Relay protection digital intelligent operation and maintenance system and method

Abstract

The invention discloses a relay protection digital intelligent operation and maintenance system and method, and belongs to the technical field of relay protection. The system comprises a log recording module, a data acquisition module, an intelligent analysis module, a security judgment module, a database and mobile communication equipment, the log recording module is used for recording equipment ledger information; the data acquisition module is used for acquiring current, voltage and surface temperature change conditions in the equipment operation process; the intelligent analysis and calculation module is used for determining the change condition of the heat loss ratio of the equipment; establishing an equipment state analysis model, and determining the optimal heat loss ratio duration required to be intercepted and analyzed forwards when the safety state of the equipment is analyzed; the safety judgment module is used for calculating a safety risk value of the equipment and judging whether the current equipment has a safety fault risk or not; the database is used for storing historical operation data; the mobile communication device is used for digital display.

Description

Technical Field

[0001] The present invention relates to the technical field of relay protection, and specifically to a digital intelligent operation and maintenance system and method for relay protection. Background Art

[0002] Relay protection is an important technology used to protect the safe operation of power equipment and power lines in power systems. It detects abnormal conditions in the power system and automatically cuts off the faulty part when necessary, preventing the fault from expanding and ensuring the stable operation of the power system. At the same time, it relies on the relay protection operation data at the plant and station end, through centralized data management and mining, and the promotion of the application of digital operation and maintenance technology, it reduces the workload of on-site regular inspections and improves the informatization rate and operation and maintenance management level of on-site operation and maintenance work.

[0003] With the continuous growth of the scale of power grids and the continuous improvement of operation and maintenance requirements, it is difficult for operation and maintenance personnel to discover and deal with potential safety hazards in advance in a timely manner. This problem can be effectively solved through statistical analysis of relay protection and online monitoring of secondary equipment, but a single collection of data cannot accurately reflect the health status of the equipment. In the existing technology, it is difficult to determine a safety threshold that is both safe and does not frequently trigger false alarms. Frequent false alarms may lead to additional maintenance and inspection work, waste manpower and material resources, and increase equipment maintenance costs. Summary of the invention

[0004] The purpose of the present invention is to provide a digital and intelligent operation and maintenance system and method for relay protection to solve the problems raised in the above-mentioned background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a digital intelligent operation and maintenance method for relay protection, the method comprising the following steps:

[0006] S10, record equipment ledger information; the ledger information includes equipment name, model, installation location and historical usage time; wherein the historical usage time represents the sum of the equipment's historical operation time and the current operation time;

[0007] S20, when the equipment is operating, obtaining the operating data of the equipment during operation, and storing the operating data in a database as historical data; the operating data includes changes in current, voltage and surface temperature;

[0008] S30, determining the change of the heat loss ratio of the equipment according to the change of the current, voltage and surface temperature during the operation of the equipment; establishing an equipment status analysis model based on the historical operation data and the determined heat loss ratio, and determining the optimal heat loss ratio time required for forward interception analysis when analyzing the safety status of the equipment;

[0009] S40, calculating the equipment safety risk value according to the optimal heat loss ratio duration determined by the equipment, and judging whether the current equipment has a safety failure risk according to the calculated safety risk value; when the current equipment is normal, repeating step S40; when the current equipment has a safety failure risk, controlling the relay protection device to disconnect the equipment power supply connection, and executing step S50;

[0010] S50: Issue a security alert for devices with security failure risks, and send the corresponding ledger information to the mobile communication device of the administrator.

