length of the first current initiation quantity sequence; q1(k) be the kth value of the first current initiation quantity sequence; the time corresponding to the kth value is t; the formula for calculating the kth value of the first current initiation quantity sequence is: q1(k) = |i a (t)-i b (t)|+|i b (t)-i c (t)|+|i c (t)-i a (t)|, the first voltage initiation sequence is: M U ={q1(1), q1(2), q1(3)...q1(k)...q1(L)}, where M U Let L be the first voltage initiation quantity sequence; L be the length of the first voltage initiation quantity sequence; q1(k) be the kth value of the first voltage initiation quantity sequence; the time corresponding to the kth value is t; the formula for calculating the kth value of the first voltage initiation quantity sequence is: q1(k) = |U a (t)-U b (t)|+|U b (t)-U c (t)|+|U c (t)-U a (t)|, where k is a non-zero natural number.

[0015] For example, in some embodiments of the first aspect of this disclosure, calculating the first start-up quantity average change sequence and the second start-up quantity variance sequence based on sampled data further includes: calculating the first start-up quantity average sequence based on the first start-up quantity sequence; the calculation formula for the first start-up quantity average sequence is:

[0016]

[0017] Where v1(k) is the kth value of the first starting quantity average sequence; q1(j) is the jth value of the first starting quantity sequence; N1 is the data length for calculating the first starting quantity average, where j and k are both non-zero natural numbers; and the second starting quantity variance sequence is calculated based on the first starting quantity average sequence.

[0018] For example, in some embodiments of the first aspect of this disclosure, calculating the first start-up quantity average change sequence and the second start-up quantity variance sequence based on sampled data further includes: calculating the first start-up quantity average change sequence based on the first start-up quantity average sequence; the calculation formula for the first start-up quantity average change sequence is: d1(k)=|v1(k)-v1(kT)|, where d1(k) is the kth value of the first start-up quantity average change sequence; v1(kT) is the kTth value of the first start-up quantity average sequence; T is the step size for calculating the change; and calculating the second start-up quantity variance sequence based on the first start-up quantity average sequence.

[0019] For example, in some embodiments of the first aspect of this disclosure, calculating the second startup quantity variance sequence based on the first startup quantity average sequence includes: calculating the second startup quantity average sequence based on the first startup quantity average sequence; the calculation formula for the second startup quantity average sequence is:

[0020]

[0021] Where v2(k) is the kth value of the second start-up quantity average sequence; v1(j) is the jth value of the first start-up quantity average sequence; N2 is the data length for calculating the second start-up quantity average; and the second start-up quantity variance sequence is calculated based on the second start-up quantity average sequence.

[0022] For example, in some embodiments of the first aspect of this disclosure, the formula for calculating the variance sequence of the second initiation quantity based on the average sequence of the second initiation quantity is as follows:

[0023]

[0024] Wherein, s2(k) is the kth value of the second starting quantity variance sequence; v2(j) is the jth value of the second starting quantity average sequence; and v1(j) is the jth value of the first starting quantity average sequence.

[0025] For example, in some embodiments of the first aspect of this disclosure, the transient quantity protection initiation method further includes: calculating a first initiation quantity variance sequence based on a first initiation quantity sequence; the calculation formula for the first initiation quantity variance sequence is:

[0026]

[0027] Wherein, s1(k) is the kth value of the first starting quantity variance sequence; v1(j) is the jth value of the first starting quantity average sequence; q1(j) is the jth value of the first starting quantity sequence.

[0028] For example, in some embodiments of the first aspect of this disclosure, the first threshold is M. set1 First threshold M set1The calculation formula is: M set1 =D set +f(s1(kT)), where D set s1(KT) is a preset value; s1(KT) is the KTth value of the variance sequence of the first starting quantity; f is a function that varies with s1(KT).

