A variable frequency cabinet temperature control and front cabin positive pressure collaborative distribution system and method based on a fixed frequency dust removal air source

Abstract

The application discloses a variable-frequency cabinet temperature control and front cabin positive pressure collaborative distribution system and method based on a constant-frequency dust removal air source, which comprises a constant-frequency fan, a main air duct, a variable-frequency cabinet branch air duct, a front cabin branch air duct, an air volume adjusting actuator, a temperature sensor, a positive pressure state monitoring sensor and a controller. The controller is configured to control the corresponding air volume adjusting actuator based on the monitoring data of each temperature sensor to adjust the air volume distributed to each variable-frequency cabinet area, realize temperature control of the variable-frequency cabinet, and based on the monitoring data of the positive pressure state monitoring sensor, collaboratively adjust the air volume proportion distributed to the front cabin and each variable-frequency cabinet area under the constraint that the total air volume provided by the constant-frequency fan is constant, so as to maintain the positive pressure of the front cabin. The application solves the long-existing conflict between the heat dissipation and heat preservation requirements of the variable-frequency cabinet and the front cabin positive pressure maintenance requirements by dynamically distributing the air volume through a closed-loop control algorithm under the physical constraint of constant total air volume, and realizes efficient and intelligent utilization of the limited air source.

Description

Technical Field

[0001] This invention relates to the field of electrical control and ventilation technology for large mining machinery, and in particular to a variable frequency cabinet temperature control and front compartment positive pressure collaborative distribution system and method based on a fixed frequency dust removal air source. Background Technology

[0002] Large mining excavators (electric shovels) are typically equipped with independent dust collection systems. These systems use fixed-frequency fans to provide a constant airflow for dust collection. This air source is usually also directed to the inverter cabinet area for heat dissipation and provides positive pressure air to the front compartment of the equipment to prevent dust intrusion. However, existing technologies have the following significant drawbacks:

[0003] The airflow distribution is simplistic and lacks coordination: Under the constraint of a constant total airflow from the fixed-frequency fan, existing systems mostly use simple on / off valve control, which cannot achieve refined and dynamic airflow distribution between the heat dissipation (or insulation) requirements of the frequency converter cabinet and the positive pressure maintenance requirements of the front compartment. When the frequency converter cabinet requires a large amount of airflow for heat dissipation, it may lead to insufficient positive pressure in the front compartment; conversely, in order to ensure positive pressure in the front compartment, the heat dissipation effect of the frequency converter cabinet may be sacrificed.

[0004] Lack of low-temperature protection: Traditional solutions only focus on high-temperature heat dissipation. In low-temperature environments (especially in frigid regions), continuous fixed-frequency cold air blowing onto the inverter cabinet will actually exacerbate heat loss inside the cabinet, leading to excessively low internal temperatures, which may cause component failure or difficulty in starting the equipment. Existing systems lack proactive insulation logic.

[0005] Weak regional independent control capability: When the equipment has multiple frequency converter cabinets and the temperature requirements are inconsistent, the existing system is difficult to achieve differentiated and precise air volume control for each area.

[0006] The conflict between maintaining positive pressure and the need for heat dissipation: Essentially, this is a concrete manifestation of the first defect. Given a fixed total airflow, these two needs are in a competitive relationship, with one increasing as the other decreases, and there is a lack of an effective coordination mechanism.

[0007] In view of this, there is an urgent need for a system and method that can intelligently and collaboratively meet the dual requirements of multi-mode temperature control (heat dissipation / heat preservation) and positive pressure maintenance of the front compartment of the frequency converter cabinet under constant total air volume. Summary of the Invention

[0008] In view of this, the present invention provides a system and method for coordinated distribution of temperature control and positive pressure in the front compartment of a variable frequency cabinet based on a fixed frequency dust removal air source. It can achieve the optimization and redistribution of constant total air volume between the "multiple variable frequency cabinet areas" and the "equipment front compartment" without changing the original operating state of the fixed frequency dust removal fan, or adding additional air source and energy consumption, by constructing an intelligent closed-loop control system of "perception-decision-execution".

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] A variable frequency cabinet temperature control and front compartment positive pressure coordinated distribution system based on a fixed-frequency dust removal air source includes: a fixed-frequency fan, a main air duct, variable frequency cabinet branch air ducts, front compartment branch air ducts, an airflow regulating actuator, a temperature sensor, a positive pressure status monitoring sensor, and a controller; the fixed-frequency fan provides a constant total airflow; the main air duct is connected to the outlet of the fixed-frequency fan; both the variable frequency cabinet branch air ducts and the front compartment branch air ducts are connected to the main air duct, with the outlet of the variable frequency cabinet branch air duct leading to the corresponding variable frequency cabinet area, and the outlet of the front compartment branch air duct leading to the front compartment; each set of variable frequency cabinet branch air ducts and the front compartment branch air ducts is provided with at least one set; each set of variable frequency cabinet branch air ducts is equipped with an airflow regulating actuator. It is used to regulate the airflow through its branch; each frequency converter cabinet area is equipped with a temperature sensor, and the positive pressure status monitoring sensor is located in the front compartment; the controller is communicatively connected to each temperature sensor, the positive pressure status monitoring sensor, and each airflow regulation actuator; the controller is configured to: control the corresponding airflow regulation actuator based on the monitoring data of each temperature sensor to regulate the airflow distributed to each frequency converter cabinet area, thereby achieving temperature control of the frequency converter cabinet; and based on the monitoring data of the positive pressure status monitoring sensor, under the constraint of a constant total airflow provided by the fixed frequency fan, coordinately adjust the airflow ratio distributed to the front compartment and each frequency converter cabinet area to maintain positive pressure in the front compartment.

