CN116402349A - A risk early warning method for cable trench tube wells - Google Patents

Abstract

The present invention provides a risk early warning method for cable trench pipe wells, comprising: collecting environmental data during cable operation in real time through preset sensors; performing normalization processing on the environmental data, and determining the corresponding characteristic quantities in the environmental data The probability of the fault state; screen the maximum value in the probability of the fault state corresponding to each characteristic quantity, and use the maximum value as the probability of various faults occurring in the operating state of the cable at this time; according to the cable at this time Score the severity of the consequences of the faults caused by the cable running, and determine the corresponding risk value according to the scoring result; match the risk value with the preset risk level division table, And determine the corresponding early warning information according to the matching result. The invention establishes a risk early warning evaluation body for cable operation; visualizes the risk early warning and provides corresponding auxiliary opinions; prevents and timely predicts possible faults during cable operation.

Description

A risk early warning method for cable trench tube wells

technical field

The invention relates to the technical field of risk early warning for cable trench pipe wells, in particular to a risk early warning method for cable trench pipe wells.

Background technique

With the acceleration of urbanization scale expansion and construction speed, the construction of corresponding urban ancillary facilities has also developed rapidly, and the power cable power supply network has also developed rapidly. Higher requirements are also put forward. At present, most power companies in the country are still in the planned maintenance stage for the management of main cables in power tunnels and trenches. Generally, regular inspections are used to check the operation status of cables. From an economic point of view and a technical point of view, planned maintenance has great limitations. For example, regular testing and maintenance have caused a lot of direct and indirect economic waste, and many insulation defects and potential failures cannot be found in time.

Due to the large number of underground power supply networks in the urban distribution network, the management is difficult and there are many outstanding problems. The environment of underground cables is harsh, unable to obtain power, signal interference, unstable wireless signals, no suitable monitoring equipment, and power cable problems are mostly dealt with after the event, and cannot be prevented in advance, resulting in too many alarms and complaints for power outage failures, which reduces the quality of power grid services. Especially in the high temperature and heavy load season, a large number of inspections are carried out to inspect the safety of the manhole cover in the well ditch to prevent theft and damage, and the water accumulation in the well ditch, but it is impossible to grasp it in real time, prevent it, and predict it in time.

At present, there are many evaluation methods for cable operation status, but the methods and systems for early warning of cable risks are still not perfect. There is a lack of a complete early warning system for cable operation risks, and there is a lack of a method for visualizing risk early warning.

Contents of the invention

The purpose of the present invention is to propose a risk early warning method for cable trench pipe wells, solve how to carry out risk assessment on cables, better provide judgment basis for electric power professionals to implement decision-making and planning construction, and visually display the risk level technology question.

On the one hand, a risk early warning method for cable trench wells is provided, including:

Collecting environmental data during cable operation in real time through preset sensors, wherein each characteristic quantity in the environmental data includes at least the temperature and humidity of the cable operating environment, the temperature of the cable core, the grounding current, and the partial discharge of the cable;

performing normalization processing on the environmental data, and determining the probability of a failure state corresponding to each characteristic quantity in the environmental data;

Screening the maximum value in the probability of the fault state corresponding to each feature quantity, and using the maximum value as the probability of various faults occurring in the cable's operating state at this time;

Score the severity of consequences caused by the faults caused by the cable operation according to the probability of various faults occurring in the operating state of the cable at this time, and determine the corresponding risk value according to the scoring results;

The risk value is matched with a preset risk level classification table, and corresponding early warning information is determined according to the matching result, and a visualization result corresponding to the early warning information is output.

Preferably, it also includes:

Combining the characteristic quantities in the environmental data measured at a certain moment and the fault conditions that may occur during cable operation corresponding to each characteristic quantity to form a set of corresponding cable state characteristics:

为测电缆运行状态对状态特征量x_i的概率，/>

为被测电缆运行状态对故障状态y_j的概率，x_i(i＝1,2,3,4)为某一时刻测量的所述环境数据中各特征量，y_j(j＝1,2,3,4，5)为各特征量对应的电缆运行时可能出现的故障情况。Wherein, X is the state collection of each characteristic quantity in the described environmental data, and Y is the state collection of possible failure situations that may occur during cable operation corresponding to each characteristic quantity,

In order to measure the probability of the cable running state to the state characteristic quantity x _i , />

is the probability of the operating state of the tested cable to the fault state y _j , x _i (i=1,2,3,4) is each feature quantity in the environmental data measured at a certain moment, y _j (j=1,2 , 3, 4, 5) are the fault conditions that may occur when the cable corresponding to each characteristic quantity is running.