[0029] According to a second aspect of this disclosure, a transient quantity protection start-up device is provided, comprising: a data acquisition unit, which performs high-pass filtering and high-frequency sampling processing on transient quantities connected to the transient quantity protection start-up device to obtain acquired data; a processing unit, which receives the acquired data and calculates a first start-up quantity average value change sequence and a second start-up quantity variance sequence based on the acquired data; a judgment unit, which judges the magnitude of any first start-up quantity average value change in the first start-up quantity average value change sequence and a first threshold, and judges the magnitude of the second start-up quantity variance before a preset time of the first start-up quantity average value change and a second threshold; and an execution unit, which receives the judgment result from the judgment unit, and when the judgment result is that any first start-up quantity average value change is greater than the first threshold, and the second start-up quantity variance before the preset time of the first start-up quantity average value change is less than the second threshold, the execution unit executes a transient quantity protection start-up action.

[0030] According to a third aspect of this disclosure, a non-volatile computer-readable storage medium is provided, on which a computer program is stored, the computer program causing a transient protection start-up device to implement the transient protection start-up method as described above.

[0031] According to a fourth aspect of this disclosure, an electronic device for transient quantity protection startup is provided, comprising: one or more processors; a storage device for storing one or more programs; wherein when one or more programs are executed by one or more processors, the one or more processors implement the transient quantity protection startup method as described above.

[0032] The technical solution of this application compares the change in the average value of the first activation quantity and the variance of the second activation quantity with a preset threshold, and makes a comprehensive fault judgment on the protected power system based on the average value and change of the transient quantity. The transient quantity protection activation method provided by this application can effectively improve the reliability of transient quantity protection when a power system fault occurs. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 A flowchart 1000 is shown, illustrating a transient quantity protection initiation method according to an example embodiment of this application;

[0035] Figure 2 Figure 2000 illustrates a data processing procedure according to an example embodiment of this application;

[0036] Figure 3 Figure 3000 illustrates another data processing procedure according to an example embodiment of this application;

[0037] Figure 4 A schematic diagram 4000 of a transient quantity protection start device according to an example embodiment of this application is shown.

[0038] Figure label:

[0039] Transient quantity protection start device 1; data acquisition unit 10; processing unit 30; judgment unit 50; execution unit 70. Detailed Implementation

[0040] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this application will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted.

[0041] The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced without one or more of these specific details, or other methods, components, materials, devices, etc. In these cases, well-known structures, methods, devices, implementations, materials, or operations will not be shown or described in detail.

[0042] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0043] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order.

[0044] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0045] According to one aspect of this application, a transient quantity protection initiation method is provided. Figure 1 A flowchart 1000 is shown for a transient quantity protection initiation method according to an example embodiment of this application.

[0046] See Figure 1 Method 1000 includes steps S110 to S190.

[0047] In step S110, the transient quantity protection activation device acquires the sampling data.

[0048] The sampled data is obtained by high-pass filtering and high-frequency sampling of transient quantities in the protected power system.

[0049] Optionally, transient quantities include current transients and voltage transients.

[0050] For example, if the transient quantity is a current transient quantity, obtain the three-phase current value of the current transient quantity. If the transient quantity is a voltage transient quantity, obtain the three-phase voltage value of the voltage transient quantity.

[0051] Figure 2 Figure 2000 illustrates a data processing procedure according to an example embodiment of this application. Figure 3 This diagram illustrates another data processing procedure according to an example embodiment of the present application.

[0052] See Figure 2 and Figure 3 Data processing includes high-pass filtering and high-frequency sampling of transient quantities. The following section combines... Figure 2 and Figure 3 To describe Figure 1 Step S110 in the process.

[0053] For example, see Figure 2 When the transient quantity is a current transient quantity, in step S110, the three-phase current values ​​of the current transient quantity are i′ respectively. a (t), i′ b (t), i′ c (t).

[0054] When the transient quantity is a current transient quantity, step S110 also involves setting the three-phase current value i′ of the current transient quantity. a (t), i′ b (t), i′c (t) are processed by high-pass filtering to obtain i a (t), i b (t), i c (t).

