Intelligent positive pressure explosion-proof energy-saving cabinet and variable frequency control method thereof

Abstract

The application discloses an intelligent positive pressure explosion-proof energy-saving cabinet and a variable frequency control method thereof. The energy-saving cabinet comprises a positive pressure explosion-proof cabinet body, a main cavity and a secondary cavity which are isolated from each other, an intelligent control unit, a variable frequency driving unit, an Internet of Things communication unit and an intelligent power protection unit. The intelligent control unit is used for acquiring pressure safety state information of the main cavity, collecting load or power grid side operation parameters, and generating frequency control instructions and start-stop instructions according to a preset control strategy or the operation parameters. The variable frequency driving unit is used for receiving the frequency control instructions and the start-stop instructions, and driving a motor to operate based on the instructions. The Internet of Things communication unit is used for uploading data and issuing instructions between the intelligent control unit and a remote monitoring terminal. The intelligent power protection unit is used for comprehensively protecting and metering input electric energy, and uploading protection state information and electric energy data to the intelligent control unit or the remote monitoring terminal. The application realizes the cooperation of intrinsic safety and high-efficiency energy saving in a dangerous environment, and improves the intelligent level and energy efficiency management capability of the equipment.

Description

Technical Field

[0001] This invention relates to the field of industrial explosion-proof electrical equipment technology, specifically to an intelligent positive pressure explosion-proof energy-saving cabinet and its frequency conversion control method. Background Technology

[0002] In environments with explosive gases, such as those in the petroleum, chemical, pharmaceutical, and mining industries, the electrical control devices that drive equipment such as fans and pumps must meet strict explosion-proof requirements.

[0003] Currently, the main control solutions employed are explosion-proof control cabinets, traditional positive-pressure explosion-proof cabinets, or split-type solutions. Explosion-proof control cabinets rely on heavy outer shells for protection, resulting in bulky cabinets, poor heat dissipation, and the need for power outages and opening the cover during maintenance, impacting production continuity. Traditional positive-pressure explosion-proof cabinets create a positive pressure barrier by filling the cabinet with protective gas, but their control systems only perform basic ventilation and pressure maintenance functions, lacking deep integration with the intelligent control of internal loads, and failing to achieve coordinated operation of safety protection and energy-saving speed regulation. Split-type solutions place the frequency converter control equipment in a safe area, driving equipment in the hazardous area via long cables, resulting in large cable voltage drop losses, high initial investment, and the inability to implement local real-time monitoring. These technical solutions generally suffer from a disconnect between safety and energy saving; the explosion-proof safety system and the motor energy-saving control system are independent, making it difficult to achieve high energy efficiency while ensuring inherent safety. Furthermore, existing devices lack sufficient intelligence, lacking comprehensive perception capabilities of internal pressure status, motor operating parameters, and process variables, relying on manual inspections for maintenance, and experiencing delayed fault warnings. Furthermore, equipment commissioning and maintenance are complex; replacing motors or adjusting control parameters requires specialized personnel to enter hazardous areas, resulting in low efficiency and high risk. In terms of energy efficiency management, the lack of precise electricity metering and analysis methods makes it impossible to effectively assess energy-saving effects, hindering refined energy management. These deficiencies make it difficult for electrical control devices in hazardous environments to simultaneously ensure inherent safety and operational efficiency, necessitating technological integration to address the synergy between safety protection and energy-saving control.

[0004] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0005] In view of this, the present invention provides an intelligent positive pressure explosion-proof energy-saving cabinet and its frequency conversion control method, which solves the problem of the separation between safety protection and energy-saving control, realizes the synergy of inherent safety and high-efficiency energy saving in hazardous environments, and improves the intelligence level and energy efficiency management capability of the equipment.

[0006] In a first aspect, the present invention provides an intelligent positive pressure explosion-proof energy-saving cabinet, comprising: The positive pressure explosion-proof enclosure includes a main chamber and a secondary chamber that are isolated from each other; The main cavity forms a positive pressure working chamber for accommodating user equipment. A positive pressure sensing system and a gas distribution system are installed inside the main cavity. The positive pressure sensing system is used to monitor the internal pressure of the main cavity. The gas distribution system is used to uniformly distribute protective gas into the main cavity. The secondary chamber constitutes an explosion-proof chamber or increased safety chamber for accommodating control components; an automatic control system, a ventilation system, and an alarm system are installed within the secondary chamber; the automatic control system is electrically connected to the positive pressure sensing system, the ventilation system, and the alarm system respectively; the ventilation system includes an inlet control valve and an exhaust control valve; the inlet control valve is connected to an inlet port on the positive pressure explosion-proof cabinet via an inlet pipe; the exhaust control valve is connected to an exhaust port on the positive pressure explosion-proof cabinet via an exhaust pipe; the automatic control system is used to control the opening and closing of the inlet control valve and the exhaust control valve according to the pressure value monitored by the positive pressure sensing system, so as to perform gas replacement and maintain a safe positive pressure in the main chamber, and trigger the alarm system when the pressure is abnormal; An intelligent control unit is located in the secondary cavity and is communicatively connected to the automatic control system. It is used to obtain pressure safety status information of the main cavity from the automatic control system. The intelligent control unit is also connected to a sensor located in the main cavity or on the load side through an explosion-proof terminal block or an isolated signal converter. It is used to collect operating parameters of the load or the power grid side and generate frequency control commands and start / stop commands according to a preset control strategy or the operating parameters. A variable frequency drive unit is disposed in the main cavity and is connected to the main power supply, the drive motor and the intelligent control unit respectively. It is used to receive frequency control commands and start / stop commands from the intelligent control unit and drive the motor to run based on the commands. An Internet of Things (IoT) communication unit is disposed within the sub-cavity and is communicatively connected to the intelligent control unit, for transmitting data and issuing commands between the intelligent control unit and the remote monitoring terminal; The intelligent power protection unit is connected in series with the input terminal of the main power supply and connected to the intelligent control unit or the Internet of Things (IoT) communication unit. It is used to comprehensively protect and meter the input power, and upload the protection status information and power data to the intelligent control unit or to the remote monitoring terminal through the IoT communication unit.

[0007] Secondly, this invention provides a frequency conversion control method for an intelligent positive pressure explosion-proof energy-saving cabinet, applicable to intelligent positive pressure explosion-proof energy-saving cabinets, comprising the following steps: S1. The system is powered on. The automatic control system executes the ventilation procedure and continuously monitors the pressure in the main chamber. The intelligent control unit initializes and obtains the pressure status flag from the automatic control system. S2. When a start command is received, the intelligent control unit checks the safety interlock conditions. If the pressure status indicator shows that it is safe and the ventilation process has been completed, it proceeds to S3; otherwise, it prohibits start-up and triggers an alarm. S3. The intelligent control unit sends generator parameters to the frequency converter drive unit and triggers the frequency converter drive unit to perform motor parameter self-identification. S4. The intelligent control unit calculates the target frequency command based on the set control mode and the process parameters or load data collected from the sensors in real time, and sends the target frequency command and the running command to the frequency converter drive unit to drive the motor to run. S5. During operation, the intelligent control unit continuously monitors the pressure status information in the main cavity from the automatic system, the electrical and process operating parameters from the sensors, and the operating status of the frequency converter drive unit. S6. When abnormal pressure, electrical fault, or inverter fault is detected, the intelligent control unit immediately issues a shutdown command to the inverter drive unit and sends fault alarm information to the remote monitoring terminal through the Internet of Things communication unit.

