Electrical cabinet condensation defense method and system based on environmental parameter monitoring

Abstract

The invention discloses an electrical cabinet condensation defense method and system based on environmental parameter monitoring. The method comprises the following steps: acquiring temperature and humidity information of multiple points in an electrical cabinet and outside the cabinet in real time; calculating a dew point temperature and a condensation risk index in the cabinet; predicting the lowest temperature and humidity change rate in the cabinet in the next time period in the control period; based on the minimum temperature and humidity change rate prediction value in the cabinet and the current condensation risk index, whether the electrical cabinet meets the condensation risk trend criterion is judged, if yes, the electrical cabinet enters a condensation risk suppression linkage control mode, and if not, the electrical cabinet enters a condensation risk defense self-adaptive mode; and in the condensation risk suppression linkage control process, when the current condensation risk index of the electrical cabinet is lower than a condensation risk index threshold value, entering a condensation risk defense self-adaptive mode, and otherwise, entering a next control period. Data acquisition is comprehensive and accurate, the dew point temperature can be accurately calculated, the control strategy is intelligent and flexible, equipment can operate according to needs, condensation is effectively prevented, and the energy-saving effect is remarkable.

Description

Technical Field

[0001] This invention belongs to the field of power equipment environmental control technology, specifically relating to a method and system for preventing condensation in electrical cabinets based on environmental parameter monitoring. Background Technology

[0002] Condensation is one of the core hazards threatening the safe and stable operation of electrical equipment. In enclosed electrical equipment such as substation terminal boxes and control cabinets, condensation significantly increases the leakage current on the insulation surface, causing surface flashover or even explosion and fire, seriously threatening the reliability of the power system. Studies have shown that the non-uniform distribution of condensation on the insulation surface distorts the electric field strength, induces partial discharge, accelerates the deterioration of the insulation medium, and ultimately leads to breakdown failure. Traditional condensation defense technologies mostly rely on a single temperature and humidity threshold to trigger heating or ventilation, which has the following defects: (1) passive response is lagging and cannot intervene in time at the initial stage of condensation formation; (2) sensors are easily affected by local environmental interference, resulting in a high false trigger rate; (3) the continuous operation of the heating module leads to excessive energy consumption and lacks intelligent adjustment capabilities.

[0003] Chinese patent application CN119065429A discloses a method and device for preventing condensation in electrical cabinets. Applied to anti-condensation electrical cabinets, it generates an alarm signal for an alarm module based on the real-time temperature and humidity signals inside and outside the cabinet and their relationship to a preset threshold. A heating device and a cooling and dust removal device respond to the control signal to maintain the electrical cabinet at a preset constant value. However, this patented solution only controls the temperature and humidity by the average values ​​inside and outside the cabinet, failing to consider temperature and humidity differences in different areas inside the cabinet (such as upper and lower shelves, and the inside of the cabinet door), resulting in monitoring blind spots. The single average calculation method may mask localized high humidity or low temperature risk points, leading to control lag.

[0004] Chinese patent application CN118689141A discloses a climate-compensated anti-condensation control system and method for high-voltage switchgear. It generates temperature and humidity change curves based on temperature data, humidity data, historical temperature data, and historical humidity data; generates a temperature-water vapor saturation curve based on these curves; generates control commands based on the temperature-water vapor saturation curve, temperature change curve, and humidity change curve; and controls the start and stop of heaters and fans based on these commands. However, the control commands in this technical solution are only based on the comparison between the temperature-water vapor saturation curve and the temperature and humidity change curves, essentially remaining a threshold-driven single-closed-loop control. When the temperature difference and humidity change trends inside and outside the cabinet contradict each other (e.g., high temperature inside the cabinet but low humidity), the control logic cannot be dynamically adjusted.

[0005] Chinese patent application CN117878735A discloses a method, system, terminal, and storage medium for preventing condensation in an electrical control cabinet. If the temperature difference is less than a first preset temperature threshold, a processing scheme is generated based on the current temperature. If the current humidity and / or current temperature are not obtained, the temperature and humidity change trends are obtained based on historical temperature and humidity records. If the humidity and / or temperature change trends do not meet the corresponding change requirements, the target electrical control cabinet is heated based on a preset temperature control device, and an alarm is triggered. However, this scheme only generates a processing scheme based on the temperature difference and preset threshold, without considering dynamic factors such as the rate of humidity change and temperature change trends. For example, when the humidity inside the cabinet rises rapidly but has not yet exceeded the threshold, the system cannot provide an early warning or initiate pre-processing measures.

[0006] In summary, existing technical solutions are insufficient to break the vicious cycle of "condensation formation - electric field distortion - insulation failure". There is an urgent need for a proactive defense solution with multi-modal collaborative control to achieve precise intervention from the source of condensation generation mechanism and improve the insulation reliability of electrical equipment. Summary of the Invention

[0007] To address the technical problem that existing technologies struggle to break the vicious cycle of "condensation formation - electric field distortion - insulation failure," this invention proposes a condensation prevention method and system for electrical cabinets based on environmental parameter monitoring. By fusing multimodal data to detect condensation risk levels and combining predictive control with multi-stage execution strategies, precise intervention before condensation formation is achieved. Real-time acquisition of temperature and humidity information inside and outside the cabinet, coupled with intelligent control strategies, balances the temperature difference between the inside and outside of the cabinet, effectively preventing condensation and improving the operational safety of electrical equipment.