[0011] Preferably, the controller is configured to execute a temperature-priority control strategy: prioritizing the response to the monitoring data of the temperature sensor to meet the temperature requirements of each inverter cabinet area; when the temperature requirements of all inverter cabinet areas are met, then responding to the monitoring data of the positive pressure status monitoring sensor to correct the airflow distribution in order to maintain positive pressure in the front compartment.

[0012] Preferably, the temperature priority control strategy includes a low-temperature insulation mode and a high-temperature heat dissipation mode: In the low-temperature insulation mode, when the temperature sensor detects a temperature below a first preset threshold, the low-temperature insulation mode is activated, controlling the corresponding airflow adjustment actuator to reduce or shut off the airflow to the inverter cabinet area; In the high-temperature heat dissipation mode, when the temperature sensor detects a temperature above a second preset threshold, the high-temperature heat dissipation mode is activated, controlling the corresponding airflow adjustment actuator to increase the airflow to the inverter cabinet area.

[0013] Preferably, the variable frequency cabinet temperature control and front compartment positive pressure coordinated distribution system based on fixed frequency dust removal air source further includes: a heater, each of the variable frequency cabinet areas is provided with the heater, the heater is communicatively connected to the controller; in the low temperature insulation mode, the controller is also configured to start the corresponding heater while reducing or shutting down the air volume.

[0014] Preferably, the positive pressure state monitoring sensor is a PM2.5 particulate matter concentration sensor or a differential pressure sensor.

[0015] Preferably, the air volume regulating actuator includes a cylinder and a sealing door driven by the cylinder; the sealing door is disposed in the corresponding frequency converter branch air duct; the stroke of the cylinder is related to the opening and closing angle of the sealing door, and an increase in the stroke of the cylinder causes the opening and closing angle of the sealing door to increase, thereby increasing the air volume flowing through the branch.

[0016] Preferably, the controller performs multi-level discrete position control on the cylinder.

[0017] Preferably, the multi-stage is five stages, from stage one to stage five, corresponding to 0%, 25%, 50%, 75% and 100% of the cylinder stroke, respectively. The opening states of the sealing door are respectively: the sealing door is completely closed, the sealing door is slightly open, the sealing door is half open, the sealing door is mostly open and the sealing door is fully open.

[0018] Preferably, the controller supports both local automatic control mode and remote control mode.

[0019] This invention also proposes a method for coordinated distribution of temperature control and positive pressure in the front compartment of a variable frequency drive (VFD) cabinet based on a fixed-frequency dust removal air source. This method is applied to any of the above embodiments of the coordinated distribution system for temperature control and positive pressure in the front compartment of a VFD cabinet based on a fixed-frequency dust removal air source. The method includes: acquiring temperature monitoring data for each VFD cabinet area and positive pressure status monitoring data for the front compartment; determining the temperature control requirements for each VFD cabinet area based on the temperature monitoring data; under the constraint of a constant total airflow provided by a fixed-frequency fan, generating control commands for the airflow adjustment actuators on the branch ducts of each VFD cabinet based on the temperature control requirements and positive pressure status monitoring data; and executing the control commands to dynamically adjust the airflow ratio distributed to each VFD cabinet area and the front compartment, so as to simultaneously meet the temperature control requirements of the VFD cabinet and the positive pressure maintenance requirements of the front compartment.

[0020] Preferably, the step of determining the temperature control requirements of each inverter cabinet area based on the temperature monitoring data includes: if the temperature of a certain inverter cabinet area is lower than a first preset threshold, it is determined that the area needs to enter a low-temperature insulation mode mainly by reducing air volume and starting heating; if the temperature of a certain inverter cabinet area is higher than a second preset threshold, it is determined that the area needs to enter a high-temperature heat dissipation mode mainly by increasing air volume.

[0021] Preferably, the step of generating control commands based on the temperature control requirements and the positive pressure status monitoring data specifically includes: firstly generating a first control command based on the temperature control requirements to adjust the airflow distribution to meet the temperature requirements; after the temperature requirements of all frequency converter cabinet areas are met, if it is determined from the positive pressure status monitoring data that the positive pressure in the front compartment is insufficient, then generating a second control command, the second control command being used to adjust the airflow distribution to increase the airflow to the front compartment while maintaining the temperature of each frequency converter cabinet area within the limit.

[0022] Preferably, the generation of the second control command includes: first, reducing the branch air volume corresponding to the inverter cabinet area that is not currently in high-temperature heat dissipation mode; if the air volume is still insufficient, then within the allowable temperature range, reducing the branch air volume corresponding to the inverter cabinet area that is currently in high-temperature heat dissipation mode.

[0023] Preferably, the dynamic adjustment of the air volume ratio allocated to each inverter cabinet area and the front compartment is achieved by controlling the stroke of the cylinder. Specifically, increasing the air volume flowing to a certain inverter cabinet area is achieved by increasing the stroke of the corresponding cylinder, which results in a decrease in the air volume flowing to the front compartment; decreasing the air volume flowing to a certain inverter cabinet area is achieved by decreasing the stroke of the corresponding cylinder, which results in an increase in the air volume flowing to the front compartment.

[0024] Preferably, the method for coordinated distribution of variable frequency cabinet temperature control and front compartment positive pressure based on fixed frequency dust removal air source further includes an alarm step: when the temperature of any variable frequency cabinet area continues to be abnormally high beyond a first time threshold, or the positive pressure state of the front compartment continues to be abnormally high beyond a second time threshold, an alarm message is generated and sent.