[0008] As can be seen from the above, the intelligent positive pressure explosion-proof energy-saving cabinet and its frequency conversion control method provided in this application solve the problem of the separation between safety protection and energy-saving control by integrating the positive pressure explosion-proof cabinet, intelligent control unit and frequency conversion drive unit, etc., realize the synergy of inherent safety and high-efficiency energy saving in dangerous environments, and improve the intelligence level and energy efficiency management capability of the equipment. Attached Figure Description

[0009] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0010] Figure 1 This is a structural frame diagram of an intelligent positive pressure explosion-proof energy-saving cabinet according to an embodiment of the present invention; Figure 2 This is a flowchart illustrating an intelligent positive pressure explosion-proof energy-saving cabinet and its frequency conversion control method according to an embodiment of the present invention. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0012] Traditional explosion-proof control cabinets suffer from limitations such as bulkiness, poor heat dissipation, and the need for power outages for maintenance; traditional positive-pressure explosion-proof cabinets lack deep integration and safety interlocks with internal process controls, making energy-saving speed regulation impossible; and split-type solutions face problems such as high cable loss, high investment, and insufficient local monitoring. These solutions generally suffer from a disconnect between safety and energy conservation, low levels of intelligence, inconvenient debugging and maintenance, and a lack of energy efficiency assessment.

[0013] In this regard, such as Figure 1 As shown, this application proposes an intelligent positive pressure explosion-proof energy-saving cabinet, which aims to solve the above problems by deeply integrating positive pressure explosion protection, variable frequency speed regulation, Internet of Things monitoring and intelligent power management functions.

[0014] A positive-pressure explosion-proof enclosure is a device used to safely house electrical equipment in hazardous environments. Its interior is physically separated into a main chamber and a secondary chamber. The main chamber is designed as a positive-pressure working chamber to house non-explosion-proof user equipment, preventing the entry of explosive gases by maintaining an internal pressure higher than the external ambient pressure. The secondary chamber is designed as an explosion-proof or increased-safety chamber to house control components, ensuring the safe operation of the control system.

[0015] A positive pressure sensing system is configured inside the main cavity, and its function is to monitor the gas pressure inside the main cavity in real time. By feeding the pressure data back to the automatic control system, the positive pressure sensing system provides the basic data for maintaining a safe positive pressure in the main cavity.

[0016] A gas distribution system is configured within the main chamber, and its function is to evenly distribute protective gas (such as clean air or inert gas) throughout the main chamber. This ensures that explosive gases within the main chamber can be effectively displaced and a uniform positive pressure environment is maintained.

[0017] The automatic control system, located in the secondary chamber, is the core control component for the safe operation of the positive pressure explosion-proof enclosure. Its main function is to control the opening and closing of the intake and exhaust control valves in the ventilation system based on the pressure value monitored by the positive pressure sensor system, thereby executing the gas replacement procedure and maintaining a safe positive pressure within the main chamber. When abnormal pressure occurs, the system will also trigger an alarm.

[0018] The intelligent control unit, located in the secondary chamber, serves as the intelligent decision-making center for the entire intelligent positive pressure explosion-proof energy-saving cabinet. It communicates with the automatic control system to obtain pressure safety status information from the main chamber and connects to sensors located in the main chamber or on the load side via explosion-proof terminals or an isolated signal converter. Figure 1 (Not shown in the diagram) This unit collects operating parameters from the load or the power grid. Based on these parameters or preset control strategies, it generates frequency control commands and start / stop commands to achieve intelligent control of the drive motor.

[0019] The variable frequency drive unit is located within the main cavity. Its function is to receive frequency control commands and start / stop commands from the intelligent control unit and drive the motor according to these commands. Through variable frequency speed regulation, this unit can achieve efficient and energy-saving operation of the motor.

[0020] An IoT communication unit is configured within the secondary cavity, its function being to establish a communication link between the intelligent control unit and the remote monitoring terminal. Through this unit, operational data can be uploaded to the remote monitoring terminal, and commands issued by the remote monitoring terminal can also be transmitted to the intelligent control unit, thereby enabling remote monitoring and management.

[0021] The intelligent power protection unit is connected in series at the input of the main power supply. Its function is to provide comprehensive protection and metering of the input electrical energy. It can monitor power quality and provide protection in case of abnormal conditions such as overload and short circuit. At the same time, the unit can accurately measure electrical energy data and upload protection status information and electrical energy data to the intelligent control unit or to the remote monitoring terminal through the Internet of Things communication unit, providing data support for energy efficiency management.

[0022] The intelligent positive pressure explosion-proof energy-saving cabinet in this embodiment is designed to ensure safe operation in hazardous environments and to achieve intelligent control and energy saving of the equipment.

[0023] This intelligent positive pressure explosion-proof energy-saving cabinet includes a positive pressure explosion-proof cabinet body. The cabinet interior is divided into a main chamber and a secondary chamber, which are mutually isolated. The main chamber is designed as a working positive pressure chamber to house user equipment requiring explosion-proof protection, such as frequency converter drive units. To achieve positive pressure protection, a gas distribution system and a positive pressure sensing system are installed within the main chamber. The positive pressure sensing system can be a simple pressure switch that sends a signal when the pressure falls below a set value. The gas distribution system can consist of an air inlet and multiple dispersed nozzles to introduce and diffuse protective gas into the main chamber. The secondary chamber is designed as an explosion-proof or increased safety chamber to house control components with higher explosion-proof requirements, such as automatic control systems, intelligent control units, and IoT communication units. This isolation design ensures the safe coexistence of components with different explosion-proof ratings.

[0024] The automatic control system, located in the secondary chamber, is the core of the positive pressure explosion-proof safety system. This system is electrically connected to the positive pressure sensing system, the ventilation system, and the alarm system. The ventilation system includes an intake control valve and an exhaust control valve, which are connected to the intake and exhaust ports on the positive pressure explosion-proof enclosure via intake and exhaust pipes, respectively. The automatic control system controls the opening and closing of the intake and exhaust control valves based on the pressure value monitored by the positive pressure sensing system. For example, before startup, the automatic control system can pre-purge by opening the intake and exhaust control valves to ensure that there is no explosive gas in the main chamber. During normal operation, the automatic control system can maintain a safe positive pressure in the main chamber simply by controlling the opening of the intake control valve. When an abnormal pressure is detected in the main chamber, the automatic control system will trigger the alarm system, for example, by issuing a warning through an audible and visual alarm.

[0025] An intelligent control unit is located within the secondary chamber and communicates with the automatic control system. This control unit obtains pressure safety status information from the automatic control system for the main chamber, such as by reading a digital or analog signal to determine if the main chamber pressure is within a safe range. Furthermore, the intelligent control unit connects to sensors located within the main chamber or on the load side via explosion-proof terminals or isolated signal converters. These sensors can be used to collect load operating parameters, such as motor speed and load current, or grid-side operating parameters, such as voltage and frequency. Based on these collected operating parameters or a preset control strategy, the intelligent control unit generates frequency control commands and start / stop commands. For example, a simple open-loop control strategy can be used to issue start commands and fixed-frequency commands at specific times.

