Running risk assessment method and device of relay protection equipment and medium

Abstract

The invention discloses an operation risk assessment method and device for relay protection equipment and a medium. The method comprises the following steps: extracting indexes from physical quantities of relay protection, and constructing an index set of relay protection abnormity diagnosis; according to the index set, establishing a causal logic relation between each relay protection abnormal identification state quantity and a relay protection incorrect action, and constructing a fault tree of protection incorrect action risk assessment; introducing a probability weight into the fault tree to obtain a probability fault tree; and based on the probability fault tree, calculating a risk assessment result of the relay protection incorrect action.

Description

Technical Field

[0001] The present invention relates to the technical field of relay protection technology for power systems, and more particularly to a method, device and medium for evaluating the operational risk of relay protection equipment. Background Art

[0002] (1) Construction of relay protection risk assessment state quantity

[0003] Relay protection risk assessment relies primarily on online relay protection operation information. According to the "Technical Specification for Online Monitoring and Analysis of Relay Protection and Safety Automatic Devices" (GB / T40599-2021) and the "Substation Relay Protection Information Specification" (DL / T 1782-2017), online relay protection operation information primarily includes five categories: actions, alarms, state changes, online monitoring, and intermediate node information. Extracting indicators from these five categories of information, determining whether relay protection risks exist based on their values, identifying risks promptly, guiding operations and maintenance personnel to mitigate them, and preventing incorrect relay protection operation are crucial for ensuring the safe and stable operation of the power grid.

[0004] In addition, there are few reports on how to comprehensively determine indicators from these physical quantities, analyze the effectiveness of the indicators, and select indicators that can effectively diagnose the operational risks of relay protection.

[0005] (2) Relay protection operation risk assessment

[0006] Currently, various methods have been proposed to improve the operational reliability of relay protection systems. Relay protection risk assessments are often based on equipment status evaluation results. For example, according to the "Guidelines for Relay Protection Status Evaluation" (Q / GDW 11285-2022), indicators reflecting the health of relay protection equipment hardware, secondary circuits, and channels, as well as indicators reflecting the overall operational reliability and failure risk of the equipment, are calculated to determine the overall health of the equipment. Furthermore, the failure rate of the relay protection equipment is calculated based on the mapping relationship between the relay protection equipment status evaluation results and the equipment failure rate. Furthermore, the overall operational risk of the relay protection equipment is determined by combining the importance of the relay protection equipment's location in the power grid. Currently, due to the relative maturity of relay protection status evaluation technology, the technique of deriving the overall risk level of relay protection by analyzing relay protection status evaluation results is widely used. However, the "Guidelines for Relay Protection Status Evaluation" (Q / GDW 11285-2022) focuses on the health of relay protection equipment and primarily assesses the risk of equipment failure, but does not address the risk assessment of improper relay protection equipment operation.

[0007] Standards such as the Technical Specification for Online Monitoring and Analysis of Relay Protection and Safety Automatic Devices (GB / T40599-2021) propose that online monitoring and diagnostic systems for relay protection should have functions such as homology comparison, trend analysis, and mutation monitoring. These functions can identify multiple operational hazards that may cause incorrect relay protection operation, providing important methodological guidance for relay protection risk assessment. These methods have been widely applied on-site and have played a significant role in reducing the possibility of incorrect relay protection operation. However, existing methods only list the state quantities that can cause incorrect relay protection operation, but do not systematically sort out the ways in which each state quantity affects incorrect relay protection operation (i.e., the ways in which different state quantity anomalies affect incorrect relay protection operation), thereby forming a risk assessment system for incorrect relay protection operation and further evaluating the risk of incorrect relay protection operation caused by different abnormal relay protection state quantities. Summary of the Invention

[0008] In view of the deficiencies in the prior art, the present invention provides a method, device and medium for evaluating the operational risk of relay protection equipment.

[0009] According to one aspect of the present invention, a method for evaluating the operational risk of a relay protection device is provided, comprising:

[0010] Extract indicators from the physical quantities of relay protection and construct an indicator set for relay protection abnormality diagnosis;

[0011] Based on the indicator set, a causal logical relationship is established between each relay protection abnormal identification state quantity and the incorrect operation of the relay protection, and a fault tree for incorrect protection operation risk assessment is constructed;

[0012] Introduce probability weights into the fault tree to obtain a probabilistic fault tree;

[0013] Based on the probabilistic fault tree, the risk assessment results of incorrect relay protection operation are calculated.

[0014] Optionally, indicators are extracted from the physical quantities of the relay protection to construct an indicator set for relay protection abnormality diagnosis, including:

[0015] Extracting an initial index set from the physical quantities of relay protection, where the physical quantities include sampling, online monitoring and wave recording physical quantities;

[0016] The effectiveness of the initial indicator set is judged, and the indicator set is constructed based on the effective initial indicators.

[0017] Optionally, an initial indicator set is extracted from the physical quantities of the relay protection, including:

[0018] Conduct trend analysis on historical operation information of physical quantities and extract trend analysis indicators;

[0019] Conduct analog fluctuation analysis on physical quantities and extract fluctuation characteristic indicators;

[0020] Conduct homologous data comparison and analysis on physical quantities and extract homologous comparison feature indicators;

[0021] Perform switching fluctuation analysis on physical quantities and extract switching fluctuation indicators;

[0022] Extracting harmonic component indices of physical quantities and single physical quantity value indices;

[0023] The initial indicator set is determined based on the change trend analysis indicator, fluctuation characteristic indicator, homology comparison characteristic indicator, switching quantity fluctuation indicator, harmonic component indicator and single physical quantity value indicator.

[0024] Optionally, a change trend analysis is performed on the historical operation information of the physical quantity to extract change trend analysis indicators, including:

[0025] Select the data ramp judgment time t in the physical quantity k0 ;

[0026] Define the most recent measurement point as (t0, d0), and define the starting point of the ramp as (t0-t k0 ,d k0 );

[0027] If (t0-t k0 ,t0) time range, any two adjacent measurement points d x and d (x+1) The slopes of the two are all the same sign, and |d0-d k0 |>0.1|d k0 |, it is determined that the curve has changed monotonically, and the physical quantity has a trend of continuous increase or continuous decrease. The trend analysis index is calculated. K=(d0-d k0 ) / (t0-t k0 )。

[0028] Optionally, analog fluctuation analysis is performed on the physical quantity to extract fluctuation characteristic indicators, including:

[0029] Extract the most recent measurement value of the physical quantity and all measurement values ​​within this period;

[0030] Determine the xth measurement point as (t(d x ),d x ) and its two surrounding points (t(d x-1 ),d x-1 ) and (t(d x+1 ),d x+1 )’s first slope K x+ and the second slope K x- ;

[0031] If the first slope K x+and the second slope K x- If they are of different signs, then (|K x- |>0.1|d x |)∪(|K x+ |>0.1|d x |)=1. If so, it is judged that a value fluctuation has occurred at this point; if not, it is judged that a continuous data change has occurred;

[0032] Take all the points where the value fluctuates within the period, assuming there are m points, and then take the starting and ending points of two periods to construct m+2 fluctuation points;

[0033] Define the bth occurrence point excluding the starting point and the ending point as (t(D b ),D b ) and compare the b-th occurrence point (t(D b ),D b ) and the occurrence points on both sides (t(D b-1 ),D b-1 ) and (t(D b+1 ),D b+1 ) is calculated based on the absolute value of the numerical difference between the two values ​​and the fluctuation characteristic index D bk =min(|D b -D b-1 |,|D b+1 -D b |) / D b , where t(D b ) is the sampling time of the bth fluctuation point, D b is the sampling value.

