Intelligent monitoring device for power distribution cabinet

Abstract

The application relates to the technical field of power distribution cabinet monitoring, and discloses an intelligent monitoring device for a power distribution cabinet, which comprises: an information acquisition unit which acquires the air temperature, air humidity, equipment surface temperature, load current, residual current and smoke concentration in the power distribution cabinet; a monitoring processing unit which determines the current load state according to the load current, judges the thermal state of the power distribution cabinet based on the difference between the air temperature and the temperature rise reference, and judges the condensation state of the power distribution cabinet; a verification processing unit which comprehensively judges the environmental risk type of the power distribution cabinet based on the thermal state and the condensation state, and performs risk verification on the environmental risk type based on the residual current and the smoke concentration; and an environment adjusting unit which executes environment adjustment based on the environmental risk type after risk verification, and releases the corresponding environment adjustment when the newly determined environmental risk type meets the risk release condition. The application ensures the reliability of intelligent monitoring of the power distribution cabinet.

Description

Technical Field

[0001] This invention relates to the field of power distribution cabinet monitoring technology, and more specifically, to an intelligent monitoring device for power distribution cabinets. Background Technology

[0002] As a crucial piece of equipment in power distribution systems, switchboards typically house circuit breakers, contactors, busbars, instrument transformers, and other electrical components. The operating environment inside the switchboard directly impacts the insulation performance and operational stability of these electrical devices. During continuous operation, changes in load current cause variations in the degree of heating within the switchboard. Changes in air temperature and humidity can gradually bring the busbar connection area, circuit breaker area, and inner walls of the switchboard closer to the air dew point, creating a risk of condensation. Furthermore, localized overheating and condensation may be accompanied by increased residual current or changes in smoke concentration.

[0003] In the prior art, Chinese invention patent application CN109510311A discloses a monitoring device for the operating environment of a power distribution cabinet and its usage method. This device includes a temperature and humidity acquisition module, a smoke detection module, a flame detection module, and a leakage current detection module. It monitors the internal temperature, humidity, smoke, flame, and residual current of the power distribution cabinet. The front-end main control unit compares the collected temperature, humidity, smoke concentration, and flame radiation intensity with corresponding thresholds. For leakage current information, the residual current is converted into voltage and compared with a preset threshold. An alarm is triggered when the voltage exceeds the corresponding threshold. However, in actual operation, the load level of the power distribution cabinet, the internal air temperature, air humidity, equipment surface temperature, residual current, and smoke concentration may change simultaneously. When judging solely based on comparisons between each monitoring parameter and fixed thresholds, the lack of correlation verification between different monitoring parameters makes it difficult to further distinguish between thermal anomalies, condensation anomalies, and complex anomalies accompanied by leakage current or smoke changes. This can easily lead to inaccurate assessment of the power distribution cabinet's environmental risks and make it difficult to implement targeted adjustments based on different risk states, thus affecting the accuracy and reliability of the power distribution cabinet's operating environment monitoring.

[0004] Therefore, it is necessary to design an intelligent monitoring device for power distribution cabinets to solve the problems existing in the current technology. Summary of the Invention

[0005] In view of this, the present invention proposes an intelligent monitoring device for power distribution cabinets, which aims to solve the above-mentioned problems.

[0006] This invention proposes an intelligent monitoring device for a power distribution cabinet, comprising: The information acquisition unit is configured to collect data on air temperature, air humidity, equipment surface temperature, load current, residual current, and smoke concentration inside the power distribution cabinet. The monitoring and processing unit is configured to determine the current load state based on the load current, determine the temperature rise reference corresponding to the current load state in historical operating data, determine the thermal state of the distribution cabinet based on the difference between the air temperature and the temperature rise reference, determine the condensation margin based on the minimum value of the air temperature, the air humidity and the equipment surface temperature, and determine the condensation state of the distribution cabinet. The verification processing unit is configured to comprehensively determine the environmental risk type of the power distribution cabinet based on the thermal state and the condensation state, and to perform risk verification on the environmental risk type based on the residual current and the smoke concentration. The environmental control unit is configured to perform at least one of the following environmental controls based on the environmental risk type after risk verification: ventilation and heat dissipation, dehumidification, or anti-condensation heating. After performing the environmental control, the environmental risk type is redefined. When the redefined environmental risk type meets the risk relief conditions, the corresponding environmental control is deactivated.

[0007] Furthermore, in determining the temperature rise reference corresponding to the current load state, the following steps are included: The monitoring and processing unit extracts historical stable data from the historical operating data of the power distribution cabinet, showing that the cabinet door is closed, the load current is within a stable range, and no environmental abnormality alarms are generated. Based on the load current, the historical stable data is divided into several load intervals, and the stable air temperature corresponding to each load interval is determined. The load interval of the load current is determined, and the corresponding stable air temperature is used as the temperature rise reference for the current load state.

[0008] Furthermore, when determining the thermal state of the distribution cabinet based on the difference between the air temperature and the temperature rise reference, the following steps are included: The monitoring and processing unit takes the difference between the air temperature and the temperature rise benchmark corresponding to the current load state as the temperature deviation, and obtains the direction of change of the air temperature within the continuous monitoring period. When the temperature deviation does not exceed the temperature difference threshold and the direction of change does not show a continuous increase, the distribution cabinet is determined to be in a thermally stable state. When the temperature deviation exceeds the temperature difference threshold, or when the direction of change shows a continuous increase, the power distribution cabinet is determined to be in a thermal abnormality state.

[0009] Furthermore, in determining the condensation state of the distribution cabinet, the following steps are taken: The monitoring and processing unit determines the air dew point temperature based on the air temperature and the air humidity. The minimum value of the equipment surface temperature is determined based on the temperature detection points set in the busbar connection area, circuit breaker area and cabinet inner wall area, and the difference between the minimum value and the air dew point temperature is determined as the condensation margin. When the condensation margin is greater than or equal to the condensation safety margin, the distribution cabinet is determined to be in a condensation safety state. When the condensation margin is less than the condensation safety margin, the distribution cabinet is determined to be in a condensation risk state.