[0026] The variable frequency drive unit is located within the main chamber and is connected to the main power supply, the drive motor, and the intelligent control unit. This unit receives frequency control commands and start / stop commands from the intelligent control unit. For example, upon receiving a start command and a 50Hz frequency command, the unit will drive the motor to operate at a 50Hz frequency. By adjusting the output frequency and voltage, the unit can control the motor's speed and output power, thereby achieving speed control of the load.

[0027] An IoT communication unit is located within the secondary cavity and communicates with the intelligent control unit. This IoT communication unit is used for data uploading and command issuance between the intelligent control unit and the remote monitoring terminal. For example, the intelligent control unit can upload collected operating parameters, equipment status, and other data to the remote monitoring terminal via the IoT communication unit for operator viewing. Simultaneously, the remote monitoring terminal can also issue start, stop, or frequency adjustment commands to the intelligent control unit via the IoT communication unit. The remote monitoring terminal can be a simple local display screen or a computer connected to a network.

[0028] The intelligent power protection unit is connected in series at the input of the main power supply and linked to an intelligent control unit or an IoT communication unit. This unit provides comprehensive protection and metering of the input electrical energy. For example, it can monitor the current and voltage of the main power supply and provide protection in case of overcurrent or undervoltage. Simultaneously, the unit can also meter the real-time power and cumulative energy consumption of the equipment. This protection status information and energy data can be uploaded to the intelligent control unit for local processing, or uploaded to a remote monitoring terminal via the IoT communication unit for remote monitoring and management.

[0029] This embodiment of the intelligent positive pressure explosion-proof energy-saving cabinet effectively solves the problems of traditional solutions, such as the separation of safety and energy saving, low level of intelligence, inconvenient maintenance, and lack of energy efficiency assessment, by deeply integrating the positive pressure explosion-proof cabinet body, automatic control system, intelligent control unit, frequency conversion drive unit, Internet of Things communication unit, and intelligent power protection unit. While ensuring inherent safety in hazardous environments, this solution achieves intelligent frequency conversion speed regulation and high-efficiency energy-saving operation of the drive motor, and provides comprehensive electrical protection, remote monitoring, and data management capabilities, thereby improving the safety, intelligence level, and economic benefits of equipment operation.

[0030] This application further proposes a safety interlock mechanism between the intelligent control unit and the automatic control system. This safety interlock mechanism is a logical or physical protection measure to ensure that the system can only perform critical operations after specific safety conditions are met. Its core function is to prevent the frequency converter drive unit from starting if the main cavity's safety status is not confirmed, thereby avoiding potential explosion hazards. This mechanism can be implemented through software logic, i.e., the intelligent control unit sets conditional judgments in its internal program, or it can be implemented through hardware circuitry, such as through relays or a safety programmable logic controller (PLC) for physical signal interlocking.

[0031] Specifically, the intelligent control unit is only authorized to send a start command to the variable frequency drive unit when it receives a confirmation signal from the automatic control system indicating that the main chamber pressure is normal and the ventilation process is complete. This confirmation signal, generated by the automatic control system and sent to the intelligent control unit, explicitly indicates that the pressure within the main chamber has reached and been maintained within the safe positive pressure range, and that the necessary ventilation process has been completed according to the preset procedure. This signal is the automatic control system's authoritative judgment on the safe state of the main chamber environment and is a prerequisite for the intelligent control unit to perform subsequent operations. This means that the intelligent control unit is only authorized to send a start command to the variable frequency drive unit after receiving the confirmation signal from the automatic control system. Before this, even if the internal operating logic of the intelligent control unit indicates that it can start, it will be prevented by this safety interlock mechanism.

[0032] Furthermore, if the confirmation signal fails during operation, the intelligent control unit immediately issues a stop command to the variable frequency drive unit. Confirmation signal failure refers to any situation during equipment operation where the automatic control system detects that the main chamber pressure is below the safety threshold, the ventilation process is interrupted or incomplete, or communication between the automatic control system and the intelligent control unit is interrupted, resulting in the main chamber's safety status no longer meeting requirements. In such cases, the automatic control system will no longer issue or will withdraw the confirmation signal. When the confirmation signal fails, the intelligent control unit will respond immediately, sending an emergency stop command to the variable frequency drive unit, forcing the drive motor to stop. This immediate response mechanism aims to minimize the risks caused by positive pressure environment failures and ensure the safety of equipment and personnel.

[0033] Through the above technical solution, a safety interlock mechanism is established between the intelligent control unit and the automatic control system. This ensures that the intelligent control unit must obtain confirmation signals from the automatic control system confirming that the main chamber pressure is normal and the ventilation process is complete before starting the variable frequency drive unit. This effectively avoids the risk of the variable frequency drive unit being mistakenly started when the main chamber environment of the positive pressure explosion-proof cabinet does not meet safety requirements. Furthermore, during equipment operation, if the safety confirmation signal of the main chamber fails, the intelligent control unit can immediately issue a shutdown command, forcing the equipment to stop operating and thus promptly eliminating potential safety hazards. This dual-protection mechanism significantly improves the overall operational safety of the intelligent positive pressure explosion-proof energy-saving cabinet, ensuring the safety of personnel and equipment in hazardous environments, preventing explosions caused by environmental anomalies, and providing more reliable protection for industrial production.

[0034] This application further proposes that the sensor includes at least one of the following: a current transformer and a voltage transformer for acquiring motor parameters, a pressure sensor or a flow meter for acquiring process parameters, and a force sensor for acquiring equipment mechanical load.

[0035] Specifically, current transformers and voltage transformers are used to collect motor parameters. A current transformer is a specialized instrument that proportionally transforms a large current into a smaller current, used to monitor the magnitude and waveform of the current flowing through the motor in real time to analyze the motor's load, operating efficiency, and abnormal conditions. A voltage transformer is a specialized instrument that proportionally transforms a high voltage into a low voltage, used to monitor the voltage applied across the motor in real time. Combined with current data, key electrical parameters such as the motor's input power and power factor can be calculated. These transformers are typically installed on the power line between the frequency converter drive unit and the motor, and communicate with the intelligent control unit through explosion-proof terminals or isolated signal converters to ensure safe data transmission in an explosion-proof environment.

[0036] Pressure sensors or flow meters are used to collect process parameters. Pressure sensors detect pressure signals and convert them into usable output signals for real-time monitoring of fluid pressure in pipes, containers, or systems to assess pump operating status and system load. Flow meters measure the flow rate of fluids (liquids, gases, steam), monitoring the fluid velocity or instantaneous flow rate and cumulative flow in pipes in real time, such as monitoring air volume or the flow rate of transported media. These sensors directly reflect the actual needs and operating conditions of the process. Their output signals are typically electrical signals, transmitted to the intelligent control unit via an explosion-proof isolation module, providing crucial feedback data for the intelligent control unit to perform process-based closed-loop control.