[0025] Preferably, the method for coordinated distribution of temperature control and positive pressure in the variable frequency cabinet based on a fixed frequency dust removal air source further includes setting an adjustment dead zone: when the absolute value of the deviation between the temperature value monitored by the temperature sensor and the preset threshold is less than or equal to a dead zone threshold, the adjustment command to the air volume adjustment actuator is not triggered.

[0026] Preferably, an adjustment command is generated and executed only after the temperature value detected by the temperature sensor remains abnormal for more than a first preset delay time; and after executing an adjustment command, at least a second preset interval time is waited before responding to the next temperature abnormality and generating a new adjustment command.

[0027] The beneficial effects of this invention are as follows:

[0028] 1. This application solves the long-standing conflict between the heat dissipation and insulation requirements of the frequency converter cabinet and the positive pressure maintenance requirements of the front compartment by dynamically allocating air volume through a closed-loop control algorithm under the physical constraint of constant total air volume, and realizes the efficient and intelligent utilization of limited air source.

[0029] 2. This application introduces a low-temperature insulation mode, which actively reduces or cuts off the supply of cold air and starts heating when the temperature inside the cabinet is too low. This fundamentally avoids the problem of fixed-frequency cold air aggravating the heat loss of the equipment in low-temperature environments, and ensures the normal start-up and operation of the equipment in cold regions.

[0030] 3. This application achieves precise and smooth adjustment of the air volume of each branch by adopting multi-level (e.g., five-level) discrete control combined with sensor feedback, avoiding the impact of sudden air volume changes on the system. It supports setting differentiated temperature thresholds for each frequency converter cabinet area and has remote monitoring and alarm functions, meeting the operation and maintenance needs of complex working conditions and modern unattended mines.

[0031] 4. This application utilizes the existing fixed-frequency dust collector fan of the equipment as the air source and achieves functional improvement through optimized distribution strategy. There is no need to add an extra fan or modify the fan to a variable frequency one, which saves the equipment modification cost and operating energy consumption to the greatest extent.

[0032] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0033] Figure 1 This is a control flowchart of the collaborative allocation system of the present invention;

[0034] Figure 2 This is a control flowchart of the temperature-priority regulation of the present invention;

[0035] Figure 3 This is a control flowchart for positive pressure maintenance (PM2.5 correction) of the present invention;

[0036] Figure 4 This is a schematic diagram of the fixed-frequency air source air volume distribution principle of the present invention;

[0037] Figure 5 This is the heat dissipation mode graded adjustment rule table of the present invention;

[0038] Figure 6 This is the thermal insulation mode graded adjustment rule table of the present invention;

[0039] Figure 7 This is a schematic diagram of the overall structure of the collaborative allocation system of the present invention (perspective one);

[0040] Figure 8 This is a schematic diagram of the overall structure of the collaborative allocation system (perspective two) of the present invention;

[0041] Figure 9 This is a layout diagram of the PM2.5 sensor and temperature sensor of the present invention;

[0042] Figure 10 This is a control principle diagram of the PLC input module of the present invention;

[0043] Figure 11 This is a control principle diagram of the PLC output module of the present invention;

[0044] Figure 12 This is a pneumatic schematic diagram of the collaborative distribution system of the present invention. Detailed Implementation

[0045] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0047] The basic principle of this invention lies in: based on the law of conservation of air volume, within the total air volume of a fixed-frequency fan... Under constant conditions, the total air volume distributed to the inverter cabinet area is dynamically changed by adjusting the opening (i.e., air resistance) of each branch duct. and the air volume allocated to the front compartment And satisfy When heat dissipation is required for a specific inverter cabinet, its branch opening is increased, and the... Correspondingly Reduce; when it is necessary to maintain positive pressure in the front compartment or to insulate the frequency converter cabinet, reduce the branch opening of the frequency converter cabinet and reduce ,make Increase.

[0048] The following is for reference. Figures 1 to 12 This invention describes a variable frequency cabinet temperature control and front compartment positive pressure collaborative distribution system based on a fixed frequency dust removal air source in an embodiment of the invention.

[0049] This application discloses a variable frequency cabinet temperature control and front compartment positive pressure coordinated distribution system based on a fixed frequency dust removal air source, comprising: a fixed frequency fan, a main air duct, variable frequency cabinet branch air ducts, front compartment branch air ducts, an air volume adjustment actuator, a temperature sensor, a positive pressure status monitoring sensor, and a controller; the fixed frequency fan is used to provide a constant total air volume; the main air duct is connected to the air outlet of the fixed frequency fan; both the variable frequency cabinet branch air ducts and the front compartment branch air ducts are connected to the main air duct, with the outlet of the variable frequency cabinet branch air duct leading to the corresponding variable frequency cabinet area, and the outlet of the front compartment branch air duct leading to the front compartment; each variable frequency cabinet branch air duct and each front compartment branch air duct is provided with at least one set; each set of variable frequency cabinet branch air ducts is equipped with an air volume adjustment actuator. The controller is configured to: regulate the airflow through its respective branch; install a temperature sensor in each inverter cabinet area and a positive pressure monitoring sensor in the front compartment; communicate with each temperature sensor, positive pressure monitoring sensor, and airflow regulating actuator; and, based on the monitoring data from each temperature sensor, control the corresponding airflow regulating actuator to adjust the airflow distributed to each inverter cabinet area, thereby achieving temperature control of the inverter cabinets; and, based on the monitoring data from the positive pressure monitoring sensor, coordinately adjust the airflow ratio distributed to the front compartment and each inverter cabinet area under the constraint of a constant total airflow provided by the fixed-frequency fan, in order to maintain positive pressure in the front compartment.