[0011] A digital intelligent operation and maintenance system for relay protection, the system comprising a log recording module, a data acquisition module, an intelligent analysis module, a safety judgment module, a database and a mobile communication device;

[0012] The log recording module is used to record the equipment ledger information; the ledger information includes the equipment name, model, installation location and historical usage time; wherein the historical usage time represents the superposition of the equipment's historical operation time and the current operation time; the data acquisition module is used to obtain the changes in current, voltage and surface temperature during the equipment operation process; the intelligent analysis and calculation module is used to determine the changes in the equipment's heat loss ratio based on the changes in current, voltage and surface temperature during the equipment operation process, and to establish an equipment status analysis model based on historical operation data and the determined heat loss ratio, and to determine the optimal heat loss ratio duration required for forward interception analysis when analyzing the equipment's safety status; the safety judgment module is used to calculate the equipment safety risk value based on the optimal heat loss ratio duration determined by the equipment, and to judge whether the current equipment has a safety failure risk based on the calculated safety risk value; the database is used to store historical operation data; the historical operation data includes the changes in current, voltage and surface temperature during the equipment operation process; the mobile communication device is used to digitally display the equipment ledger information, the changes in current, voltage and surface temperature during the equipment operation process, and the calculated safety risk value;

[0013] Among them, a temperature sensor and a relay protection device are installed on the surface of the equipment; the temperature sensor is used to monitor the temperature change of the surface of the equipment; the relay protection device is used to disconnect the power connection of the equipment when there is a risk of safety failure of the equipment.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: by establishing an equipment status analysis model, the operating data during the equipment operation process is analyzed, and the safety risk value is calculated, the accuracy of the equipment safety failure risk judgment is improved, and the possibility of system false alarms is reduced; by centralized management and mining of operating data, the comprehensive collection of multi-dimensional information on relay protection power grid faults is achieved, and the management goals of auxiliary analysis, intelligent judgment and mobile application are achieved, the timeliness of power grid fault analysis is improved, the professional level of comprehensive analysis and accurate judgment of power grid faults is greatly improved, and the safe and stable operation of the power grid is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the steps of a digital intelligent operation and maintenance method of relay protection of the present invention;

[0016] Figure 2 It is a structural schematic diagram of a digital operation and maintenance system for relay protection of the present invention. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] See also Figure 1-Figure 2 , the present invention provides a technical solution:

[0019] See also Figure 1 In the first embodiment, a digital intelligent operation and maintenance method for relay protection is provided, and the method comprises the following steps:

[0020] S10. Record equipment inventory information; the inventory information includes equipment name, model, installation location and historical usage time; wherein the historical usage time represents the sum of the equipment's historical operation time and current operation time.

[0021] Furthermore, the device is installed with a temperature sensor and a relay protection device; the temperature sensor is used to monitor the change of the surface temperature of the device; the relay protection device is used to disconnect the power supply connection of the device when there is a risk of safety failure of the device.

[0022] It should be noted that the equipment includes but is not limited to primary equipment in power plants such as power transformers, power capacitors and reactors; wherein the timestamps of when the equipment starts and ends operation are recorded, and the historical operation duration and current operation duration of the equipment are determined based on the recorded timestamps.

[0023] S20. When the equipment is operating, the operating data of the equipment during operation is obtained, and the operating data is stored in a database as historical data; the operating data includes changes in current, voltage and surface temperature.

[0024] In this embodiment, by connecting with the online monitoring equipment of the secondary equipment in the form of data interface service, the substation equipment operation data is obtained, the equipment status analysis model is established, and the real-time information transmission of the power wireless virtual private network is utilized to monitor the operation data. Through centralized management and mining of data, the comprehensive collection of multi-dimensional information of relay protection power grid faults is achieved.

[0025] S30. Determine the change in the heat loss ratio of the equipment according to the changes in the current, voltage and surface temperature during the operation of the equipment; establish an equipment status analysis model based on the historical operation data and the determined heat loss ratio, and determine the optimal heat loss ratio duration required for forward analysis when analyzing the safety status of the equipment.