Preferably, the environment data is normalized according to the following formula:

Among them, f(x) is the normalization result, x is each feature quantity in the environmental data, min(x) is the lower threshold of normalization processing, and Max(x) is the upper threshold of normalization processing.

Preferably, the probability of a failure state corresponding to each feature quantity in the environmental data is determined according to the following formula:

Among them, P(x) is the probability of the fault state corresponding to each feature quantity, k is the probability calculation coefficient of the fault state, and n is the calculation coefficient of the probability calculation threshold of the fault state.

Preferably, the scoring the severity of consequences caused by faults caused by cable operation according to the probability of various faults occurring in the operating state of the cable at this time includes:

The probability of various faults occurring in the operating state of the cable at this time is processed according to the preset normalization rules, and the probability normalization result η _i (i=1, 2, 3, 4) is obtained;

Score the probability normalization result to obtain the scoring result.

Preferably, the probability normalized results are scored according to the following formula:

Among them, ψ _i is the final score value, Ψ _k is the score value, k is the score sequence number corresponding to the probability normalization result, and n is the maximum number of scores.

Preferably, said determining the corresponding risk value according to the scoring result includes:

Value at risk is calculated according to the following formula:

Among them, λ is the risk value.

Preferably, said matching said risk value with a preset risk level division table includes:

When the risk value is within the preset first risk value range, it is determined as the first risk level;

When the risk value is within the preset second risk value range, it is determined as the second risk level;

When the risk value is within the preset third risk value range, it is judged as the third risk level;

When the risk value is within the preset fourth risk value range, it is determined as the fourth risk level;

When the risk value is within the preset fifth risk value range, it is determined as the fifth risk level.

Preferably, said determining corresponding warning information according to the matching result includes:

When it is at the first risk level, output the first warning message that the cable is in good condition and there is no risk;

When it is at the second risk level, the second early warning information is output as the cable is running normally, and there is a small probability that it will cause a power outage for small-scale loads;

At the third risk level, the output of the third early warning information is that the cable operation status needs attention, and there is a high probability that it will cause a power outage for small-scale loads;

When it is at the fourth risk level, the fourth early warning information is output as abnormal cable operation status, which will cause power outage of loads in a large area;

When it is at the fifth risk level, the output of the fifth early warning information is that there is a serious fault in the cable operation state, which will cause a power outage of all loads.

Preferably, it also includes:

Determine the risk assessment system for cable operation based on real-time collection of environmental data during cable operation;

The risk assessment system at least includes a target layer, an index layer, and a fault layer, wherein the target layer is used to comprehensively judge the risk level of the cable during operation, and this layer includes at least the temperature and humidity of the operating environment, the temperature of the cable core, Ground current, partial discharge of the cable; the index layer is used to reflect the evaluation state quantity index corresponding to the fault that may occur during cable operation; the fault layer is used for the fault that may occur during cable operation, and this layer includes at least the cable fire , cable breaks, short circuit faults, ground faults and disconnection faults.

In summary, implementing the embodiments of the present invention has the following beneficial effects:

The risk early warning method for cable trench tube wells provided by the present invention establishes a risk early warning evaluation system for cable operation, including the types of state feature quantities, sample data, and risk early warning levels; the risk early warning is visualized, and corresponding auxiliary treatment opinions are proposed ; It can prevent and timely predict the faults that may occur during cable operation.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, obtaining other drawings based on these drawings still belongs to the scope of the present invention without any creative effort.

Fig. 1 is a schematic diagram of the main flow of a risk warning method for cable trench pipe wells in an embodiment of the present invention.

Fig. 2 is a logical schematic diagram of a risk warning method for a cable trench well in an embodiment of the present invention.

Fig. 3 is a schematic diagram of a risk assessment system in an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings.