[0034] Optionally, the expression of the homology comparison feature index diff is:

[0035]

[0036] Where Δt represents the sampling interval, t1 represents the time interval for calculating the difference; y A (t i ),y B (t i ) represent the sampling values ​​of the homologous data points A and B respectively.

[0037] Optionally, the initial indicator set is judged for effectiveness, and an indicator set is constructed based on the effective initial indicators, including:

[0038] The objectivity, significance and timeliness of each initial indicator in the initial indicator set are judged to construct an indicator set.

[0039] Optionally, the probability weight is determined as follows:

[0040] K1 / p1=K2 / p2=…=K i / p i =…=K j / p j =…

[0041] K1+K2+…+K N =M

[0042] Where, M is the set reference value; N is the total number of risk assessment links; K i / K j The size is the probability p that the risk assessment link i leads to incorrect action of the relay protection i The probability p of incorrect relay protection action caused by risk assessment link j j Ratio; i=1,2,3...N; j=1,2,3...N; K i , K j are the probability weights of risk assessment link i and j for the incorrect operation of relay protection.

[0043] Optionally, based on the probabilistic fault tree, calculate the risk assessment results of incorrect relay protection operation, including:

[0044] Based on the probabilistic fault tree, obtain the abnormal state quantity where abnormalities exist;

[0045] De-duplicate the abnormal state quantity to obtain non-repeated abnormal state quantity;

[0046] Calculate risk assessment results based on non-repeated abnormal state quantities Where K(y k ) is the risk of incorrect relay protection operation caused by risk assessment link k, and 1≤k≤β, where β is the number of non-repeated abnormal state quantities.

[0047] According to another aspect of the present invention, there is provided an operation risk assessment device for relay protection equipment, comprising:

[0048] The first building module is used to extract indicators from the physical quantities of the relay protection and build an indicator set for relay protection abnormality diagnosis;

[0049] The second construction module is used to establish a causal logical relationship between each relay protection abnormality identification state quantity and the incorrect operation of the relay protection based on the indicator set, and to construct a fault tree for risk assessment of incorrect protection operation;

[0050] An acquisition module is used to introduce probability weights into the fault tree and obtain a probabilistic fault tree;

[0051] The calculation module is used to calculate the risk assessment results of incorrect operation of relay protection based on the probabilistic fault tree.

[0052] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the storage medium stores a computer program, and the computer program is used to execute the method according to any one of the above aspects of the present invention.

[0053] According to another aspect of the present invention, an electronic device is provided, comprising: a processor; a memory for storing instructions executable by the processor; and the processor for reading the executable instructions from the memory and executing the instructions to implement the method described in any one of the above aspects of the present invention.

[0054] Therefore, the present invention proposes a state quantity index suitable for relay protection risk assessment. Using this index system, the operating risks of relay protection equipment can be discovered. On this basis, the abnormal relay protection state quantity is used as the bottom event of the fault tree, combined with the probability weight K, to calculate the risk probability of the top event "incorrect protection action" and issue a risk warning in a timely manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0056] Figure 1 1 is a flow chart of a method for evaluating the operational risk of a relay protection device provided by an exemplary embodiment of the present invention;

[0057] Figure 2 This is a graph showing a change pattern of redundant data of the same source provided by an exemplary embodiment of the present invention;

[0058] Figure 3 1 is a schematic diagram of a set of candidate indicators for relay protection risk assessment provided by an exemplary embodiment of the present invention;

[0059] Figure 4 2 sets of protection homology comparison anomaly schematic diagrams provided by an exemplary embodiment of the present invention;

[0060] Figure 5 2 sets of schematic diagrams of protection homology comparison anomalies provided by an exemplary embodiment of the present invention;

[0061] Figure 6 1 is a schematic diagram of a fault tree for incorrect operation of relay protection provided by an exemplary embodiment of the present invention;

[0062] Figure 7 1 is a schematic structural diagram of an operation risk assessment device for relay protection equipment provided by an exemplary embodiment of the present invention;

[0063] Figure 8 This is a structure of an electronic device provided by an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0064] Below, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0065] It should be noted that the relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

[0066] Those skilled in the art will understand that the terms "first" and "second" in the embodiments of the present invention are only used to distinguish different steps, devices or modules, and neither represent any specific technical meaning nor indicate the necessary logical order between them.

[0067] It should also be understood that, in the embodiments of the present invention, “a plurality of” may refer to two or more than two, and “at least one” may refer to one, two or more than two.

[0068] It should also be understood that any component, data or structure mentioned in the embodiments of the present invention can generally be understood as one or more, unless explicitly limited or otherwise indicated in the context.

[0069] In addition, the term "and / or" in this invention merely describes an association relationship between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Furthermore, the character " / " in this invention generally indicates that the related objects are in an "or" relationship.

[0070] It should also be understood that the description of the various embodiments of the present invention focuses on the differences between the various embodiments, and the same or similar aspects thereof can be referenced with each other. For the sake of brevity, they will not be described one by one.

[0071] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0072] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0073] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0074] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0075] Embodiments of the present invention can be applied to electronic devices such as terminal devices, computer systems, and servers, and can operate in conjunction with numerous other general-purpose or specialized computing system environments or configurations. Examples of well-known terminal devices, computing systems, environments, and / or configurations suitable for use with terminal devices, computer systems, servers, and other electronic devices include, but are not limited to, personal computer systems, server computer systems, thin clients, thick clients, handheld or laptop devices, microprocessor-based systems, set-top boxes, programmable consumer electronics, network personal computers, minicomputer systems, mainframe computer systems, and distributed cloud computing technology environments including any of the above.