[0010] Furthermore, when comprehensively assessing the environmental risk type of the power distribution cabinet, the following factors are considered: When the power distribution cabinet is in the thermally stable state and the condensation safe state, the verification processing unit determines that the environmental risk type of the power distribution cabinet is the environmentally stable state; When the power distribution cabinet is in the thermal abnormal state and the condensation safe state, the verification and processing unit determines that the environmental risk type of the power distribution cabinet is heat accumulation risk; When the power distribution cabinet is in the thermally stable state and the condensation risk state, the verification processing unit determines that the environmental risk type of the power distribution cabinet is condensation risk; When the power distribution cabinet is in both the thermal anomaly state and the condensation risk state, the verification processing unit determines that the environmental risk type of the power distribution cabinet is a composite environmental risk.

[0011] Furthermore, when verifying the environmental risk types, the following are included: The verification processing unit extracts the residual current benchmark of the stable operation of the distribution cabinet from the historical operation data, determines the difference between the residual current and the residual current benchmark as the residual current deviation, and determines whether the smoke concentration increases within the continuous monitoring period. When the environmental risk type is condensation risk and the residual current deviation exceeds the leakage deviation threshold, the condensation risk is upgraded to condensation leakage risk. When the environmental risk type is thermal accumulation risk and the smoke concentration continues to increase, the thermal accumulation risk is upgraded to overheated smoke risk. When the environmental risk type is the composite environmental risk, and the residual current deviation exceeds the leakage deviation threshold, and / or the smoke concentration continues to increase, the composite environmental risk is upgraded to a composite severe risk.

[0012] Furthermore, the risk verification of the aforementioned environmental risk types also includes: When the environmental risk type is the stable environmental state and the residual current deviation exceeds the leakage deviation threshold, the verification processing unit determines that there is an electrical abnormality and outputs an electrical abnormality alarm.

[0013] Furthermore, when performing environmental adjustments, this includes: If the risk of heat buildup or the risk of overheated smoke are present, the environmental control unit will activate ventilation and heat dissipation to increase the air exchange rate inside the distribution cabinet. If the risk of condensation is present, the environmental control unit will activate dehumidification and / or anti-condensation heating; If there is a risk of condensation leakage, the environmental control unit will activate dehumidification and / or anti-condensation heating, and output the electrical abnormality alarm. If the combined environmental risk is as described, the environmental control unit will activate ventilation and heat dissipation, and dehumidification, and / or anti-condensation heating; If the combined severe risk is detected, the environmental control unit outputs an emergency alarm and sends a power-off control command to the circuit breaker control device of the power distribution cabinet.

[0014] Furthermore, when redefining the type of environmental risk, this includes: If the redefined environmental risk type is lower than before the environmental adjustment was performed, and was not the composite severe risk or the condensation leakage risk before the environmental adjustment was performed, the environmental adjustment unit continues to perform environmental adjustment based on the redefined environmental risk type. If the redefined environmental risk type has not decreased relative to before the environmental adjustment was performed, the environmental adjustment unit continues to perform environmental adjustment.

[0015] Furthermore, when redefining the type of environmental risk, it also includes: If the redefined environmental risk type is the stable environmental state, and there is no residual current deviation exceeding the leakage deviation threshold, the environmental adjustment unit determines that the risk removal condition is met and releases the corresponding environmental adjustment.

[0016] Compared with existing technologies, the beneficial effects of this invention are as follows: In summary, by acquiring the air temperature, air humidity, equipment surface temperature, load current, residual current, and smoke concentration inside the distribution cabinet, the monitoring of independent environmental parameters is transformed into an environmental risk assessment process with a sequential correlation. The current load state is determined based on the load current, and a temperature rise benchmark corresponding to the current load state is retrieved from historical stable operating data. This ensures that the air temperature assessment is based on the current actual load conditions, reducing the possibility of misjudgments of thermal anomalies caused by natural temperature rise due to normal load increases. The air dew point is determined by air temperature and humidity, and the condensation margin is determined using the lowest equipment surface temperature in the busbar connection area, circuit breaker area, and cabinet inner wall area. This allows condensation risk assessment to no longer rely solely on air humidity but to reflect the local surface state most easily accessible to the dew point. By combining thermal and condensation states, and using residual current deviation and smoke concentration changes to re-verify different environmental risks, different risks can be distinguished, improving the ability to identify different abnormal states. Environmental adjustments are performed based on the verified risk type, and relevant data are re-collected and the environmental risk type is determined after the environmental adjustments are performed. This forms a closed-loop monitoring process that includes multi-parameter collection, load-related temperature rise judgment, condensation status judgment, risk classification, secondary verification, targeted adjustment and risk reconfirmation, which improves the accuracy and reliability of identifying environmental risks in the distribution cabinet. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of an intelligent monitoring device for a power distribution cabinet provided in an embodiment of the present invention; Figure 2 A logic flowchart for comprehensively determining the environmental risk type of a power distribution cabinet, provided in an embodiment of the present invention; Figure 3 The following is a logic flowchart for adjusting the execution environment provided in an embodiment of the present invention. Detailed Implementation

[0019] 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. 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.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] See Figure 1-3 As shown in some embodiments of this application, an intelligent monitoring device for a power distribution cabinet includes: The information acquisition unit is configured to collect data on air temperature, air humidity, equipment surface temperature, load current, residual current, and smoke concentration inside the power distribution cabinet. The monitoring and processing unit is configured to determine the current load status based on the load current, determine the temperature rise reference corresponding to the current load status in the historical operating data, determine the thermal status of the distribution cabinet based on the difference between the air temperature and the temperature rise reference, determine the condensation margin based on the minimum value of the air temperature, air humidity and equipment surface temperature, and determine the condensation status of the distribution cabinet. The verification processing unit is configured to comprehensively determine the environmental risk type of the power distribution cabinet based on thermal and condensation conditions, and to perform risk verification based on residual current and smoke concentration. The environmental control unit is configured to perform at least one of the following environmental controls based on the environmental risk type after risk verification: ventilation and heat dissipation, dehumidification, or anti-condensation heating. After performing the environmental control, the environmental risk type is redefined. When the redefined environmental risk type meets the risk removal conditions, the corresponding environmental control is removed.