As shown in Fig. 1 and Fig. 2, it is a schematic diagram of an embodiment of a risk warning method for a cable trench well provided by the present invention. In this embodiment, the method includes the steps of:

Step S1, collect real-time environmental data during cable operation through preset sensors, wherein each characteristic quantity in the environmental data includes at least the temperature and humidity of the cable operating environment, the temperature of the cable core, the grounding current and the partial discharge of the cable; That is, sensors are used to collect real-time data and historical data of the above-mentioned state quantities during cable operation.

In a specific embodiment, the risk assessment system during cable operation is determined according to the real-time collection of environmental data during cable operation;

As shown in Figure 3, the risk assessment system includes at least a target layer, an index layer, and a fault layer, wherein the target layer is used to comprehensively judge the risk level of the cable during operation, and this layer includes at least the temperature and humidity of the operating environment , the temperature of the cable core, the grounding current, the partial discharge of the cable; the index layer is used to reflect the evaluation state quantity index corresponding to the fault that may occur during cable operation; the fault layer is used for the fault that may occur during cable operation, This layer includes at least cable fire, cable break, short-circuit faults, ground faults, and disconnection faults. It is understandable that comprehensively considering the complex operating environment during cable operation, the correlation with risk assessment, and the principles of easy access and practicability, combined with the requirements of relevant standards and regulations, a risk assessment system for cable operation is established. Among them, the evaluation index system is divided into three layers: target layer, index layer, and fault layer. The target layer is used to comprehensively judge the risk level of the cable during operation; Evaluate the state quantity index; where the fault layer is the fault that may occur when the cable is running. The indicator layer includes the temperature and humidity of the operating environment, the temperature of the cable core, the grounding current, and the partial discharge of the cable. The fault layer includes cable fire, cable break, short-circuit fault, ground fault, and disconnection fault. The state feature quantity includes the following: the temperature and humidity of the operating environment, the temperature of the cable core, the grounding current, and the partial discharge of the cable.

Specifically, the above four kinds of monitoring data measured at a certain moment are respectively named _xi (i=1, 2, 3, 4), and then the fault conditions that may occur during cable operation (fire, rupture, short circuit fault, grounding Faults and disconnection faults) are named as y _j (j=1,2,3,4,5) respectively. Based on this, the set expression of the cable for the state characteristics is obtained. Among them, each feature quantity in the environmental data measured at a certain moment and the fault conditions that may occur during cable operation corresponding to each feature quantity form a set of corresponding cable state characteristics:

为测电缆运行状态对状态特征量x_i的概率，/>

为被测电缆运行状态对故障状态y_j的概率，x_i(i＝1,2,3,4)为某一时刻测量的所述环境数据中各特征量，y_j(j＝1,2,3,4，5)为各特征量对应的电缆运行时可能出现的故障情况。Wherein, X is the state collection of each characteristic quantity in the described environmental data, and Y is the state collection of possible failure situations that may occur during cable operation corresponding to each characteristic quantity,

In order to measure the probability of the cable running state to the state characteristic quantity x _i , />

is the probability of the operating state of the tested cable to the fault state y _j , x _i (i=1,2,3,4) is each feature quantity in the environmental data measured at a certain moment, y _j (j=1,2 , 3, 4, 5) are the fault conditions that may occur when the cable corresponding to each characteristic quantity is running.

Step S2, normalize the environmental data, and determine the probability of the failure state corresponding to each feature in the environmental data; that is, normalize the environmental data, and calculate the feature by the membership function The probability of the quantity corresponding to the fault state is the degree of membership.

In a specific embodiment, the environment data is normalized according to the following formula:

Among them, f(x) is the normalization result, x is each feature quantity in the environmental data, min(x) is the lower threshold of normalization processing, and Max(x) is the upper threshold of normalization processing.

Determine the probability of the failure state corresponding to each feature quantity in the environmental data according to the following formula:

Among them, P(x) is the probability of the fault state corresponding to each feature quantity, k is the probability calculation coefficient of the fault state, and n is the calculation coefficient of the probability calculation threshold of the fault state. Among them, the larger the P(x) is, the higher the probability that the cable belongs to the fault condition y _j after the characteristic quantity x _i appears during operation; on the contrary, the smaller the P(x) is, the lower the possibility is.

Specifically, 3) A 4×3 fuzzy judgment matrix is formed by the degree of membership. like:

The comprehensive weight is determined by the combined weighting method, which is a commonly used method in the field, and will not be described in detail in the present invention.