[0076] Electronic devices such as terminal devices, computer systems, and servers can be described in the general context of computer system-executable instructions (such as program modules) executed by a computer system. Generally, program modules can include routines, programs, object programs, components, logic, data structures, etc., which perform specific tasks or implement specific abstract data types. Computer systems / servers can be implemented in a distributed cloud computing environment, where tasks are performed by remote processing devices linked via a communication network. In a distributed cloud computing environment, program modules can be located on local or remote computing system storage media, including storage devices.

[0077] Exemplary Methods

[0078] Figure 1 FIG. 1 is a flow chart of a method for evaluating the operational risk of a relay protection device provided by an exemplary embodiment of the present invention. This embodiment can be applied to electronic devices, such as Figure 1 As shown, the operation risk assessment method 100 of the relay protection device includes the following steps:

[0079] Step 101: extracting indicators from physical quantities of relay protection and constructing an indicator set for relay protection abnormality diagnosis;

[0080] Step 102: establishing a causal logical relationship between each relay protection abnormality identification state quantity and the incorrect relay protection operation based on the indicator set, and constructing a fault tree for incorrect protection operation risk assessment;

[0081] Step 103: introducing probability weights into the fault tree to obtain a probabilistic fault tree;

[0082] Step 104: Calculate the risk assessment result of incorrect relay protection operation based on the probabilistic fault tree.

[0083] Specifically, the present invention constructs a relay protection operation abnormal state quantity system to grasp the risk level of incorrect relay protection operation. The specific implementation process is as follows:

[0084] (1) Step 1: The present invention first constructs a state set for relay protection abnormality diagnosis, and the steps are as follows:

[0085] Step 1-1: Extract indicators from physical quantities such as relay protection sampling, online monitoring, and wave recording;

[0086] Step 1-2: Propose a method for determining the effectiveness of initial indicators (candidate indicators), judge the effectiveness of the indicators, and construct an indicator set.

[0087] The specific implementation process is:

[0088] Step 1-1: Obtain the corresponding indicators by numerically analyzing the original physical quantities. The numerical analysis algorithms for relay protection physical quantities mainly include the following:

[0089] 1) Trend Analysis. Trend analysis analyzes whether a physical quantity shows a trend of continuous increase or decrease based on its historical operating information. If a physical quantity shows a trend of continuous increase or decrease, it may indicate an operational risk and requires prompt investigation and elimination of abnormal risks.

[0090] The specific steps of trend analysis are:

[0091] ①First select the data climbing judgment time t k0 .

[0092] ② Define the most recent measurement point as (t0, d0). Define the starting point of the slope as (t0-t k0 ,d k0 )If (t0-t k0 ,t0) time range, any two adjacent points d x and d (x+1) The slopes of the two are all the same sign, and |d0-d k0 |>0.1|d k0 |, it is determined that the curve has changed monotonically, and the physical quantity has a trend of continuous increase or decrease.

[0093] ③If the physical quantity is determined to have an upward or downward trend in step ②, Indicators for trend analysis— Change slope K=(d0-d k0 ) / (t0-t k0 ).

[0094] 2) Analog value fluctuation analysis: If the physical value continues to fluctuate, the relay protection equipment may be at risk, and it is necessary to conduct risk anomaly investigation and fault elimination as soon as possible.

[0095] The specific steps of fluctuation analysis are:

[0096] ① The data is the most recent measurement value and all the measurement values ​​within the current period.

[0097] ②Let the xth measurement point be (t(d x ),d x ), determine the relationship between it and the two surrounding points (t(d x-1 ),d x-1 ) and (t(d x+1 ),d x+1 ) is calculated as:

[0098] K x+ =(d x+1 -d x ) / (t(d x+1 )-t(d x )) (1)

[0099] K x- =(d x -d x-1 ) / (t(d x )-t(d x-1 ))

[0100] ③ Such as K x- With K x+ Different signs, then judge (|K x- |>0.1|d x |)∪(|K x+ |>0.1|d x |)=1. If so, the point is judged to have experienced a value fluctuation. If not, it is judged to be a suspected continuous data change.

[0101] If a point where data fluctuation occurs is found, the following steps are followed to obtain the fluctuation characteristic index:

[0102] ① In one cycle, take all the points where the value fluctuation occurs, assuming there are m points. Then take the starting point and the ending point (the most recent measurement point) of two cycles, a total of m+2 points. Define the bth point excluding the starting point and the ending point as (t(D b ),D b ), where t(D b ) is the sampling time of the bth fluctuation point, D b is the sampling value. If there is no value fluctuation point in a period, it is considered that no fluctuation occurs.

[0103] ②Compare the b-th occurrence point (t(D b ),D b ) and the occurrence points on both sides (t(D b-1 ),D b-1 ) and (t(D b+1 ),D b+1 ) and take D bk=min(|D b -D b-1 |,|D b+1 -D b |) / D b .

[0104] Definition D bk The amplitude of fluctuation is used to measure the degree of fluctuation of physical quantities.

[0105] 3) Homologous data comparison and analysis. Using the physical quantities of primary equipment as the input source, perform homologous data comparison on the physical quantities actually obtained between protection equipment at the same station or between protection equipment at different stations. Based on the sampling results of the same physical quantities by different protection equipment, reverse analysis is performed to determine whether there are operational risks in the sampling process of the protection equipment. After obtaining the relevant physical quantities of the protection equipment for comparison, it is possible to determine whether there are differences in the protection equipment sampling from different perspectives, including:

[0106] ① Amplitude. Based on the degree of difference in the amplitude of the same physical quantity between protection devices, determine whether there is any abnormality in the physical quantity collection of the protection device;

[0107] ② Phase angle. Based on the difference in the phase angles of the same physical quantity between the protection devices, determine whether there is any abnormality in the physical quantity collection of the protection devices (Note: the determination of the phase angle difference needs to be achieved through analysis of the recorded waveform);

[0108] ③ Waveform. Since the values ​​of measurement points such as current and voltage fluctuate within a certain range, the differences may be large when comparing cross-sectional data. Therefore, the comparison algorithm needs to use the integration method for calculation. Taking the comparison of analog data of the same source as an example, suppose two data points A and B of the same source have the following change patterns over time: Figure 2 shown.

[0109] Then, during the time period 0-t1, the difference between the two values ​​of A and B can be expressed by the area between their corresponding curves:

[0110]

[0111] Where: the numerator represents the area between the two curves A and B, and the denominator is the area between curve A and the horizontal coordinate (the area between curve B and the horizontal coordinate can also be used)

[0112] Δt represents the sampling interval, and t1 represents the time interval for calculating the difference. A (t i ),y B (t i ) represent the sampling values ​​of A and B respectively.

[0113] 4) Switching quantity fluctuation analysis: The number of switching quantity changes per unit time is taken to determine whether there is a frequent switching quantity fluctuation, thereby realizing the state quantity extraction for relay protection risk assessment.