[0050] Specifically, the collaborative distribution system of this application constructs a complete control closed loop. A fixed-frequency fan, acting as a constant air source, delivers airflow to the distribution network through the main duct. The distribution network includes at least one front compartment branch duct leading to the equipment front compartment and at least one inverter cabinet branch duct leading to the inverter cabinet. Each inverter cabinet branch duct is equipped with an airflow regulating actuator, such as an electric damper or pneumatic door. The sensing layer consists of temperature sensors installed inside each inverter cabinet and positive pressure monitoring sensors (such as PM2.5 sensors) installed in the front compartment. The decision-making center is a controller (such as a PLC), which collects all sensor signals and calculates control commands for each airflow regulating actuator based on a built-in algorithm, thereby achieving dynamic and collaborative airflow distribution.

[0051] In some embodiments, the controller is configured to execute a temperature-priority control strategy: prioritizing the response to monitoring data from temperature sensors to meet the temperature requirements of each inverter cabinet area; and when the temperature requirements of all inverter cabinet areas are met, then responding to monitoring data from positive pressure status monitoring sensors to correct the airflow distribution in order to maintain positive pressure in the front compartment.

[0052] Specifically, in this embodiment, the controller sets the temperature control of the frequency converter cabinets as the highest priority. The system first processes the temperature signals of all frequency converter cabinets. Only when the temperature of all frequency converter cabinets is within a safe or normal range will the controller fine-tune the current airflow distribution ratio based on the data from the front compartment positive pressure monitoring sensor. This strategy ensures that the operational safety of the core electrical components (frequency converter cabinets) is always the top priority.

[0053] The strategy in this embodiment clarifies the priorities in collaborative control and resolves the decision-making problem when temperature control and positive pressure maintenance may conflict instantly. Its effect is to ensure that the temperature safety of the frequency converter cabinet is prioritized under all circumstances, thereby improving the reliability of system operation.

[0054] In some embodiments, the temperature priority control strategy includes a low-temperature insulation mode and a high-temperature heat dissipation mode: Low-temperature insulation mode: When the temperature sensor detects that the temperature is lower than a first preset threshold, the low-temperature insulation mode is activated, and the corresponding airflow adjustment actuator is controlled to reduce or shut off the airflow to the inverter cabinet area to prevent cold air from continuing to carry away heat from the cabinet; High-temperature heat dissipation mode: When the temperature sensor detects that the temperature is higher than a second preset threshold, the high-temperature heat dissipation mode is activated, and the corresponding airflow adjustment actuator is controlled to increase the airflow to the inverter cabinet area to enhance heat dissipation.

[0055] In this embodiment, the introduction of a low-temperature insulation mode directly solves the fatal flaw of "lack of low-temperature protection." Its effect is to give the system bidirectional temperature regulation capabilities, enabling it to cope with both overheating and overcooling, greatly expanding the equipment's adaptability and stability in harsh environments (such as high-altitude and cold regions).

[0056] In some embodiments, the variable frequency cabinet temperature control and front compartment positive pressure coordinated distribution system based on fixed frequency dust removal air source further includes: a heater, each variable frequency cabinet area is provided with a heater, and the heater is communicatively connected to the controller; in low temperature insulation mode, the controller is also configured to start the corresponding heater while reducing or shutting down the air volume.

[0057] Specifically, in low-temperature insulation mode, simply reducing airflow is sometimes insufficient to quickly raise the temperature. Therefore, the system is also equipped with an auxiliary heater in each inverter cabinet area, which is also controlled by the controller. When entering low-temperature insulation mode, the controller reduces airflow while activating the heater in the corresponding cabinet to actively heat the electrical components, ensuring they quickly return to a safe operating temperature.

[0058] In this embodiment, the integration of the heater and the linkage with the low-temperature insulation mode form a complete low-temperature protection scheme. Its effect is to significantly accelerate the preheating speed of equipment in low-temperature environments, effectively solve the problem of equipment failure to start or unstable component operation caused by excessively low temperatures, and improve the system's environmental adaptability.

[0059] In some embodiments, the positive pressure monitoring sensor is a PM2.5 particulate matter concentration sensor or a differential pressure sensor. Specifically, the positive pressure monitoring sensor of this application is preferably a PM2.5 particulate matter concentration sensor. The principle is as follows: when the positive pressure in the front cabin is sufficient, external dust is difficult to penetrate, resulting in a low PM2.5 concentration inside the cabin; when the positive pressure is insufficient, dust-laden air from outside seeps in, causing the PM2.5 concentration inside the cabin to increase. Therefore, PM2.5 concentration can serve as an indirect indicator for evaluating the effectiveness of the positive pressure. Alternatively, a differential pressure sensor can be used to directly measure the pressure difference between the front cabin and the external environment, thereby more directly determining the positive pressure status.

[0060] In some embodiments, the air volume regulating actuator includes a cylinder and a sealing door driven by the cylinder; the sealing door is disposed in the corresponding frequency converter branch air duct; the stroke of the cylinder is related to the opening and closing angle of the sealing door, and an increase in the stroke of the cylinder causes an increase in the opening and closing angle of the sealing door, thereby increasing the air volume flowing through the branch.

[0061] Specifically, the cylinder acts as the power component, and the extension and retraction of its piston rod drives the sealing gate to rotate around its axis, thereby changing the opening and closing angle of the sealing gate in the air duct. The larger the opening angle of the sealing gate, the smaller the flow resistance of the branch air duct, and the greater the air volume flowing through the branch under the condition of a constant total fan head. The stroke of the cylinder is positively correlated with the opening and closing angle of the sealing gate (and the air volume determined by it).