[0022] Specifically, the information acquisition unit is used to generate the basic monitoring data required for judgment, the monitoring and processing unit completes the first state judgment related to the thermal environment and condensation environment inside the distribution cabinet, the verification and processing unit further verifies the environmental risk type determined in the first step using residual current and smoke concentration, and the environmental adjustment unit performs targeted environmental adjustment based on the verified risk type, and forms a monitoring closed loop through re-detection and re-judgment.

[0023] This embodiment does not compare air temperature, air humidity, residual current, and smoke concentration separately with a fixed threshold. Instead, it first establishes a temperature rise benchmark that matches the current operating conditions based on the current load status of the distribution cabinet. Then, it determines whether the current air temperature is abnormal relative to the temperature rise benchmark. At the same time, it judges the condensation state by the relationship between air temperature, air humidity, and equipment surface temperature. After obtaining the thermal state and condensation state, it forms an environmental risk type. Furthermore, it verifies whether the corresponding environmental risk is accompanied by electrical abnormalities or smoke changes by checking the residual current and smoke concentration, so that different environmental states can be distinguished.

[0024] Specifically, the information acquisition unit may include air temperature and humidity detection components, equipment surface temperature detection components, load current detection components, residual current detection components, and smoke detection components. These specific detection components can all use existing sensors that are compatible with their detection objects. This application is not intended to limit specific models, but rather to perform correlation processing on various detection results.

[0025] Air temperature is temperature data that reflects the overall thermal state of the air inside the distribution cabinet, while air humidity is relative humidity data of the air inside the distribution cabinet. Air temperature and air humidity are used together to determine the dew point temperature of the air inside the cabinet. Equipment surface temperature is not measured at just one location, but at least the surface temperatures of the busbar connection area, circuit breaker area, and cabinet inner wall area are measured. The reason for choosing different locations is that their states in the operating environment of the distribution cabinet differ. The busbar connection area and circuit breaker area are representative electrical equipment areas inside the distribution cabinet, while the cabinet inner wall reflects the surface temperature state formed after heat exchange between the cabinet and the surrounding environment. Regarding the risk of condensation, it is not the average surface temperature that determines whether condensation occurs first, but rather the detection location with the lowest temperature usually approaches the air dew point earlier. Therefore, this application further determines the minimum value from the surface temperatures of each piece of equipment and uses this minimum value as the basis for calculating the condensation margin.

[0026] Load current indicates the current operating load of the distribution cabinet. When the load changes, the heating level of its internal electrical components also changes accordingly. Therefore, even without environmental anomalies, the air temperature inside the cabinet may differ under different load conditions during stable operation. Using the same fixed air temperature threshold for judgment could lead to misjudging normal temperature rises under high load conditions, or ignoring abnormal temperature rises under low load conditions due to a high threshold setting. Using load current to determine the current load state and further searching for the corresponding temperature rise benchmark in historical operating data ensures accurate judgment. Residual current reflects potential leakage current changes in the distribution cabinet's electrical circuits. Smoke concentration reflects whether smoke changes inside the cabinet are related to the further development of abnormal temperature rises.

[0027] First, environmental risk types are determined using temperature, humidity, and surface temperature. Then, residual current and smoke concentration are used for risk verification. This processing sequence distinguishes the internal environmental conditions from the electrical manifestations that accompany environmental anomalies. During data collection, various data are acquired according to a continuous monitoring cycle. The continuous monitoring cycle can be set based on the distribution cabinet's capacity, internal space, temperature change rate, and sensor response speed. For distribution cabinets operating continuously, a fixed sampling interval can be used to acquire data, with several consecutive sampling results forming a continuous monitoring cycle. The continuous monitoring cycle should not only include a single sampling point; otherwise, a single instantaneous fluctuation in air temperature or smoke concentration can easily affect subsequent judgments. The continuous monitoring cycle should also not be set too long to avoid reducing the speed of anomaly identification. This embodiment does not limit the monitoring cycle. During equipment commissioning, the sampling cycle can be dynamically selected by recording the actual rate of change of each monitoring parameter during operation, load changes, and environmental changes. When determining the temperature rise benchmark corresponding to the current load state, the monitoring and processing unit first extracts historical stable data from the historical operating data of the distribution cabinet. Historical operating data consists of air temperature, load current, and related operating status data generated and saved during previous operation of the distribution cabinet. Not all historical data is used to establish the temperature rise benchmark; historical stable data must meet the following conditions: the cabinet door is closed, the load current is within a stable range, and no environmental anomaly alarms have been generated. The cabinet door must be closed to prevent rapid exchange of air between the inside and outside of the cabinet, which would cause the collected air temperature to not represent the stable temperature of the distribution cabinet under normal closed operating conditions. For example, if the cabinet door is opened for an extended period during maintenance, even if the load current is the same as during normal operation, the air temperature inside the cabinet may change significantly due to the entry of outside air. Using this data as the temperature rise benchmark would affect subsequent thermal status judgments; therefore, it is excluded from the historical stable data.

[0028] A stable load current means that, within the observation period used to generate historical stable data, the load current does not show a significant continuous increase or decrease. The stable load current range can be determined by the actual current fluctuations during the normal operation of the distribution cabinet. For example, during equipment commissioning or historical data accumulation, the natural fluctuations of the current under normal stable load in a continuous sampling period can be statistically analyzed, and the upper limit of normal fluctuation can be used as the basis for setting the stable load range. It should be noted that the stable load range is not used to determine whether the distribution cabinet is overloaded, but rather to filter data that can represent the stable air temperature under a certain load condition. If the load current is increasing rapidly, even if the air temperature has not yet increased significantly, the air temperature may continue to rise due to thermal inertia over a period of time. Therefore, the data at this moment is not suitable as a temperature rise benchmark. No environmental anomaly alarm is generated when no environmental anomaly is generated according to the existing monitoring status during the corresponding operating phase used to generate historical stable data. This condition avoids the reverse inclusion of air temperature at times when abnormal heat accumulation, condensation, or other obvious environmental anomalies have occurred into the normal temperature rise benchmark.

[0029] The monitoring and processing unit divides historical stable data into several load intervals based on load current and determines the corresponding stable air temperature for each load interval. There is no limit to the number of load intervals; the specific number can be determined based on the rated current range of the distribution cabinet and the actual load distribution. For example, if a distribution cabinet mainly operates under three conditions—low load, medium load, and high load—it can form three load intervals. If the load variation range is wide, more load intervals can be added so that the stable air temperature corresponding to each interval can represent the corresponding load state.