[0114] 5) Harmonics: By calculating the harmonic components of the analog quantity, it is determined whether there are any operational risks in the relay protection equipment.

[0115] 6) Value. Directly obtain or calculate the value of a single physical quantity and compare it with upper and lower thresholds to determine whether the equipment has operational risks.

[0116] Step 1-2: Propose a method to determine the effectiveness of candidate indicators. The effectiveness of candidate indicators can be determined from three aspects:

[0117] 1) Observability of indicators: This means whether the indicator can effectively characterize the abnormality under abnormal conditions of the device.

[0118] 2) The significance of the indicator. This means whether the device is actually abnormal when the indicator shows abnormal characteristics.

[0119] 3) Timeliness of indicators. This means that when a device abnormality occurs and can be expressed through this indicator, can this indicator be used to promptly detect the abnormality and eliminate the fault (that is, after the indicator reflects the existence of an operational risk in the equipment, can it support the operation and maintenance personnel to take necessary measures to prevent the occurrence of incorrect relay protection operation), thereby avoiding incorrect relay protection operation.

[0120] When the observability, significance and timeliness of an indicator are high, the effectiveness of the indicator is strong.

[0121] (2) Step 2: This application proposes an algorithm for assessing the risk of incorrect relay protection operation, which includes the following three steps:

[0122] 1) Step 2-1: A fault tree for incorrect protection action risk assessment was constructed based on the indicator set. A causal logical relationship was established between each relay protection abnormality identification state variable and incorrect relay protection action. A systematic deductive relationship was established between various relay protection device abnormality types and incorrect relay protection action, forming an inference network that integrates different risk assessment state variables to incorrect relay protection action.

[0123] 2) Step 2-2: The fault tree only reflects the logical relationship between different events. By introducing the concept of probability weight, a quantitative assessment of the risk level can be achieved, which can effectively reflect the effect of different indicators on the incorrect operation of relay protection.

[0124] 3) Step 2-3: Based on the probability weights, deduce the risk probability of incorrect relay protection operation. When the relay protection operating state is abnormal, calculate the risk level of incorrect relay protection operation.

[0125] The specific evaluation algorithm and evaluation process are described below.

[0126] 1) Step 2-1: Construct a fault tree model for incorrect relay protection operation, establish a causal logical relationship between each relay protection risk assessment state quantity and incorrect relay protection operation, and systematically construct the deductive relationship between various abnormal types of relay protection equipment and incorrect relay protection operation, forming a system for evaluating incorrect relay protection operation.

[0127] The currently summarized state quantities that can reflect abnormal relay protection operation are divided according to different links of the relay protection equipment. In fact, the reliable operation of relay protection equipment depends on the combined effects of a series of links, such as voltage sampling, current sampling, switch quantity sampling, equipment DC power supply, and equipment aging. The risk assessment state quantity can reflect whether there is a risk in a certain link of the relay protection equipment. The operational risk of each link can cause the overall relay protection to operate incorrectly. By establishing the concept of "risk assessment link", the correlation between the currently extracted risk assessment state quantities and the incorrect relay protection operation events is connected. That is, the incorrect operation event of the relay protection equipment is caused by the operational risk of the relay protection link, and the operational risk of the relay protection link is caused by the abnormal state quantity event. This makes it easier to analyze the deduction path of the abnormal state quantity causing the incorrect relay protection operation event.

[0128] 2) Step 2-2: Introduce the concept of "probability weight" to conduct a probabilistic assessment of the relationship between the operational risks of the relay protection link and the overall incorrect operation of the relay protection, and understand the probabilistic correlation between abnormalities in different links of the relay protection and incorrect operation of the relay protection.

[0129] In the fault tree for risk assessment of incorrect relay protection operation, different risk assessment links have different effects on the probability of incorrect relay protection operation. Some risk assessment links have a strong impact on the probability of incorrect relay protection operation events, while some risk assessment links have a weak impact on the probability of incorrect relay protection operation events. Although the fault tree for risk assessment of incorrect relay protection operation has established a logical association between different risk assessment links and incorrect relay protection operation, it has not been able to show the strength of the probability association between the two. The concept of "probability weight" is introduced and mathematically expressed using the symbol K to reflect the strength of the probability association of different relay protection risk assessment links with incorrect relay protection operation events. For relay protection risk assessment links i and j, define K i , K j are the probability weights of the risk assessment link for the incorrect action of relay protection, K i / K j The size is the probability p that the risk assessment link i leads to incorrect action of the relay protection i The probability p of incorrect relay protection action caused by risk assessment link j j The ratio is:

[0130] K i / K j =p i / p j (3)

[0131] is equivalent to:

[0132] K1 / p1=K2 / p2=…=K i / p i =…=K j / p j =… (4)

[0133] Set the reference value M, that is, K1+K2+…+K N =M, and combining the above formula, we can derive the probability weights of different risk assessment links. Where N is the total number of risk assessment links.

[0134] 3) Steps 2-3: Calculate the relay protection risk assessment state and determine whether any abnormalities exist. For any abnormal relay protection risk assessment state, search for the corresponding risk assessment link to derive the path leading to incorrect relay protection operation caused by the abnormal state. Combined with the probability weight K, the risk of incorrect relay protection operation is comprehensively calculated.

[0135] Assume that there are α abnormal state quantities, which are denoted as x1, x2, ..., x α , the corresponding risk assessment links are recorded as y1, y2, ..., y α In the fault tree of incorrect relay protection operation, the intermediate event "operation risk in the relay protection equipment link" may be caused by more than one abnormal state quantity, and several abnormal state quantities may correspond to the same risk assessment link. α After removing duplicates, we obtain β non-repeated risk assessment links, which are recorded as y1, y2, …, yβ respectively.

[0136] The reliable operation of relay protection depends on the reliable operation of multiple links of relay protection equipment. Incorrect operation of relay protection may be caused by different links. The operation risks of different links of relay protection have a parallel relationship with the overall incorrect operation of relay protection. It can be seen that when obtaining the probability weight K(y) of incorrect operation of relay protection in a single risk assessment link, k ), the probability weights of incorrect relay protection actions caused by different risk assessment links are summed to obtain the overall risk of incorrect relay protection actions, which is calculated as follows: Based on this, the risk assessment of incorrect relay protection operation is completed. k ) is the risk of incorrect operation of relay protection due to risk assessment link k, and 1≤k≤β.

[0137] In one embodiment of the present invention, the specific implementation process is as follows:

[0138] (1) Step 1: Construction of relay protection operation risk assessment state quantity

[0139] The method of the present invention is used to construct a state quantity set for relay protection risk assessment.