[0026] Specifically, the method steps are:

[0027] According to the changes of current, voltage and surface temperature during the operation of the equipment, the change curves of equipment current, voltage and surface temperature with time t are determined respectively to obtain I(t), V(t) and W(t);

[0028] Wherein, I(t) represents the curve of the change of the current during the operation of the equipment with time t; V(t) represents the curve of the change of the voltage during the operation of the equipment with time t; W(t) represents the curve of the change of the surface temperature during the operation of the equipment with time t;

[0029] According to I(t), V(t) and W(t), calculate the change curve H(t) of the heat loss ratio of the equipment over time t:

[0030]

[0031] Wherein, d[V(t)*I(t)] represents the differential of V(t)*I(t); d[W(t)] represents the differential of W(t); M represents the mass of the equipment material; C represents the specific heat capacity of the equipment material;

[0032] According to H(t), the change of the heat loss ratio of the equipment is obtained;

[0033] Establish an equipment status analysis model, retrieve the historical operation data of equipment safety failure from the database for analysis, determine the timestamp of equipment safety failure, and intercept the change of heat loss ratio for S time as the training data of the equipment status analysis model according to the intercepted training data. According to the intercepted training data, the change curves of heat loss ratio of equipment with time t in different historical operation data are obtained. m (t); According to H1(t), H2(t), ..., H m (t), train the equipment status analysis model, and determine the heat loss ratio duration N of each historical operation data forward intercepted and analyzed when the performance of the trained equipment status analysis model is the maximum; wherein the value of N satisfies the conditional formula:

[0034]

[0035] Among them, S represents the duration of the change of the heat loss ratio in the historical operation data; m represents the number of historical operation data of equipment safety failures retrieved and analyzed from the database; t j Indicates the timestamp of the equipment safety failure in the jth historical operation data analyzed; H i represents the heat loss ratio of the equipment at time stamp i; Indicates the average heat loss ratio of the jth historical operating data analyzed in the satisfied conditional formula; j = 1, 2, ..., m; i = t j -N, t j -N+1, ..., t j ; N≤S; P represents the number of indicators reflecting the performance of the equipment status analysis model; Δt represents the time step;

[0036] The calculated N is used as the optimal heat loss ratio time required for forward interception analysis when analyzing the safety status of the equipment.

[0037] It should be noted that the equipment safety failure refers to the situation where the equipment hardware failure causes the equipment to be unable to continue operating; the heat loss ratio refers to the ratio of the surface temperature change to the current and voltage changes during the equipment operation process. The heat loss ratio is calculated to reflect the energy conversion efficiency of the equipment during operation. The larger the corresponding H value, the worse the energy conversion efficiency of the equipment and the lower the safety level. By establishing an equipment status analysis model, the historical operating data of equipment safety failures are used as training data for the model, and the index number P reflecting the performance of the equipment status analysis model is calculated. The larger the value of P, the better the performance of the model. The optimal heat loss ratio duration for forward interception analysis is determined based on the maximum value of P, which improves the accuracy of equipment safety failure judgment and reduces the possibility of system false alarms.

[0038] S40, calculating the equipment safety risk value according to the optimal heat loss ratio duration determined by the equipment, and judging whether the current equipment has a safety failure risk according to the calculated safety risk value; when the current equipment is normal, repeating step S40; when the current equipment has a safety failure risk, controlling the relay protection device to disconnect the equipment power supply connection, and executing step S50;

[0039] Specifically, the method steps are:

[0040] Determine the timestamps corresponding to the equipment safety failures in the historical operation data, and obtain the heat loss ratio set A under the timestamps corresponding to the equipment safety failures. Divide the set A into a training set A1 and a validation set A2. Use the neural network model to train the training set A1, and cross-validate the validation set A2 with the trained neural network model. Use the cross-validation results as evaluation indicators to determine the minimum heat loss ratio threshold K when the equipment safety failure risk occurs. min ;

[0041] Determine the curve H(t) of the change of the heat loss ratio of the equipment over time t, and calculate the change F(t) of the equipment safety risk value over time t according to the optimal heat loss ratio duration determined by the equipment:

[0042]

[0043] Where, ε represents the integral variable; tN≤ε≤t;