[0008] To achieve the above-mentioned objectives, the present invention specifically adopts the following technical solution.

[0009] This invention discloses a method for preventing condensation in electrical cabinets based on environmental parameter monitoring, comprising the following steps:

[0010] Step 1: Collect temperature and humidity information from multiple points inside and outside the electrical cabinet in real time during each control cycle;

[0011] Step 2: Based on the acquired signals, obtain the current lowest temperature T0 and humidity S1 inside the cabinet, and calculate the dew point temperature T inside the cabinet. d Condensation Risk Index (CRI); Predict the lowest temperature (T) inside the cabinet for the next period within this control cycle. f0 and humidity change rate dS f / dt;

[0012] Step 3: Based on the predicted values ​​of the lowest temperature and humidity change rate inside the cabinet and the current condensation risk index (CRI), determine whether the electrical cabinet meets the condensation risk trend criteria. If it does, proceed to Step 4, the condensation risk suppression linkage control mode; otherwise, proceed to Step 5, the condensation risk defense adaptive mode.

[0013] Step 4: Control the fan, dehumidifier, and heater in tandem. When the current condensation risk index (CRI) of the electrical cabinet is lower than the condensation risk threshold, proceed to step 5; otherwise, return to step 1.

[0014] Step 5: Based on the current lowest temperature T0 inside the cabinet, the humidity inside the cabinet S1, the ambient humidity outside the cabinet S2, and the dew point temperature T d It implements adaptive control of condensation risk defense mode.

[0015] More preferably,

[0016] In step 1, temperature and humidity sensors are installed on the upper, middle, and lower layers of the electrical cabinet, as well as on the inside of the cabinet door, to collect the air temperature T at the top of the cabinet. top Central air temperature T mid Bottom air temperature T bot Cabinet door surface temperature T door and top air humidity S top Central air humidity S mid Bottom air humidity S bot Cabinet door surface humidity S door .

[0017] More preferably,

[0018] In step 2, the humidity S1 inside the cabinet is determined as follows:

[0019] S1=αS bot +βS door +δS mid +εS top ;

[0020] Among them, α+β+δ+ε=1, and α>β>δ>ε.

[0021] More preferably,

[0022] In step 2, the dew point temperature T inside the cabinet is... d Calculate as follows:

[0023] T d =[(0.66077-lgE) w [)×237.3] / (lgE w -8.16077)

[0024] Among them, T dE represents the dew point temperature inside the cabinet. w This represents the pressure of the saturated water vapor inside the electrical cabinet.

[0025] More preferably,

[0026] The current pressure E of saturated water vapor inside the electrical cabinet w Calculate as follows:

[0027]

[0028] Among them, R H =(S top +S mid +S bot +S door ) / 4; T=0.35T door +0.30T bot +0.25T mid +0.10T top .

[0029] More preferably,

[0030] In step 2, the condensation risk index (CRI) is:

[0031] CRI=(S1-S2)+0.5×(T d -T0).

[0032] More preferably,

[0033] In step 3, the condensation risk criterion is:

[0034] T f0 -T d ≤T th0 And dS f / dt≥ΔS th And CRI ≥ CRI th0 ;

[0035] Among them, T th0 ΔS is the set dew point temperature difference threshold. th CRI is the threshold for humidity change rate. th0 This is the threshold for the condensation risk index.

[0036] More preferably,

[0037] In step 4, the linkage control mode specifically includes:

[0038] When the condensation risk trend criterion is met, the heater is started first, until T... door ≥T d +T th1 Then turn on the dehumidifier until S1≤Sth0 Finally, start the fan and let it run continuously until CRI. <CRI th0 ;

[0039] Among them, T door T represents the surface temperature of the electrical cabinet door. th1 S is the threshold temperature difference between the cabinet door surface temperature and the dew point temperature. th0 The humidity threshold inside the cabinet; CRI th0 This is the threshold value for the condensation risk index in the linkage control mode.

[0040] More preferably,

[0041] In step 5, the specific control strategy for the adaptive control of the condensation risk defense mode is as follows:

[0042] When the current lowest temperature T0 inside the cabinet is greater than or equal to the ambient temperature T2 outside the cabinet, the first adaptive control strategy is implemented to reduce the humidity inside the cabinet by ventilation and / or dehumidification; when the current lowest temperature T0 inside the cabinet is less than the ambient temperature T2 outside the cabinet, the second adaptive control strategy is implemented to control the humidity inside the cabinet and the surface temperature of the cabinet at the same time to prevent condensation on the low-temperature surface.

[0043] More preferably,

[0044] The first adaptive control strategy is:

[0045] When the humidity inside the cabinet is greater than the humidity outside the cabinet and also exceeds the humidity risk threshold, the dehumidifier and exhaust fan will be turned on.

[0046] When the humidity inside the cabinet is greater than the humidity outside the cabinet, but not greater than the humidity risk threshold, only the exhaust fan is turned on.

[0047] If the humidity inside the cabinet is not higher than the humidity outside the cabinet, but exceeds the humidity risk threshold, the dehumidifier will be turned on.

[0048] Otherwise, the control fan, dehumidifier, and heater will all be in standby mode.

