A method and system for supervising equipment of an unattended substation in the mining industry

Abstract

The application discloses a kind of mining unattended substation equipment supervision method and system, it is related to mining power system intelligent technical field, obtains the composite temperature signal collected by composite temperature sensor at electrical connection point in substation and the line load current, environmental parameter that current transformer real-time acquisition, based on environmental parameter and line load current, composite temperature signal is dynamically compensated correction and screening, obtain monitoring temperature;Based on monitoring temperature, calculate the temperature rise rate and three-phase imbalance degree input in preset fault location model, output the early warning level of potential insulation fault point determination temperature anomaly coefficient, calculate comprehensive fault coefficient, according to comprehensive fault coefficient judges fault state and executes corresponding equipment protection strategy, utilize temperature change and line load current change trend to carry out fault analysis to connection point, to find overheating problem in advance, prevent the risk of short circuit and subsequent step-out trip caused by overheating.

Description

Technical Field

[0001] This invention relates to the field of intelligent power system technology in mining, specifically to a method and system for monitoring equipment in unmanned substations in mining. Background Technology

[0002] Unmanned intelligent substations in mining operations are core power supply and distribution units ensuring safe production in mines. Under traditional three-stage current protection or time-differential protection modes, due to the short underground power supply distance and low cable impedance, the instantaneous tripping protection of switches at all levels above the fault point may simultaneously meet the operating conditions. If there is a lack of effective rapid communication and coordination mechanisms between protection devices, "over-tripping" can easily occur. This means that the fault should be cleared by the downstream switch closest to the fault point, but is mistakenly tripped by the upstream switch first, leading to an unreasonable expansion of the power outage area and seriously threatening mine ventilation, drainage, and production safety.

[0003] In existing over-trip monitoring systems, the problem of over-tripping under short-circuit conditions is often solved by adding a short-circuit current acquisition module and a blocking controller, and by using the blocking signal to coordinate the action of multiple protection devices. However, considering that electrical connection points of circuit breakers, transformers, and cables in high-voltage switchgear in substations are prone to local overheating (usually exceeding the insulation heat resistance limit of 70℃-90℃) due to increased contact resistance, overload, and insulation aging during long-term operation, this becomes a direct precursor to insulation degradation. High temperatures accelerate the carbonization and breakdown of insulation materials, which may eventually lead to serious phase-to-phase or ground-to-ground short-circuit faults.

[0004] Therefore, there is an urgent need to develop an effective method for monitoring and accurately locating the precursors of insulation faults (abnormal temperatures) to prevent short circuits and subsequent cascading trips caused by overheating. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for monitoring equipment in unmanned substations in mining areas. By installing composite temperature sensors to collect the temperature status of electrical connection points, and using temperature changes and line load current trends to analyze faults at the connection points, overheating problems can be detected in advance, preventing short circuits and subsequent cascading trips caused by overheating.

[0006] To achieve the above objectives, this application proposes the following solution: On the one hand, this invention provides a method for monitoring equipment in unmanned substations in mining areas, specifically including the following steps: S1. Acquire the composite temperature signal collected by the composite temperature sensor at the electrical connection point in the substation and the line load current collected in real time by the current transformer. Preprocess the composite temperature signal to obtain the initial composite temperature signal. S2. Collect environmental parameters within the substation, dynamically compensate and correct the initial composite temperature signal based on the environmental parameters and line load current, and filter the corrected composite temperature signal to obtain the monitored temperature. S3. Calculate the temperature rise rate and three-phase imbalance based on the monitored temperature, input the temperature rise rate and three-phase imbalance into the preset fault location model, output the warning level of potential insulation fault points, and determine the temperature anomaly coefficient according to the warning level. S4. Calculate the short-circuit current coefficient based on the real-time collected load current and the preset instantaneous overcurrent protection setting. Calculate the comprehensive fault coefficient based on the temperature anomaly coefficient and the short-circuit current coefficient. Determine the fault status based on the comprehensive fault coefficient and execute the corresponding equipment protection strategy.

[0007] In some specific implementations, the composite temperature signal includes contact temperature and non-contact temperature. The contact temperature is collected by a CT-inductive power-generating wireless temperature sensor that is in close contact with the surface of the electrical connection point, and the non-contact temperature is collected by an infrared temperature sensor facing the same electrical connection point. The composite temperature signal is electromagnetically shielded and filtered to obtain the initial composite temperature signal.

[0008] In some specific implementation schemes, environmental parameters include ambient temperature and ambient humidity, and dynamic compensation correction includes: The contact temperature signal is corrected, and the corrected contact temperature signal T_comp is: T_comp = T_c - α·(T_amb - T_ref) - β·(H - H_ref) - γ·(I - I_ref)2 where T_c represents the initial contact temperature, T_amb represents the ambient temperature, H represents the ambient humidity, I represents the line load current, T_ref, H_ref and I_ref represent the preset reference values, and α, β and γ represent the preset compensation coefficients.

