An intelligent cooling control system and method for a variable frequency drive motor of a mining scraper conveyor

Abstract

The application discloses an intelligent cooling control system and method for a variable-frequency driving motor of a mine scraper conveyor, and comprises a variable-frequency integrated unit, a cooling water control unit and a data communication unit; the variable-frequency integrated unit comprises a programmable controller; the programmable controller is configured to: when detecting that the motor is in a forward rotation state or a reverse rotation state, control an explosion-proof electric stop valve to open; when detecting that the motor is in a stop state and the motor winding temperature is lower than a first preset temperature threshold, control the explosion-proof electric stop valve to close; and when detecting that the motor winding temperature reaches or exceeds a second preset temperature threshold, control the frequency converter to stop and trigger an alarm, the second preset temperature threshold being greater than the first preset temperature threshold. The application directly links the cooling water opening instruction with the motor operating state, ensures that the motor is immediately supplied with cooling water once starting, and solves the problems of insufficient heat dissipation and rapid winding temperature rise in the initial starting period of the motor caused by manual operation delay.

Description

Technical Field

[0001] This invention relates to the field of automatic control technology for underground electromechanical equipment in coal mines, and in particular to an intelligent cooling control system and method for a variable frequency drive motor of a mining scraper conveyor. Background Technology

[0002] In modern, high-yield, and efficient coal mines, scraper conveyors are the core transportation equipment at the coal mining face, and their drive motors generally adopt high-power, high-voltage frequency converters. To ensure stable operation of the motor in the heavy-load, high-temperature underground environment, forced cooling with water is usually employed.

[0003] Currently, the control of motor cooling water in coal mines mainly relies on manual operation. Operators judge valve opening and closing based on experience or simple temperature indicators. This control method has significant drawbacks: First, it suffers from severe control lag. If cooling water is not supplied in time after the motor starts, the winding temperature will rise rapidly, easily triggering overheat protection and causing unplanned shutdowns, affecting production continuity. Second, it easily leads to water waste and secondary problems. After production ends, if the cooling water is not shut off in time, the water will continue to mix into the coal conveying system, forming "water coal," which not only reduces the calorific value of marketable coal and increases subsequent washing and processing costs, but may also cause conveyor belt slippage, chute blockage, and other malfunctions. Finally, manual control has low intelligence, poor reliability, and high labor intensity, which is inconsistent with the development direction of intelligent coal mines.

[0004] In existing technologies, while some variable frequency drive (VFD) units possess temperature monitoring and remote control functions, they fail to deeply integrate these functions with the cooling water control logic to form a closed-loop automatic control system. Temperature monitoring is only used for post-event alarms and cannot actively drive valves; remote control is also not specifically designed for on-demand cooling water supply. Therefore, there is an urgent need for an intelligent solution that can automatically and accurately control the cooling water supply based on the real-time operating conditions of the motor. Summary of the Invention

[0005] In view of this, the present invention provides an intelligent cooling control system and system for a variable frequency drive motor of a mining scraper conveyor, which can realize on-demand cooling water supply, automatic start and stop, over-temperature protection and remote monitoring.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An intelligent cooling control system for a variable frequency drive motor of a mining scraper conveyor includes: a variable frequency integrated unit, comprising a motor body, a frequency converter, and a programmable controller integrated within the variable frequency integrated unit, the programmable controller being configured to acquire motor winding temperature signals and motor operating status signals, the motor operating status signals including forward rotation, reverse rotation, and stop; a cooling water control unit, comprising an explosion-proof electric shut-off valve installed on the motor cooling water inlet pipe, and a control relay connected to the programmable controller for driving the opening and closing of the explosion-proof electric shut-off valve; and a data communication unit configured to transmit the motor winding temperature signal... The motor operating status signal, the status information and fault information of the explosion-proof electric shut-off valve are uploaded to the mine's upper-level monitoring system. The programmable controller (PLC) has embedded intelligent control logic configured to perform the following operations: when the motor is detected to be rotating forward or in reverse, the explosion-proof electric shut-off valve is opened; when the motor is detected to be stopped and the motor winding temperature is lower than a first preset temperature threshold, the explosion-proof electric shut-off valve is closed; when the motor winding temperature is detected to reach or exceed a second preset temperature threshold, the frequency converter is stopped and an alarm is triggered, where the second preset temperature threshold is greater than the first preset temperature threshold.