[0030] The load intervals should cover the range of load currents commonly encountered during normal operation of the distribution cabinet. If the intervals are set too wide, the same interval may simultaneously contain load states with significantly different heating levels, reducing the representativeness of the stable air temperature. If the intervals are set too narrow, some load intervals may have insufficient data. Therefore, the interval width can be determined based on the actual distribution of load current after the distribution cabinet has accumulated a certain amount of historical operating data. In one specific implementation, load intervals can also be formed based on the proportion of the distribution cabinet's rated load, for example, dividing the rated load range into several levels, and then obtaining the stable air temperature from the historical stable data corresponding to each level.

[0031] The stable air temperature can be determined based on multiple sets of historical air temperatures within the corresponding load range. Specifically, a representative average temperature from a historical stable period can be selected, or the stable air temperature can be determined based on the concentrated distribution of multiple stable operating periods. The goal is not to pursue a specific instantaneous temperature value, but rather to determine the air temperature level typically corresponding to the long-term normal operation of the distribution cabinet under that load level. To ensure the temperature rise benchmark is sufficiently representative, stable operating data under different load ranges can be recorded after the distribution cabinet is put into normal operation for the initial establishment of historical data. Within a specific load range, it should be ensured that the load current has entered a stable range, and the corresponding data should only be used as historical stable data after the air temperature inside the cabinet no longer shows a significant and continuous increase. This avoids the risk of an excessively low temperature rise benchmark due to the cabinet temperature not yet reaching a stable state during load switching.

[0032] The monitoring and processing unit determines the load range to which the load current belongs and uses the corresponding stable air temperature as the temperature rise benchmark for the current load state. Therefore, the temperature rise benchmark changes with the load state. For example, the normal stable air temperature of the same distribution cabinet may be at one level under a lower load, but may naturally rise to another level under a higher load. Subsequent thermal status assessment focuses on "how much the current air temperature deviates from the expected air temperature under the current load state," rather than simply determining whether the air temperature itself has reached a certain uniform value. When determining the thermal status based on air temperature and the temperature rise benchmark, the monitoring and processing unit uses the difference between the current air temperature and the temperature rise benchmark corresponding to the current load state as the temperature deviation, and simultaneously obtains the direction of air temperature change within the continuous monitoring period.

[0033] Temperature deviation indicates the degree to which the current air temperature deviates from its normal stable level. For example, under a certain load condition, the historical stable operating air temperature is 32°C, while the current air temperature is 34°C. The temperature deviation reflects a certain degree of increase in the current temperature relative to the temperature rise baseline. To further determine whether it is a thermal anomaly, the temperature deviation can be compared with a temperature difference threshold. The temperature difference threshold is determined based on the normal fluctuation range of air temperature in historical stable data, the detection error of the air temperature sensor, and the desired margin for anomaly identification.

[0034] Specifically, firstly, the maximum deviation of air temperature from the normal temperature rise benchmark during multiple historical stable periods within the same load range is statistically analyzed. Then, considering the allowable error of the temperature detection component itself, a judgment margin is set based on this margin. This ensures that normal air temperature fluctuations do not exceed the temperature difference threshold, while significant deviations from the normal temperature level under the current load condition can be identified. For example, if the air temperature fluctuates only slightly around the temperature rise benchmark during historical stable operation within a certain load range, the temperature difference threshold can be set slightly higher than the upper limit of this normal fluctuation. For application environments with large natural temperature fluctuations within the cabinet, the temperature difference threshold can be appropriately increased; for distribution cabinets with relatively stable temperatures and greater sensitivity to abnormal temperature rises, the temperature difference threshold can be appropriately decreased. Therefore, the temperature difference threshold originates from the specific stable operating state of the distribution cabinet itself. In addition to temperature deviation, this application also considers the direction of air temperature change within the continuous monitoring period. Although the current temperature deviation has not yet exceeded the temperature difference threshold, if the air temperature is continuously rising, it may still indicate that heat is accumulating inside the cabinet.

[0035] A sustained upward trend in temperature change is determined by arranging multiple air temperature samples chronologically within a continuous monitoring period. When multiple consecutive samples show an overall increase, and this increase is not caused by fluctuations at a single sampling point, a sustained upward trend is identified. When the temperature deviation does not exceed the temperature difference threshold and there is no sustained upward trend, the monitoring and processing unit determines the distribution cabinet to be in a thermally stable state, indicating that the current air temperature is close to the historical normal operating temperature under the same load condition, and there is no trend of further heat accumulation. However, when the temperature deviation exceeds the temperature difference threshold, even if the temperature does not continue to rise within the continuous monitoring period, it indicates that the current temperature has significantly deviated from the normal level corresponding to this load condition, thus identifying it as a thermal anomaly. Similarly, when the temperature deviation has not yet exceeded the temperature difference threshold, but the air temperature shows a sustained upward trend, it is also identified as a thermal anomaly. This avoids having to wait for the air temperature deviation to eventually exceed the temperature difference threshold before identifying the anomaly, ensuring that developing heat accumulation is detected before the temperature deviation further expands.

[0036] While determining the thermal state, the monitoring and processing unit determines the condensation margin based on air temperature, air humidity, and equipment surface temperature. The monitoring and processing unit determines the air dew point temperature based on the current air temperature and humidity. The air dew point temperature represents the temperature level at which water vapor begins to reach saturation when the air cools to a corresponding temperature under the current air humidity conditions. The air dew point temperature can be determined using existing temperature-humidity-dew point correspondences, or it can be determined using a calculation formula. The calculation process for the air dew point temperature is lengthy and well-established, and will not be described in detail here. It is important to emphasize that this application does not solely rely on whether the air humidity exceeds a certain humidity threshold to determine the condensation risk. Even if two monitoring sessions yield the same air humidity, the condensation risk may differ if the equipment surface temperatures are different. Therefore, after obtaining the air dew point temperature, it is necessary to continue acquiring multiple equipment surface temperatures.