[0062] In this embodiment, the cylinder-driven method has advantages such as simple structure, large thrust, strong resistance to dust pollution, and suitability for harsh mining environments. This mechanism provides a reliable and durable actuator for precise airflow adjustment.

[0063] In some embodiments, the controller performs multi-level discrete position control on the cylinder. The controller's control of the cylinder (or other actuator) is not a simple "on / off" binary control, but rather divides its stroke into multiple discrete fixed positions (levels) for control. The controller outputs a target level command based on the control algorithm, driving the cylinder to move to the designated position and hold it. Multi-level discrete control avoids the abrupt changes in airflow caused by traditional on / off valves, resulting in smoother system regulation and reduced airflow impact and mechanical shock to the actuator. Furthermore, multi-level discrete position control can also be replaced by analog continuous control.

[0064] Furthermore, as shown in Table 1 – Five-Level Airflow Control Logic, the multi-level system comprises five levels, from level one to level five, corresponding to 0%, 25%, 50%, 75%, and 100% of the cylinder stroke, respectively. The corresponding opening states of the sealing door are: completely closed, slightly open, half-open, mostly open, and fully open. These five levels are essentially linearly related to the airflow, providing the controller with sufficiently fine adjustment granularity. Five-level control achieves a good balance between control precision and system complexity. It is more precise than three-level control, enabling finer airflow distribution; at the same time, it is simpler, lower in cost, and more reliable than true analog continuous control.

[0065] Table 1 - Level 5 Airflow Control Logic

[0066] level Cylinder stroke Door sealing status The air volume of this branch Front compartment airflow (reverse relationship) Level-0 0% Completely shut down Minimum maximum Level-1 25% Slightly open smaller Larger Level-2 50% Half open medium medium Level-3 75% Most of them are open Larger smaller Level-4 100% Fully open maximum Minimum

[0067] In some embodiments, the controller supports both local automatic control mode and remote control mode. The system user interface supports multiple control modes. Local automatic mode is the default operating mode, where the controller operates fully automatically. Remote control mode allows operators to monitor and intervene in the system from a remote control room, such as checking the status, manually adjusting the airflow of a specific channel, or switching operating modes. This aligns with the trend towards less manned and unmanned operation of mining equipment.

[0068] This invention also proposes a method for coordinated distribution of temperature control and positive pressure in a variable frequency drive (VFD) cabinet based on a fixed-frequency dust removal air source. This method is applied to the VFD cabinet temperature control and positive pressure distribution system based on any one of claims 1-9, comprising: acquiring temperature monitoring data for each VFD cabinet area and positive pressure status monitoring data for the front compartment; determining the temperature control requirements for each VFD cabinet area based on the temperature monitoring data; under the constraint of a constant total airflow provided by a fixed-frequency fan, generating control commands for the airflow adjustment actuators on the branch ducts of each VFD cabinet based on the temperature control requirements and positive pressure status monitoring data; executing the control commands to dynamically adjust the airflow ratio distributed to each VFD cabinet area and the front compartment, so as to simultaneously meet the temperature control requirements of the VFD cabinet and the positive pressure maintenance requirements of the front compartment.

[0069] Specifically, firstly, the system continuously collects temperature and positive pressure data. Secondly, the core decision-making process, based on the "temperature priority" principle, calculates how to meet the temperature requirements of all frequency converter cabinets (which could be for heat dissipation or insulation) while simultaneously considering the positive pressure requirements of the front compartment, under a constant total airflow constraint, and generates specific actuator control commands. Finally, these commands are executed to complete the dynamic redistribution of airflow. This method defines, from a process perspective, how to achieve coordinated distribution under a fixed-frequency air source, transforming the system's hardware configuration into executable intelligent control logic.

[0070] In some embodiments, based on temperature monitoring data, the temperature control requirements of each inverter cabinet area are determined, including: if the temperature of a certain inverter cabinet area is lower than a first preset threshold, it is determined that the area needs to enter a low-temperature insulation mode that mainly reduces airflow and starts heating; if the temperature of a certain inverter cabinet area is higher than a second preset threshold, it is determined that the area needs to enter a high-temperature heat dissipation mode that mainly increases airflow.

[0071] Specifically, this method not only identifies high-temperature heat dissipation needs (temperature above a second preset threshold), but more importantly, it clearly identifies low-temperature insulation needs (temperature below a first preset threshold). For low-temperature insulation needs, the core control action is "reducing airflow," which is the opposite of "increasing airflow" for high-temperature heat dissipation. This is precisely the key to solving the side effects of fixed-frequency air sources in low-temperature environments. This method clarifies the logical judgment criteria for bidirectional temperature control, making the controller's decisions based on evidence. In particular, the determination of low-temperature insulation needs is a prerequisite for realizing the low-temperature protection function of this invention.

[0072] In some embodiments, control commands are generated based on temperature control requirements and positive pressure status monitoring data. Specifically, this includes: firstly generating a first control command based on temperature control requirements to adjust the airflow distribution to meet temperature requirements; and secondly generating a second control command if the positive pressure in the front compartment is insufficient after the temperature requirements in all frequency converter cabinet areas are met, based on the positive pressure status monitoring data. The second control command is used to adjust the airflow distribution to increase the airflow to the front compartment while maintaining the temperature in each frequency converter cabinet area within the limit.