[0037] Force sensors, used to collect data on the mechanical load of equipment, are devices that convert the magnitude of force into an electrical signal output. They are used to monitor the actual mechanical load of motor-driven equipment in real time, such as measuring the torque, tension, or pressure experienced by conveyor belts, mixers, or fans. Using the load data acquired by the force sensor, the intelligent control unit can more accurately determine whether the motor is at its optimal operating point or whether there are overloads or underloads, thereby optimizing the output of the variable frequency drive unit. Force sensors are typically installed at critical points in the mechanical transmission chain, and their signals must be transmitted to the intelligent control unit after explosion-proof isolation treatment.

[0038] Through the aforementioned technical solutions, the intelligent control unit can acquire more comprehensive and accurate operational data. Specifically, current transformers and voltage transformers provide real-time electrical parameters of the motor, enabling the intelligent control unit to accurately assess the motor's load, efficiency, and health status. This allows for refined frequency control based on the motor's actual operating state, preventing the motor from operating at suboptimal efficiency points and effectively reducing energy consumption. Pressure sensors or flow meters directly reflect the actual needs of the process. For example, by monitoring pipeline pressure or fluid flow, the intelligent control unit can dynamically adjust the output frequency of the variable frequency drive unit based on real-time changes in process parameters to maintain process parameter stability and avoid energy waste and product quality fluctuations caused by over-driving or under-driving. Furthermore, the application of force sensors allows the intelligent control unit to directly sense the mechanical load of the equipment, thereby adjusting the motor speed in a timely manner when the load changes. This ensures that the motor always operates at the efficiency best matched to the current load, further improving the system's energy-saving effect and operational stability. These multi-dimensional, high-precision sensor data collectively provide strong data support for the intelligent control unit, enabling it to execute more advanced control strategies, such as process closed-loop PID control. This significantly improves the overall system's intelligence level, operational efficiency, and energy-saving effect while ensuring explosion-proof safety.

[0039] This application proposes an improved solution, wherein the variable frequency drive unit is designed as a vector control variable frequency drive with motor parameter self-identification function. Simultaneously, the intelligent control unit is also used to receive motor nameplate parameters via the IoT communication unit and send them to the variable frequency drive unit during the initial commissioning of the equipment or when the motor is replaced, thereby triggering the variable frequency drive unit to perform a motor parameter self-identification operation.

[0040] Specifically, the variable frequency drive unit employs vector control technology, an advanced motor control method. By decomposing the stator current of an AC motor into excitation and torque components, it achieves independent control of the motor's flux and torque, thereby enabling the AC motor to achieve excellent dynamic performance and a wide speed range similar to that of a DC motor. This control method significantly improves the motor's operating efficiency, response speed, and control accuracy. Furthermore, the variable frequency drive unit integrates a motor parameter self-identification function. This means that it can automatically measure and identify key electrical parameters of the motor, such as stator resistance, rotor resistance, stator leakage inductance, rotor leakage inductance, and mutual inductance, without disassembling the motor, using internal algorithms. Typically, the inverter injects specific test signals into the motor when it is stationary or running at low speed and calculates these parameters based on the motor's response. This function greatly simplifies the inverter's commissioning process and ensures the accuracy of the motor model parameters upon which the control algorithm relies.

[0041] Based on this, the intelligent control unit acts as a coordinator in this scenario. It not only receives instructions from the remote monitoring terminal but also translates these instructions into specific operations for the variable frequency drive unit. When the equipment is first put into operation or a new drive motor is replaced, the intelligent control unit interacts with the remote monitoring terminal via the IoT communication unit, receiving basic parameters such as rated power, rated voltage, rated current, rated frequency, and rated speed recorded on the motor nameplate. These motor nameplate parameters are prerequisites or auxiliary information for activating the motor parameter self-identification function. After receiving these parameters, the intelligent control unit sends them to the variable frequency drive unit. Upon receiving these parameters and the trigger command from the intelligent control unit, the variable frequency drive unit activates its built-in motor parameter self-identification program, automatically completing the measurement and storage of precise electrical parameters of the motor.

[0042] Through the above technical solution, the variable frequency drive unit is designed as a vector control variable frequency drive with motor parameter self-identification function. The intelligent control unit coordinates its self-identification process via the IoT communication unit at specific times (such as initial commissioning or motor replacement), effectively solving the problems of complex and error-prone motor parameter configuration in traditional variable frequency drive commissioning. Vector control technology ensures high-performance and high-efficiency motor operation, while the motor parameter self-identification function guarantees the accuracy of the motor model parameters upon which the vector control algorithm relies, thereby avoiding performance degradation and energy loss due to parameter mismatch. Furthermore, through the collaboration of the intelligent control unit and the IoT communication unit, remote configuration and self-identification triggering of motor parameters are realized, greatly simplifying on-site commissioning and improving system deployment efficiency and maintenance convenience. This not only enhances the overall control accuracy and energy-saving effect of the intelligent positive pressure explosion-proof energy-saving cabinet but also strengthens the system's intelligence and remote management capabilities, ensuring stable and efficient operation of the equipment under various working conditions.

[0043] This application further proposes that the IoT communication unit supports at least one of 4G, 5G, NB-IoT or Ethernet communication protocols; the remote monitoring terminal is a mobile APP or a cloud server platform.

[0044] Specifically, the IoT communication unit is a key component for connecting the intelligent positive-pressure explosion-proof energy-saving cabinet to external networks. It supports multiple communication protocols to ensure flexible, reliable, and wide-coverage data transmission. For example, in scenarios requiring high-speed, high-bandwidth data transmission, such as real-time video monitoring or uploading large amounts of sensor data, the IoT communication unit can integrate a 4G or 5G cellular module, accessing the operator's network via a SIM card. For low-power, wide-coverage, and small-data-volume transmission scenarios, such as equipment status monitoring or periodic data reporting, the IoT communication unit can integrate an NB-IoT module, leveraging its low-power characteristics to extend device battery life (if applicable) and reduce communication costs. Furthermore, in industrial sites with wired network infrastructure, the IoT communication unit can integrate an Ethernet interface, connecting to a local area network or industrial Ethernet via standard Ethernet cables, providing a stable connection with high bandwidth and low latency.

[0045] Meanwhile, the remote monitoring terminal serves as the interface or platform for users or management systems to interact with the intelligent positive pressure explosion-proof energy-saving cabinet. It is used to receive equipment data, send control commands, and view alarm information. This can be represented by a mobile app or a cloud server platform. The mobile app provides a mobile, user-friendly interface, allowing users to monitor and operate the cabinet anytime, anywhere via smartphones or tablets. This app can be developed for iOS or Android, interacting with the cloud server platform or directly with IoT communication units via APIs. The cloud server platform provides centralized data storage, processing, analysis, and visualization capabilities, supporting advanced functions such as multi-device management, historical data querying, and report generation. This platform can be built on web technology, accessible through a browser, or provide API interfaces for third-party system integration, typically offering high availability, scalability, and security.