[0140] Without loss of generality, the physical quantities selected in this example include five items: analog sampling value, input value, differential current, device temperature, and DC operating voltage within the station, and two items: analog sampling value and differential current between stations. The indicators extracted from these physical quantities are:

[0141] 1) From the physical quantity of the analog sampling value, through the comparison and analysis of the homologous data, three indicators can be obtained: the amplitude deviation of the homologous comparison, the phase angle deviation of the homologous comparison, and the waveform deviation of the homologous comparison.

[0142] 2) From the physical quantity of the switch quantity sampling value, the two indicators that can be obtained are the value deviation of the homologous comparison and the frequency of switch quantity fluctuation.

[0143] 3) From the physical quantity of differential current, the indicator that can be obtained is the differential current amplitude.

[0144] 4) From the device temperature physical quantity, two indicators can be obtained: temperature value and temperature change slope.

[0145] 5) From the physical quantity of the device's DC working voltage, two indicators can be obtained: the DC working voltage value and the DC working voltage change slope.

[0146] The indicators composed of inter-station physical quantities are the same as the indicators composed of intra-station physical quantities, and the present application will not elaborate on them.

[0147] Based on this, candidate indicators for relay protection risk assessment can be obtained from physical quantities, such as Figure 3 shown.

[0148] exist Figure 3 Based on the set of candidate indicators for relay protection risk assessment, the effectiveness of the candidate indicators is judged.

[0149] 1) Determine the observability of candidate indicators. For example, for the device temperature value indicator, in one case of incorrect relay protection operation, the device temperature reached 110°C, indicating that in this case, the device temperature value candidate indicator is observable; in another case of incorrect relay protection operation, the device temperature is normal, indicating that in this case, the device temperature value candidate indicator is not observable; comprehensively analyze multiple cases of incorrect relay protection operation, and count the number of cases in which this indicator can effectively represent equipment abnormalities. The greater the proportion of all incorrect relay protection operations, the higher the effectiveness of the indicator;

[0150] 2) Determine the significance of candidate indicators. Use a combination of operating experience and case statistics to determine the significance of candidate indicators. For example, when the device temperature value is slightly abnormal, the probability of the device actually being abnormal (and thus causing incorrect protection action) is small, while when the device differential current amplitude is slightly abnormal, the probability of the device actually being abnormal (and thus causing incorrect protection action) is high;

[0151] 3) Determine the timeliness of candidate indicators. Assuming the indicator can effectively characterize relay protection anomalies, calculate the ratio of cases where the indicator can be detected in advance and avoided through timely action to the total number of cases where the indicator can effectively characterize relay protection anomalies. For example, the relay protection differential current indicator can detect insulation anomalies in the relay protection CT circuit. If the insulation anomaly is gradual, the differential current indicator can be used to detect it and take timely measures to eliminate the anomaly. However, if the insulation anomaly is transient, the differential current indicator can characterize the anomaly but cannot alert operators and help them eliminate the anomaly in a timely manner.

[0152] Compare and analyze the observability, significance, and timeliness of different candidate indicators to determine their effectiveness and select the best relay protection risk assessment indicators. In terms of in-station indicators, the following are included:

[0153] Analog quantity sampling same-source comparison amplitude deviation, phase angle deviation, waveform deviation, switch quantity same-source comparison value deviation, switch quantity fluctuation frequency, differential current value, temperature value, temperature change slope, DC working voltage value, DC working voltage change slope.

[0154] In terms of inter-station indicators, they include:

[0155] Analog sampling is compared with the amplitude deviation, phase angle deviation, waveform deviation and differential current value of the same source.

[0156] Take the incorrect action of a relay protection as an example. Under the 3 / 2 connection, the two sets of busbar protection and transformer protection receive the transformer branch current information collected by the transformer merging unit respectively. The first set of busbar differential protection and transformer protection receive the current information of the first set of transformer merging unit, and the second set of busbar differential protection and transformer protection receive the current information of the second set of transformer merging unit. The sampling quantity comparison between the first and second sets of protection is as follows: Figure 4 shown.

[0157] Depend on Figure 4 It can be seen that there are significant differences in the transformer branch currents between bus differential protection set A and bus differential protection set B, and there are also significant differences in the transformer branch currents between transformer protection set A and transformer protection set B. This is reflected in the significant differences in amplitude and waveform indicators in the homologous comparison. Homologous comparison can identify operational hazards of relay protection equipment and provide early warnings.

[0158] Case 2 is a phase deviation case, such as Figure 5 As shown, by integrating the waveform differences between the two sets of protection points point by point, it is found that although the amplitudes of the two sets of protection currents are consistent, the phase angles are deviated, which is manifested in a serious anomaly in the "phase angle deviation" indicator. Applying the indicator proposed in this application can identify operational hazards of relay protection equipment and provide early warning.

[0159] (2) Step 2: Relay protection risk assessment

[0160] Taking the construction of the fault tree of incorrect relay protection operation and the actual process of incorrect relay protection operation risk warning as an example, the specific implementation process of this application is explained.

[0161] 1) Step 2-1: Obtain the relay protection risk assessment state quantity and construct a fault tree of incorrect relay protection operation.

[0162] Through case analysis, the relay protection risk assessment status is obtained, including:

[0163] 1. High voltage harmonic content; 2. Abnormal voltage homologous comparison; 3. Frequent fluctuations in switch quantity sampling; 4. Abnormal switch quantity homologous comparison; 5. The temperature of the protection equipment has an upward trend; 6. The temperature value of the protection equipment is high; 7. The differential current has an upward trend; 8. The differential current value is high; 9. Abnormal current homologous comparison; 10. The DC voltage of the equipment fluctuates frequently; 11. The DC voltage of the equipment has an upward trend; 12. The DC voltage of the equipment has a downward trend.

[0164] The existing relay protection risk assessment method determines whether the relay protection equipment has an operation risk based on the above-mentioned state quantities. However, it fails to complete the risk assessment of incorrect relay protection operation.

[0165] This application considers all aspects of the relay protection function implementation. Different links have operational risks that can lead to incorrect protection operation. Based on this, the incorrect protection operation event is divided into multiple link operational risk events. Specifically, it is divided into five risk assessment links: voltage sampling, switch quantity sampling, equipment operation aging, current sampling, and internal power supply. The association relationship between the five risk assessment links and 12 risk assessment status quantities is established, including:

[0166] ① The voltage sampling link is associated with two state quantities: high voltage harmonic content and abnormal voltage homologous comparison. An abnormality in any of these state quantities means that there is an operational risk in the voltage sampling link;

[0167] ② The switch quantity sampling link is associated with two state quantities: frequent fluctuations in switch quantity sampling and abnormal switch quantity homology comparison. Any abnormality in either state quantity means that there is an operational risk in the switch quantity sampling link;

[0168] ③ The equipment operation aging link is associated with the rising trend of the protection equipment temperature and the high protection equipment temperature value. An abnormality in any of the two status quantities means that the equipment is at risk of operation aging;

[0169] ④ The current sampling link has a correlation with the three state quantities of increasing trend of differential current, high differential current value, and abnormal current source comparison. Any abnormality in any state quantity means that there is an operational risk in the current sampling link;

[0170] ⑤ There is a correlation between the three status quantities of the internal power supply link and the equipment DC voltage: frequent fluctuations, an upward trend in the equipment DC voltage, and a downward trend in the equipment DC voltage. Any abnormality in any of these status quantities means that there is an operational risk in the internal power supply link.