[0049] More preferably,

[0050] The second adaptive control strategy is:

[0051] When the humidity inside the cabinet is greater than the humidity outside the cabinet and is also greater than the humidity risk threshold, and the lowest temperature inside the cabinet, T0, is not greater than the dew point temperature, the dehumidifier, exhaust fan, and heater should be turned on simultaneously.

[0052] When the humidity inside the cabinet is greater than the humidity outside the cabinet and is also greater than the humidity risk threshold, but the lowest temperature inside the cabinet, T0, is greater than the dew point temperature, the dehumidifier and exhaust fan should be turned on simultaneously.

[0053] When the humidity inside the cabinet is greater than the humidity outside the cabinet but not greater than the humidity risk threshold, and the lowest temperature inside the cabinet, T0, is not greater than the dew point temperature, the exhaust fan and heater should be turned on simultaneously.

[0054] When the humidity inside the cabinet is greater than the humidity outside the cabinet but not greater than the humidity risk threshold, and the lowest temperature inside the cabinet, T0, is greater than the dew point temperature, only the exhaust fan is turned on.

[0055] When the humidity inside the cabinet is not greater than the humidity outside the cabinet, but is greater than the humidity risk threshold, and the lowest temperature inside the cabinet, T0, is not greater than the dew point temperature, the dehumidifier and heater should be turned on simultaneously.

[0056] When the humidity inside the cabinet is not greater than the humidity outside the cabinet, but is greater than the humidity risk threshold, and the lowest temperature inside the cabinet, T0, is greater than the dew point temperature, only the dehumidifier is turned on.

[0057] Otherwise, the control fan, dehumidifier, and heater will all be in standby mode.

[0058] Another aspect of the present invention discloses an electrical cabinet condensation prevention system based on the aforementioned method, including a temperature and humidity acquisition module, a dew point temperature and condensation risk index calculation module, a minimum temperature and humidity change rate prediction module, a condensation risk trend judgment module, and an anti-condensation control module.

[0059] The temperature and humidity acquisition module collects temperature and humidity information from multiple points inside and outside the electrical cabinet in real time.

[0060] The dew point temperature and condensation risk index calculation module calculates the dew point temperature and condensation risk index inside the cabinet based on the collected information.

[0061] Minimum temperature and humidity change rate prediction module, predicts the minimum temperature and humidity change rate for the next period;

[0062] The condensation risk trend judgment module judges the condensation risk trend based on the predicted values ​​of the lowest temperature and humidity change rate inside the cabinet and the current condensation risk index (CRI).

[0063] Based on the condensation risk trend, the anti-condensation control module activates either the condensation risk suppression linkage control mode or the condensation risk defense adaptive control mode.

[0064] The beneficial effects of this invention are compared with those of the prior art:

[0065] (1) Based on the rational layout of multiple sensors inside and outside the electrical cabinet, this invention achieves comprehensive coverage of temperature and humidity information at different heights and in different areas inside the cabinet, as well as in the external environment. Compared with the traditional single-sensor monitoring method, it can capture more subtle differences in temperature and humidity, greatly reducing monitoring blind spots.

[0066] (2) The dew point temperature and condensation risk index calculation module and the minimum temperature and humidity change rate prediction module of the present invention can quickly receive and integrate a large amount of data from multiple sensors, and calculate the dew point temperature inside the cabinet accordingly. Furthermore, it can extract key characteristic parameters such as the temperature and humidity difference inside and outside the cabinet, the difference between the dew point temperature and the minimum temperature inside the cabinet. Through in-depth analysis of these data and parameters, the system can gain a more comprehensive and in-depth understanding of the environmental conditions and changing trends inside and outside the electrical cabinet, providing a scientific and accurate basis for decision-making for the control module.

[0067] (3) The anti-condensation control module of this invention employs an advanced intelligent control strategy, which can generate targeted control signals according to different environmental conditions and states, enabling the coordinated operation of the fan, dehumidifier, and heater. Under different temperature and humidity scenarios, the system can flexibly switch operating modes. For example, when the temperature difference between inside and outside the cabinet is large but the humidity does not exceed the threshold, the fan is activated alone for ventilation and cooling; when the humidity inside the cabinet is high but the temperature difference is small, only the dehumidifier is activated to reduce humidity; and in high-humidity and high-temperature-difference condensation-risk scenarios, both the fan and dehumidifier are activated simultaneously to achieve rapid and effective environmental regulation. This precise control strategy can adapt to various complex environmental changes to the greatest extent possible, effectively preventing the formation of condensation.

[0068] Compared to traditional condensation control methods that rely on continuous heating or single-device operation, the system of this invention achieves on-demand operation of the equipment through intelligent control strategies, avoiding unnecessary energy consumption. While ensuring effective condensation control, it significantly reduces energy costs. For example, the coordinated operation mode of the fan and dehumidifier can precisely control the on / off times of the equipment according to actual environmental needs, greatly improving energy efficiency and demonstrating significant energy-saving advantages. Attached Figure Description

[0069] Figure 1 This is a schematic diagram of the process for the condensation prevention method for electrical cabinets based on environmental parameter monitoring according to the present invention;

[0070] Figure 2 This is a flowchart of an embodiment of the present invention's method for preventing condensation in electrical cabinets based on environmental parameter monitoring. Detailed Implementation

[0071] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this invention.