[0009] In some specific implementation schemes, environmental parameters include dust concentration D, and dynamic compensation correction includes: The non-contact temperature signal is calibrated, and the calibrated non-contact temperature signal T_rcomp is: T_rcomp = T_r / e -kD Where T_r represents the initial non-contact temperature, and k is the attenuation coefficient.

[0010] In some specific implementation schemes, the process of filtering the corrected composite temperature signal is as follows: Compare the line load current I with the preset starting current threshold I_min. If I ≥ I_min, the monitored temperature T_final is the corrected contact temperature signal and is marked as the contact-dominated mode; If I < I_min, the monitored temperature T_final is the corrected non-contact temperature signal and is marked as the non-contact-dominated mode.

[0011] In some specific embodiments, the warning levels include: When the temperature rise rate exceeds the first rate threshold within the first continuous time period and the three-phase unbalance degree is greater than the first temperature difference threshold, a first-level warning is output; When the temperature rise rate exceeds the second rate threshold within the second continuous time period, and the second rate threshold is greater than the first rate threshold, or the three-phase unbalance degree is greater than the second temperature difference threshold, and the second temperature difference threshold is greater than the first temperature difference threshold, a second-level warning is output; When the monitored temperature is greater than the first temperature threshold and the temperature rise rate exceeds the second rate threshold, a third-level warning is output; When the monitored temperature is greater than the second temperature threshold, the second temperature threshold is greater than the first temperature threshold, and the monitored temperature still shows an upward trend when the line load current is stable, a fourth-level warning is output.

[0012] In some specific embodiments, the specific process of calculating the comprehensive fault coefficient is as follows: According to the load current I collected in real time and the preset instantaneous trip protection setting value I_sd, calculate the short-circuit current coefficient K_i = min(1.0, I / I_sd); According to the temperature rise rate v and the load current I, calculate the temperature rise trend coefficient K = v / I; According to the temperature rise trend coefficient K and the preset reference trend coefficient K_ref, calculate the trend deviation coefficient ΔK = max(0, (K - K_ref) / K_ref); Based on the short-circuit current coefficient, temperature anomaly coefficient, and trend deviation coefficient, fit the comprehensive fault coefficient K_f: K_f = w1·K_t + w2·K_i + w3·ΔK Where, w1, w2, w3 are preset weight coefficients and w1 + w2 + w3 = 1.

[0013] In some specific embodiments, the specific process of judging the fault state according to the comprehensive fault coefficient and implementing the corresponding equipment protection strategy is as follows: Compare the comprehensive fault coefficient with the preset first action threshold Th1 and second action threshold Th2, where Th1 > Th2: If the comprehensive fault coefficient ≥ Th1, it is determined that the fault status is an emergency fault, a tripping action signal is sent to the protector of the local substation to control the tripping of the local main switch, and an emergency locking signal is sent to the upper-level substation to force the upper-level substation to extend the instantaneous protection action delay; If Th2 ≤ K_f < Th1, it is determined that the fault status is a warning fault, a warning signal is sent to the protector of the local substation, a temperature correction coefficient is added to the preset instantaneous protection setting value, the instantaneous protection action threshold is reduced, and a temperature warning linkage signal is sent to the upper-level substation at the same time; If K_f < Th2, it is determined that the fault status is a monitoring state, and only data is recorded without protection actions.

[0014] In some specific implementation schemes, step S1 further includes: According to the line load current collected in real time, when the line load current is less than the preset instantaneous protection setting value, the warning monitoring of steps S2 - S4 is performed; When the line load current is greater than or equal to the preset instantaneous protection setting value, the short-circuit point is located, the instantaneous protection functions of the local substation main switch and the upper-level substation branch switch are locked, and the branch switch closest to the short-circuit point is controlled to trip instantaneously.