[0044] F(t) and K min For comparison; when F(t) <K min When F(t)≥K min When the device is judged to have a safety failure risk, the relay protection device is controlled to disconnect the power supply of the device;

[0045] It should be noted that in this method, by constructing a BP neural network, the set A is divided into a training set A1 and a validation set A2, the forward propagation process of the input training set A1 through the neural network is calculated, the mean square error MSE is used to calculate the difference between the neural network prediction and the actual label, and the gradient of the loss function with respect to each weight is calculated by the chain rule, and the neural network weights are updated using the gradient descent algorithm until the neural network reaches the best performance, and then the network performance is evaluated by the validation set A2 to determine the minimum heat loss ratio threshold K when the risk of equipment safety failure occurs min ; By calculating the integral average of the heat loss ratio from tN to t, F(t) and K minComparison can be made to determine whether the current equipment has a safety failure risk, thus preventing system misjudgment due to some abnormal conditions. At the same time, centralized management and mining of operating data can be achieved to realize the comprehensive collection of multi-dimensional information on relay protection power grid failures, achieving the management goals of auxiliary analysis, intelligent judgment and mobile applications, greatly improving the professional level of comprehensive analysis and accurate judgment of power grid failures, and ensuring the safe and stable operation of the power grid.

[0046] S50: Send a security alert to the device with a risk of security failure, and send the corresponding ledger information to the mobile communication device.

[0047] Furthermore, when the current equipment is at risk of safety failure, the relay protection device is controlled to disconnect the power supply of the equipment, a safety alarm is issued for the equipment at risk of safety failure, and the equipment ledger information for the safety alarm is determined, and the alarm signal and equipment ledger information are sent to a mobile communication device; the management personnel can view the equipment ledger information, the changes in current, voltage and surface temperature during the equipment operation process, and the calculated safety risk value through the mobile communication device.

[0048] Understandably, by displaying in a visual manner on a mobile communication device, a basis is provided for troubleshooting and inspection work of operation and maintenance personnel, and on-site real-time data is provided for expert remote diagnosis; the mobile communication device includes but is not limited to mobile phones and tablet devices.

[0049] See also Figure 2 , in the second embodiment: a relay protection digital intelligent operation and maintenance system is provided, the system includes a log recording module, a data acquisition module, an intelligent analysis module, a safety judgment module, a database and a mobile communication device;

[0050] The log recording module is used to record the equipment ledger information; the ledger information includes the equipment name, model, installation location and historical usage time; wherein the historical usage time represents the superposition of the equipment's historical operation time and the current operation time; the data acquisition module is used to obtain the changes in current, voltage and surface temperature during the equipment operation process; the intelligent analysis and calculation module is used to determine the changes in the equipment's heat loss ratio based on the changes in current, voltage and surface temperature during the equipment operation process, and to establish an equipment status analysis model based on historical operation data and the determined heat loss ratio, and to determine the optimal heat loss ratio duration required for forward interception analysis when analyzing the equipment's safety status; the safety judgment module is used to calculate the equipment safety risk value based on the optimal heat loss ratio duration determined by the equipment, and to judge whether the current equipment has a safety failure risk based on the calculated safety risk value; the database is used to store historical operation data; the historical operation data includes the changes in current, voltage and surface temperature during the equipment operation process; the mobile communication device is used to digitally display the equipment ledger information, the changes in current, voltage and surface temperature during the equipment operation process, and the calculated safety risk value;

[0051] Among them, the device is equipped with a temperature sensor and a relay protection device; the temperature sensor is used to monitor the change of the surface temperature of the device; the relay protection device is used to disconnect the power connection of the device when there is a risk of safety failure in the device.