[0055] High-pass filtering is a filtering method that allows high-frequency signals to pass through normally, while blocking low-frequency signals below a set threshold.

[0056] According to the example embodiment, the three-phase current value i′ of the transient quantity at the transient quantity protection device is generally collected by a current transformer. a (t), i′ b (t), i′ c (t). The current value collected by the current transformer is the secondary current. In addition to the required transient current, the secondary current also contains some power frequency quantities and noise.

[0057] Power frequency quantities typically have a frequency of 50Hz or 60Hz, while transient quantities have a frequency much higher than that of power frequency quantities. Therefore, the three-phase current values ​​of the collected transient current quantities need to be high-pass filtered to remove impurities such as power frequency quantities and low-frequency noise, thereby improving the signal-to-noise ratio of the transient current quantities.

[0058] See Figure 2 In step S110, the data processing procedure also includes processing the three-phase current values ​​i obtained after high-pass filtering. a (t), i b (t), i c (t) is subjected to high-frequency sampling to obtain i a (k), i b (k), i c (k).

[0059] High-frequency sampling refers to collecting data at a frequency higher than a preset value. According to the example embodiment, the sampling frequency of high-frequency sampling is not less than 10kHz.

[0060] See Figure 3 , Figure 3 This refers to the data processing procedure for the three-phase voltage values ​​of voltage transient quantities.

[0061] If the transient quantity is a voltage transient quantity, in step S110, the three-phase voltage value u′ of the voltage transient quantity is obtained. a (t), u′ b (t), u′ c (t). In step S110, the three-phase voltage value u′ a (t), u′ b (t), u′ c (t) The three-phase voltage value u of the voltage transient is obtained after high-pass filtering and high-frequency sampling.a (k), u b (k), u c (k).

[0062] The data processing procedure for the three-phase voltage values ​​of voltage transients is the same as that for the three-phase current values ​​of current transients, and will not be described in detail here.

[0063] Through the above embodiments, by performing data processing such as high-pass filtering and high-frequency sampling on transient quantities, impurities such as power frequency quantities and noise in the collected data can be removed, thereby obtaining relatively clean transient quantity collected data.

[0064] In step S130, based on the sampled data, the first starting amount average change sequence and the second starting amount variance sequence are calculated.

[0065] For example, the first initiation sequence is calculated based on the sampled data.

[0066] Optionally, in step S130, if the transient quantity is a current transient quantity, the first starting quantity sequence is a first current starting quantity sequence.

[0067] For example, the first current initiation sequence is:

[0068] M I ={q1(1), q1(2), q1(3),…, q1(k),…, q1(L)}

[0069] Among them, M I Let L be the first current initiation quantity sequence; L be the length of the first current initiation quantity sequence; q1(k) be the kth value of the first current initiation quantity sequence; and the time corresponding to the kth value is t.

[0070] According to the example embodiment, the kth value of the first current initiation quantity sequence is the three-phase current value i of the current transient quantity at time t. a (t), i b (t), i c It is calculated by summing the absolute values ​​of (t).

[0071] For example, the formula for calculating the kth value of the first current initiation sequence is:

[0072] q1(k)=|i a (t)|+|i b (t)|+|i c (t)|.

[0073] Optionally, according to the example embodiment, in order to eliminate the common bias and noise interference between the various current phases, the k-th value of the first current initiation quantity sequence can be obtained from the three-phase current value i of the current transient quantity at time t. a(t), i b (t), i c It is calculated by summing the absolute values ​​of the phase-to-phase currents (t).

[0074] For example, the formula for calculating the kth value of the first current initiation sequence is:

[0075] q1(k)=|i a (t)-i b (t)|+|i b (t)-i c (t)|+|i c (t)-i a (t)|, where k is a non-zero natural number.

[0076] Optionally, in step S130, if the transient quantity is a voltage transient quantity, the first initiation quantity sequence is a first voltage initiation quantity sequence.