[0046] Through the aforementioned technical solutions, the IoT communication unit, supporting multiple mainstream communication protocols such as 4G, 5G, NB-IoT, and Ethernet, significantly enhances the deployment flexibility and adaptability of the intelligent positive pressure explosion-proof energy-saving cabinet in different industrial environments, ensuring the reliability and real-time performance of data transmission. Whether requiring high-speed wireless transmission, low-power wide-area coverage, or stable wired connections, the system provides effective communication guarantees. Simultaneously, designing the remote monitoring terminal as a mobile APP or cloud server platform can meet the monitoring and management needs of different users. The mobile APP provides a convenient mobile operating experience, enabling users to monitor equipment status and perform remote control anytime, anywhere; while the cloud server platform provides powerful data storage, analysis, and management capabilities, facilitating centralized and professional equipment operation and maintenance and energy efficiency analysis. This combination of multi-protocol support and multi-terminal selection significantly improves the remote monitoring and management efficiency of the intelligent positive pressure explosion-proof energy-saving cabinet, optimizes the user experience, and provides a solid and reliable communication foundation for data uploading and command issuance between the intelligent control unit and the intelligent power protection unit.

[0047] This application further proposes that the preset control strategy includes a process closed-loop PID control algorithm. The intelligent control unit, in process closed-loop PID control mode, adjusts the frequency control command in real time through PID calculation based on the deviation between the measured and setpoint values ​​of the process parameters fed back by the pressure sensor or flow meter, in order to maintain constant process parameters.

[0048] Among them, the process closed-loop PID control algorithm is a feedback control algorithm widely used in the field of industrial control. Its core lies in generating the control output by calculating the weighted sum of the proportional, integral, and derivative components. In this application, this algorithm is used as a high-level control strategy preset within the intelligent control unit, and its logic module is integrated into the firmware or software of the intelligent control unit. When the system needs to precisely control specific process parameters, the intelligent control unit will activate this PID control mode and perform calculations based on the pre-configured PID parameters (such as the proportional coefficient Kp, integral time Ti, and derivative time Td).

[0049] Specifically, the intelligent control unit continuously receives real-time process parameter measurements from pressure sensors or flow meters via explosion-proof terminals or isolated signal converters. These sensors convert physical quantities (such as pressure and flow) into electrical signals and transmit them to the intelligent control unit. The intelligent control unit compares the received real-time measurements with the target value (i.e., the setpoint) set by the operator or the host system, calculating the current deviation. This deviation is then input into the built-in PID algorithm module, which performs proportional, integral, and derivative operations based on preset PID parameters to generate a dynamic control quantity. This control quantity is then converted into the frequency control command required by the variable frequency drive unit. For example, if the PID calculation indicates that the current process parameter is lower than the setpoint, requiring an increase in motor speed to increase output, the intelligent control unit will generate a higher frequency command and send it to the variable frequency drive unit. This process is continuous and real-time; the intelligent control unit repeats the above steps at preset sampling and control cycles (e.g., every tens or hundreds of milliseconds), thereby achieving dynamic and precise adjustment of the frequency control command.

[0050] Through the above technical solution, the intelligent control unit can utilize a closed-loop PID control algorithm to perform precise PID calculations based on the deviation between the measured and setpoint values ​​of process parameters fed back in real time by pressure sensors or flow meters, and adjust the frequency control commands of the variable frequency drive unit in real time. This closed-loop feedback mechanism enables the system to dynamically respond to various disturbances in the process, such as load changes and fluctuations in media characteristics, thereby accurately maintaining the process parameters (such as pressure or flow) in the main chamber or on the load side at preset constant values. This not only significantly improves the stability and control accuracy of the process, avoiding the impact of parameter fluctuations on production efficiency and product quality, but also, by optimizing the motor operating frequency, ensures that the drive motor always operates near its optimal efficiency point, further enhancing the energy-saving effect of the entire intelligent positive pressure explosion-proof energy-saving cabinet.

[0051] This application further proposes that the intelligent positive pressure explosion-proof energy-saving cabinet also includes a main power contactor. This main power contactor is an electromagnetic switching device used to connect or disconnect the main circuit. It typically consists of a coil, a contact system, and an arc-extinguishing device. Its rated voltage, current, and breaking capacity should match the power rating and main power characteristics of the frequency converter drive unit and comply with the electrical equipment selection requirements for explosion-proof areas. The main power contactor is connected in series in the main power input circuit of the frequency converter drive unit. This connection ensures that the main power contactor can directly control the overall power supply of the frequency converter drive unit. When the contactor is disconnected, the frequency converter drive unit will completely lose power and cannot continue to operate, thus achieving complete shutdown and safety isolation. Furthermore, the main power contactor is electrically connected to the automatic control system, enabling the automatic control system to remotely operate the contactor by controlling the on / off state of its coil, thereby achieving emergency power-off control of the frequency converter drive unit. Specifically, the automatic control system is used to disconnect the main power contactor to cut off the total power input of the frequency converter drive unit when the main chamber pressure is detected to be lower than a preset minimum safety threshold. The automatic control system contains a pressure comparison module or logic judgment unit. When the real-time pressure value falls below a preset minimum safety threshold, this logic unit triggers an output signal, which directly controls the coil of the main power contactor to disconnect from the power supply. The preset minimum safety threshold is usually strictly set according to explosion-proof standards, equipment type, and application environment.

[0052] Through the above technical solution, when the main chamber pressure drops below the preset minimum safety threshold, the automatic control system can immediately and forcibly disconnect the main power contactor, thereby physically cutting off the total power input to the frequency converter drive unit. This provides a direct, hard-connected hardware-level safety interlock mechanism, which, compared to relying solely on the intelligent control unit to issue shutdown commands or alarm prompts, can more quickly and thoroughly eliminate potential electrical sparks or overheating risks, minimizing the probability of explosion in hazardous environments. This solution provides an additional, independent hardware safety protection layer for the intelligent positive pressure explosion-proof energy-saving cabinet, significantly improving the system's inherent safety protection capabilities and operational reliability, ensuring the safe operation of the equipment under extreme conditions.

[0053] like Figure 2 As shown, this application further proposes a frequency conversion control method for an intelligent positive pressure explosion-proof energy-saving cabinet. This method is applied to the aforementioned intelligent positive pressure explosion-proof energy-saving cabinet and specifically includes the following steps: S1. The system is powered on. The automatic control system executes the ventilation procedure and continuously monitors the pressure in the main chamber. The intelligent control unit initializes and obtains the pressure status flag from the automatic control system. S2. When a start command is received, the intelligent control unit checks the safety interlock conditions. If the pressure status indicator shows that it is safe and the ventilation process has been completed, it proceeds to S3; otherwise, it prohibits start-up and triggers an alarm. S3. The intelligent control unit sends generator parameters to the frequency converter drive unit and triggers the frequency converter drive unit to perform motor parameter self-identification. S4. The intelligent control unit calculates the target frequency command based on the set control mode and the process parameters or load data collected from the sensors in real time, and sends the target frequency command and the running command to the frequency converter drive unit to drive the motor to run. S5. During operation, the intelligent control unit continuously monitors the pressure status information in the main cavity from the automatic system, the electrical and process operating parameters from the sensors, and the operating status of the frequency converter drive unit. S6. When abnormal pressure, electrical fault, or inverter fault is detected, the intelligent control unit immediately issues a shutdown command to the inverter drive unit and sends fault alarm information to the remote monitoring terminal through the Internet of Things communication unit.