Step S3, screen the maximum value of the probability of the fault state corresponding to each feature quantity, and use the maximum value as the probability of various faults occurring in the current operating state of the cable; that is, based on the principle of maximum membership degree, calculate The probability of various faults occurring in the operating state of the cable at this time.

Step S4, according to the probability of various faults occurring in the operating state of the cable at this time, the severity of the consequences caused by the faults caused by the cable operation is scored, and the corresponding risk value is determined according to the scoring results; that is, for convenience Calculate and compare, and normalize the calculated probability of various faults occurring in the operating state of the cable at this time.

In a specific embodiment, the probability of various faults occurring in the operating state of the cable at this time is processed according to a preset normalization rule to obtain a probability normalization result η _i (i=1,2,3,4) ; Score the probability normalization result to get the scoring result.

The probability normalized results are scored according to the following formula:

Among them, ψ _i is the final score value, Ψ _k is the score value, k is the score sequence number corresponding to the probability normalization result, and n is the maximum number of scores. It is understandable that the severity of consequences caused by faults caused by cable operation is different, so a scoring method is used, and the score is between [0-1] to represent the difference in severity of faults. The scoring method can use expert scoring or program scoring according to the specific situation. When using expert scoring, n can represent the number of experts.

Specifically, the risk value is calculated according to the following formula:

Among them, λ is the risk value.

Step S5, matching the risk value with a preset risk level classification table, determining corresponding early warning information according to the matching result, and outputting a visualization result corresponding to the early warning information. That is, based on the risk value, the risk level of the cable is divided, different risk levels are visualized, and the high risk level is given priority to alarm.

In a specific embodiment, the matching of the risk value with a preset risk level division table includes:

When the risk value is within the preset first risk value range, it is determined as the first risk level;

When the risk value is within the preset second risk value range, it is determined as the second risk level;

When the risk value is within the preset third risk value range, it is judged as the third risk level;

When the risk value is within the preset fourth risk value range, it is determined as the fourth risk level;

When the risk value is within the preset fifth risk value range, it is determined as the fifth risk level.

Among them, the risk value is divided into risk levels as shown in Table 1:

Table 1 Risk Level Classification Table

risk value 0.0-0.1 0.2-0.4 0.4-0.6 0.6-0.8 0.8-1.0 risk level Risk level v ₁ Risk level v ₂ Risk level v ₃ Risk level v ₄ Risk level v ₅

Specifically, said determining the corresponding early warning information according to the matching result includes:

When it is at the first risk level, output the first warning message that the cable is in good condition and there is no risk;

When it is at the second risk level, the second early warning information is output as the cable is running normally, and there is a small probability that it will cause a power outage for small-scale loads;

At the third risk level, the output of the third early warning information is that the cable operation status needs attention, and there is a high probability that it will cause a power outage for small-scale loads;

When it is at the fourth risk level, the fourth early warning information is output as abnormal cable operation status, which will cause power outage of loads in a large area;

When it is at the fifth risk level, the output of the fifth early warning information is that there is a serious fault in the cable operation state, which will cause a power outage of all loads.

Among them, the visual display of early warning information is as follows:

Risk Level Risk Consequences Advice on Risks

In summary, implementing the embodiments of the present invention has the following beneficial effects:

The risk early warning method for cable trench tube wells provided by the present invention establishes a risk early warning evaluation system for cable operation, including the types of state feature quantities, sample data, and risk early warning levels; the risk early warning is visualized, and corresponding auxiliary treatment opinions are proposed ; It can prevent and timely predict the faults that may occur during cable operation.

The above disclosures are only preferred embodiments of the present invention, and certainly cannot limit the scope of rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope of the present invention.