[0171] According to the correlation between the relay protection incorrect action event and the relay protection risk assessment link, and the correlation between the relay protection risk assessment link and the state quantity abnormality, the relay protection incorrect action fault tree is constructed as follows: Figure 6 shown.

[0172] 2) Step 2-2: Determine the probability weight of incorrect protection action caused by the relay protection risk assessment link. The probability weight K is used to describe the strength of the probability correlation between different relay protection risk assessment links and the relay protection incorrect action event. The probability weights of the five risk assessment links of voltage sampling, switch sampling, equipment aging, current sampling, and internal power supply are respectively expressed using K. a , K b , K c , K d , K e Operation experience shows that the operation risk of the current sampling link often leads to incorrect operation of the relay protection. The probability weight K corresponding to the current sampling link is d The probability of incorrect relay protection operation caused by the risk of aging operation of the equipment is relatively low, and the probability weight K corresponding to the aging operation link of the equipment is relatively low. c Smaller. Without loss of generality, let M = 1, that is, K a +K b +K c +K d +K e =1, the probability p of incorrect relay protection action caused by abnormal voltage sampling link a , the probability p that the relay protection will not operate correctly due to abnormality in the switch sampling link b , the probability p of incorrect relay protection action caused by equipment aging c , the probability p that the relay protection will not operate correctly due to abnormal current sampling link d , the probability p that the internal power supply abnormality causes the relay protection to incorrectly operate e, combined with formula (3) and (4), the probability weights K of the five risk assessment links are calculated a , K b , K c , K d , K e .in:

[0173]

[0174] 3) Step 2-3: Apply the probability weight of incorrect protection operation caused by the incorrect protection operation fault tree and the relay protection risk assessment link to assess the risk of incorrect protection operation.

[0175] Analyze each of the aforementioned state variables to determine if any are abnormal. If so, determine the risk assessment link for the relay protection system based on the fault tree for incorrect relay protection operation. Then, calculate the risk of incorrect relay protection device operation based on the probability weights corresponding to the relay protection links with operational risks.

[0176] Example 1: By analyzing various state variables, it is found that the relay protection device has two anomalies: high differential current value and abnormal current source comparison. According to the fault tree of incorrect relay protection operation, the relay protection risk assessment link corresponding to the two anomalies is the current sampling link. The probability weight K of the relay protection current sampling link causing incorrect protection operation is obtained. c , it is inferred that the risk probability of incorrect relay protection action is the probability weight K of incorrect relay protection action caused by the relay protection current sampling link c , to realize the risk assessment of incorrect operation of relay protection.

[0177] Example 2: By analyzing various state quantities, it is found that the relay protection equipment has two anomalies: frequent fluctuations in switch quantity sampling and an upward trend in the DC voltage of the equipment. According to the fault tree of incorrect relay protection operation, the relay protection risk assessment link corresponding to the frequent fluctuations in switch quantity sampling is the switch quantity sampling link, and the relay protection risk assessment link corresponding to the upward trend in the DC voltage of the equipment is the internal power supply link. The probability weights K of the relay protection switch quantity sampling link and the internal power supply link causing incorrect protection operation are obtained respectively b , K e , it is inferred that the risk probability of incorrect relay protection action is the probability weight K of incorrect relay protection action caused by the relay protection switch sampling link b The probability weight K of the internal power supply link causing incorrect relay protection action e The sum of K b +K e , to realize the risk assessment of incorrect operation of relay protection.

[0178] Therefore, the present invention proposes a state quantity index suitable for relay protection risk assessment. Using this index system, the operating risks of relay protection equipment can be discovered. On this basis, the abnormal relay protection state quantity is used as the bottom event of the fault tree, combined with the probability weight K, to calculate the risk probability of the top event "incorrect protection action" and issue a risk warning in a timely manner.

[0179] Exemplary devices

[0180] Figure 7 FIG. 1 is a schematic diagram of the structure of an operation risk assessment device for relay protection equipment provided by an exemplary embodiment of the present invention. Figure 7 As shown, the apparatus 700 includes:

[0181] A first constructing module 710 is configured to extract indicators from physical quantities of relay protection and construct an indicator set for relay protection abnormality diagnosis;

[0182] The second construction module 720 is used to establish a causal logical association between each relay protection abnormality identification state quantity and the incorrect relay protection action according to the indicator set, and to construct a fault tree for incorrect protection action risk assessment;

[0183] An acquisition module 730 is used to introduce probability weights into the fault tree to obtain a probabilistic fault tree;

[0184] The calculation module 740 is used to calculate the risk assessment result of incorrect operation of the relay protection based on the probabilistic fault tree.

[0185] Optionally, the first building block 710 includes:

[0186] The extraction submodule is used to extract the initial indicator set from the physical quantities of the relay protection, where the physical quantities include sampling, online monitoring and recording physical quantities;

[0187] The discriminant submodule is used to judge the effectiveness of the initial indicator set and construct an indicator set based on the effective initial indicators.

[0188] Optionally, extract submodules, including:

[0189] A first analysis unit is used to perform a change trend analysis on the historical operation information of the physical quantity and extract a change trend analysis index;

[0190] The second analysis unit is used to perform analog fluctuation analysis on the physical quantity and extract fluctuation characteristic indicators;

[0191] The third analysis unit is used to perform homologous data comparison analysis on physical quantities and extract homologous comparison feature indicators;

[0192] a fourth analysis unit, configured to perform switching quantity fluctuation analysis on the physical quantity and extract a switching quantity fluctuation index;

[0193] An extraction unit, used for extracting harmonic component indices of physical quantities and single physical quantity value indices;

[0194] The determination unit is used to determine an initial indicator set based on a change trend analysis indicator, a fluctuation characteristic indicator, a homology comparison characteristic indicator, a switching quantity fluctuation indicator, a harmonic component indicator, and a single physical quantity value indicator.