[0054] The specific implementation of the above method is as follows: In step S1, "system power-on" refers to connecting the intelligent positive pressure explosion-proof energy-saving cabinet to the main power supply and starting power. At this time, "the automatic control system executes the ventilation procedure" means that the automatic control system, by controlling the opening and closing of the intake and exhaust control valves, introduces clean protective gas to purge the main cavity, ensuring that the concentration of flammable and explosive gases inside the main cavity drops below a safe level. This process usually lasts for a period of time to meet explosion-proof requirements. "Continuously monitoring the pressure inside the main cavity" means that the automatic control system uses a positive pressure sensing system to obtain the pressure value inside the main cavity in real time and compares it with the preset safe positive pressure range to ensure that the main cavity is always maintained at a safe positive pressure state higher than the external atmospheric pressure, preventing the intrusion of external dangerous gases. "Intelligent control unit initialization" means that after receiving power, the intelligent control unit performs a series of preparatory work, such as self-testing, loading the operating system and application programs, and configuring the communication interface, to enter an operable state. "Obtaining pressure status flags from the automatic control system" means that the intelligent control unit receives key safety status information, such as whether the main cavity pressure is normal and whether the ventilation procedure is completed, through the communication interface with the automatic control system. This flag is a prerequisite for subsequent operations (such as starting the frequency converter drive unit).

[0055] In step S2, "receiving the start command" can originate from the local operation panel, a remote monitoring terminal (via an IoT communication unit), or a higher-level control system. "The intelligent control unit checks the safety interlock conditions" means that upon receiving the start command, the intelligent control unit will not execute it immediately but will first verify a series of preset safety conditions. The core of these conditions is "the pressure status indicator shows safety and the ventilation process is complete," confirming that the pressure inside the main chamber is within a safe positive pressure range and that sufficient ventilation has been completed, eliminating potential explosion risks. This safety interlock mechanism is crucial for ensuring the safe operation of the equipment in hazardous environments, preventing the equipment from being started under unsafe conditions. "Prohibiting start and triggering an alarm" means that if the safety interlock conditions are not met, the intelligent control unit will refuse to execute the start command and will issue a warning to the operator or remote monitoring terminal via an alarm system (e.g., audible and visual alarms, remote notification), indicating a safety hazard requiring manual intervention or troubleshooting.

[0056] In step S3, "the intelligent control unit sends generator parameters to the frequency converter drive unit" means that the intelligent control unit sends the basic nameplate parameters of the connected motor, such as rated power, rated voltage, rated current, rated frequency, and number of pole pairs, to the frequency converter drive unit through the communication interface. These parameters are the basis for the precise control of the frequency converter drive unit. "Triggering the frequency converter drive unit to perform motor parameter self-identification" means that the intelligent control unit sends a command to enable the frequency converter drive unit to automatically measure and calculate the equivalent circuit parameters of the motor (such as stator resistance, rotor resistance, leakage inductance, etc.) by applying specific voltage and current signals to the motor under no-load or light-load conditions. This self-identification function is particularly important for vector control frequency converters, as it can significantly improve the control accuracy and operating efficiency of the frequency converter for the motor, ensuring that the motor can obtain optimal drive performance under various operating conditions.

[0057] In step S4, the "set control mode" can include various modes such as constant speed control, multi-speed control, process closed-loop PID control, and remote optimization control, which the user can select according to actual process requirements. "Process parameters or load data collected in real time from sensors" refers to the real-time data obtained by the intelligent control unit from sensors (such as pressure sensors, flow meters, current transformers, voltage transformers, force sensors, etc.) located in the main cavity or on the load side through explosion-proof terminals or isolated signal converters. This data reflects the current operating status of the equipment and process requirements. "Calculating the target frequency command" means that the intelligent control unit, based on the selected control mode and the real-time collected data, uses corresponding control algorithms (such as PID algorithms, fuzzy control algorithms, etc.) to calculate the motor drive frequency that the variable frequency drive unit should output. For example, in PID control mode, the frequency will be adjusted according to the deviation of process parameters. "Sending the target frequency command and operating command to the variable frequency drive unit" means that the intelligent control unit sends the calculated frequency command and operating commands such as start / stop and forward / reverse rotation to the variable frequency drive unit through the communication interface, so that it drives the motor according to the commands.

[0058] In step S5, "continuous monitoring" refers to the intelligent control unit continuously acquiring data from multiple sources during motor operation. "Pressure status information within the main chamber from the automatic control system" ensures continuous safety in the explosion-proof environment. "Electrical and process operating parameters from sensors" include motor current, voltage, power, speed, process pressure, flow rate, and temperature; this data is used to evaluate equipment performance, diagnose faults, and perform energy-saving analysis. "Operating status of the variable frequency drive unit" includes the inverter's output frequency, output current, output voltage, internal temperature, and fault codes; this information helps determine the inverter's own operating condition. Through multi-dimensional data monitoring, the intelligent control unit can comprehensively grasp the system's operating status.

[0059] In step S6, "pressure anomaly" refers to the pressure inside the main chamber being lower than the safety threshold or exceeding the allowable range, indicating a potential failure of the explosion-proof environment. "Electrical fault" may include motor overload, short circuit, phase loss, overvoltage, undervoltage, etc., which can endanger equipment and personnel safety. "Inverter fault" refers to internal anomalies within the inverter drive unit itself, such as overcurrent, overvoltage, overheating, or IGBT failure. "The intelligent control unit immediately issues a stop command to the inverter drive unit" is an emergency safety measure designed to quickly cut off the motor power supply to prevent the fault from escalating or causing secondary accidents. "Sending fault alarm information to the remote monitoring terminal via the IoT communication unit" ensures that managers can promptly obtain equipment status information, perform remote diagnosis and scheduling maintenance, and improve fault response efficiency.

[0060] Through the above technical solution, this application provides a systematic variable frequency control method. In the operation of the intelligent positive pressure explosion-proof energy-saving cabinet, this method first ensures the explosion-proof safety status of the main cavity through an automatic control system, and the intelligent control unit performs initialization and safety interlock checks, effectively preventing the equipment from starting under unsafe conditions and greatly improving the inherent safety of the system. Secondly, by sending generator parameters to the variable frequency drive unit through the intelligent control unit and triggering self-identification, optimal matching between the frequency converter and the motor is ensured, improving drive efficiency and control accuracy. During operation, the intelligent control unit continuously monitors pressure, electrical, and process parameters from multiple dimensions and can quickly respond to abnormal situations, promptly shutting down the machine and issuing alarms, thereby ensuring stable operation of the equipment and personnel safety under complex working conditions. Furthermore, combined with an IoT communication unit, remote monitoring and fault diagnosis are realized, significantly improving the system's intelligent management level and operation and maintenance efficiency, ultimately achieving an organic combination of explosion-proof safety, energy efficiency, and intelligent control.

[0061] This application further proposes that the control mode includes at least one of the following: local constant speed or multi-speed control mode; process closed-loop PID control mode, wherein the intelligent control unit adjusts the frequency control command in real time through PID calculation based on the deviation between the measured value and the set value of the process parameters fed back by the pressure sensor or flow meter, so as to maintain the constant process parameters; remote optimization mode, wherein the intelligent control unit uploads the operating data to the cloud server through the Internet of Things communication unit, and receives the optimized frequency command or operating curve issued by the cloud server for execution.