[0077] For example, the first voltage initiation sequence is:

[0078] M U ={q1(1),q1(2),q1(3)....q1(k)....q1(L)}

[0079] Among them, M U Let L be the first voltage initiation quantity sequence; L be the length of the first voltage initiation quantity sequence; q1(k) be the kth value of the first voltage initiation quantity sequence; and t be the time corresponding to the kth value.

[0080] According to the example embodiment, the kth value of the first voltage initiation quantity sequence is obtained through the three-phase voltage value u of the voltage transient quantity at time t. a (t), u b (t), u c It is calculated by summing the absolute values ​​of (t).

[0081] For example, the formula for calculating the kth value of the first voltage initiation sequence is:

[0082] q1(k)=|U a (t)|+|U b (t)|+|U c (t)|.

[0083] Optionally, according to the example embodiment, in order to eliminate the common bias and noise interference between the various voltage phases, the k-th value of the first voltage initiation quantity sequence can be obtained from the three-phase voltage value u of the voltage transient quantity at time t. a (t), u b (t), u c The sum of the absolute values ​​of the phase-to-phase voltages (t) is used to calculate the value.

[0084] For example, the formula for calculating the kth value of the first voltage initiation sequence is:

[0085] q1(k)=|U a (t)-U b (t)|+|U b (t)-U c (t)|+|U c (t)-U a (t)|, where k is a non-zero natural number.

[0086] Optionally, in step S130, a first start-up quantity average value sequence is calculated based on the first start-up quantity sequence.

[0087] The formula for calculating the average sequence of the first initiation quantity is:

[0088]

[0089] Where v1(k) is the kth value of the first start-up quantity average sequence; q1(j) is the jth value of the first start-up quantity sequence; N1 is the data length for calculating the first start-up quantity average, where j and k are both non-zero natural numbers.

[0090] According to the example embodiment, the data length N1 for calculating the average value of the first startup quantity should be greater than the maximum variation period of the random noise. The specific value of N1 depends on the conditions of the selected hardware facility.

[0091] Optionally, in step S130, the change sequence of the first start-up quantity average value is calculated based on the first start-up quantity average value sequence.

[0092] According to the example embodiment, the kth value of the change sequence of the first start-up quantity average value is calculated based on the absolute value of the difference between the kth value and the kTth value of the first start-up quantity average value.

[0093] For example, the formula for calculating the average change sequence of the first initiation quantity is:

[0094] d1(k) = |v1(k) - v1(kT)|

[0095] Where d1(k) is the kth value of the first starting quantity average change sequence; v1(kT) is the kTth value of the first starting quantity average sequence; and T is the step size for calculating the change.

[0096] Through the above embodiments, the average change sequence of the first initiation quantity is calculated using the first initiation quantity sequence to characterize the instantaneous change of the transient quantity within a certain step size.

[0097] Optionally, in step S130, a second start-up quantity average sequence is calculated based on the first start-up quantity average sequence.

[0098] For example, the formula for calculating the average sequence of the second initiation quantity is:

[0099]

[0100] Where v2(k) is the kth value of the second startup quantity average sequence; v1(j) is the jth value of the first startup quantity average sequence; and N2 is the data length for calculating the second startup quantity average.

[0101] According to the example embodiment, the data length N2 for calculating the average value of the second startup quantity can be further shortened based on the data length N1 for calculating the average value of the first startup quantity.

[0102] For example, N2 = N1 / 2.

[0103] Optionally, in step S130, the second start-up quantity variance sequence is calculated based on the second start-up quantity average sequence.

[0104] The formula for calculating the variance sequence of the second initiation quantity is:

[0105]

[0106] Wherein, s2(k) is the kth value of the second starting quantity variance sequence; v2(j) is the jth value of the second starting quantity average sequence; and v1(j) is the jth value of the first starting quantity average sequence.

[0107] In the above embodiments, in step S130, a second start-up quantity average sequence is calculated from the first start-up quantity average sequence, and a second start-up quantity variance sequence is calculated from the second start-up quantity average sequence.