[0195] Optionally, the first analysis unit includes:

[0196] Select the data ramp judgment time t in the physical quantity k0 ;

[0197] Define the most recent measurement point as (t0, d0), and define the starting point of the ramp as (t0-t k0 ,d k0 );

[0198] If (t0-t k0 ,t0) time range, any two adjacent measurement points d x and d (x+1) The slopes of the two are all the same sign, and |d0-d k0 |>0.1|d k0 |, it is determined that the curve has changed monotonically, and the physical quantity has a trend of continuous increase or continuous decrease. The trend analysis index is calculated. K=(d0-d k0 ) / (t0-t k0 )。

[0199] Optionally, the second analysis unit includes:

[0200] Extract the most recent measurement value of the physical quantity and all measurement values ​​within this period;

[0201] Determine the xth measurement point as (t(d x ),d x ) and its two surrounding points (t(d x-1 ),d x-1 ) and (t(d x+1 ),d x+1 )’s first slope K x+ and the second slope K x- ;

[0202] If the first slope K x+ and the second slope K x- If they are of different signs, then (|K x- |>0.1|d x |)∪(|K x+ |>0.1|d x|)=1. If so, it is judged that a value fluctuation has occurred at this point; if not, it is judged that a continuous data change has occurred;

[0203] Take all the points where the value fluctuates within the period, assuming there are m points, and then take the starting and ending points of two periods to construct m+2 fluctuation points;

[0204] Define the bth occurrence point excluding the starting point and the ending point as (t(D b ),D b ) and compare the b-th occurrence point (t(D b ),D b ) and the occurrence points on both sides (t(D b-1 ),D b-1 ) and (t(D b+1 ),D b+1 ) is calculated based on the absolute value of the numerical difference between the two values ​​and the fluctuation characteristic index D bk =min(|D b -D b-1 |,|D b+1 -D b |) / D b , where t(D b ) is the sampling time of the bth fluctuation point, D b is the sampling value.

[0205] Optionally, the expression of the homology comparison feature index diff is:

[0206]

[0207] Where Δt represents the sampling interval, t1 represents the time interval for calculating the difference; y A (t i ),y B (t i ) represent the sampling values ​​of the homologous data points A and B respectively.

[0208] Optionally, the discrimination submodule includes:

[0209] The discrimination unit is used to discriminate the objectivity, significance and timeliness of each initial indicator in the initial indicator set and construct an indicator set.

[0210] Optionally, the probability weight is determined as follows:

[0211] K1 / p1=K2 / p2=…=K i / p i =…=K j / p j =…

[0212] K1+K2+…+KN =M

[0213] Where, M is the set reference value; N is the total number of risk assessment links; K i / K j The size is the probability p that the risk assessment link i leads to incorrect action of the relay protection i The probability p of incorrect relay protection action caused by risk assessment link j j Ratio; i=1,2,3...N; j=1,2,3...N; K i , K j are the probability weights of risk assessment link i and j for the incorrect operation of relay protection.

[0214] Optionally, the calculation module 740 includes:

[0215] The acquisition submodule is used to obtain the abnormal state quantity of the abnormality based on the probabilistic fault tree;

[0216] The deduplication submodule is used to remove duplicate abnormal state quantities to obtain non-repeated abnormal state quantities;

[0217] The calculation submodule is used to calculate the risk assessment results based on the non-repeated abnormal state quantity Where K(y k ) is the risk of incorrect relay protection operation caused by risk assessment link k, and 1≤k≤β, where β is the number of non-repeated abnormal state quantities.

[0218] Exemplary electronic devices

[0219] Figure 8 This is the structure of an electronic device provided by an exemplary embodiment of the present invention. Figure 8 As shown, the electronic device 80 includes one or more processors 81 and a memory 82 .

[0220] The processor 81 may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions.

[0221] The memory 82 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may, for example, include random access memory (RAM) and / or cache memory (cache), etc. The non-volatile memory may, for example, include read-only memory (ROM), a hard disk, a flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 81 may execute the program instructions to implement the methods of the software programs of the various embodiments of the present invention described above and / or other desired functions. In one example, the electronic device may further include: an input device 83 and an output device 84, which are interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0222] In addition, the input device 83 may also include, for example, a keyboard, a mouse, etc.

[0223] The output device 84 can output various information to the outside. The output device 84 can include, for example, a display, a speaker, a printer, a communication network and a remote output device connected thereto.

[0224] Of course, to simplify, Figure 8 Only some of the components related to the present invention in the electronic device are shown, and components such as a bus, an input / output interface, etc. are omitted. In addition, the electronic device may further include any other appropriate components according to specific application conditions.

[0225] Exemplary computer program products and computer-readable storage media

[0226] In addition to the above-mentioned methods and devices, an embodiment of the present invention may also be a computer program product, which includes computer program instructions, which, when executed by a processor, enable the processor to perform the steps of the method according to various embodiments of the present invention described in the above "Exemplary Method" section of this specification.

[0227] The computer program product may be written in any combination of one or more programming languages ​​to implement the operations of embodiments of the present invention, including object-oriented programming languages ​​such as Java, C++, and conventional procedural programming languages ​​such as C or similar programming languages. The program code may be executed entirely on the user's computing device, partially on the user's computing device, as a stand-alone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0228] In addition, an embodiment of the present invention may also be a computer-readable storage medium having computer program instructions stored thereon, which, when executed by a processor, enable the processor to execute the steps of the method according to various embodiments of the present invention described in the above "Exemplary Method" section of this specification.

[0229] The computer-readable storage medium can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can, for example, include but is not limited to a system, system or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination thereof. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0230] The basic principles of the present invention have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in the present invention are merely illustrative and non-limiting, and should not be construed as necessarily possessed by each embodiment of the present invention. Furthermore, the specific details disclosed above are provided for illustrative purposes and to facilitate understanding, and are not intended to be limiting. These details do not necessarily limit the present invention to being implemented using these specific details.

[0231] Each embodiment in this specification is described in a progressive manner, with each embodiment focusing on its differences from the other embodiments. References to the same or similar parts between the various embodiments are sufficient. For system embodiments, since they largely correspond to method embodiments, their description is relatively simple. For relevant parts, references to the description of the method embodiments are sufficient.

[0232] The block diagrams of the devices, systems, equipment, and systems involved in the present invention are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, systems, equipment, and systems can be connected, arranged, or configured in any manner. Words such as "including," "comprising," "having," and the like are open-ended words, meaning "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or" and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

[0233] The method and system of the present invention may be implemented in many ways. For example, the method and system of the present invention may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above sequence of steps for the method is for illustration only, and the steps of the method of the present invention are not limited to the sequence specifically described above, unless otherwise specified. In addition, in some embodiments, the present invention may also be implemented as a program recorded in a recording medium, which includes machine-readable instructions for implementing the method according to the present invention. Thus, the present invention also covers recording media that store programs for executing the method according to the present invention.