[0062] Specifically, local constant speed or multi-speed control mode is a basic motor operation control method suitable for simple operating conditions where speed or flow requirements are relatively fixed, or where switching between a few preset speed points is only required. In this mode, the intelligent control unit pre-stores one or more fixed frequency setpoints. When constant speed mode is selected, the intelligent control unit directly sends a constant frequency control command to the variable frequency drive unit, causing the motor to run at a fixed speed. When multi-speed mode is selected, the intelligent control unit can switch between different preset frequency setpoints based on external input signals (such as commands from the operation panel), preset time programs, or simple logical judgments, and adjust the frequency control command sent to the variable frequency drive unit accordingly. This mode is simple and reliable to implement, and can meet the basic requirements for stable operation in many industrial applications.

[0063] The closed-loop PID control mode is a more precise control strategy designed to maintain key process parameters (such as pressure and flow rate) precisely at their setpoints through real-time feedback and adjustment. In this mode, the intelligent control unit receives real-time process parameter measurements from sensors such as pressure sensors or flow meters. Internally, the intelligent control unit runs a PID (Proportional-Integral-Derivative) control algorithm, comparing the current measurement with the preset process parameter setpoints and calculating the deviation. Based on this deviation, the PID algorithm generates an adjustment variable, which the intelligent control unit converts into a corresponding frequency control command and sends to the variable frequency drive unit. The variable frequency drive unit adjusts the output frequency and speed of the drive motor according to this command, thereby changing the output of fans, pumps, or other actuators to eliminate the deviation in process parameters and stabilize them near the setpoints. PID parameters (such as the proportional coefficient Kp, integral time Ti, and derivative time Td) can be self-tuned online or manually optimized according to specific process characteristics to ensure the response speed and stability of the control system.

[0064] The remote optimization mode utilizes IoT and cloud computing technologies to achieve intelligent and remote management and optimization of equipment operation. In this mode, the intelligent control unit uploads various operational data of the intelligent positive pressure explosion-proof energy-saving cabinet, including motor operating parameters, process parameters, energy consumption data, and equipment status information, to a cloud server in real time via the IoT communication unit. The cloud server uses big data analytics, machine learning algorithms, or expert systems to deeply process and analyze this massive amount of data, combining it with historical operating data, production plans, energy prices, and other external information to generate more refined and optimized frequency commands or operating curves. These optimized commands or curves are then sent to the intelligent control unit via the IoT communication unit, which parses and converts them into frequency control commands executable by the frequency converter drive unit, thereby achieving remote intelligent optimized operation of the equipment. This mode not only enables energy efficiency optimization of a single device but also supports collaborative optimization between multiple devices, such as peak shaving and valley filling based on grid load conditions or dynamic adjustment of equipment operating strategies based on production scheduling, to maximize overall production efficiency and energy-saving effects.

[0065] Through the above technical solutions, the frequency conversion control method of this application can flexibly select the most suitable control strategy according to different industrial application scenarios and process requirements. Local constant speed or multi-speed control modes provide basic and stable operating options to meet the needs of simple operating conditions; the process closed-loop PID control mode achieves precise, real-time control of key process parameters, significantly improving process stability and reducing fluctuations, thereby optimizing product quality and energy consumption; the remote optimization mode introduces cloud intelligence, enabling the control strategy to be dynamically adjusted based on more comprehensive data and more complex algorithms, achieving deeper levels of energy saving and operational efficiency improvement, and supporting remote management and maintenance. These diverse and switchable control modes greatly enhance the adaptability, control accuracy, and energy efficiency of the intelligent positive pressure explosion-proof energy-saving cabinet, effectively solving the problem of limited system performance under a single control mode, and providing users with a more flexible, efficient, and intelligent frequency conversion control solution.

[0066] This application further proposes that an intelligent control unit or cloud server, based on the power data uploaded by the intelligent power protection unit, periodically calculates the cumulative power consumption, operating time and load characteristics of the frequency converter drive unit, calculates the actual energy saving and energy saving rate, and automatically generates an energy efficiency analysis report.

[0067] Specifically, the intelligent power protection unit is connected in series at the input of the main power supply. It is responsible for the comprehensive protection and metering of the input electrical energy, and uploads the collected electrical energy data to the intelligent control unit or to a remote monitoring terminal via the Internet of Things (IoT) communication unit. This electrical energy data includes, but is not limited to, instantaneous power, cumulative energy consumption, voltage, current, and power factor. The intelligent control unit or cloud server then uses this precise electrical energy data for subsequent energy efficiency analysis. The intelligent control unit, as the local processing core, can perform real-time or near real-time energy efficiency data processing; while the cloud server has more powerful storage and computing capabilities, enabling it to process large-scale, long-term energy efficiency data and perform more complex analyses.

[0068] Based on the acquired power data, the intelligent control unit or cloud server periodically compiles statistics on the operation data of the variable frequency drive unit. "Periodically" can be set according to actual needs, such as daily, weekly, or monthly. The statistics mainly include the cumulative power consumption, operating time, and load characteristics of the variable frequency drive unit. Cumulative power consumption is calculated based on the power data provided by the intelligent power protection unit; operating time can be accurately recorded by monitoring the start / stop status of the variable frequency drive unit or by issuing start / stop commands from the intelligent control unit; load characteristics are assessed by analyzing parameters such as current, voltage, and power during operation, combined with motor parameters, to evaluate the motor's load under different operating conditions, such as light load, heavy load, or variable load.

[0069] Subsequently, the intelligent control unit or cloud server calculates the actual energy savings and energy efficiency rate. The calculation of actual energy savings typically requires a baseline, which is the energy consumption required under the same operating conditions without variable frequency drive or using traditional control methods. This baseline can be established using historical data, theoretical models, or preset parameters. The actual energy savings are the difference between the baseline energy consumption and the actual energy consumption of the variable frequency drive unit. The energy efficiency rate is the ratio of the actual energy savings to the baseline energy consumption, usually expressed as a percentage. These calculation results intuitively reflect the economic benefits brought by variable frequency drive technology.

[0070] Ultimately, the system can automatically generate an energy efficiency analysis report. This report summarizes the aforementioned statistical data and calculation results, presenting them in a clear and structured format, such as charts, graphs, or text descriptions. The report content may include key indicators such as cumulative power consumption trends, operating time distribution, load characteristic analysis, actual energy savings, and energy efficiency rates. This report can be accessed by users through remote monitoring terminals (such as mobile apps or cloud server platforms), providing them with a comprehensive overview of energy efficiency.

[0071] Through the above technical solutions, the intelligent positive pressure explosion-proof energy-saving cabinet can achieve precise quantification and visual management of the energy efficiency of the frequency converter drive unit. Based on the power data uploaded by the intelligent power protection unit, the intelligent control unit or cloud server can automatically and periodically calculate the cumulative power consumption, operating time, and load characteristics of the frequency converter drive unit, and calculate the actual energy savings and energy efficiency rate. This allows users to clearly and intuitively understand the actual economic benefits brought by the frequency converter drive, rather than just relying on theoretical energy-saving potential. The automatically generated energy efficiency analysis report not only simplifies the tedious work of manual statistics and analysis, improving data accuracy and consistency, but also provides users with a continuous energy efficiency tracking and management tool. Users can identify potential energy-saving optimization opportunities based on the data in the report, such as adjusting operating strategies to adapt to load changes or performing equipment maintenance to improve efficiency, thereby further enhancing the overall operating efficiency and economic value of the intelligent positive pressure explosion-proof energy-saving cabinet.