[0108] In step S150, the transient quantity protection start device determines that any change in the average value of the first start quantity in the first start quantity average value change sequence is greater than the first threshold.

[0109] For example, in step S150, the magnitude of any change in the average value of the first start-up quantity in the first start-up quantity average change sequence is compared with the first threshold.

[0110] According to the example embodiment, any change in the average value of the first startup quantity in the sequence of changes in the average value of the first startup quantity is d1(k), and the first threshold is M. set1 .

[0111] Optionally, in step S150, a first start-up quantity variance sequence is calculated based on the first start-up quantity sequence.

[0112] For example, the formula for calculating the variance sequence of the first initiation quantity is:

[0113]

[0114] Wherein, s1(k) is the kth value of the first starting quantity variance sequence; v1(j) is the jth value of the first starting quantity average sequence; q1(j) is the jth value of the first starting quantity sequence.

[0115] Optionally, the first threshold M set1 For dynamic thresholds, the first threshold M set1 Calculated using the variance sequence of the first initiation quantity. First threshold M set1 It is the sum of the function values ​​of the preset value and the KTth value of the variance sequence of the first starting quantity.

[0116] For example, determining the change in the average value of the first start-up quantity relative to the first threshold M. set1 The first judgment equation is: d1(k)>M set1 .

[0117] According to the example embodiment, the first threshold is M. set1 The calculation formula is:

[0118] M set1 =D set +f(s1(kT))

[0119] Among them, D set s1(KT) is a preset value; s1(KT) is the KTth value of the variance sequence of the first starting quantity; f is a function that varies with s1(KT).

[0120] For example, the function to solve s1(KT) is f(s1(kT))=as1(kT), where a is a preset first coefficient.

[0121] For example, the function for solving s1(KT) is: Where b is a preset second coefficient.

[0122] In the above embodiment, in step S150, the transient quantity protection start device determines the magnitude of any one of the first start quantity average value changes in the first start quantity average value change sequence and the first threshold.

[0123] When any change in the average value of the first start-up quantity in the sequence of first start-up quantity changes is greater than the first threshold, proceed to step S170.

[0124] In step S170, the transient quantity protection start device determines that the variance of the second start quantity is less than the second threshold before a preset time of the change in the average value of the first start quantity.

[0125] For example, in step S170, when the change in the average value of the first starting quantity satisfies the first judgment equation: d1(k)>M set1 At that time, the transient quantity protection start device determines the magnitude of the second start quantity variance and the second threshold before the preset time of the change in the average value of the first start quantity.

[0126] For example, the second threshold is M set2 The second threshold M set2 The second judgment equation is:

[0127] s2(k-△k)<M set2

[0128] According to the example embodiment, the second threshold M set2 The second threshold M is a preset value. set2 Based on the actual noise stability setting of the transient quantity protection start-up device, the better the noise stability, the lower the second threshold M. set2 The lower the value, the better.

[0129] △k is the interval step size corresponding to the preset time. The setting of △k needs to take into account factors such as the rate of change of the transient quantity. The value of △k needs to be set according to the specific actual situation.

[0130] According to the example embodiment, the step size of △k generally does not exceed the number of sampling points corresponding to a preset time of 500us.

[0131] In the above embodiment, in step S170, the transient quantity protection start device determines the magnitude of the second start quantity variance and the second threshold before the preset time of the change in the average value of the first start quantity.

[0132] When the variance of the second start-up quantity before the preset time of the change in the average value of the first start-up quantity is greater than the second threshold, proceed to step S190.

[0133] In step S190, the transient quantity protection starting device activates the transient quantity protection.

[0134] For example, in step S190, when the change in the average value of the first starting quantity and the variance of the second starting quantity satisfy the first judgment equation and the second judgment equation respectively, the transient quantity protection starting device determines that a fault has occurred in the power system and starts the transient quantity protection.

[0135] Transient protection performs protective actions to quickly isolate fault points in the power grid.