[0008] Preferably, the motor winding temperature signal is acquired by a PT100 temperature sensor installed in the motor body, and the output signal of the PT100 temperature sensor is connected to the temperature acquisition interface of the programmable controller.

[0009] Preferably, the programmable controller obtains the motor operating status signal by reading the internal operating status flag bit, and the state of the operating status flag bit is determined based on the inverter's operating enable signal or external start / stop control command.

[0010] Preferably, the first preset temperature threshold is not greater than 40°C, and the second preset temperature threshold is not less than 60°C.

[0011] Preferably, the first preset temperature threshold and the second preset temperature threshold can be remotely configured and modified through the mine's upper-level monitoring system.

[0012] Preferably, the control relay is an intrinsically safe intermediate relay for mining, and its control terminal is connected to the digital output port of the programmable controller.

[0013] Preferably, the explosion-proof electric shut-off valve is a mining explosion-proof electric shut-off valve, and its control power supply is provided by the intrinsically safe or explosion-proof power supply provided by the frequency converter unit.

[0014] Preferably, the data communication unit is connected to the mine's upper-level monitoring system via a CAN bus or industrial Ethernet.

[0015] Preferably, the data communication unit is further configured to receive remote instructions issued by the mine upper monitoring system, and the remote instructions include parameter configuration instructions and equipment status query instructions.

[0016] The present invention also proposes an intelligent cooling control method for a variable-frequency drive motor of a mining scraper conveyor, which is applied to the intelligent cooling control system for a variable-frequency drive motor of a mining scraper conveyor according to any one of the above embodiments, and includes the following steps: S1. System initialization, setting a first preset temperature threshold T1 and a second preset temperature threshold T2, where T1 < T2; S2. Real-time acquisition of the motor operation status signal and the motor winding temperature signal; S3. Judging the operation status of the motor; S4. If it is judged that the motor is in the forward rotation state or the reverse rotation state, output a cooling start instruction, control the explosion-proof electric stop valve to open, and return to step S2; S5. If it is judged that the motor is in the stop state, further judge whether the current motor winding temperature is lower than the first preset temperature threshold T1; S6. If the current motor winding temperature is lower than the first preset temperature threshold T1, output a cooling stop instruction, control the explosion-proof electric stop valve to close, and return to step S2; if the current motor winding temperature is not lower than the first preset temperature threshold T1, return to step S2; S7. Synchronously monitor whether the motor winding temperature reaches or exceeds the second preset temperature threshold T2; S8. If the motor winding temperature reaches or exceeds the second preset temperature threshold T2, control the frequency converter to stop and trigger an alarm.

[0017] Preferably, in step S2, the sampling period of the real-time acquisition does not exceed 1 second.

[0018] Preferably, between step S5 and S6, there is also step S5a: judging whether the state that the motor winding temperature is lower than the first preset temperature threshold T1 lasts for a preset stable time, and if so, enter step S6.

[0019] Preferably, step S8 further includes: recording fault-related data.

[0020] Preferably, step S8 further includes: uploading the recorded fault-related data to the mine upper monitoring system through the data communication unit.

[0021] Preferably, the fault-related data includes fault type, fault occurrence time, motor winding temperature at the time of fault occurrence, and motor operation status.

[0022] The beneficial effects of the present invention are:

[0023] 1. This application directly links the cooling water start command with the motor operating status, ensuring that cooling water is supplied immediately once the motor starts (regardless of forward or reverse rotation). This fundamentally solves the problem of insufficient heat dissipation and rapid rise in winding temperature in the early stage of motor start-up caused by delays in manual operation, significantly reducing the probability of unplanned shutdowns caused by overheating and ensuring the continuous and efficient operation of the fully mechanized mining face.

[0024] 2. This application introduces a closed-loop temperature feedback mechanism. After the motor stops, the cooling system is not immediately shut off, but is continuously monitored until the winding temperature drops below a safe threshold (e.g., 40°C) before the valve is closed. This "delayed shutdown" strategy ensures that the motor's residual heat is fully removed, avoids the ineffective waste of water resources after shutdown, and completely prevents cooling water from continuously flowing into the transportation system and mixing with the raw coal, thus stabilizing the quality of the marketable coal and reducing washing costs.

[0025] 3. This application establishes a dual closed-loop control logic of "priority triggering of operating signals + temperature signal feedback judgment" and sets up an over-temperature emergency protection mechanism. The system can automatically sense the operating conditions, make intelligent decisions, and execute precisely without human intervention. This not only significantly reduces the labor intensity of workers but also avoids human error through programmed precise control, thereby improving the reliability and safety of the entire cooling system.