[0015] In a second aspect, the present application provides a mining unattended substation equipment supervision system, including: It includes a power distribution control center arranged in each level of substation. The power distribution control center includes a power monitoring station equipped with an edge computing unit, an electrical connection point monitoring module, an environmental parameter acquisition sensor, and a switch protection device connected to the power monitoring station. Among them: The electrical connection point monitoring module is used to collect the composite temperature signal and the line load current at the electrical connection point in the substation through a composite temperature sensor and a current transformer, and preprocess the composite temperature signal to obtain an initial composite temperature signal; The environmental parameter acquisition sensor is used to collect the environmental parameters in the substation; The edge computing unit includes: The temperature correction module is used to dynamically compensate and correct the initial composite temperature signal based on the environmental parameters and the line load current, and screen the corrected composite temperature signal to obtain the monitored temperature; The warning module is used to calculate the temperature rise rate and the three-phase unbalance degree based on the monitored temperature, input the temperature rise rate and the three-phase unbalance degree into a preset fault location model, output the warning level of potential insulation fault points, and determine the temperature anomaly coefficient according to the warning level; The fault analysis module is used to calculate the short-circuit current coefficient based on the real-time collected load current I and the preset instantaneous overcurrent protection setting, calculate the comprehensive fault coefficient based on the temperature anomaly coefficient and the short-circuit current coefficient, determine the fault status based on the comprehensive fault coefficient, and generate the corresponding equipment protection strategy. Switch protection devices are used to execute protection actions in the corresponding equipment protection strategy.

[0016] The advantages of this invention over the prior art are as follows: This invention achieves continuous 24 / 7 monitoring of the temperature at electrical connection points by simultaneously setting up a composite temperature sensor, setting up contact and non-contact temperature measurement units at electrical connection points, and automatically switching the dominant temperature measurement mode according to the load current. This avoids the "temperature measurement dead zone" problem of CT induction power-driven wireless temperature sensors that cannot work under light load or no load. Combining multiple parameters such as absolute temperature, temperature rise rate, three-phase imbalance, and load current, a four-level early warning mechanism is adopted to accurately identify potential insulation fault points, distinguish between overload heating and poor contact heating, and provide early warning before poor contact develops into a short circuit, realizing the leap from "passive tripping" to "active early warning". By integrating temperature and current dual parameters for judgment, false alarms caused by load fluctuations are avoided. Attached Figure Description

[0017] Figure 1 A flowchart of a method for monitoring equipment in an unattended substation in a mining industry, provided by an embodiment of the present invention; Figure 2 This is a connection diagram of a lockout controller in an unattended substation equipment monitoring system for mining, provided as an embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention.

[0020] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0021] Furthermore, for clarity and brevity, descriptions of well-known structures, functions, and configurations may have been omitted. Those skilled in the art will recognize that various changes and modifications can be made to the examples described herein without departing from the spirit and scope of this disclosure.

[0022] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0023] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0024] Example 1 This embodiment provides a monitoring system for unattended substation equipment in mining operations, wherein, as... Figure 2 As shown, the unmanned substation in the mining area comprises multiple levels from top to bottom: surface substation, underground central substation, and substations in each mining area. Each level of substation has a main switch and branch switches. The surface substation is the first-level substation, supplying power to the second-level substation (underground central substation). When a fault occurs in a lower-level network and all lower-level switches fail to operate, the relevant switches in the first-level substation serve as final backup. The underground central substation supplies power to the second-level substation, which in turn supplies power to the third-level substation (mining area substation). When a branch switch in the third-level substation fails to operate, the branch switch in the second-level substation supplying power to the faulty mining area will act as backup protection, tripping after a time-limited overcurrent protection delay. Simultaneously, the main switch of the second-level substation will also receive a blocking signal. Each mining area substation is a Class III substation. When a short circuit occurs downstream of a branch switch in a mining area substation (such as a line supplying power to a mobile substation or distribution point), that branch switch is the "branch switch closest to the short circuit point" and should trip first.

[0025] A monitoring center station is set up in the ground substation, and a power control center is set up in the underground central substation and each mining area substation. Each power monitoring station is connected to a ring network switch. The core switch and each ring network switch are connected through the industrial ring network, and each power monitoring station is connected to the monitoring center station through the industrial ring network and the core switch. Specifically, each power control center includes a power monitoring station equipped with an edge computing unit, an electrical connection point monitoring module installed at each electrical connection point in the switchgear, environmental parameter acquisition sensors, and switch protection devices connected to the power monitoring station. The environmental parameter acquisition sensors include ambient temperature sensors, ambient humidity sensors, and dust concentration sensors installed in the substation; used to collect environmental parameters within the substation; the environmental parameters include ambient temperature, ambient humidity, and dust concentration. The electrical connection point monitoring module is used to collect composite temperature signals and line load currents through composite temperature sensors and current transformers at electrical connection points within the substation. It preprocesses the composite temperature signals to obtain an initial composite temperature signal. The electrical connection point monitoring module includes: Composite temperature sensors are installed at electrical connections such as switchgear contacts, busbar connection points, and cable joints. Each composite temperature sensor includes both a contact temperature measurement unit and a non-contact infrared temperature measurement unit. The contact temperature measurement unit is installed close to the surface of the electrical connection point, and the non-contact infrared temperature measurement unit is installed facing the same electrical connection point. Specifically, the contact temperature measurement unit is a CT-inductive power-generating wireless temperature sensor, and the non-contact infrared temperature measurement unit is an infrared temperature sensor. A current transformer that is electrically connected to the line where the electrical connection point is located is used to collect the line load current of the line in real time. The signal preprocessing unit is used to perform electromagnetic shielding, filtering, and opto-isolation processing on the acquired composite temperature signal, and to perform analog-to-digital conversion to output the initial composite temperature signal. The signal preprocessing unit includes a signal conditioning circuit and an analog-to-digital converter. The signal conditioning circuit includes an electromagnetic shielding module and a high anti-interference filtering module (EMI filter) to solve the distortion of the temperature measurement signal caused by strong electromagnetic interference generated by mine frequency converters, etc. The isolation safety barrier includes an intrinsically safe isolation safety barrier for mining. The isolation safety barrier includes a linear optocoupler isolation circuit and an energy limiting circuit to ensure the intrinsic safety of the monitoring system and isolate dangerous energy on the high-voltage side.