[0136] Through the above embodiments, the technical solution of this application judges the occurrence of faults in the protected power system by comparing the change in the average value of the first start-up quantity and the variance of the second start-up quantity with the preset threshold, based on the average value and change of the transient quantity.

[0137] By performing high-pass filtering and high-frequency sampling on the sampled data, the influence of power frequency quantities and noise in transient quantities can be avoided, resulting in relatively clean sampled data. At the same time, averaging the transient quantities can avoid the problem of frequent false starts of transient quantity protection caused by interference.

[0138] The transient protection initiation method provided in this application does not require setting a blocking time after transient protection is initiated, and can initiate transient protection multiple times in a short period of time. This method can initiate multiple times when a transitional fault occurs in the power system within a short period of time, effectively improving the reliability of transient protection when a power system fault occurs.

[0139] According to another aspect of this application, a transient quantity protection starting device is also provided. Figure 4 A schematic diagram 4000 of a transient quantity protection start device according to an example embodiment of this application is shown.

[0140] See Figure 4 The transient quantity protection start device 1 includes a data acquisition unit 10, a processing unit 30, a judgment unit 50, and an execution unit 70.

[0141] According to the example embodiment, the data acquisition unit 10 performs high-pass filtering and high-frequency sampling processing on the transient quantity connected to the transient quantity protection start device 1 to obtain the acquired data.

[0142] Optionally, transient quantities include current transients and voltage transients.

[0143] High-pass filtering is a filtering method that allows high-frequency signals to pass through normally, while blocking low-frequency signals below a set threshold.

[0144] According to the example embodiment, the three-phase current value i′ of the transient quantity protection starting device 1 is generally collected by a current transformer. a (t), i′ b (t), i′ c (t). The current value collected by the current transformer is the secondary current. In addition to the required transient value, the secondary current also contains some power frequency quantity and noise.

[0145] Power frequency quantities typically have a frequency of around 50Hz, while transient quantities have a frequency much higher than that of power frequency quantities. Therefore, the three-phase current values ​​of the acquired transient current quantities need to be high-pass filtered to remove impurities such as power frequency quantities and low-frequency noise, thereby improving the signal-to-noise ratio of the transient current quantities.

[0146] The three-phase current values, after high-pass filtering, still need to undergo high-frequency sampling to obtain the acquired three-phase current transient data with a sampling frequency of not less than 10kHz. a (k), i b(k), i c (k).

[0147] Similarly, the three-phase voltage value u′ of the transient quantity protection start device 1 collected by the voltage transformer is... a (t), u′ b (t), u′ c (t) After high-pass filtering and high-frequency sampling, the collected data of the three-phase voltage transients are obtained: u a (k), u b (k), u c (k).

[0148] The processing unit 30 receives the collected data and, based on the collected data, calculates the first start-up quantity average change sequence and the second start-up quantity variance sequence.

[0149] According to an example embodiment, the transient quantity protection start device 1 includes the transient quantity protection start method as described above.

[0150] The above-described transient quantity protection start-up method has already described in detail the process and calculation formula for obtaining the average value change sequence of the first start-up quantity and the variance sequence of the second start-up quantity, so it will not be elaborated on further.

[0151] The judgment unit 50 judges the magnitude of any change in the average value of the first start-up quantity in the sequence of changes in the average value of the first start-up quantity and the magnitude of the first threshold, and judges the magnitude of the variance of the second start-up quantity before the preset time of the change in the average value of the first start-up quantity and the magnitude of the second threshold.

[0152] The execution unit 70 receives the judgment result from the judgment unit 50. When the judgment result is that the change in the average value of any first start-up quantity is greater than the first threshold, and the variance of the second start-up quantity before the preset time of the change in the average value of the first start-up quantity is less than the second threshold, the execution unit 70 performs the transient quantity protection start-up action.

[0153] Through the above embodiments, the technical solution of this application judges the occurrence of faults in the protected power system by comparing the magnitude of the change in the average value of the first start-up quantity and the magnitude of the variance of the second start-up quantity, based on the average value and change of the transient quantity.