[0072] like Figure 1As shown, this invention discloses a method for preventing condensation in electrical cabinets based on environmental parameter monitoring, comprising the following steps:

[0073] Step 1: Collect temperature and humidity information from multiple points inside and outside the electrical cabinet in real time during each control cycle;

[0074] Temperature and humidity sensors are installed on the upper, middle, and lower layers of the electrical cabinet, as well as on the inside of the cabinet door, to collect the air temperature T at the top of the cabinet. top Central air temperature T mid Bottom air temperature T bot Cabinet door surface temperature T door and top air humidity S top Central air humidity S mid Bottom air humidity S bot Cabinet door surface humidity S door .

[0075] Step 2: Based on the acquired signals, obtain the current lowest temperature T0 and humidity S1 inside the cabinet, and calculate the dew point temperature T inside the cabinet. d Condensation Risk Index (CRI); Predict the lowest temperature (T) inside the cabinet for the next period within this control cycle. f0 and humidity change rate dS f / dt;

[0076] The humidity S1 inside the cabinet is determined as follows:

[0077] S1=αS bot +βS door +δS mid +εS top ;

[0078] Among them, α+β+δ+ε=1, and α>β>δ>ε.

[0079] Because the impact of humidity at different heights and locations inside the cabinet on the risk of condensation varies: the bottom (cable entrance) is more susceptible to moisture intrusion due to its proximity to the cable trench, so humidity has a higher weight; the top and cabinet door have better air circulation, but the cabinet surface temperature is low, making condensation more likely; the middle area is where equipment is concentrated, and the humidity distribution is relatively uniform, so its weight is moderate; therefore, following the principle of "risk priority, while taking into account uniformity," higher weights are assigned to high-risk areas (such as the bottom and cabinet door). In this application, α = 0.35, β = 0.30, δ = 0.25, and ε = 0.1 are preferred.

[0080] The internal dew point temperature T of the cabinet d Calculate as follows:

[0081] First, calculate the pressure E of the saturated water vapor inside the electrical cabinet. w :

[0082]

[0083] Among them, R H =(S top +S mid +S bot +S door ) / 4; T=0.35T door +0.30T bot +0.25T mid +0.10T top .

[0084] Then, calculate the dew point temperature T inside the cabinet. d :

[0085] T d =[(0.66077-lgE) w [)×237.3] / (lgE w -8.16077)

[0086] Among them, T d This refers to the dew point temperature inside the cabinet.

[0087] The Condensation Risk Index (CRI) is calculated using the following formula:

[0088] CRI=(S1-S2)+0.5×(T d -T0).

[0089] For the lowest temperature T inside the cabinet f0 and humidity change rate dS f As those skilled in the art will understand, the minimum temperature T inside the cabinet for the next period within the current control cycle can be predicted using a neural network model or by fitting a curve to historical data. f0 and humidity change rate dS f / dt. Furthermore, it can determine the prediction time window based on the precision requirements of control. This invention will not elaborate further on this aspect.

[0090] Step 3: Based on the lowest temperature T inside the cabinet f0 Based on the predicted humidity change rate and the current condensation risk index (CRI), determine whether the electrical cabinet meets the condensation risk trend criteria. If it does, proceed to step 4, the condensation risk suppression linkage control mode; otherwise, proceed to step 5, the condensation risk defense adaptive mode.

[0091] Combined with appendix Figure 1 The judgment process shown requires a three-level progressive logic to determine the condensation risk trend in this step:

[0092] (1) Temperature risk assessment: Calculate the predicted minimum temperature T inside the cabinet. f0 With dew point temperature Td The difference, when (T) f0 -T d )≤T th0 (T th0 At a temperature of 2-5℃, the potential conditions for condensation at the temperature level are met;

[0093] (2) Humidity trend judgment: When the predicted humidity change rate is ≥ ΔS th (ΔS th When the humidity is preferably 0.3%-0.8% / h, the risk is considered to be increasing.

[0094] (3) Comprehensive risk assessment: Current condensation risk index CRI ≥ CRI th0 (CRI th0 When the optimal ratio is 1.5-3), the overall risk meets the standard.

[0095] When all three conditions are met, proceed to step 4, the condensation risk suppression linkage control mode; if any condition is not met, proceed to step 5, the condensation risk defense adaptive control mode.

[0096] Step 4: Control the fan, dehumidifier, and heater in tandem. When the current condensation risk index (CRI) of the electrical cabinet is lower than the condensation risk threshold, proceed to step 5; otherwise, return to step 1.

[0097] When the condensation risk criterion is met, the heater is started first, until T... door ≥T d +T th1 Then turn on the dehumidifier until S1≤S th0 Finally, start the fan and let it run continuously until CRI. <CRI th0 ;

[0098] Among them, T door T represents the surface temperature of the electrical cabinet door. th1 S is the threshold temperature difference between the cabinet door surface temperature and the dew point temperature. th0 The humidity threshold inside the cabinet; CRI th0 This is the threshold value for the condensation risk index in the linkage control mode. In this application, T... th1 The preferred temperature range is [2.7℃, 3.3℃], S th0 The preferred range is [45%, 55%], CRI th0 The preferred range is [1.8, 2.2].