[0037] The equipment surface temperature includes at least the measured values ​​from temperature detection points in the busbar connection area, circuit breaker area, and cabinet inner wall area. The monitoring and processing unit compares these equipment surface temperatures and determines the minimum value. In the same air environment, the surface with the lowest temperature is closest to the air dew point and is more likely to reach condensation conditions first. For example, the inner wall of the cabinet may be lower than the surface temperature of other electrical components inside the cabinet due to the influence of low external temperatures, while in another operating state, the surface temperature of a certain circuit breaker area or busbar connection area may be even lower. Therefore, instead of fixing a specific detection point as the condensation determination location, the minimum equipment surface temperature is dynamically selected from the current detection points. The difference between the minimum equipment surface temperature and the air dew point temperature is determined as the condensation margin. The larger the condensation margin, the greater the temperature gap between the lowest equipment surface temperature and the air dew point; the smaller the condensation margin, the closer the coldest surface is to the air dew point, increasing the risk of condensation.

[0038] The condensation safety margin is used to distinguish between a safe condensation state and a condensation risk state. The condensation safety margin can be determined based on the error of the temperature and humidity sensor, the error in the equipment surface temperature detection, and a pre-set parameter. Because sensors have a certain measurement deviation, if the condensation safety margin is directly set to zero, the actual local area may be very close to a condensation state when the detected value still shows the equipment surface temperature slightly above the air dew point. In one implementation, environmental commissioning is performed before the distribution cabinet is put into operation, allowing the air humidity to change gradually, and recording the difference between the lowest equipment surface temperature and the air dew point under different air temperature and humidity conditions. This difference is then combined with the sensor's allowable error to determine the condensation safety margin. For example, the condensation safety margin can be set as a temperature difference within a few degrees Celsius. Its specific value is determined by the actual distribution cabinet structure, detection accuracy, and site environment, and is not limited to a fixed value. The principle for setting it is to prevent frequent risk assessments during normal fluctuations.

[0039] When the condensation margin is greater than or equal to the condensation safety margin, it indicates that the current lowest equipment surface temperature is still sufficiently far from the air dew point, and the monitoring and processing unit determines that the distribution cabinet is in a condensation-safe state. When the condensation margin is less than the condensation safety margin, the distribution cabinet is determined to be in a condensation-risk state. At this time, the lowest equipment surface temperature has entered the risk zone close to the air dew point. After obtaining the thermal state and condensation state, the verification and processing unit comprehensively determines the environmental risk type based on the combination of the two.

[0040] Specifically, when the distribution cabinet is in a thermally stable state and a condensation-safe state, the verification processing unit classifies the environmental risk type as an environmentally stable state. An environmentally stable state indicates that the current air temperature does not show significant anomalies relative to the temperature rise baseline corresponding to the current load state, and there is a sufficient condensation safety margin between the lowest equipment surface temperature and the air dew point, meaning no significant anomalies are found from either the thermal or condensation environment perspectives. When the distribution cabinet is in a thermally abnormal state and a condensation-safe state, the environmental risk type is classified as heat accumulation risk. In this case, the air temperature inside the distribution cabinet has significantly deviated from the stable level corresponding to the current load state, or the air temperature has been continuously rising during the continuous monitoring period, but the lowest equipment surface temperature still maintains a condensation safety margin with respect to the air dew point. Therefore, the main anomaly in this state is heat accumulation, not condensation.

[0041] When the distribution cabinet is in a thermally stable state and a condensation risk state, the environmental risk type is determined to be condensation risk. At this time, the overall air temperature under the current load condition is still within the normal thermal range, but due to the combination of air humidity and the lowest equipment surface temperature, the condensation margin is lower than the condensation safety margin. Therefore, the anomaly is mainly manifested as the equipment surface approaching the dew point. When the distribution cabinet is simultaneously in a thermally abnormal state and a condensation risk state, the environmental risk type is determined to be a composite environmental risk. Composite environmental risk indicates that, on the one hand, there is an abnormal or continuous temperature rise inside the cabinet that is mismatched with the current load condition; on the other hand, the condensation margin between the lowest equipment surface temperature and the air dew point is insufficient. Because both environmental anomalies exist simultaneously, it is no longer separately classified as heat accumulation risk or condensation risk. By further converting "temperature alarm" and "humidity alarm" into environmental risk classifications with clear correlations, the direct judgment of condensation is avoided when a certain air humidity value is high but there is still sufficient condensation margin, and the judgment bias of directly determining normal temperature rise under high load as heat accumulation is also avoided.

[0042] The verification processing unit extracts the residual current benchmark for stable operation of the distribution cabinet from historical operating data. The residual current benchmark represents the residual current level of the distribution cabinet under normal and stable operating conditions, rather than directly using a leakage current value that is detached from the actual state of the distribution cabinet. When establishing the residual current benchmark, residual current data is selected from historical data confirming stable operation of the distribution cabinet. Data with environmental anomaly alarms is removed, and the benchmark is formed based on multiple operating cycles. For the same distribution cabinet, its normal residual current level may differ due to variations in wiring structure, insulation condition, and connected equipment. Therefore, using its own historical stable data as a benchmark helps identify abnormal changes relative to the normal state of the distribution cabinet.

[0043] The difference between the current residual current and the residual current reference is defined as the residual current deviation. The residual current deviation reflects whether the current residual current has significantly increased relative to the normal operating level of the distribution cabinet. The leakage deviation threshold is determined based on the fluctuation range of the residual current during the historical stable operation of the distribution cabinet and the necessary judgment margin. Specifically, the maximum normal deviation of the residual current relative to the reference during historical stable operation can be statistically analyzed, and a sensor error margin is added to this normal deviation as the basis for setting the leakage deviation threshold. Therefore, the leakage deviation threshold and the residual current reference are two different concepts. The residual current reference represents the normal level, while the leakage deviation threshold represents the maximum allowable deviation from the normal level. If the current residual current deviation exceeds the leakage deviation threshold, it indicates that the residual current has experienced an abnormal increase in fluctuation relative to the historical stable level.