[0073] Specifically, this method details how the controller coordinates temperature control and positive pressure requirements. The logic is two-step: First, it unconditionally prioritizes meeting the temperature control requirements of all inverter cabinets, generating airflow distribution instructions to ensure temperature safety. Second, assuming the first step is completed and temperature safety is maintained, it checks the positive pressure in the front compartment. If the positive pressure is insufficient, it makes a "gentle" readjustment to the airflow distribution, appropriately increasing the airflow to the front compartment without causing any inverter cabinet temperature to exceed limits. This is a robust strategy of "safety first, optimization later." Its effect is to maximize the auxiliary goal of maintaining positive pressure in the front compartment while absolutely ensuring the safety of core equipment, making the collaborative control both intelligent and reliable.

[0074] In some embodiments, generating a second control command includes: first reducing the branch airflow corresponding to the inverter cabinet area that is not currently in high-temperature heat dissipation mode; if the airflow is still insufficient, then reducing the branch airflow corresponding to the inverter cabinet area that is currently in high-temperature heat dissipation mode within the allowable temperature range.

[0075] Specifically, when an increase in front compartment airflow is needed, the system first attempts to "borrow" airflow from the inverter cabinet branches that currently have no cooling requirements (by reducing their opening), as reducing the airflow in these branches usually does not immediately cause the temperature to exceed the limit. If the front compartment airflow is still insufficient after this adjustment, the system will, within a certain safety margin, attempt to appropriately reduce the airflow in branches that are currently cooling but whose temperature control has stabilized, and closely monitor their temperature changes. The effect is to maximize positive pressure airflow for the front compartment while minimizing the impact on the inverter cabinet's cooling effect, reflecting the "refined" and "intelligent" nature of the coordinated allocation.

[0076] In some embodiments, the air volume ratio allocated to each inverter cabinet area and the front compartment is dynamically adjusted by controlling the stroke of the cylinder. Increasing the air volume flowing to a certain inverter cabinet area is achieved by increasing the stroke of the corresponding cylinder, which results in a decrease in the air volume flowing to the front compartment; decreasing the air volume flowing to a certain inverter cabinet area is achieved by decreasing the stroke of the corresponding cylinder, which results in an increase in the air volume flowing to the front compartment.

[0077] Specifically, this method reveals the fundamental physical mechanism for dynamically distributing airflow by controlling the actuator (cylinder). The core relationship is: increasing the cylinder stroke of a specific frequency converter branch (opening the damper) → increasing the airflow through that branch → since the total airflow is constant, an increase in the sum of airflow from all branches means a decrease in the total airflow leading to the front compartment. Conversely, the opposite is also true. This inverse relationship of "one increasing, the other decreasing" is the physical basis for this invention's ability to redistribute airflow without changing the total airflow. The effect is that the entire high-level control logic is built upon solid and reliable physical laws, ensuring that control commands can be executed accurately and predictably.

[0078] In some embodiments, the method for coordinated distribution of temperature control and positive pressure in the variable frequency cabinet based on a fixed frequency dust removal air source further includes an alarm step: when the temperature in any variable frequency cabinet area continuously exceeds a first time threshold, or the positive pressure in the front compartment continuously exceeds a second time threshold, an alarm message is generated and sent.

[0079] Specifically, the system features a delayed alarm mechanism. An alarm will only be triggered when any monitored parameter (temperature or PM2.5 concentration) remains abnormal for an extended period exceeding a preset time window (e.g., temperature exceeding the limit for 10 seconds). This avoids false alarms caused by momentary sensor interference or brief system fluctuations. Alarm information can be sent to a remote monitoring center.

[0080] In this embodiment, the delayed alarm mechanism improves the accuracy and effectiveness of alarms and reduces unnecessary operational and maintenance interventions. The remote alarm function ensures that abnormal conditions can be detected and handled in a timely manner, improving the maintainability and operational security of the entire equipment system.

[0081] In some embodiments, the method for coordinated distribution of temperature control and positive pressure in the front compartment of the variable frequency cabinet based on a fixed frequency dust removal air source further includes setting an adjustment dead zone: when the absolute value of the deviation between the temperature value monitored by the temperature sensor and the preset threshold is less than or equal to a dead zone threshold, the adjustment command to the air volume adjustment actuator is not triggered.

[0082] To improve the system's anti-interference capability and prevent frequent actuator movements due to minor temperature fluctuations, the controller's control logic integrates a dead-zone function. Specifically, when determining whether to trigger a regulation command, the controller does not simply compare the real-time temperature with a preset threshold (such as the maximum allowable temperature T). max Minimum allowable temperature T min Instead of making a direct comparison, it calculates an effective deviation, which is equal to the difference between the real-time temperature and the threshold (or target temperature) on which the most recent adjustment was based. The controller considers a meaningful adjustment request only when the absolute value of this effective deviation exceeds a preset dead-zone threshold Δ (e.g., ±0.5℃), thus initiating the subsequent judgment and command generation process. If temperature fluctuations are within the dead-zone threshold range, they are considered normal fluctuations, and the current control state remains unchanged.

[0083] In this embodiment, the introduction of a dead-zone adjustment mechanism significantly improves the control accuracy and reliability of the system. Its effect lies in effectively filtering out minute temperature fluctuations caused by sensor measurement noise, instantaneous environmental disturbances, or brief changes in airflow, preventing these inaccurate, minute "abnormal" signals from triggering unnecessary or even oscillating adjustment actions. This significantly reduces mechanical wear on actuators (such as cylinders and dampers), reduces system energy consumption, and improves the stability and smoothness of the entire temperature control system.

[0084] In some embodiments, an adjustment command is generated and executed only after the temperature value detected by the temperature sensor remains abnormal for more than a first preset delay time; and after executing an adjustment command, at least a second preset interval is waited before responding to the next temperature abnormality and generating a new adjustment command.