[0099] Step 5: Based on the current lowest temperature T0 inside the cabinet, the humidity inside the cabinet S1, the ambient humidity outside the cabinet S2, and the dew point temperature T d Control the adaptive mode for condensation risk defense;

[0100] When the current lowest temperature T0 inside the cabinet is greater than or equal to the ambient temperature T2 outside the cabinet, the first adaptive control strategy is implemented to reduce the humidity inside the cabinet by ventilation and / or dehumidification; when the current lowest temperature T0 inside the cabinet is less than the ambient temperature T2 outside the cabinet, the second adaptive control strategy is implemented to control the humidity inside the cabinet and the surface temperature of the cabinet at the same time to prevent condensation on the low-temperature surface.

[0101] The first adaptive control strategy is:

[0102] When the humidity inside the cabinet is greater than the humidity outside the cabinet and also exceeds the humidity risk threshold, the dehumidifier and exhaust fan will be turned on.

[0103] When the humidity inside the cabinet is greater than the humidity outside the cabinet, but not greater than the humidity risk threshold, only the exhaust fan is turned on.

[0104] If the humidity inside the cabinet is not higher than the humidity outside the cabinet, but exceeds the humidity risk threshold, the dehumidifier will be turned on.

[0105] Otherwise, the control fan, dehumidifier, and heater will all be in standby mode.

[0106] The second adaptive control strategy is:

[0107] When the humidity inside the cabinet is greater than the humidity outside the cabinet and is also greater than the humidity risk threshold, and the lowest temperature inside the cabinet, T0, is not greater than the dew point temperature, the dehumidifier, exhaust fan, and heater should be turned on simultaneously.

[0108] When the humidity inside the cabinet is greater than the humidity outside the cabinet and is also greater than the humidity risk threshold, but the lowest temperature inside the cabinet, T0, is greater than the dew point temperature, the dehumidifier and exhaust fan should be turned on simultaneously.

[0109] When the humidity inside the cabinet is greater than the humidity outside the cabinet but not greater than the humidity risk threshold, and the lowest temperature inside the cabinet, T0, is not greater than the dew point temperature, the exhaust fan and heater should be turned on simultaneously.

[0110] When the humidity inside the cabinet is greater than the humidity outside the cabinet but not greater than the humidity risk threshold, and the lowest temperature inside the cabinet, T0, is greater than the dew point temperature, only the exhaust fan is turned on.

[0111] When the humidity inside the cabinet is not greater than the humidity outside the cabinet, but is greater than the humidity risk threshold, and the lowest temperature inside the cabinet, T0, is not greater than the dew point temperature, the dehumidifier and heater should be turned on simultaneously.

[0112] When the humidity inside the cabinet is not greater than the humidity outside the cabinet, but is greater than the humidity risk threshold, and the lowest temperature inside the cabinet, T0, is greater than the dew point temperature, only the dehumidifier is turned on.

[0113] Otherwise, the control fan, dehumidifier, and heater will all be in standby mode.

[0114] In this application, the humidity risk threshold is preferably in the range of [45%, 55%].

[0115] This invention also claims protection for an electrical cabinet condensation prevention system based on the aforementioned method, including a temperature and humidity acquisition module, a dew point temperature and condensation risk index calculation module, a minimum temperature and humidity change rate prediction module, a condensation risk trend judgment module, and an anti-condensation control module.

[0116] The temperature and humidity acquisition module collects temperature and humidity information from multiple points inside and outside the electrical cabinet in real time.

[0117] The dew point temperature and condensation risk index calculation module calculates the dew point temperature and condensation risk index inside the cabinet based on the collected information.

[0118] Minimum temperature and humidity change rate prediction module, predicts the minimum temperature and humidity change rate for the next period;

[0119] The condensation risk trend judgment module judges the condensation risk trend based on the predicted values ​​of the lowest temperature and humidity change rate inside the cabinet and the current condensation risk index (CRI).

[0120] Based on the condensation risk trend, the anti-condensation control module activates either the condensation risk suppression linkage control mode or the condensation risk defense adaptive control mode.

[0121] Examples, as shown in the appendix Figure 2 The image shows an embodiment of an electrical cabinet condensation prevention method based on environmental parameter monitoring according to the present invention. The steps are as follows:

[0122] Step 1: Install temperature and humidity sensors on the upper, middle, and lower layers of the electrical cabinet, as well as on the inside of the cabinet door, to collect the air temperature T at the top of the cabinet. top Central air temperature T mid Bottom air temperature T bot Cabinet door surface temperature T door and corresponding humidity S top 、S mid 、S bot 、S door The external sensor is set 1m away from the cabinet, at the same height as the middle layer sensor inside the cabinet, to collect ambient temperature T2 and ambient humidity S2, enabling real-time collection of temperature and humidity at multiple points inside the cabinet and outside the cabinet, covering the cabinet surface temperature, air temperature and relative humidity;

[0123] Step 2: Extract the air temperature and humidity inside and outside the cabinet, and the lowest temperature inside the cabinet, T0 = min(T), based on the data collected by the sensors of the electrical cabinet. top ,T mid ,T bot ,T door ), and calculate the dew point temperature T inside the cabinet. d, Indoor humidity S1 and condensation risk index CRI; Predict the minimum indoor temperature T in the next period of this control cycle. f0 and humidity change rate dS f / dt;

[0124] The humidity S1 inside the cabinet is determined as follows:

[0125] S1=αS bot +βS door +δS mid +εS top ;

[0126] Among them, α+β+δ+ε=1, and α>β>δ>ε.