[0052] Furthermore, the intelligent analysis module includes a data processing unit, a heat loss ratio calculation unit, a model management unit and an intelligent training unit;

[0053] The data processing unit is used to determine the change curves of the equipment current, voltage and surface temperature over time according to the change of the current, voltage and surface temperature during the operation of the equipment;

[0054] The heat loss ratio calculation unit is used to calculate the change curve of the heat loss ratio of the equipment over time to obtain the change of the heat loss ratio of the equipment;

[0055] The model management unit is used to establish an equipment status analysis model, retrieve historical operation data of equipment safety failures from the database for analysis, determine the timestamp of equipment safety failures, and intercept the changes in heat loss ratios based on the timestamp of safety failures as training data for the equipment status analysis model;

[0056] The intelligent training unit is used to obtain a curve of the change of the heat loss ratio of the equipment in different historical operation data over time based on the intercepted training data, train the equipment status analysis model, determine the heat loss ratio duration of the forward interception analysis in each historical operation data when the performance of the trained equipment status analysis model is maximum, and use it as the optimal heat loss ratio duration required for the forward interception analysis when analyzing the safety status of the equipment.

[0057] Further, the safety judgment module includes a threshold determination unit, a safety risk value calculation unit and an intelligent judgment management unit;

[0058] The threshold determination unit is used to determine the minimum heat loss ratio threshold when the risk of equipment safety failure occurs;

[0059] The safety risk value calculation unit is used to determine the change curve of the heat loss ratio of the equipment over time, and calculate the change of the safety risk value of the equipment over time according to the optimal heat loss ratio duration determined by the equipment;

[0060] The intelligent judgment unit is used to judge whether the current device has a safety failure risk; when the current device is normal, the device safety failure risk judgment is repeated; when the current device has a safety failure risk, the relay protection device is controlled to disconnect the device power connection, a safety alarm is issued for the device with a safety failure risk, and the corresponding ledger information is sent to the mobile communication device;

[0061] In this embodiment:

[0062] The data acquisition module is connected to the database; the database is connected to the intelligent analysis module; the intelligent analysis module is connected to the security judgment module; the security judgment module is connected to the mobile communication device; the log recording module is connected to the security judgment module; the log recording module is connected to the mobile communication device;

[0063] The data processing unit sends the determined curves of changes of the equipment current, voltage and surface temperature over time to the heat loss ratio calculation unit; the heat loss ratio calculation unit sends the obtained changes of the equipment's heat loss ratio to the model management unit; the model management unit sends the model management unit to the intelligent training unit; the threshold determination unit sends the determined minimum heat loss ratio threshold when the equipment safety failure risk occurs to the intelligent judgment unit; the changes of the equipment safety risk value calculated by the safety risk value calculation unit over time are sent to the intelligent judgment unit; when the current equipment is normal, the intelligent judgment unit repeats the equipment safety failure risk judgment; when the current equipment has a safety failure risk, the intelligent judgment unit controls the relay protection device to disconnect the equipment power connection, sends a safety alarm signal to the mobile control device, and requests the log recording module to send the equipment ledger information corresponding to the safety failure risk to the mobile communication device.

[0064] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A digital intelligent operation and maintenance method for relay protection, characterized in that: The method comprises the following steps: S10, record equipment ledger information; the ledger information includes equipment name, model, installation location and historical usage time; wherein the historical usage time represents the sum of the equipment's historical operation time and the current operation time; S20, when the equipment is operating, obtaining the operating data of the equipment during operation, and storing the operating data in a database as historical data; the operating data includes changes in current, voltage and surface temperature; S30, determining the change of the heat loss ratio of the equipment according to the change of the current, voltage and surface temperature during the operation of the equipment; establishing an equipment status analysis model based on the historical operation data and the determined heat loss ratio, and determining the optimal heat loss ratio time required for forward interception analysis when analyzing the safety status of the equipment; S40, calculating the equipment safety risk value according to the optimal heat loss ratio duration determined by the equipment, and judging whether the current equipment has a safety failure risk according to the calculated safety risk value; when the current equipment is normal, repeating step S40; when the current equipment has a safety failure risk, controlling the relay protection device to disconnect the equipment power supply connection, and executing step S50; S50: Send a security alert to the device with a risk of security failure, and send the corresponding ledger information to the mobile communication device.