[0072] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An intelligent positive pressure explosion-proof energy-saving cabinet, characterized in that, include: The positive pressure explosion-proof enclosure includes a main chamber and a secondary chamber that are isolated from each other; The main cavity forms a positive pressure working chamber for accommodating user equipment. A positive pressure sensing system and a gas distribution system are installed inside the main cavity. The positive pressure sensing system is used to monitor the internal pressure of the main cavity. The gas distribution system is used to uniformly distribute protective gas into the main cavity. The secondary chamber constitutes an explosion-proof chamber or increased safety chamber for accommodating control components; an automatic control system, a ventilation system, and an alarm system are installed within the secondary chamber; the automatic control system is electrically connected to the positive pressure sensing system, the ventilation system, and the alarm system respectively; the ventilation system includes an inlet control valve and an exhaust control valve; the inlet control valve is connected to an inlet port on the positive pressure explosion-proof cabinet via an inlet pipe; the exhaust control valve is connected to an exhaust port on the positive pressure explosion-proof cabinet via an exhaust pipe; the automatic control system is used to control the opening and closing of the inlet control valve and the exhaust control valve according to the pressure value monitored by the positive pressure sensing system, so as to perform gas replacement and maintain a safe positive pressure in the main chamber, and trigger the alarm system when the pressure is abnormal; An intelligent control unit is located in the secondary cavity and is communicatively connected to the automatic control system. It is used to obtain pressure safety status information of the main cavity from the automatic control system. The intelligent control unit is also connected to a sensor located in the main cavity or on the load side through an explosion-proof terminal block or an isolated signal converter. It is used to collect operating parameters of the load or the power grid side and generate frequency control commands and start / stop commands according to a preset control strategy or the operating parameters. A variable frequency drive unit is disposed in the main cavity and is connected to the main power supply, the drive motor and the intelligent control unit respectively. It is used to receive frequency control commands and start / stop commands from the intelligent control unit and drive the motor to run based on the commands. An Internet of Things (IoT) communication unit is disposed within the sub-cavity and is communicatively connected to the intelligent control unit, for transmitting data and issuing commands between the intelligent control unit and the remote monitoring terminal; The intelligent power protection unit is connected in series with the input terminal of the main power supply and connected to the intelligent control unit or the Internet of Things (IoT) communication unit. It is used to comprehensively protect and meter the input power, and upload the protection status information and power data to the intelligent control unit or to the remote monitoring terminal through the IoT communication unit.

2. The intelligent positive pressure explosion-proof energy-saving cabinet according to claim 1, characterized in that, A safety interlock mechanism is provided between the intelligent control unit and the automatic control system; the intelligent control unit is only allowed to send a start command to the variable frequency drive unit when it receives a confirmation signal from the automatic control system indicating that the main chamber pressure is normal and the air exchange process is completed; if the confirmation signal fails during operation, the intelligent control unit immediately sends a stop command to the variable frequency drive unit.

3. The intelligent positive pressure explosion-proof energy-saving cabinet according to claim 2, characterized in that, The sensor includes at least one of the following: a current transformer and a voltage transformer for collecting motor parameters; a pressure sensor or a flow meter for collecting process parameters; and a force sensor for collecting equipment mechanical load.

4. The intelligent positive pressure explosion-proof energy-saving cabinet according to claim 1, characterized in that, The variable frequency drive unit is a vector control variable frequency drive with motor parameter self-identification function; The intelligent control unit is also used to receive motor nameplate parameters through the Internet of Things communication unit and send them to the variable frequency drive unit when the equipment is first debugged or the motor is replaced, so as to trigger the variable frequency drive unit to perform motor parameter self-identification operation.

5. The intelligent positive pressure explosion-proof energy-saving cabinet according to claim 1, characterized in that, The IoT communication unit supports at least one of the following communication protocols: 4G, 5G, NB-IoT, or Ethernet; the remote monitoring terminal is a mobile APP or a cloud server platform.

6. The intelligent positive pressure explosion-proof energy-saving cabinet according to claim 3, characterized in that, The preset control strategy includes a process closed-loop PID control algorithm; The intelligent control unit is used to adjust the frequency control command in real time through PID calculation based on the deviation between the measured value and the set value of the process parameters fed back by the pressure sensor or flow meter in the process closed-loop PID control mode, so as to maintain the constant process parameters.

7. The intelligent positive pressure explosion-proof energy-saving cabinet according to claim 1, characterized in that, The intelligent positive pressure explosion-proof energy-saving cabinet also includes a main power contactor; the main power contactor is connected in series in the main power input circuit of the frequency converter drive unit and is electrically connected to the automatic control system; The automatic control system is also used to disconnect the main power contactor to cut off the total power input of the frequency converter drive unit when the main chamber pressure is detected to be lower than the preset minimum safety threshold.

8. A frequency conversion control method for an intelligent positive pressure explosion-proof energy-saving cabinet, applied to the intelligent positive pressure explosion-proof energy-saving cabinet according to any one of claims 1-7, characterized in that, Includes the following steps: S1. The system is powered on. The automatic control system executes the ventilation procedure and continuously monitors the pressure in the main chamber. The intelligent control unit initializes and obtains the pressure status flag from the automatic control system. S2. When a start command is received, the intelligent control unit checks the safety interlock conditions. If the pressure status indicator shows that it is safe and the ventilation process has been completed, it proceeds to S3; otherwise, it prohibits start-up and triggers an alarm. S3. The intelligent control unit sends generator parameters to the frequency converter drive unit and triggers the frequency converter drive unit to perform motor parameter self-identification. S4. The intelligent control unit calculates the target frequency command based on the set control mode and the process parameters or load data collected from the sensors in real time, and sends the target frequency command and the running command to the frequency converter drive unit to drive the motor to run. S5. During operation, the intelligent control unit continuously monitors the pressure status information in the main cavity from the automatic system, the electrical and process operating parameters from the sensors, and the operating status of the frequency converter drive unit. S6. When abnormal pressure, electrical fault, or inverter fault is detected, the intelligent control unit immediately issues a shutdown command to the inverter drive unit and sends fault alarm information to the remote monitoring terminal through the Internet of Things communication unit.

9. The frequency conversion control method according to claim 8, characterized in that, The control mode includes at least one of the following: Local constant speed or multi-speed control mode; In the process closed-loop PID control mode, the intelligent control unit adjusts the frequency control command in real time through PID calculation based on the deviation between the measured value and the set value of the process parameters fed back by the pressure sensor or flow meter, so as to maintain the constant process parameters. In the remote optimization mode, the intelligent control unit uploads operating data to the cloud server through the Internet of Things communication unit, and receives optimized frequency commands or operating curves from the cloud server for execution.

10. The frequency conversion control method according to claim 8, characterized in that, The method further includes: Based on the power data uploaded by the intelligent power protection unit, the intelligent control unit or cloud server periodically calculates the cumulative power consumption, operating time and load characteristics of the frequency converter drive unit, calculates the actual energy saving and energy saving rate, and automatically generates an energy efficiency analysis report.

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