[0026] Edge computing units include: The temperature correction module is used to dynamically compensate and correct the initial composite temperature signal based on environmental parameters and line load current, and to filter the corrected composite temperature signal to obtain the monitoring temperature. The early warning module is used to calculate the temperature rise rate and three-phase imbalance based on the monitored temperature, input the temperature rise rate and three-phase imbalance into the preset fault location model, output the early warning level of potential insulation fault points, and determine the temperature anomaly coefficient according to the early warning level. The fault analysis module is used to calculate the short-circuit current coefficient based on the real-time collected load current I and the preset instantaneous overcurrent protection setting, calculate the comprehensive fault coefficient based on the temperature anomaly coefficient and the short-circuit current coefficient, determine the fault status based on the comprehensive fault coefficient, and generate the corresponding equipment protection strategy. The fault analysis module sends the comprehensive fault coefficient and the corresponding protection strategy instruction to the interlocking controller and the mine intelligent integrated protector.

[0027] The switch protection device is used to execute the protection actions in the corresponding equipment protection strategy. The switch protection device includes a mining intelligent integrated protector installed in the main switch of the substation and a blocking controller installed on the busbar of the substation. The blocking controllers are interconnected and connected to the power control center and the monitoring center station. The blocking controller is connected to the mining intelligent integrated protector through a blocking line. The mining intelligent integrated protector is connected to any branch switch in the next-level substation through a communication line for receiving / sending blocking signals.

[0028] The interlocking controller receives interlocking action signals from the fault analysis module based on the fault status or receives short-circuit current signals, and sends short-circuit interlocking signals to the mine-use intelligent integrated protection device in the main switch of the substation. It also sends the short-circuit switch position to the monitoring center station.

[0029] The intelligent integrated protection device for mining is used to receive short-circuit blocking signals sent by the blocking controller. Before the time-limited overcurrent protection delay of the intelligent integrated protection device for mining is overdue, it blocks the main switch trip coil to prevent it from tripping, and blocks the instantaneous overcurrent protection function of the branch switch of the upstream substation to prevent the branch switch from tripping over the cascade. After the time-limited overcurrent protection delay of the intelligent integrated protection device for mining is overdue, if there is still a large current flowing through it, it will control the main switch to trip.

[0030] Example 2 like Figure 1 As shown, this embodiment, based on the monitoring system of Embodiment 1, provides a method for monitoring unmanned substation equipment in mining, specifically including the following steps: S1. Acquire the composite temperature signal collected by the composite temperature sensor at the electrical connection point in the substation and the line load current collected in real time by the current transformer. Preprocess the composite temperature signal to obtain the initial composite temperature signal. The composite temperature signal includes contact temperature and non-contact temperature. The contact temperature is collected by a CT-inductive power-generating wireless temperature sensor that is in close contact with the surface of the electrical connection point, while the non-contact temperature is collected by an infrared temperature sensor facing the same electrical connection point. The composite temperature signal is electromagnetically shielded and filtered to obtain the initial composite temperature signal.

[0031] S2. Based on the real-time collected line load current, when the line load current is greater than or equal to the preset instantaneous overcurrent protection setting, the blocking logic is executed, and at the same time, the local cache is checked to see if a temperature warning linkage signal sent by the lower-level substation is received; if a temperature warning linkage signal sent by the lower-level substation is received at the same time, the electrical connection point corresponding to the signal is used as the priority point for investigation of suspected fault points, and the action delay of this level of protection can be shortened according to the warning level in the temperature warning linkage signal. If no temperature warning signal is received, the original short-circuit blocking logic will be executed. The short-circuit point will be located, and the instantaneous overcurrent protection functions of the main switch of this substation and the branch switches of the upstream substation will be blocked. The branch switch closest to the short-circuit point will be immediately tripped. After tripping, the warning signal will be associated with the short-circuit event and stored for post-event analysis.