Claims (10)

1. A risk early warning method for a cable trench tube well, characterized in that it comprises: Collecting environmental data during cable operation in real time through preset sensors, wherein each characteristic quantity in the environmental data includes at least the temperature and humidity of the cable operating environment, the temperature of the cable core, the grounding current, and the partial discharge of the cable; performing normalization processing on the environmental data, and determining the probability of a failure state corresponding to each characteristic quantity in the environmental data; Screening the maximum value in the probability of the fault state corresponding to each feature quantity, and using the maximum value as the probability of various faults occurring in the cable's operating state at this time; Score the severity of consequences caused by the faults caused by the cable operation according to the probability of various faults occurring in the operating state of the cable at this time, and determine the corresponding risk value according to the scoring results; The risk value is matched with a preset risk level classification table, and corresponding early warning information is determined according to the matching result, and a visualization result corresponding to the early warning information is output. 2. The method of claim 1, further comprising: Combining the characteristic quantities in the environmental data measured at a certain moment and the fault conditions that may occur during cable operation corresponding to each characteristic quantity to form a set of corresponding cable state characteristics:

Wherein, X is the state collection of each characteristic quantity in the described environmental data, and Y is the state collection of possible failure situations that may occur during cable operation corresponding to each characteristic quantity,

In order to measure the probability of the cable running state to the state characteristic quantity x _i ,

is the probability of the operating state of the tested cable to the fault state y _j , x _i (i=1,2,3,4) is each feature quantity in the environmental data measured at a certain moment, y _j (j=1,2 , 3, 4, 5) are the fault conditions that may occur when the cable corresponding to each characteristic quantity is running. 3. The method according to claim 2, characterized in that, the environment data is normalized according to the following formula:

Among them, f(x) is the normalization result, x is each feature quantity in the environmental data, min(x) is the lower threshold of normalization processing, and Max(x) is the upper threshold of normalization processing. 4. The method according to claim 3, wherein the probability of the failure state corresponding to each feature quantity in the environmental data is determined according to the following formula:

Among them, P(x) is the probability of the fault state corresponding to each feature quantity, k is the probability calculation coefficient of the fault state, and n is the calculation coefficient of the probability calculation threshold of the fault state. 5. The method according to claim 4, wherein the scoring of the severity of consequences caused by faults caused during cable operation according to the probability of various faults occurring in the operating state of the cable at this time comprises: The probability of various faults occurring in the operating state of the cable at this time is processed according to a preset normalization rule, and the probability normalization result η _i (i=1,2,3,4) is obtained; Score the probability normalization result to obtain the scoring result. 6. The method of claim 5, wherein the probability normalization result is scored according to the following formula:

Among them, ψ _i is the final score value, Ψ _k is the score value, k is the score sequence number corresponding to the probability normalization result, and n is the maximum number of scores. 7. The method according to claim 6, wherein said determining the corresponding risk value according to the scoring result comprises: Value at risk is calculated according to the following formula:

Among them, λ is the risk value. 8. The method according to claim 7, wherein said matching said risk value with a preset risk level division table comprises: When the risk value is within the preset first risk value range, it is determined as the first risk level; When the risk value is within the preset second risk value range, it is determined as the second risk level; When the risk value is within the preset third risk value range, it is judged as the third risk level; When the risk value is within the preset fourth risk value range, it is determined as the fourth risk level; When the risk value is within the preset fifth risk value range, it is determined as the fifth risk level. 9. The method according to claim 8, wherein said determining corresponding early warning information according to the matching result comprises: When it is at the first risk level, output the first warning message that the cable is in good condition and there is no risk; When it is at the second risk level, the second early warning information is output as the cable is running normally, and there is a small probability that it will cause a power outage for small-scale loads; At the third risk level, the output of the third early warning information is that the cable operation status needs attention, and there is a high probability that it will cause a power outage for small-scale loads; When it is at the fourth risk level, the fourth early warning information is output as abnormal cable operation status, which will cause power outage of loads in a large area; When it is at the fifth risk level, the output of the fifth early warning information is that there is a serious fault in the cable operation state, which will cause a power outage of all loads. 10. The method of claim 1, further comprising: Determine the risk assessment system for cable operation based on real-time collection of environmental data during cable operation; The risk assessment system at least includes a target layer, an index layer, and a fault layer, wherein the target layer is used to comprehensively judge the risk level of the cable during operation, and this layer includes at least the temperature and humidity of the operating environment, the temperature of the cable core, Ground current, partial discharge of the cable; the index layer is used to reflect the evaluation state quantity index corresponding to the fault that may occur during cable operation; the fault layer is used for the fault that may occur during cable operation, and this layer includes at least the cable fire , cable breaks, short circuit faults, ground faults and disconnection faults.

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