[0026] 4. The core control functions of this application are implemented based on the existing programmable controller within the frequency converter integrated machine, eliminating the need for an additional independent control cabinet or PLC. System integration can be completed simply by adding explosion-proof electric shut-off valves and intrinsically safe relays, and utilizing the controller's available I / O ports and communication interfaces. This solution offers strong compatibility and is particularly suitable for rapid, low-cost intelligent upgrades of existing mining equipment.

[0027] 5. This application uses a data communication unit to upload motor temperature, operating status, valve status, and fault information to the mine's upper-level monitoring system in real time, enabling the ground dispatch center to centrally monitor the cooling status of underground equipment and trace historical data. It supports remote parameter configuration and command issuance, providing data support for condition-based maintenance and preventative maintenance of equipment, and improving the level of intelligent management in coal mine production.

[0028] 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

[0029] Figure 1 This is a schematic diagram of the intelligent cooling control system of the present invention;

[0030] Figure 2 This is a flowchart of the intelligent cooling control method of the present invention. Detailed Implementation

[0031] 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.

[0032] 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.

[0033] The following is for reference. Figure 1 and Figure 2 This invention describes an intelligent cooling control system for a variable frequency drive motor of a mining scraper conveyor.

[0034] This application discloses an intelligent cooling control system for a variable frequency drive motor of a mine scraper conveyor, comprising: a variable frequency integrated unit, a cooling water control unit, and a data communication unit; the variable frequency integrated unit includes a motor body, a frequency converter, and a programmable controller integrated inside the variable frequency integrated unit, the programmable controller being configured to collect motor winding temperature signals and motor operating status signals, the motor operating status signals including forward rotation, reverse rotation, and stop; the cooling water control unit includes an explosion-proof electric shut-off valve installed on the motor cooling water inlet pipe, and a control relay connected to the programmable controller for driving the opening and closing of the explosion-proof electric shut-off valve; the data communication unit is configured to upload the motor winding temperature signal, the motor operating status signal, the status information and fault information of the explosion-proof electric shut-off valve to the mine upper-level monitoring system.

[0035] The programmable controller has embedded intelligent control logic and is configured to perform the following operations: when the motor is detected to be in forward or reverse rotation, the explosion-proof electric shut-off valve is opened; when the motor is detected to be stopped and the motor winding temperature is lower than the first preset temperature threshold, the explosion-proof electric shut-off valve is closed; when the motor winding temperature is detected to reach or exceed the second preset temperature threshold, the frequency converter is stopped and an alarm is triggered, wherein the second preset temperature threshold is greater than the first preset temperature threshold.

[0036] Specifically, the variable frequency drive unit is the control core and information source of the system, and its integrated programmable controller is responsible for running the intelligent control logic. The cooling water control unit is the system's actuator, and its explosion-proof electric shut-off valve is connected in series on the motor cooling water inlet pipe and is driven by the controller through a control relay. The data communication unit is the channel for the system to interact with the upper-level management.

[0037] The technical solution of this application constructs a complete closed-loop automatic control system. Compared with manual control, it can achieve real-time and automatic matching between cooling water supply and actual motor operating conditions. Its advancement lies in the deep integration of independent temperature monitoring, operation control, and valve actuation through intelligent logic, forming a collaborative control mechanism with autonomous decision-making capabilities, thus solving the fundamental problem of inaccurate and untimely control caused by reliance on human experience.

[0038] In some embodiments, the motor winding temperature signal is acquired by a PT100 temperature sensor installed in the motor body, and the output signal of the PT100 temperature sensor is connected to the temperature acquisition interface of the programmable controller.

[0039] Specifically, the PT100 sensor features high measurement accuracy and good stability. Its resistance signal is connected to the programmable controller's dedicated analog input module or temperature acquisition interface via a three-wire or four-wire connection. The controller's internal A / D conversion and calculation program then converts it into a digital temperature value.

[0040] In this embodiment, a high-precision PT100 sensor is used to directly measure the winding temperature. The signal is accurate and reliable, providing precise temperature feedback for the intelligent control logic. Compared to external or indirect temperature measurement methods, this method can more directly and quickly reflect the true thermal state of the motor's core heat-generating components, ensuring the accuracy of temperature control and the timeliness of protective actions.

[0041] In some embodiments, the programmable controller obtains the motor operating status signal by reading the internal operating status flag bit, and the status of the operating status flag bit is determined based on the inverter's operating enable signal or external start / stop control command.