[0127] Because the impact of humidity at different heights and locations inside the cabinet on the risk of condensation varies: the bottom (cable entrance) is more susceptible to moisture intrusion due to its proximity to the cable trench, so humidity has a higher weight; the top and cabinet door have better air circulation, but the cabinet surface temperature is low, making condensation more likely; the middle area is where equipment is concentrated, and the humidity distribution is relatively uniform, so its weight is moderate; therefore, following the principle of "risk priority, while taking into account uniformity," higher weights are assigned to high-risk areas (such as the bottom and cabinet door). In this embodiment, α = 0.35, β = 0.30, δ = 0.25, and ε = 0.1 are preferred.

[0128] The internal dew point temperature T of the cabinet d Calculate as follows:

[0129] First, calculate the pressure E of the saturated water vapor inside the electrical cabinet. w :

[0130]

[0131] Among them, R H =(S top +S mid +S bot +S door ) / 4; T=0.35T door +0.30T bot +0.25T mid +0.10T top .

[0132] Then, calculate the dew point temperature T inside the cabinet. d :

[0133] T d =[(0.66077-lgE) w [)×237.3] / (lgE w -8.16077)

[0134] Among them, Td This refers to the dew point temperature inside the cabinet.

[0135] The Condensation Risk Index (CRI) is calculated using the following formula:

[0136] CRI=(S1-S2)+0.5×(T d -T0).

[0137] For the lowest temperature T inside the cabinet f0 and humidity change rate dS f As those skilled in the art will understand, the minimum temperature T inside the cabinet for the next period within the current control cycle can be predicted using a neural network model or by fitting a curve to historical data. f0 and humidity change rate dS f / dt. Furthermore, it can determine the prediction time window based on the precision requirements of control. This invention will not elaborate further on this aspect.

[0138] Step 3: Based on the lowest temperature T inside the cabinet f0 Based on the predicted humidity change rate and the current condensation risk index (CRI), determine whether the electrical cabinet meets the condensation risk trend criterion; if it does, proceed to step 4, the condensation risk suppression linkage control mode; otherwise, proceed to step 5, the condensation risk defense adaptive mode; the condensation risk criterion is:

[0139] T f0 -T d ≤T th0 And dS f / dt≥ΔS th And CRI ≥ CRI th0 ;

[0140] Among them, T th0 ΔS is the set dew point temperature difference threshold. th CRI is the threshold for humidity change rate. th0 This is the threshold for the condensation risk index. In this embodiment, T... th0 Preferably 2℃, ΔS th Preferably 0.5% / h, CRI th0 The preferred value is 2.

[0141] Step 4: When the condensation risk criterion is met, the preheating mode is immediately triggered: the heater starts running in advance, so that T door ≥T d +3℃; simultaneously, the dehumidifier starts until S1≤50%; the fan continues to run until CRI<2 to balance the internal and external temperature difference; then, the dehumidification and ventilation strategies are dynamically adjusted according to the real-time CRI value. When the current condensation risk index (CRI) of the electrical cabinet is lower than the condensation risk threshold, proceed to step 5; otherwise, return to step 1.

[0142] Step 5: Based on the current lowest temperature inside the cabinet T0, the ambient temperature outside the cabinet T2, the humidity inside the cabinet S1, the ambient humidity outside the cabinet S2, and the dew point temperature T... d In addition to the humidity risk threshold S3, the adaptive mode for condensation risk defense is controlled, and the specific control method is as follows:

[0143] When the lowest temperature inside the cabinet T0 is greater than or equal to the ambient temperature outside the cabinet T2, the core objective is to reduce the humidity inside the cabinet through ventilation or dehumidification to avoid the risk of condensation caused by the temperature inside the cabinet being higher than that outside.

[0144] Furthermore, the following control strategy is implemented:

[0145] Scenario 1: When S1>S2, the humidity inside the cabinet is higher than outside, so ventilation should be prioritized to reduce humidity;

[0146] Furthermore, when S1>S3, dehumidification is required, so the dehumidifier and fan are started, and the heater is turned off; when S1≤S3, the humidity meets the standard, so only the fan is started for ventilation, and the dehumidifier and heater are turned off.

[0147] Scenario 2: When S1≤S2, the humidity inside the cabinet is not higher than that outside. The decision to dehumidify is made based on the comparison between the detected real-time humidity and the humidity risk threshold.

[0148] Furthermore, when S1>S3, dehumidification is required; the dehumidifier is started, and the fan and heater are turned off. When S1≤S3, the humidity meets the standard, and all operating devices are turned off.

[0149] When the lowest temperature inside the cabinet is lower than the temperature outside the cabinet, the core objective is to simultaneously control humidity and cabinet surface temperature to prevent condensation on the low-temperature surface (at this time, the cabinet surface temperature is likely to be lower than the dew point temperature).

[0150] Furthermore, the following control strategy is implemented:

[0151] Scenario 1: When S1>S2, the humidity inside the cabinet is higher, requiring ventilation and dehumidification. Whether to heat depends on the dew point temperature.