2. According to claim 1, a digital intelligent operation and maintenance method for relay protection is characterized in that: The device is installed with a temperature sensor and a relay protection device; the temperature sensor is used to monitor the change of the surface temperature of the device; the relay protection device is used to disconnect the power connection of the device when there is a risk of safety failure of the device.

3. A digital intelligent operation and maintenance method for relay protection according to claim 2, characterized in that: The method steps of step S30 are: S301, according to the changes of the current, voltage and surface temperature of the equipment during the operation process, respectively determine the change curves of the equipment current, voltage and surface temperature with time t to obtain I(t), V(t) and W(t); Wherein, I(t) represents the curve of the change of the current during the operation of the equipment with time t; V(t) represents the curve of the change of the voltage during the operation of the equipment with time t; W(t) represents the curve of the change of the surface temperature during the operation of the equipment with time t; S302. According to I(t), V(t) and W(t), calculate the change curve H(t) of the heat loss ratio of the equipment over time t: Wherein, d[V(t)*I(t)] represents the differential of V(t)*I(t); d[W(t)] represents the differential of W(t); M represents the mass of the equipment material; C represents the specific heat capacity of the equipment material; According to H(t), the change of the heat loss ratio of the equipment is obtained; S303, establish an equipment status analysis model, retrieve historical operation data of equipment safety failure from the database for analysis, determine the timestamp of equipment safety failure, intercept the change of heat loss ratio for S time periods forward according to the timestamp of safety failure as training data of the equipment status analysis model, and obtain the change curves of heat loss ratio of equipment with time t in different historical operation data according to the intercepted training data H1(t), H2(t), ..., H m (t); According to H1(t), H2(t), ..., H m (t), train the equipment status analysis model, and determine the heat loss ratio duration N of each historical operation data forward intercepted and analyzed when the performance of the trained equipment status analysis model is the maximum; wherein the value of N satisfies the conditional formula: Among them, S represents the duration of the change of the heat loss ratio in the historical operation data; m represents the number of historical operation data of equipment safety failures retrieved and analyzed from the database; t j Indicates the timestamp of the equipment safety failure in the jth historical operation data analyzed; H i represents the heat loss ratio of the equipment at time stamp i; Indicates the average heat loss ratio of the jth historical operating data analyzed in the satisfied conditional formula; j = 1, 2, ..., m; i = t j -N, t j -N+1, ..., t j ; N≤S; P represents the number of indicators reflecting the performance of the equipment status analysis model; Δt represents the time step; S304, using the calculated N as the optimal heat loss ratio duration required for forward interception analysis when analyzing the safety status of the equipment.

4. A digital intelligent operation and maintenance method for relay protection according to claim 3, characterized in that: The method steps of step S40 are: S401, respectively determine the timestamps corresponding to the equipment safety failures in the historical operation data, and obtain the heat loss ratio set A at the timestamps corresponding to the equipment safety failures; divide the set A into a training set A1 and a validation set A2, train the training set A1 using a neural network model, and cross-validate the validation set A2 with the trained neural network model, and use the cross-validation results as an evaluation index to determine the minimum heat loss ratio threshold K when the equipment safety failure risk occurs. min ; S402, determine the change curve H(t) of the heat loss ratio of the equipment over time t, and calculate the change F(t) of the equipment safety risk value over time t according to the optimal heat loss ratio duration determined by the equipment: Wherein, ε represents the integral variable; H(ε) represents the curve of the heat loss ratio of the equipment changing with time ε; tN≤ε≤t; S403, F(t) and K min For comparison; when F(t) <K min When F(t)≥K min When the device is judged to have a safety failure risk, the relay protection device is controlled to disconnect the power supply of the device.