[0234] It should also be noted that, in the system, device and method of the present invention, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent schemes of the present invention. The above description of the disclosed aspects is provided to enable any technician in this field to make or use the present invention. Various modifications to these aspects will be very obvious to those skilled in the art, and the general principles defined here can be applied to other aspects without departing from the scope of the present invention. Therefore, the present invention is not intended to be limited to the aspects shown here, but according to the widest scope consistent with the principles disclosed here and novel features.

[0235] The above description has been presented for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present invention to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A method for evaluating the operational risk of a relay protection device, characterized in that: include: Extract indicators from the physical quantities of relay protection and construct an indicator set for relay protection abnormality diagnosis; Establishing a causal logic relationship between each relay protection abnormality identification state quantity and the incorrect operation of the relay protection based on the indicator set, and constructing a fault tree for risk assessment of incorrect protection operation; Introducing probability weights into the fault tree to obtain a probabilistic fault tree; Based on the probabilistic fault tree, a risk assessment result of incorrect relay protection operation is calculated.

2. The method according to claim 1, characterized in that Extract indicators from the physical quantities of relay protection and construct an indicator set for relay protection abnormality diagnosis, including: Extracting an initial indicator set from the physical quantities of the relay protection, wherein the physical quantities include sampling, online monitoring and wave recording physical quantities; The validity of the initial indicator set is judged, and the indicator set is constructed according to the valid initial indicators.

3. The method according to claim 2, characterized in that An initial index set is extracted from the physical quantities of the relay protection, including: Performing a change trend analysis on the historical operation information of the physical quantity and extracting a change trend analysis indicator; Performing analog fluctuation analysis on the physical quantity to extract fluctuation characteristic indicators; Performing homologous data comparison analysis on the physical quantity and extracting homologous comparison feature indicators; Performing switching quantity fluctuation analysis on the physical quantity and extracting a switching quantity fluctuation index; extracting harmonic component indices and single physical quantity value indices of the physical quantity; The initial indicator set is determined based on the change trend analysis indicator, the fluctuation characteristic indicator, the homology comparison characteristic indicator, the switching quantity fluctuation indicator, the harmonic component indicator and the single physical quantity value indicator.

4. The method according to claim 3, characterized in that Performing a change trend analysis on the historical operation information of the physical quantity and extracting a change trend analysis indicator includes: Select the data ramp determination time t in the physical quantity k0 ; Define the most recent measurement point as (t0, d0), and define the starting point of the ramp as (t0-t k0 ,d k0 ); If (t0-t k0 ,t0) time range, any two adjacent measurement points d x and d (x+1) The slopes of the two are all the same sign, and |d0-d k0 |>0.1|d k0 |, it is determined that the curve has changed monotonically, and the physical quantity has a trend of continuous increase or decrease. The trend analysis index is calculated. K=(d0-d k0 ) / (t0-t k0 )。 5. The method according to claim 3, characterized in that Performing analog fluctuation analysis on the physical quantity and extracting fluctuation characteristic indicators includes: Extract the most recent measurement value of the physical quantity and all measurement values ​​within this period; Determine the xth measurement point as (t(d x ),d x ) and its two surrounding points (t(d x-1 ),d x-1 ) and (t(d x+1 ),d x+1 )’s first slope K x+ and the second slope K x- ; If the first slope K x+ and the second slope K x- If they are of different signs, then (|K x- |>0.1|d x |)∪(|K x+ |>0.1|d x |)=1. If so, it is judged that a value fluctuation has occurred at this point; if not, it is judged that a continuous data change has occurred; Take all the points where the value fluctuates within the period, assuming there are m points, and then take the starting and ending points of two periods to construct m+2 fluctuation points; Define the bth occurrence point excluding the starting point and the ending point as (t(D b ),D b ) and compare the b-th occurrence point (t(D b ),D b ) and the occurrence points on both sides (t(D b-1 ),D b-1 ) and (t(D b+1 ),D b+1 ) is the absolute value of the difference between the two values, and the fluctuation characteristic index D is calculated. bk =min(|D b -D b-1 |,|D b+1 -D b |) / D b , where t(D b ) is the sampling time of the bth fluctuation point, D b is the sampling value.

6. The method according to claim 3, characterized in that The expression of the homology comparison characteristic index diff is: Where Δt represents the sampling interval, t1 represents the time interval for calculating the difference; y A (t i ),y B (t i ) represent the sampling values ​​of the homologous data points A and B respectively.

7. The method according to claim 2, characterized in that The validity of the initial indicator set is judged, and the indicator set is constructed based on the valid initial indicators, including: The objectivity, significance and timeliness of each initial indicator in the initial indicator set are judged to construct the indicator set.

8. The method according to claim 1, characterized in that The probability weight is determined as follows: K1 / p1=K2 / p2=…=K i / p i =…=K j / p j =… K1+K2+…+K N =M Where, M is the set reference value; N is the total number of risk assessment links; K i / K j The size is the probability p that the risk assessment link i leads to incorrect action of the relay protection i The probability p of incorrect relay protection action caused by risk assessment link j j Ratio; i=1,2,3...N; j=1,2,3...N; K i , K j are the probability weights of risk assessment link i and j for the incorrect operation of relay protection.

9. The method according to claim 1, characterized in that Based on the probabilistic fault tree, the risk assessment results of incorrect relay protection operation are calculated, including: Based on the probabilistic fault tree, obtaining an abnormal state quantity where an abnormality exists; Deduplication of the abnormal state quantity to obtain a non-repeated abnormal state quantity; Calculate the risk assessment result based on the non-repeated abnormal state quantity Where K(y k ) is the risk of incorrect relay protection operation caused by risk assessment link k, and 1≤k≤β, where β is the number of non-repeated abnormal state quantities.

10. An operation risk assessment device for relay protection equipment, characterized in that: include: The first building module is used to extract indicators from the physical quantities of the relay protection and build an indicator set for relay protection abnormality diagnosis; The second construction module is used to establish a causal logical association between each relay protection abnormality identification state quantity and the incorrect operation of the relay protection according to the indicator set, and to construct a fault tree for risk assessment of incorrect protection operation; An acquisition module, configured to introduce probability weights into the fault tree to acquire a probabilistic fault tree; The calculation module is used to calculate the risk assessment result of incorrect operation of the relay protection based on the probabilistic fault tree.

11. A computer-readable storage medium, characterized in that The storage medium stores a computer program, and the computer program is used to execute the method according to any one of claims 1 to 9.

12. An electronic device, characterized in that: The electronic device comprises: processor; a memory for storing instructions executable by the processor; The processor is configured to read the executable instructions from the memory and execute the instructions to implement the method according to any one of claims 1 to 9.

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