[0152] Furthermore, when S1>S3, dehumidification is required. In this case, if T0≤T d (If the cabinet surface temperature is less than or equal to the dew point temperature, condensation is likely to occur), then the dehumidifier, fan, and heater will be activated; if T0 > T d (If the cabinet surface temperature is greater than the dew point temperature, the risk is low), then start the dehumidifier and fan, and turn off the heater;

[0153] When S1≤S3, the humidity meets the standard. At this time, if T0≤T d (Condensation prevention is still necessary), then start the fan and heater; if T0>T d (If there is no risk of condensation, then turn on the fan for ventilation and turn off the dehumidifier and heater;

[0154] Case 2: When S1≤S2, the humidity inside the cabinet is not higher than that outside, and the main functions are dehumidification and heating;

[0155] Furthermore, when S1>S3, dehumidification is required. In this case, if T0≤T d If the cabinet surface temperature is low, start the dehumidifier and heater, and turn off the fan; if T0 > T d If the surface temperature is sufficient, start the dehumidifier and turn off the fan and heater.

[0156] When S1≤S3, the humidity meets the standard, and all actuators are shut down.

[0157] In this embodiment, the humidity risk threshold S3 is preferably 50%.

[0158] This invention also claims protection for an electrical cabinet condensation prevention system based on the aforementioned method, including a temperature and humidity acquisition module, a dew point temperature and condensation risk index calculation module, a minimum temperature and humidity change rate prediction module, a condensation risk trend judgment module, and an anti-condensation control module.

[0159] The temperature and humidity acquisition module collects temperature and humidity information from multiple points inside and outside the electrical cabinet in real time.

[0160] The dew point temperature and condensation risk index calculation module calculates the dew point temperature and condensation risk index inside the cabinet based on the collected information.

[0161] Minimum temperature and humidity change rate prediction module, predicts the minimum temperature and humidity change rate for the next period;

[0162] The condensation risk trend judgment module judges the condensation risk trend based on the predicted values ​​of the lowest temperature and humidity change rate inside the cabinet and the current condensation risk index (CRI).

[0163] Based on the condensation risk trend, the anti-condensation control module activates either the condensation risk suppression linkage control mode or the condensation risk defense adaptive control mode.

[0164] This invention proposes a method and system for preventing condensation in electrical cabinets based on environmental parameter monitoring. Utilizing an advanced intelligent control strategy, the system can generate targeted control signals according to different environmental conditions and states, enabling the coordinated operation of fans, dehumidifiers, and heaters. Under different temperature and humidity scenarios, the system can flexibly switch operating modes. For example, when there is a large temperature difference between the inside and outside of the cabinet but the humidity does not exceed the threshold, only the fan is activated for ventilation and cooling; when the humidity inside the cabinet is high but the temperature difference is small, only the dehumidifier is activated to reduce humidity; and in high-risk condensation scenarios with high humidity and significant temperature differences, both the fan and dehumidifier are activated simultaneously for rapid and effective environmental regulation. This precise control strategy can adapt to various complex environmental changes to the greatest extent and effectively prevent condensation.

[0165] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preventing condensation in electrical cabinets based on environmental parameter monitoring, characterized in that, The method includes the following steps: Step 1: Collect temperature and humidity information from multiple points inside and outside the electrical cabinet in real time during each control cycle; Step 2: Based on the acquired signals, obtain the current lowest temperature T0 and humidity S1 inside the cabinet, and calculate the dew point temperature T inside the cabinet. d Condensation Risk Index (CRI); Predict the lowest temperature (T) inside the cabinet for the next period within this control cycle. f0 and humidity change rate dS f / dt; Step 3: Based on the predicted values ​​of the lowest temperature and humidity change rate inside the cabinet and the current condensation risk index (CRI), determine whether the electrical cabinet meets the condensation risk trend criteria. If it does, proceed to Step 4, the condensation risk suppression linkage control mode; otherwise, proceed to Step 5, the condensation risk defense adaptive mode. Step 4: Control the fan, dehumidifier, and heater in tandem. When the current condensation risk index (CRI) of the electrical cabinet is lower than the condensation risk threshold, proceed to step 5; otherwise, return to step 1. Step 5: Based on the current lowest temperature T0 inside the cabinet, the humidity inside the cabinet S1, the ambient humidity outside the cabinet S2, and the dew point temperature T d It implements adaptive control of condensation risk defense mode.

2. The method for preventing condensation in electrical cabinets according to claim 1, characterized in that: In step 1, temperature and humidity sensors are installed on the upper, middle, and lower layers of the electrical cabinet, as well as on the inside of the cabinet door, to collect the air temperature T at the top of the cabinet. top Central air temperature T mid Bottom air temperature T bot Cabinet door surface temperature T door and top air humidity S top Central air humidity S mid Bottom air humidity S bot Cabinet door surface humidity S door .

3. The method for preventing condensation in electrical cabinets according to claim 2, characterized in that: In step 2, the humidity S1 inside the cabinet is determined as follows: S1=αS bot +βS door +δS mid +εS top ; Among them, α+β+δ+ε=1, and α>β>δ>ε.

4. The method for preventing condensation in electrical cabinets according to claim 3, characterized in that: In step 2, the dew point temperature T inside the cabinet is... d Calculate as follows: T d =[(0.66077-lgE w )×237.3] / (lgE w -8.16077) Among them, T d E represents the dew point temperature inside the cabinet. w This represents the pressure of the saturated water vapor inside the electrical cabinet.