5. A digital intelligent operation and maintenance method for relay protection according to claim 4, characterized in that: When the current equipment has a safety failure risk, the relay protection device is controlled to disconnect the equipment power connection, a safety alarm is issued for the equipment with a safety failure risk, and the equipment ledger information for the safety alarm is determined, and the alarm signal and equipment ledger information are sent to the mobile communication device; Managers can use mobile communication devices to view equipment inventory information, changes in current, voltage and surface temperature during equipment operation, and calculated safety risk values.

6. A digital intelligent operation and maintenance system for relay protection, characterized in that: The system includes a log recording module, a data collection module, an intelligent analysis module, a safety judgment module, a database and a mobile communication device; The log recording module is used to record the equipment ledger information; the ledger information includes the equipment name, model, installation location and historical usage time; wherein the historical usage time represents the superposition of the equipment's historical operation time and the current operation time; the data acquisition module is used to obtain the changes in current, voltage and surface temperature during the equipment operation process; the intelligent analysis and calculation module is used to determine the changes in the equipment's heat loss ratio based on the changes in current, voltage and surface temperature during the equipment operation process, and to establish an equipment status analysis model based on historical operation data and the determined heat loss ratio, and to determine the optimal heat loss ratio duration required for forward interception analysis when analyzing the equipment's safety status; the safety judgment module is used to calculate the equipment safety risk value based on the optimal heat loss ratio duration determined by the equipment, and to judge whether the current equipment has a safety failure risk based on the calculated safety risk value; the database is used to store historical operation data; the historical operation data includes the changes in current, voltage and surface temperature during the equipment operation process; the mobile communication device is used to digitally display the equipment ledger information, the changes in current, voltage and surface temperature during the equipment operation process, and the calculated safety risk value; Among them, the device is equipped with a temperature sensor and a relay protection device; the temperature sensor is used to monitor the change of the surface temperature of the device; the relay protection device is used to disconnect the power connection of the device when there is a risk of safety failure in the device.

7. A relay protection digital intelligent operation and maintenance system according to claim 6, characterized in that: The intelligent analysis module includes a data processing unit, a heat loss ratio calculation unit, a model management unit and an intelligent training unit; The data processing unit is used to determine the change curves of the equipment current, voltage and surface temperature over time according to the change of the current, voltage and surface temperature during the operation of the equipment; The heat loss ratio calculation unit is used to calculate the change curve of the heat loss ratio of the equipment over time to obtain the change of the heat loss ratio of the equipment; The model management unit is used to establish an equipment status analysis model, retrieve historical operation data of equipment safety failures from the database for analysis, determine the timestamp of equipment safety failures, and intercept the changes in heat loss ratios based on the timestamp of safety failures as training data for the equipment status analysis model; The intelligent training unit is used to obtain a curve of the change of the heat loss ratio of the equipment in different historical operation data over time based on the intercepted training data, train the equipment status analysis model, determine the heat loss ratio duration of the forward interception analysis in each historical operation data when the performance of the trained equipment status analysis model is maximum, and use it as the optimal heat loss ratio duration required for the forward interception analysis when analyzing the safety status of the equipment.

8. A relay protection digital intelligent operation and maintenance system according to claim 7, characterized in that: The safety judgment module includes a threshold determination unit, a safety risk value calculation unit and an intelligent judgment management unit; The threshold determination unit is used to determine the minimum heat loss ratio threshold when the risk of equipment safety failure occurs; The safety risk value calculation unit is used to determine the change curve of the heat loss ratio of the equipment over time, and calculate the change of the safety risk value of the equipment over time according to the optimal heat loss ratio duration determined by the equipment; The intelligent judgment unit is used to judge whether the current device has a safety failure risk; when the current device is normal, the device safety failure risk judgment is repeated; When the current device has a safety failure risk, the relay protection device is controlled to disconnect the device power connection, a safety alarm is issued for the device with a safety failure risk, and the corresponding ledger information is sent to the mobile communication device.

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