[0044] Simultaneously, the verification and processing unit determines whether the smoke concentration has increased within the continuous monitoring period. For example, if the smoke concentration is 0.5 g / m³, 0.6 g / m³, 0.7 g / m³, 0.8 g / m³, and 0.9 g / m³, and the overall trend is increasing, then it is determined that the smoke concentration is continuously increasing. Furthermore, this confirmation of a continuous increase in smoke concentration is consistent with the sampling period of the information acquisition unit. When the environmental risk type is condensation risk, and the residual current deviation exceeds the leakage deviation threshold, the verification and processing unit upgrades the condensation risk to a condensation leakage risk. This judgment indicates that not only is there insufficient condensation margin, but the residual current has also increased relative to historical stable levels. Compared to simple condensation risk, an abnormal residual current has emerged that reflects changes in electrical condition, requiring a further increase in the risk level.

[0045] When the environmental risk type is heat accumulation risk, and the smoke concentration continues to increase during the continuous monitoring period, the heat accumulation risk is upgraded to overheated smoke risk. Heat accumulation risk itself only indicates an abnormal thermal state of the air inside the cabinet, while the continuous increase in smoke concentration indicates that the thermal anomaly has been accompanied by new smoke changes. Further verification through smoke concentration confirms the abnormal temperature rise and the accompanying smoke development. When the environmental risk type is composite environmental risk, and the residual current deviation exceeds the leakage deviation threshold, and / or the smoke concentration continues to increase, the composite environmental risk is upgraded to composite severe risk. Here, "and / or" indicates that the abnormal residual current and the continuous increase in smoke concentration can occur simultaneously, or either one can occur. Since the composite environmental risk itself already involves both thermal anomaly and condensation risk, the occurrence of an abnormal residual current or a continuous increase in smoke on top of this indicates that the environmental anomaly is further accompanied by changes in the electrical state or smoke state; therefore, it is verified as a composite severe risk.

[0046] This application also includes a separate electrical anomaly verification for stable environmental conditions. When the environmental risk type is stable, but the residual current deviation exceeds the leakage current deviation threshold, the verification processing unit determines that an electrical anomaly exists and outputs an electrical anomaly alarm. This judgment is set because thermal stability and condensation safety only indicate that no risks have been found from the perspectives of thermal and condensation environments; it does not mean that there are no other reasons causing an increase in residual current in the distribution cabinet. If the residual current deviation still exceeds the normal range at this time, the electrical anomaly cannot be ignored simply because the environmental risk type is stable; therefore, a separate electrical anomaly alarm is output.

[0047] When the risk type is heat accumulation risk or overheating smoke risk, the environmental control unit activates ventilation and heat dissipation to increase the air exchange rate inside the distribution cabinet. The role of ventilation and heat dissipation is to facilitate the transfer of heat accumulated inside the cabinet to the external environment. For heat accumulation risk, the main environmental anomaly is an abnormal temperature rise relative to the temperature rise baseline corresponding to the current load state. For overheating smoke risk, since it is a further increase in smoke concentration on the basis of heat accumulation risk, it is still necessary to maintain ventilation and heat dissipation first to address the heat accumulation state.

[0048] When the risk type is condensation risk, the environmental control unit activates dehumidification and / or anti-condensation heating. Dehumidification reduces the humidity inside the cabinet, thereby changing the air dew point. Anti-condensation heating increases the temperature conditions in areas prone to low surface temperatures, allowing sufficient condensation margin to be restored between the lowest equipment surface temperature and the air dew point. In actual configurations, one of dehumidification or anti-condensation heating can be used depending on the environmental control equipment installed in the distribution cabinet, or both can be used simultaneously. When the risk type is condensation leakage risk, the environmental control unit activates dehumidification and / or anti-condensation heating, and simultaneously outputs an electrical abnormality alarm. Since condensation leakage risk is a further detection of residual current deviation exceeding the leakage deviation threshold on top of condensation risk, environmental control still targets condensation conditions, but simultaneously outputs an electrical abnormality alarm to indicate that the state is no longer a simple environmental risk.

[0049] When the risk type is a complex environmental risk, the environmental control unit simultaneously activates ventilation and heat dissipation, as well as dehumidification and / or anti-condensation heating. Complex environmental risks involve both thermal anomalies and condensation risks; ventilation and heat dissipation alone cannot directly address insufficient condensation, and dehumidification or anti-condensation heating alone cannot fully address the heat accumulation state. Therefore, corresponding adjustments are implemented for each of the two environmental dimensions. When the risk type is a complex severe risk, the environmental control unit outputs an emergency alarm and sends a power-off control command to the circuit breaker control device of the distribution cabinet. Since a complex severe risk involves the simultaneous existence of thermal anomalies and condensation risks, and the detection of residual current anomalies and / or a continuous increase in smoke concentration, the residual current anomaly is no longer treated as a normal environmental control state. Instead, an emergency alarm is output, and power-off control is executed through the circuit breaker control device. Environmental control is not fixed and executed until it stops after the initial risk identification; rather, the environmental risk type is re-determined after the environmental control is implemented to determine whether the current environmental control has changed the environmental risk of the distribution cabinet.

[0050] After implementing the corresponding environmental adjustments, the information acquisition unit continues to collect air temperature, air humidity, equipment surface temperature, load current, residual current, and smoke concentration using the original sampling method. The monitoring and processing unit re-determines the current load state and corresponding temperature rise baseline based on the new load current, re-determines the thermal state, and recalculates the air dew point temperature, minimum equipment surface temperature, and condensation margin, while re-evaluating the condensation state. The verification and processing unit re-determines the environmental risk type and completes risk verification using the same combination of factors. Since the load state may change after environmental adjustments, the re-evaluation process still matches the corresponding temperature rise baseline based on the current load current, rather than directly using the temperature rise baseline before environmental adjustments. This avoids using the temperature rise baseline of the original load state to evaluate the deviation of the current air temperature after load changes.

[0051] A reduction in the environmental risk type indicates that the risk level before environmental regulation will no longer be maintained after reassessment. For example, if the original environmental risk was a complex one, and after environmental regulation, the condensation condition returned to a safe level while the thermal anomaly persisted, the risk type can be reclassified as a heat accumulation risk. Alternatively, if the original risk was condensation, and after dehumidification or anti-condensation heating, the condensation margin returned to a safe margin, the environmental risk type can be further restored to a stable environmental state. If the reclassified environmental risk type is lower than before environmental regulation, and the original risk was not a complex severe risk or a condensation leakage risk, the environmental regulation unit will continue to perform environmental regulation based on the reclassified risk type. A reduction in risk type does not equate to complete environmental stability. For example, if a complex environmental risk is reduced to a heat accumulation risk, it indicates that condensation conditions have improved, but the thermal anomaly still exists. In this case, ventilation and heat dissipation must continue based on the new heat accumulation risk, and all environmental regulation cannot be stopped simply because the risk level has decreased. Complex severe risks and condensation leakage risks both involve residual current anomalies, and these will not be considered after issuing the corresponding warning.