[0032] When the line load current is less than the preset instantaneous overcurrent protection setting, execute the early warning monitoring steps S3-S5; S3. Collect environmental parameters within the substation, dynamically compensate and correct the initial composite temperature signal based on the environmental parameters and line load current, and filter the corrected composite temperature signal to obtain the monitored temperature. Contact temperature measurement is affected by a combination of ambient temperature and humidity (leading to changes in heat dissipation) and current heating (Joule heating). Using reference environmental values ​​T_ref, H_ref, and reference current I_ref (e.g., 50% of the rated current) as references, coefficients α, β, and γ are used for decoupling and compensation to eliminate interference from ambient and load fluctuations in the baseline temperature rise, highlighting the true component of abnormal heating due to contact resistance. Since mine dust attenuates infrared signals (non-contact temperature measurement is inaccurate), the attenuation effect of dust (concentration D) on infrared radiation is simulated based on Beer-Lambert's law (attenuation coefficient k) to restore the true surface radiation temperature. Environmental parameters include ambient temperature, ambient humidity, and dust concentration D. Dynamic compensation correction includes: The contact temperature signal is corrected, and the corrected contact temperature signal T_comp is: T_comp = T_c - α·(T_amb - T_ref) - β·(H - H_ref) - γ·(I - I_ref)2 where T_c represents the initial contact temperature, T_amb represents the ambient temperature, H represents the ambient humidity, I represents the line load current, T_ref, H_ref and I_ref represent the preset reference values, and α, β and γ represent the preset compensation coefficients.

[0033] The non-contact temperature signal is calibrated, and the calibrated non-contact temperature signal T_rcomp is: T_rcomp = T_r / e -kD Where T_r represents the initial non-contact temperature, and k is the attenuation coefficient.

[0034] The specific process for filtering the corrected composite temperature signal is as follows: Compare the line load current I with the preset starting current threshold I_min. If I ≥ I_min, it indicates that the load current is relatively large, and the self-heating of the conductor caused by the current is the main part. Select T_comp corrected by both the environment and current as T_final, and mark it as the contact-dominated mode; If I < I_min, it indicates that the load is light, and the hot spot characteristics under small currents such as poor contact are the main ones. At this time, the self-heating of the conductor is very small. Select T_rcomp corrected by dust as T_final, and mark it as the non-contact-dominated mode. This solves the problem of insufficient sensitivity of contact sensors under small current or no-load conditions.

[0035] S4. Calculate the temperature rise rate and three-phase unbalance degree based on the monitored temperature, input the temperature rise rate and three-phase unbalance degree into the preset fault location model, output the warning level of potential insulation fault points, and determine the temperature anomaly coefficient according to the warning level; The temperature rise rate v = dT_final / dt, and the three-phase unbalance degree ΔT_phase = max(T_final_a, T_final_b, T_final_c) - min(T_final_a, T_final_b, T_final_c); The warning levels include: When the temperature rise rate exceeds the first rate threshold V1 within the first time period T1 (10 minutes) continuously, and the three-phase unbalance degree is greater than the first temperature difference threshold ΔT1, it indicates that there is a stable temperature difference between the three phases, and there may be slight poor contact, and a first-level warning is output; When the temperature rise rate exceeds the second rate threshold V2 within the second time period T2 (5 minutes) continuously, and the second rate threshold V2 is greater than the first rate threshold V1, or the three-phase unbalance degree is greater than the second temperature difference threshold ΔT2, and the second temperature difference threshold ΔT2 is greater than the first temperature difference threshold ΔT1, it is determined that the poor contact has deteriorated, and a second-level warning is output; When the monitored temperature is greater than the first temperature threshold ΔT1 and the temperature rise rate exceeds the second rate threshold V2, the first temperature threshold T_max1 can be set to the long-term working allowable upper limit of the insulating material (such as 85°C). It indicates that it is already on the verge of danger. A third-level warning is output; When the monitored temperature is greater than the second temperature threshold T_max2 (such as the temperature at which the risk of insulation flashover occurs), the second temperature threshold T_max2 is greater than the first temperature threshold T_max1, and the monitored temperature still shows an upward trend when the line load current is stable, it is determined that the contact resistance has increased sharply, and a fourth-level warning is output.