[0085] Specifically, to ensure that the control actions are based on stable and reliable operating condition judgments and to prevent the actions from being too frequent, the control logic of the controller also includes a timing protection mechanism, including two layers of protection: "delay confirmation" and "adjustment interval".

[0086] Delayed confirmation: When the temperature sensor detects a value exceeding the preset threshold range for the first time (considering dead zones), the controller will not immediately issue an adjustment command. Instead, it will start an internal timer (e.g., 10 seconds). Only if the abnormal temperature condition persists for more than this preset delay confirmation time (first preset delay time) will the controller confirm that this is a real, continuous abnormal condition, rather than a momentary disturbance. Only then will it generate and execute the corresponding adjustment command (such as increasing or decreasing the damper opening). If the temperature returns to normal during the timing period, the timer will be reset to zero, and no action will be triggered.

[0087] Adjustment Interval: After the controller completes an adjustment command for any airflow regulating actuator, it enters an "adjustment interval" period (a second preset interval time, e.g., 30 seconds). During this period, even if the system detects a new temperature anomaly (and confirms it via a delay), the controller will temporarily suspend generating new adjustment commands until the interval ends. This interval allows the effects of the previous adjustment to fully propagate and manifest in the system (e.g., the cabinet temperature needs time to reach a new equilibrium after an airflow change), avoiding continuous, potentially contradictory, or even oscillating commands from the controller due to system inertia or feedback delays.

[0088] Other components and operations of the variable frequency cabinet temperature control and front compartment positive pressure coordinated distribution system and method based on fixed frequency dust removal air source according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0089] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0090] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A variable frequency cabinet temperature control and front compartment positive pressure coordinated distribution system based on a fixed frequency dust removal air source, characterized in that, include: A fixed-frequency fan, wherein the fixed-frequency fan is used to provide a constant total air volume; The main air duct is connected to the air outlet of the fixed-frequency fan; The variable frequency cabinet branch air duct and the front compartment branch air duct are both connected to the main air duct. The outlet of the variable frequency cabinet branch air duct leads to the corresponding variable frequency cabinet area, and the outlet of the front compartment branch air duct leads to the front compartment. At least one set of the variable frequency cabinet branch air duct and the front compartment branch air duct are provided. Air volume regulating actuator: Each of the variable frequency cabinet branch air ducts is equipped with an air volume regulating actuator to regulate the air volume flowing through its branch. Temperature sensors and positive pressure monitoring sensors are provided in each of the inverter cabinet areas. The temperature sensors are provided in each area of ​​the inverter cabinet area, and the positive pressure monitoring sensors are provided in the front compartment. The controller is communicatively connected to each of the temperature sensors, the positive pressure state monitoring sensors, and each of the air volume regulating actuators. The controller is configured to: control the corresponding airflow adjustment actuator based on the monitoring data of each temperature sensor to adjust the airflow allocated to each frequency converter cabinet area, thereby achieving temperature control of the frequency converter cabinet; and based on the monitoring data of the positive pressure state monitoring sensor, under the constraint of a constant total airflow provided by the fixed frequency fan, collaboratively adjust the airflow ratio allocated to the front compartment and each frequency converter cabinet area to maintain positive pressure in the front compartment.

2. The variable frequency cabinet temperature control and front compartment positive pressure coordinated distribution system based on a fixed frequency dust removal air source according to claim 1, characterized in that, The controller is configured to execute a temperature-priority control strategy: Prioritize responding to the monitoring data from the temperature sensor to meet the temperature requirements of each inverter cabinet area; When the temperature requirements of all frequency converter cabinet areas are met, the air volume distribution is corrected in response to the monitoring data of the positive pressure status monitoring sensor to maintain the positive pressure in the front compartment.

3. The variable frequency cabinet temperature control and front compartment positive pressure coordinated distribution system based on a fixed frequency dust removal air source according to claim 2, characterized in that, The temperature priority control strategy includes a low-temperature insulation mode and a high-temperature heat dissipation mode: The low-temperature insulation mode: When the temperature sensor detects that the temperature is lower than the first preset threshold, the low-temperature insulation mode is activated, and the corresponding air volume adjustment actuator is controlled to reduce or shut off the air volume flowing to the inverter cabinet area. The high-temperature heat dissipation mode: When the temperature sensor detects that the temperature is higher than the second preset threshold, the high-temperature heat dissipation mode is activated, and the corresponding air volume adjustment actuator is controlled to increase the air volume flowing to the inverter cabinet area.

4. The variable frequency cabinet temperature control and front compartment positive pressure coordinated distribution system based on a fixed frequency dust removal air source according to claim 3, characterized in that, Also includes: A heater is provided in each of the frequency converter cabinet areas, and the heater is communicatively connected to the controller. In the low-temperature insulation mode, the controller is also configured to activate the corresponding heater while reducing or shutting off the airflow.

5. The variable frequency cabinet temperature control and front compartment positive pressure coordinated distribution system based on a fixed frequency dust removal air source according to claim 1, characterized in that, The positive pressure state monitoring sensor is a PM2.5 particulate matter concentration sensor or a differential pressure sensor.

6. The variable frequency cabinet temperature control and front compartment positive pressure coordinated distribution system based on a fixed frequency dust removal air source according to claim 1, characterized in that, The air volume regulating actuator includes a cylinder and a sealing door driven by the cylinder; the sealing door is disposed in the corresponding frequency converter branch air duct; the stroke of the cylinder is related to the opening and closing angle of the sealing door, and an increase in the stroke of the cylinder causes the opening and closing angle of the sealing door to increase, thereby increasing the air volume flowing through the branch.