[0052] If the redefined environmental risk type has not decreased compared to before environmental regulation, the environmental regulation unit continues to perform the corresponding environmental regulation. This result indicates that at the current review node, the original risk status has not been sufficiently improved; therefore, the corresponding environmental regulation continues, and the same process is repeated in subsequent monitoring. Risk resolution conditions include two aspects: the redefined environmental risk type is an environmentally stable state, and there is no residual current deviation exceeding the leakage deviation threshold. A redefined environmental risk type of environmentally stable state indicates that thermal stability and condensation safety have been restored, meaning there is no thermal anomaly between the current air temperature and the temperature rise baseline corresponding to the load state, and sufficient condensation safety margin has been restored between the lowest equipment surface temperature and the air dew point. Simultaneously, there is no residual current deviation exceeding the leakage deviation threshold. This "no" refers to the state during environmental regulation; that is, if the initially determined environmental risk type was a composite severe risk or a condensation leakage risk, the risk resolution conditions are not met. Only when the redefined environmental risk type is an environmentally stable state, and the residual current deviation does not exceed the leakage deviation threshold, does the environmental regulation unit determine that the risk resolution conditions are met and release the corresponding environmental regulation.

[0053] In one specific embodiment of this application, the complete monitoring process of the above-mentioned device is illustrated using the continuous operation process of a power distribution cabinet as an example.

[0054] First, historical operating data is accumulated during the initial normal operation phase of the distribution cabinet, and data is selected based on the cabinet door being closed, the load current being stable, and no environmental anomaly alarms being generated. The cabinet is then divided into multiple load zones based on the historical load current distribution. Assuming that the stable air temperature corresponding to a certain load zone is 31℃, then when the current load current falls back into that load zone, 31℃ is used as the temperature rise benchmark for the current load state.

[0055] Based on historical stable data, the air temperature fluctuation within this load range is relatively small compared to the normal range of 31℃. Considering the air temperature detection error and the judgment margin, the temperature difference threshold is set to 4℃. The current information acquisition unit detects an air temperature of 36℃, which means the air temperature deviation from the temperature rise benchmark is 5℃, exceeding the 4℃ temperature difference threshold. Therefore, the distribution cabinet is determined to be in a thermal anomaly state.

[0056] The information acquisition unit collects air humidity and equipment surface temperatures in the busbar connection area, circuit breaker area, and cabinet inner wall area. Based on the current air temperature and humidity, the air dew point temperature is determined to be 25℃. The surface temperatures in the three areas are 33℃, 31℃, and 29℃, respectively. Therefore, the minimum equipment surface temperature is 29℃, and the condensation margin is 4℃. If the condensation safety margin is set to 3℃ during the current distribution cabinet commissioning, then 4℃ is greater than the condensation safety margin, and the condition is determined to be a condensation-safe state. At this time, the thermal state is an abnormal thermal state, the condensation state is a condensation-safe state, and the verification and processing unit determines the environmental risk type as heat accumulation risk.

[0057] The verification and processing unit further determines whether the smoke concentration continues to increase during the continuous monitoring period. If the smoke concentration remains stable for multiple consecutive sampling periods, the risk of heat accumulation remains. If the smoke concentration continues to increase during the continuous monitoring period, the risk of heat accumulation is upgraded to the risk of overheated smoke.

[0058] If the current verification result still indicates a risk of heat accumulation, the environmental control unit initiates ventilation and heat dissipation. After a period of operation, data collection continues. Assuming the new air temperature drops to 33°C, and the current load condition remains within the same load range, the temperature deviation decreases to 2°C, and the air temperature no longer continues to rise during subsequent continuous monitoring cycles. Therefore, the condition is reclassified as thermally stable. If the condensation margin is still greater than the condensation safety margin at this time, the environmental risk type is reclassified as an environmentally stable state. Since the deviation between the residual current and the residual current does not exceed the leakage deviation threshold, both conditions—environmentally stable state and no excess residual current deviation—are met. The environmental control unit determines that the risk relief conditions have been met and discontinues ventilation and heat dissipation.

[0059] In summary, by acquiring data on air temperature, humidity, equipment surface temperature, load current, residual current, and smoke concentration within the distribution cabinet, the monitoring of independent environmental parameters is transformed into an environmental risk assessment process with a sequential correlation. The current load state is determined based on the load current, and a temperature rise benchmark corresponding to the current load state is retrieved from historical stable operating data. This ensures that air temperature assessment is based on the actual current load conditions, reducing the possibility of misjudgments of thermal anomalies caused by natural temperature rise due to normal load increases. The air dew point is determined by air temperature and humidity, and the condensation margin is determined using the lowest equipment surface temperature in the busbar connection area, circuit breaker area, and cabinet inner wall area. This allows condensation risk assessment to reflect the local surface conditions most accessible to the dew point, rather than solely relying on air humidity. By combining thermal and condensation states, and using residual current deviation and smoke concentration changes to re-verify different environmental risks, different risks are distinguished, improving the ability to identify different abnormal states. Environmental adjustments are performed based on the verified risk type, and relevant data are re-collected and the environmental risk type is determined after the environmental adjustments are performed. This forms a closed-loop monitoring process that includes multi-parameter collection, load-related temperature rise judgment, condensation status judgment, risk classification, secondary verification, targeted adjustment and risk reconfirmation, which improves the accuracy and reliability of identifying environmental risks in the distribution cabinet.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. An intelligent monitoring device for a power distribution cabinet, characterized in that, include: The information acquisition unit is configured to collect data on air temperature, air humidity, equipment surface temperature, load current, residual current, and smoke concentration inside the power distribution cabinet. The monitoring and processing unit is configured to determine the current load state based on the load current, determine the temperature rise reference corresponding to the current load state in historical operating data, determine the thermal state of the distribution cabinet based on the difference between the air temperature and the temperature rise reference, determine the condensation margin based on the minimum value of the air temperature, the air humidity and the equipment surface temperature, and determine the condensation state of the distribution cabinet. The verification processing unit is configured to comprehensively determine the environmental risk type of the power distribution cabinet based on the thermal state and the condensation state, and to perform risk verification on the environmental risk type based on the residual current and the smoke concentration. The environmental control unit is configured to perform at least one of the following environmental controls based on the environmental risk type after risk verification: ventilation and heat dissipation, dehumidification, or anti-condensation heating. After performing the environmental control, the environmental risk type is redefined. When the redefined environmental risk type meets the risk relief conditions, the corresponding environmental control is deactivated.