[0036] When the warning level reaches Level II or above, the warning information (including location, level, and K-value) is immediately reported to the monitoring center. The monitoring center automatically calls upon the intrinsically safe camera in the corresponding area to adjust to the preset position, aim at the alarm point, switch the image to the main screen, and record video; achieving video linkage verification. A trend report and health assessment are generated. The temperature anomaly coefficient K_t is determined according to the warning level (e.g., Level I warning corresponds to K_t=0.2, Level II warning corresponds to K_t=0.5, Level III warning corresponds to K_t=0.8, and Level IV warning corresponds to K_t=1.0).

[0037] S5. Calculate the short-circuit current coefficient based on the real-time collected load current I and the preset instantaneous overcurrent protection setting. Calculate the comprehensive fault coefficient based on the temperature anomaly coefficient and the short-circuit current coefficient. Determine the fault status based on the comprehensive fault coefficient and execute the corresponding equipment protection strategy.

[0038] Specifically, the process for calculating the comprehensive failure coefficient is as follows: Based on the real-time collected load current I and the preset instantaneous overcurrent protection setting I_sd, the short-circuit current coefficient K_i =min(1.0, I / I_sd) is calculated, reflecting the current overcurrent level.

[0039] The temperature rise trend coefficient K = v / I is calculated based on the temperature rise rate v and the load current I. This coefficient is used to distinguish between overload heating and poor contact heating. If K is constant and T_final changes linearly with I, it is mostly normal overload. If K continues to increase and the growth rate of T_final far exceeds that of I, it is a typical feature of a sharp increase in contact resistance, and is judged as poor contact heating.

[0040] Based on the temperature rise trend coefficient K and the preset benchmark trend coefficient K_ref, calculate the trend deviation coefficient ΔK = max(0, (K - K_ref) / K_ref); The comprehensive fault coefficient K_f is fitted based on the short-circuit current coefficient, temperature anomaly coefficient K_t, and trend deviation coefficient: K_f= w1·K_t +w2·K_i + w3·ΔK Where w1, w2, and w3 are preset weight coefficients and w1+w2+w3=1.

[0041] Simply put, the specific process of determining the fault state based on the comprehensive fault coefficient and executing the corresponding equipment protection strategy can be summarized as follows: When the fault diagnosis layer outputs a level three or higher warning, it sends a temperature warning linkage signal to the mine intelligent integrated protection device in the main switch of the substation at this level. After receiving the signal, the mine-use intelligent integrated protector adds a temperature correction coefficient to the instantaneous overcurrent protection setting, thereby reducing the instantaneous overcurrent protection action threshold of the line. Meanwhile, send a temperature warning linkage signal to the superior substation to prompt the superior to pay attention to the abnormality of this line.

[0042] In some other embodiments, the specific process of judging the fault state according to the comprehensive fault coefficient and executing the corresponding equipment protection strategy may also be: Compare the comprehensive fault coefficient with the preset first action threshold Th1 and second action threshold Th2, where Th1 > Th2: If the comprehensive fault coefficient K_f ≥ Th1, it is determined that the fault state is an emergency fault, control the tripping of the本级总开关 (it should be the main switch of this level in Chinese, but there may be an error in the original text, assuming it is the main switch of this level), and send an emergency locking signal to the upper-level substation to force the upper-level substation to extend the quick-break protection action delay, and force the extension of its quick-break delay to prevent misoperation of the upper level.

[0043] If Th2 ≤ K_f < Th1, it is determined that the fault state is a warning fault, send a warning signal to the protector of this level substation, add a temperature correction coefficient on the basis of the preset quick-break protection setting value, reduce the quick-break protection action threshold, and at the same time send a temperature warning linkage signal to the locking controller of the upper-level substation; and use K_f as a correction factor to dynamically adjust the quick-break protection action threshold of this circuit (such as I_sd' = I_sd - ΔI_temp, where ΔI_temp is positively correlated with K_t), so that its protection range "tilts" towards the suspected fault point and prepares for a quick response.

[0044] If K_f < Th2, it is determined that the fault state is a monitoring state, and only record data without performing protection actions.

[0045] The system determines the most likely fault point by combining the comprehensive current position and the temperature rise trend and position, so as to more accurately execute selective tripping, reduce misjudgment and delay. Even in the event of an overstepping risk, after receiving the temperature warning linkage signal from the lower level, the upper-level switch can more intelligently judge whether this tripping is a reasonable backup protection rather than a pure overstepping tripping.

[0046] This solution aims to build a closed-loop control system with the capabilities of accurate early warning, rapid isolation during the event, and linkage analysis after the event, ultimately improving power supply reliability and eradicating systematic problems caused by abnormal connection points (such as inducing short circuits and causing overstepping tripping).