7. The variable frequency cabinet temperature control and front compartment positive pressure coordinated distribution system based on a fixed frequency dust removal air source according to claim 6, characterized in that, The controller performs multi-level discrete position control on the cylinder.

8. The variable frequency cabinet temperature control and front compartment positive pressure coordinated distribution system based on a fixed frequency dust removal air source according to claim 7, characterized in that, The multi-stage system consists of five stages, from stage one to stage five, corresponding to 0%, 25%, 50%, 75%, and 100% of the cylinder stroke, respectively. The corresponding opening states of the sealing door are: the sealing door is completely closed, the sealing door is slightly open, the sealing door is half open, the sealing door is mostly open, and the sealing door is fully open.

9. The variable frequency cabinet temperature control and front compartment positive pressure coordinated distribution system based on a fixed frequency dust removal air source according to claim 1, characterized in that, The controller supports both local automatic control mode and remote control mode.

10. A method for coordinated distribution of temperature control and positive pressure in a variable frequency cabinet based on a fixed-frequency dust removal air source, applied to the coordinated distribution system for temperature control and positive pressure in a variable frequency cabinet based on a fixed-frequency dust removal air source as described in any one of claims 1-9, characterized in that, The method includes: Acquire temperature monitoring data for each inverter cabinet area and positive pressure status monitoring data for the front compartment; Based on the temperature monitoring data, determine the temperature control requirements of each inverter cabinet area; Under the constraint of a constant total air volume provided by a fixed-frequency fan, control commands are generated for the air volume adjustment actuators on each variable frequency cabinet branch duct based on the temperature control requirements and the positive pressure state monitoring data. The control commands are executed to dynamically adjust the air volume ratio allocated to each inverter cabinet area and the front compartment, so as to simultaneously meet the temperature control requirements of the inverter cabinet and the positive pressure maintenance requirements of the front compartment.

11. The method for coordinated distribution of temperature control and positive pressure in the front compartment of a variable frequency cabinet based on a fixed-frequency dust removal air source, as described in claim 10, is characterized in that... The determination of temperature control requirements for each inverter cabinet area based on the temperature monitoring data includes: If the temperature in a certain inverter cabinet area is lower than the first preset threshold, it is determined that the area needs to enter a low-temperature insulation mode that mainly reduces air volume and starts heating. If the temperature in a certain inverter cabinet area is higher than the second preset threshold, it is determined that the area needs to enter a high-temperature heat dissipation mode that mainly increases airflow.

12. The method for coordinated distribution of temperature control and positive pressure in the front compartment of a variable frequency cabinet based on a fixed-frequency dust removal air source, as described in claim 10, is characterized in that... The step of generating control commands based on the temperature control requirements and the positive pressure monitoring data specifically includes: First, a first control command is generated based on the temperature control requirements to adjust the air volume distribution to meet the temperature requirements; After the temperature requirements of all frequency converter cabinet areas are met, if the positive pressure of the front compartment is insufficient based on the positive pressure status monitoring data, a second control command is generated. The second control command is used to adjust the air volume distribution to increase the air volume to the front compartment while maintaining the temperature of each frequency converter cabinet area within the limit.

13. The method for coordinated distribution of temperature control and positive pressure in the front compartment of a variable frequency cabinet based on a fixed-frequency dust removal air source, as described in claim 12, is characterized in that... The generation of the second control command includes: First, reduce the airflow in the branch circuits corresponding to the areas of the inverter cabinets that are not currently in high-temperature heat dissipation mode; If the airflow is still insufficient, reduce the airflow of the branch corresponding to the inverter cabinet area that is currently in high-temperature heat dissipation mode, within the allowable temperature range.

14. The method for coordinated distribution of temperature control and positive pressure in the front compartment of a variable frequency cabinet based on a fixed-frequency dust removal air source, as described in claim 10, is characterized in that... The dynamic adjustment of the air volume ratio allocated to each inverter cabinet area and the front compartment is achieved by controlling the stroke of the cylinder. Specifically, increasing the air volume flowing to a certain inverter cabinet area is achieved by increasing the stroke of the corresponding cylinder, which results in a decrease in the air volume flowing to the front compartment; conversely, decreasing the air volume flowing to a certain inverter cabinet area is achieved by decreasing the stroke of the corresponding cylinder, which results in an increase in the air volume flowing to the front compartment.

15. The method for coordinated distribution of temperature control and positive pressure in the front compartment of a variable frequency cabinet based on a fixed-frequency dust removal air source according to claim 10, characterized in that, It also includes an alarm step: when the temperature in any inverter cabinet area continues to be abnormally high and exceeds the first time threshold, or when the positive pressure in the front compartment continues to be abnormally high and exceeds the second time threshold, an alarm message is generated and sent.

16. The method for coordinated distribution of temperature control and positive pressure in the front compartment of a variable frequency cabinet based on a fixed-frequency dust removal air source, as described in claim 10, is characterized in that... It also includes setting an adjustment dead zone: when the absolute value of the deviation between the temperature value monitored by the temperature sensor and the preset threshold is less than or equal to a dead zone threshold, the adjustment command to the air volume adjustment actuator is not triggered.

17. The method for coordinated distribution of temperature control and positive pressure in the front compartment of a variable frequency cabinet based on a fixed-frequency dust removal air source, as described in claim 16, is characterized in that... After the temperature value detected by the temperature sensor remains abnormal for more than a first preset delay time, an adjustment command is generated and executed; and after executing an adjustment command, at least a second preset interval time is waited before responding to the next temperature abnormality and generating a new adjustment command.

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