2. The intelligent monitoring device for the power distribution cabinet according to claim 1, characterized in that, When determining the temperature rise reference corresponding to the current load state, the following is included: The monitoring and processing unit extracts historical stable data from the historical operating data of the power distribution cabinet, showing that the cabinet door is closed, the load current is within a stable range, and no environmental abnormality alarm is generated. Based on the load current, the historical stable data is divided into several load intervals, and the stable air temperature corresponding to each load interval is determined. The load interval of the load current is determined, and the corresponding stable air temperature is used as the temperature rise reference for the current load state.

3. The intelligent monitoring device for the power distribution cabinet according to claim 2, characterized in that, When determining the thermal state of the distribution cabinet based on the difference between the air temperature and the temperature rise reference, the following steps are included: The monitoring and processing unit takes the difference between the air temperature and the temperature rise benchmark corresponding to the current load state as the temperature deviation, and obtains the direction of change of the air temperature within the continuous monitoring period. When the temperature deviation does not exceed the temperature difference threshold and the direction of change does not show a continuous increase, the distribution cabinet is determined to be in a thermally stable state. When the temperature deviation exceeds the temperature difference threshold, or when the direction of change shows a continuous increase, the power distribution cabinet is determined to be in a thermal abnormality state.

4. The intelligent monitoring device for the power distribution cabinet according to claim 3, characterized in that, Determining the condensation state of the distribution cabinet includes: The monitoring and processing unit determines the air dew point temperature based on the air temperature and the air humidity. The minimum value of the equipment surface temperature is determined based on the temperature detection points set in the busbar connection area, circuit breaker area and cabinet inner wall area, and the difference between the minimum value and the air dew point temperature is determined as the condensation margin. When the condensation margin is greater than or equal to the condensation safety margin, the distribution cabinet is determined to be in a condensation safety state. When the condensation margin is less than the condensation safety margin, the distribution cabinet is determined to be in a condensation risk state.

5. The intelligent monitoring device for the power distribution cabinet according to claim 4, characterized in that, When comprehensively assessing the environmental risk type of the power distribution cabinet, the following should be included: When the power distribution cabinet is in the thermally stable state and the condensation safe state, the verification processing unit determines that the environmental risk type of the power distribution cabinet is the environmentally stable state; When the power distribution cabinet is in the thermal abnormal state and the condensation safe state, the verification and processing unit determines that the environmental risk type of the power distribution cabinet is heat accumulation risk; When the power distribution cabinet is in the thermally stable state and the condensation risk state, the verification processing unit determines that the environmental risk type of the power distribution cabinet is condensation risk; When the power distribution cabinet is in both the thermal anomaly state and the condensation risk state, the verification processing unit determines that the environmental risk type of the power distribution cabinet is a composite environmental risk.

6. The intelligent monitoring device for the power distribution cabinet according to claim 5, characterized in that, When performing risk verification on the aforementioned environmental risk types, the following are included: The verification processing unit extracts the residual current benchmark of the stable operation of the distribution cabinet from the historical operation data, determines the difference between the residual current and the residual current benchmark as the residual current deviation, and determines whether the smoke concentration increases within the continuous monitoring period. When the environmental risk type is condensation risk and the residual current deviation exceeds the leakage deviation threshold, the condensation risk is upgraded to condensation leakage risk. When the environmental risk type is thermal accumulation risk and the smoke concentration continues to increase, the thermal accumulation risk is upgraded to overheated smoke risk. When the environmental risk type is the composite environmental risk, and the residual current deviation exceeds the leakage deviation threshold, and / or the smoke concentration continues to increase, the composite environmental risk is upgraded to a composite severe risk.

7. The intelligent monitoring device for the power distribution cabinet according to claim 6, characterized in that, When verifying the environmental risk types, the following are also included: When the environmental risk type is the stable environmental state and the residual current deviation exceeds the leakage deviation threshold, the verification processing unit determines that there is an electrical abnormality and outputs an electrical abnormality alarm.

8. The intelligent monitoring device for the power distribution cabinet according to claim 7, characterized in that, When performing environmental conditioning, the following are included: If the risk of heat buildup or the risk of overheated smoke are present, the environmental control unit will activate ventilation and heat dissipation to increase the air exchange rate inside the distribution cabinet. If the risk of condensation is present, the environmental control unit will activate dehumidification and / or anti-condensation heating; If there is a risk of condensation leakage, the environmental control unit will activate dehumidification and / or anti-condensation heating, and output the electrical abnormality alarm. If the combined environmental risk is as described, the environmental control unit will activate ventilation and heat dissipation, and dehumidification, and / or anti-condensation heating; If the combined severe risk is detected, the environmental control unit outputs an emergency alarm and sends a power-off control command to the circuit breaker control device of the power distribution cabinet.

9. The intelligent monitoring device for the power distribution cabinet according to claim 8, characterized in that, When redefining the type of environmental risk, this includes: If the redefined environmental risk type is lower than before the environmental adjustment was performed, and was not the composite severe risk or the condensation leakage risk before the environmental adjustment was performed, the environmental adjustment unit continues to perform environmental adjustment based on the redefined environmental risk type. If the redefined environmental risk type has not decreased relative to before the environmental adjustment was performed, the environmental adjustment unit continues to perform environmental adjustment.

10. The intelligent monitoring device for the power distribution cabinet according to claim 9, characterized in that, When redefining the type of environmental risk, the following are also included: If the redefined environmental risk type is the stable environmental state, and there is no residual current deviation exceeding the leakage deviation threshold, the environmental adjustment unit determines that the risk removal condition is met and releases the corresponding environmental adjustment.

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