[0047] When the system does not receive a short-circuit signal, it will retrieve the temperature historical data and K_f value of the corresponding circuit. This enables, in a complex multi-branch power grid, even when it is difficult for traditional current protection to distinguish the fault point due to short lines and small impedance, the node with the highest temperature rise and the largest K_f will obtain the highest fault probability weight, significantly improving the selectivity and accuracy of the isolation action, and fundamentally eliminating the underlying cause of overstepping tripping that may be caused by the development of a temperature anomaly point into a short circuit.

[0048] In the existing wellhead and surface monitoring network + anti-overlapping trip (lock-up controller) system, add a set of intelligent temperature monitoring modules for electrical connection points, which includes sensors (composite type), signal processing (anti-interference isolation), and edge computing (dynamic compensation, mode switching, fault diagnosis model).

[0049] A method is established to convert temperature warning levels into quantifiable parameters (K_t) and integrate them with real-time current information (K_i) to form a comprehensive fault coefficient (K_f). A hierarchical collaborative protection mechanism based on K_f is established, enabling temperature warning information to proactively correct the settings of traditional protection systems (warning state) or trigger active isolation (emergency state). This mechanism also achieves deep signal linkage with the short-circuit interlocking controller / mining intelligent integrated protection device, realizing closed-loop intelligent control from status monitoring to fault isolation. Ultimately, this prevents and accurately handles various short-circuit faults and cascading trips caused by abnormal temperatures at their source.

[0050] The monitoring center records temperature and current data and the actual cause before and after each fault; it periodically uses the CNN-LSTM-CAM model to optimize the thresholds (V1, V2, ΔT1, ΔT2, T_max1, T_max2, etc.); and it distributes the optimized thresholds to the edge computing units of substations at all levels.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Based on the technical essence of the present invention, any simple modifications, equivalent substitutions, and improvements made to the above embodiments within the spirit and principles of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for monitoring equipment in an unattended substation in a mining industry, characterized in that, Specifically, the following steps are included: S1. Acquire the composite temperature signal collected by the composite temperature sensor at the electrical connection point in the substation and the line load current collected in real time by the current transformer. Preprocess the composite temperature signal to obtain the initial composite temperature signal. S2. Collect environmental parameters within the substation, dynamically compensate and correct the initial composite temperature signal based on the environmental parameters and line load current, and filter the corrected composite temperature signal to obtain the monitored temperature. S3. Calculate the temperature rise rate and three-phase imbalance based on the monitored temperature, input the temperature rise rate and three-phase imbalance into the preset fault location model, output the warning level of potential insulation fault points, and determine the temperature anomaly coefficient according to the warning level. S4. Calculate the short-circuit current coefficient based on the real-time collected load current I and the preset instantaneous overcurrent protection setting. Calculate the comprehensive fault coefficient based on the temperature anomaly coefficient and the short-circuit current coefficient. Determine the fault status based on the comprehensive fault coefficient and execute the corresponding equipment protection strategy.

2. The method for monitoring unmanned substation equipment in mining operations according to claim 1, characterized in that, The composite temperature signal includes contact temperature and non-contact temperature. The contact temperature is collected by a CT-inductive power-generating wireless temperature sensor that is in close contact with the surface of the electrical connection point, while the non-contact temperature is collected by an infrared temperature sensor facing the same electrical connection point. The composite temperature signal is electromagnetically shielded and filtered to obtain the initial composite temperature signal.

3. The method for monitoring unmanned substation equipment in mining operations according to claim 2, characterized in that, Environmental parameters include ambient temperature and ambient humidity; dynamic compensation correction includes: The contact temperature signal is corrected, and the corrected contact temperature signal T_comp is: T_comp = T_c - α·(T_amb - T_ref) - β·(H - H_ref) - γ·(I - I_ref)2 where T_c represents the initial contact temperature, T_amb represents the ambient temperature, H represents the ambient humidity, I represents the line load current, T_ref, H_ref, and I_ref represent the preset reference values, and α, β, and γ represent the preset compensation coefficients.

4. The method for monitoring unmanned substation equipment in mining operations according to claim 2, characterized in that, Environmental parameters include dust concentration D, and dynamic compensation correction includes: The non-contact temperature signal is calibrated, and the calibrated non-contact temperature signal T_rcomp is: T_rcomp = T_r / e -kD Where T_r represents the initial non-contact temperature, and k is the attenuation coefficient.

5. A method for monitoring unmanned substation equipment in mining operations according to claim 2, characterized in that, The specific process for filtering the corrected composite temperature signal is as follows: Compare the line load current I with the preset starting current threshold I_min. If I ≥ I_min, then the monitored temperature T_final is the corrected contact temperature signal and is marked as contact-dominant mode; If I < I_min, then the monitored temperature T_final is the corrected non-contact temperature signal and is marked as non-contact dominant mode.