[0154] By performing high-pass filtering and high-frequency sampling on the sampled data, the influence of power frequency quantities and noise in transient quantities can be avoided, resulting in relatively clean sampled data. At the same time, averaging the transient quantities can avoid the problem of frequent false starts of transient quantity protection caused by interference.

[0155] The transient protection initiation method provided in this application does not require setting a blocking time after transient protection is initiated, and can initiate transient protection multiple times in a short period of time. This method can initiate multiple times when a transitional fault occurs in the power system within a short period of time, effectively improving the reliability of transient protection when a power system fault occurs.

[0156] According to another aspect of this application, a non-volatile computer-readable storage medium is also provided, on which a computer program is stored, the computer program being able to implement the transient quantity protection startup method as described above.

[0157] According to another aspect of this application, a transient quantity protection startup electronic device is also provided, comprising: one or more processors; and a storage device for storing one or more programs, which, when executed by one or more processors, enable the one or more processors to implement the transient quantity protection startup method as described above.

[0158] Finally, it should be noted that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions of the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A transient quantity protection start-up method, characterized in that, include: Acquire sampling data, which is obtained by high-pass filtering and high-frequency sampling processing of transient quantities in the protected power system; Based on the sampled data, calculate the first start-up quantity average change sequence and the second start-up quantity variance sequence; Determine any one of the changes in the average value of the first startup quantity in the sequence of changes in the average value of the first startup quantity that is greater than a first threshold. Determine that the variance of the second startup quantity is less than a second threshold before a preset time period prior to the change in the average value of the first startup quantity; Initiate transient quantity protection; The transient quantities include current transient quantities and / or voltage transient quantities; The step of calculating the first start-up quantity average change sequence and the second start-up quantity variance sequence based on the sampled data includes: Calculate the first activation sequence based on the sampled data; Wherein, when the transient quantity is the current transient quantity, the first initiation quantity sequence is the first current initiation quantity sequence; When the transient quantity is the voltage transient quantity, the first initiation quantity sequence is the first voltage initiation quantity sequence; When the transient quantity is the current transient quantity and the voltage transient quantity, the first initiation quantity sequence is the first current initiation quantity sequence and the first voltage initiation quantity sequence; Calculate the first startup quantity average change sequence and the second startup quantity variance sequence based on the first startup quantity sequence.

2. The method according to claim 1, characterized in that, The first current initiation sequence is: in, is the first current initiation quantity sequence; L is the length of the first current initiation quantity sequence; This is the kth value of the first current initiation sequence; the time corresponding to the kth value is t. The formula for calculating the k-th value of the first current initiation sequence is: The first voltage initiation sequence is: in, is the first voltage initiation quantity sequence; L is the length of the first voltage initiation quantity sequence; This is the kth value of the first voltage initiation sequence; the time corresponding to the kth value is t. The formula for calculating the kth value of the first voltage initiation sequence is: Where k is a non-zero natural number.

3. The method according to claim 1, characterized in that, The first current initiation sequence is: in, is the first current initiation quantity sequence; L is the length of the first current initiation quantity sequence; This is the kth value of the first current initiation sequence; the time corresponding to the kth value is t. The formula for calculating the k-th value of the first current initiation sequence is: The first voltage initiation sequence is: in, is the first voltage initiation quantity sequence; L is the length of the first voltage initiation quantity sequence; This is the kth value of the first voltage initiation sequence; the time corresponding to the kth value is t. The formula for calculating the kth value of the first voltage initiation sequence is: Where k is a non-zero natural number.

4. The method according to claim 2 or 3, characterized in that, The step of calculating the first initiation quantity average change sequence and the second initiation quantity variance sequence based on the sampled data further includes: Calculate the first startup quantity average value sequence based on the first startup quantity sequence; The formula for calculating the first average sequence of startup quantities is: in, This is the k-th value in the first start-up quantity average sequence; This is the j-th value in the first initiation sequence; The data length for calculating the average value of the first starting quantity, where j and k are both non-zero natural numbers; The second startup variance sequence is calculated based on the first startup average sequence.