5. The method for preventing condensation in electrical cabinets according to claim 4, characterized in that: The current pressure E of saturated water vapor inside the electrical cabinet w Calculate as follows: Among them, R H =(S top +S mid +S bot +S door ) / 4; T=0.35T door +0.30T bot +0.25T mid +0.10T top .

6. The method for preventing condensation in electrical cabinets according to any one of claims 1-5, characterized in that: In step 2, the condensation risk index (CRI) is: CRI=(S1-S2)+0.5×(T d -T0)。 7. The method for preventing condensation in electrical cabinets according to claim 1, characterized in that: In step 3, the condensation risk criterion is: T f0 -T d ≤T th0 And dS f / dt≥ΔS th And CRI ≥ CRI th0 ; Among them, T th0 ΔS is the set dew point temperature difference threshold. th CRI is the threshold for humidity change rate. th0 This is the threshold for the condensation risk index.

8. The method for preventing condensation in electrical cabinets according to claim 1, characterized in that: In step 4, the linkage control mode specifically includes: When the condensation risk trend criterion is met, the heater is started first, until T... door ≥T d +T th1 Then turn on the dehumidifier until S1≤S th0 Finally, start the fan and let it run continuously until CRI. <CRI th0 ; Among them, T door T represents the surface temperature of the electrical cabinet door. th1 S is the threshold temperature difference between the cabinet door surface temperature and the dew point temperature. th0 The humidity threshold inside the cabinet; CRI th0 This is the threshold value for the condensation risk index in the linkage control mode.

9. The method for preventing condensation in electrical cabinets according to claim 1, characterized in that: In step 5, the specific control strategy for the adaptive control of the condensation risk defense mode is as follows: When the current lowest temperature T0 inside the cabinet is greater than or equal to the ambient temperature T2 outside the cabinet, the first adaptive control strategy is implemented to reduce the humidity inside the cabinet by ventilation and / or dehumidification; when the current lowest temperature T0 inside the cabinet is less than the ambient temperature T2 outside the cabinet, the second adaptive control strategy is implemented to control the humidity inside the cabinet and the surface temperature of the cabinet at the same time to prevent condensation on the low-temperature surface.

10. The method for preventing condensation in electrical cabinets according to claim 9, characterized in that: The first adaptive control strategy is: When the humidity inside the cabinet is greater than the humidity outside the cabinet and also exceeds the humidity risk threshold, the dehumidifier and exhaust fan will be turned on. When the humidity inside the cabinet is greater than the humidity outside the cabinet, but not greater than the humidity risk threshold, only the exhaust fan is turned on. If the humidity inside the cabinet is not greater than the humidity outside the cabinet, but is greater than the humidity risk threshold, the dehumidifier will be turned on. Otherwise, the control fan, dehumidifier, and heater will all be in standby mode.

11. The method for preventing condensation in electrical enclosures according to claim 9 or 10, characterized in that: The second adaptive control strategy is: When the humidity inside the cabinet is greater than the humidity outside the cabinet and is also greater than the humidity risk threshold, and the lowest temperature inside the cabinet, T0, is not greater than the dew point temperature, the dehumidifier, exhaust fan, and heater should be turned on simultaneously. When the humidity inside the cabinet is greater than the humidity outside the cabinet and is also greater than the humidity risk threshold, but the lowest temperature inside the cabinet, T0, is greater than the dew point temperature, the dehumidifier and exhaust fan should be turned on simultaneously. When the humidity inside the cabinet is greater than the humidity outside the cabinet but not greater than the humidity risk threshold, and the lowest temperature inside the cabinet, T0, is not greater than the dew point temperature, the exhaust fan and heater should be turned on simultaneously. When the humidity inside the cabinet is greater than the humidity outside the cabinet but not greater than the humidity risk threshold, and the lowest temperature inside the cabinet, T0, is greater than the dew point temperature, only the exhaust fan is turned on. When the humidity inside the cabinet is not greater than the humidity outside the cabinet, but is greater than the humidity risk threshold, and the lowest temperature inside the cabinet, T0, is not greater than the dew point temperature, the dehumidifier and heater should be turned on simultaneously. When the humidity inside the cabinet is not greater than the humidity outside the cabinet, but is greater than the humidity risk threshold, and the lowest temperature inside the cabinet, T0, is greater than the dew point temperature, only the dehumidifier is turned on. Otherwise, the control fan, dehumidifier, and heater will all be in standby mode.

12. An electrical cabinet condensation prevention system based on the method of any one of claims 1-11, comprising a temperature and humidity acquisition module, a dew point temperature and condensation risk index calculation module, a minimum temperature and humidity change rate prediction module, a condensation risk trend judgment module, and an anti-condensation control module, characterized in that: The temperature and humidity acquisition module collects temperature and humidity information from multiple points inside and outside the electrical cabinet in real time. The dew point temperature and condensation risk index calculation module calculates the dew point temperature and condensation risk index inside the cabinet based on the collected information. Minimum temperature and humidity change rate prediction module, predicts the minimum temperature and humidity change rate for the next period; The condensation risk trend judgment module judges the condensation risk trend based on the predicted values ​​of the lowest temperature and humidity change rate inside the cabinet and the current condensation risk index (CRI). Based on the condensation risk trend, the anti-condensation control module activates either the condensation risk suppression linkage control mode or the condensation risk defense adaptive control mode.

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