6. The method for monitoring unmanned substation equipment in mining operations according to claim 2, characterized in that, Warning levels include: When the rate of temperature rise exceeds the first rate threshold for a continuous first time period, and the three-phase imbalance is greater than the first temperature difference threshold, a first-level warning is issued. When the rate of temperature rise exceeds the second rate threshold for a second consecutive time period, and the second rate threshold is greater than the first rate threshold, or the three-phase imbalance is greater than the second temperature difference threshold, and the second temperature difference threshold is greater than the first temperature difference threshold, a level two warning is output. When the monitored temperature is greater than the first temperature threshold and the temperature rise rate exceeds the second rate threshold, a level three warning is issued. When the monitored temperature is greater than the second temperature threshold, the second temperature threshold is greater than the first temperature threshold, and the monitored temperature still shows an upward trend when the line load current is stable, a level four warning will be output.

7. A method for monitoring unmanned substation equipment in mining operations according to claim 2, characterized in that, The specific process for calculating the comprehensive failure coefficient is as follows: Based on the real-time collected load current I and the preset instantaneous overcurrent protection setting I_sd, the short-circuit current coefficient Ki = min(1.0, I / I_sd) is calculated. Calculate the temperature rise trend coefficient K = v / I based on the temperature rise rate v and the load current I; Based on the temperature rise trend coefficient K and the preset benchmark trend coefficient K_ref, calculate the trend deviation coefficient ΔK = max(0,(K - K_ref) / K_ref); The comprehensive fault coefficient K_f is fitted based on the short-circuit current coefficient, temperature anomaly coefficient, and trend deviation coefficient. K_f= w1·K_t +w2·K_i + w3·ΔK Where w1, w2, and w3 are preset weight coefficients and w1+w2+w3=1.

8. A method for monitoring unmanned substation equipment in mining operations according to claim 1, characterized in that, The specific process of determining the fault status based on the comprehensive fault coefficient and executing the corresponding equipment protection strategy is as follows: The overall failure coefficient is compared with the preset first action threshold Th1 and second action threshold Th2, where Th1 > Th2: If the comprehensive fault coefficient is greater than or equal to Th1, the fault status is determined to be an emergency fault. A tripping action signal is sent to the protector of this substation to control the tripping of the main switch of this substation, and an emergency blocking signal is sent to the next higher substation to force the next higher substation to extend the instantaneous overcurrent protection action delay. If Th2 ≤ K_f < Th1, the fault status is determined to be a warning fault, and a warning signal is sent to the protector of this substation. The temperature correction coefficient is added to the preset instantaneous overcurrent protection setting, the instantaneous overcurrent protection action threshold is reduced, and a temperature warning linkage signal is sent to the superior substation. If K_f < Th2, the fault state is determined to be a monitoring state, and only data is recorded without any protection action.

9. A method for monitoring unmanned substation equipment in mining operations according to claim 8, characterized in that, Step S1 also includes: Based on the real-time collected line load current, when the line load current is less than the preset instantaneous overcurrent protection setting, the early warning monitoring steps S2-S4 are executed. When the line load current is greater than or equal to the preset instantaneous overcurrent protection setting, the short circuit point is located, the instantaneous overcurrent protection function of the main switch of this substation and the branch switch of the next higher substation is locked, and the branch switch closest to the short circuit point is controlled to trip immediately.

10. A monitoring system for unmanned substation equipment in mining operations, characterized in that, This includes power control centers located in substations at all levels. Each power control center comprises a power monitoring station equipped with edge computing units, and connected to the power monitoring station are electrical connection point monitoring modules, environmental parameter acquisition sensors, and switch protection devices. The electrical connection point monitoring module is used to collect composite temperature signals and line load currents at electrical connection points in the substation through composite temperature sensors and current transformers, and to preprocess the composite temperature signals to obtain initial composite temperature signals. Environmental parameter acquisition sensors are used to collect environmental parameters within the substation. Edge computing units include: The temperature correction module is used to dynamically compensate and correct the initial composite temperature signal based on environmental parameters and line load current, and to filter the corrected composite temperature signal to obtain the monitoring temperature. The early warning module is used to calculate the temperature rise rate and three-phase imbalance based on the monitored temperature, input the temperature rise rate and three-phase imbalance into the preset fault location model, output the early warning level of potential insulation fault points, and determine the temperature anomaly coefficient according to the early warning level. The fault analysis module is used to calculate the short-circuit current coefficient based on the real-time collected load current I and the preset instantaneous overcurrent protection setting, calculate the comprehensive fault coefficient based on the temperature anomaly coefficient and the short-circuit current coefficient, determine the fault status based on the comprehensive fault coefficient, and generate the corresponding equipment protection strategy. Switch protection devices are used to execute protection actions in the corresponding equipment protection strategy.

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