5. The method according to claim 4, characterized in that, The step of calculating the first initiation quantity average change sequence and the second initiation quantity variance sequence based on the sampled data further includes: Calculate the sequence of changes in the average value of the first startup quantity based on the first startup quantity average value sequence; The formula for calculating the first starting amount average change sequence is: in, This is the k-th value in the sequence of changes in the average value of the first start-up quantity; This is the kTth value in the average sequence of the first initiation quantity; T is the step size for calculating the change. The second startup variance sequence is calculated based on the first startup average sequence.

6. The method according to claim 5, characterized in that, The step of calculating the second startup variance sequence based on the first startup quantity average sequence includes: Calculate the second startup quantity average sequence based on the first startup quantity average sequence; The formula for calculating the second average sequence of startup quantities is: in, This is the k-th value in the second start-up quantity average sequence; This is the j-th value in the first startup quantity average sequence; The data length for calculating the average value of the second startup quantity; The second startup quantity variance sequence is calculated based on the second startup quantity average sequence.

7. The method according to claim 6, characterized in that, The formula for calculating the variance sequence of the second startup quantity based on the average value sequence of the second startup quantity is as follows: in, This is the k-th value of the variance sequence of the second initiation quantity; This is the j-th value in the second startup quantity average sequence; It is the j-th value of the first start-up quantity average sequence.

8. The method according to claim 7, characterized in that, Also includes: Calculate the first startup quantity variance sequence based on the first startup quantity sequence; The formula for calculating the variance sequence of the first initiation quantity is: in, This is the k-th value of the variance sequence of the first initiation quantity; This is the j-th value in the first startup quantity average sequence; It is the j-th value of the first start-up sequence.

9. The method according to claim 8, characterized in that, The first threshold is ; The first threshold The calculation formula is: in, This is a preset value; This is the KT-th value in the variance sequence of the first initiation quantity; For follow A changing function.

10. A transient quantity protection starting device, characterized in that, include: The data acquisition unit performs high-pass filtering and high-frequency sampling processing on the transient quantities connected to the transient quantity protection start device to obtain the acquired data; The processing unit receives the collected data and, based on the collected data, calculates a first start-up quantity average change sequence and a second start-up quantity variance sequence. The transient quantities include current transient quantities and / or voltage transient quantities; the step of calculating the first starting quantity average value change sequence and the second starting quantity variance sequence based on the acquired data includes: calculating the first starting quantity sequence according to the acquired data; wherein, when the transient quantity is the current transient quantity, the first starting quantity sequence is a first current starting quantity sequence; when the transient quantity is the voltage transient quantity, the first starting quantity sequence is a first voltage starting quantity sequence; when the transient quantity is both the current transient quantity and the voltage transient quantity, the first starting quantity sequence is a first current starting quantity sequence and a first voltage starting quantity sequence; and calculating the first starting quantity average value change sequence and the second starting quantity variance sequence according to the first starting quantity sequence; The judgment unit determines the magnitude of any change in the average value of the first start-up quantity in the first start-up quantity average change sequence and the magnitude of the first threshold, and determines the magnitude of the second start-up quantity variance before a preset time of the change in the average value of the first start-up quantity and the magnitude of the second threshold. The execution unit receives the judgment result from the judgment unit. When the judgment result is that the change in the average value of any first start-up quantity is greater than the first threshold, and the variance of the second start-up quantity before the preset time of the change in the average value of the first start-up quantity is less than the second threshold, the execution unit performs a transient quantity protection start-up action.

11. A non-volatile computer-readable storage medium having a computer program stored thereon, characterized in that, The computer program enables the transient quantity protection start device to implement the method described in any one of claims 1 to 9.

12. A transient quantity protection starting electronic device, characterized in that, include: One or more processors; Storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method as described in any one of claims 1 to 9.

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