[0042] Specifically, the motor operating status signal originates from within the frequency converter. The programmable controller (PLC) reads the internal flag bit (e.g., M0.0) ​​set by the frequency converter based on its operating enable signal (such as a start command from an external control box) via the internal data bus or a specific digital input channel. When the frequency converter outputs torque and the motor is rotating in forward or reverse direction, this flag bit is set to 1; when the frequency converter stops outputting torque and the motor stops, the flag bit is set to 0. The controller can obtain the motor operating status in real time by periodically scanning this flag bit.

[0043] This embodiment directly utilizes the operating status information within the frequency converter, eliminating the need for additional speed sensors or current detection devices to determine whether the motor is running. Signal acquisition is direct, fast, and reliable, without increasing hardware costs, simplifying the system structure and improving the accuracy and response speed of status determination.

[0044] In some embodiments, the first preset temperature threshold is no greater than 40°C, and the second preset temperature threshold is no less than 60°C. Specifically, the first preset temperature threshold T1 is set to be no higher than 40°C, for example, 38°C or 40°C. This threshold is the basis for determining whether the cooling water can be safely shut off after the motor stops, and it must be lower than the typical operating temperature of the motor windings. The second preset temperature threshold T2 is set to be no lower than 60°C, for example, 60°C or 62°C. This threshold is the emergency action value for the motor winding over-temperature protection, and it is usually related to the motor insulation class and overheat protection requirements, requiring a safety margin.

[0045] In this embodiment, setting specific temperature thresholds ensures that control actions are based on a clear objective. T1 ≤ 40℃ ensures sufficient cooling time for the motor after shutdown, preventing heat buildup caused by premature water shut-off; T2 ≥ 60℃ ensures timely triggering of protection mechanisms in abnormal situations, preventing motor damage due to overheating. Clear threshold settings make system behavior predictable and manageable, improving the standardization of safety protection.

[0046] In some embodiments, the first preset temperature threshold and the second preset temperature threshold can be remotely configured and modified through a mine monitoring system. Specifically, the mine monitoring system is equipped with a parameter configuration interface, through which operators can issue configuration commands containing the values ​​of T1 and T2 to the lower-level machine (i.e., the programmable controller). The data communication unit receives the command and transmits it to the controller, which stores the new parameters in its non-volatile memory. Thereafter, the control logic will operate according to the new parameters.

[0047] This embodiment provides flexible parameter adjustment capabilities. For different motor models, different cooling conditions, or seasonal changes, maintenance personnel can remotely adjust the temperature threshold from the ground without going down into the well. This allows the system to adapt to different operating conditions, improving its adaptability and maintainability, and is one of the key functions for achieving remote intelligent management.

[0048] In some embodiments, the control relay is an intrinsically safe intermediate relay for mining applications, and its control terminal is connected to the digital output port of the programmable controller. Specifically, the control relay is an intrinsically safe intermediate relay for mining applications. Its coil control terminal is connected via a cable to the idle digital output port (DO point) of the programmable controller, such as Q0.0. When the controller needs to open the valve, the DO point outputs a high level (e.g., 24VDC), driving the relay coil to engage; when it needs to close, it outputs a low level, releasing the relay coil. The relay's output contacts are connected in series in the control circuit of the explosion-proof electric shut-off valve to control the opening and closing of the valve.

[0049] In this embodiment, an intrinsically safe relay is used as the driving element, which meets the explosion-proof safety requirements of underground coal mines. Control is achieved using the controller's idle DO points, without modifying the main controller hardware. Control functions can be implemented solely through software programming and external wiring. This method is simple, low-cost, and ensures electrical isolation between the control circuit and the power circuit, thus improving system safety.

[0050] In some embodiments, the explosion-proof electric shut-off valve is a mine-use explosion-proof electric shut-off valve, whose control power supply is provided by an intrinsically safe or explosion-proof power supply from the frequency converter unit. Specifically, the explosion-proof electric shut-off valve is an electric valve that meets the mine explosion-proof standard. Its operating power supply (such as AC127V or DC24V) is directly taken from the existing intrinsically safe or explosion-proof power output terminal inside the frequency converter controller. This power supply is designed specifically for driving external intrinsically safe or explosion-proof equipment, and its output power and short-circuit protection meet the valve driving requirements, eliminating the need for an additional independent power supply underground.

[0051] In this embodiment, the integrated power supply design simplifies the complex underground power supply wiring and reduces potential electrical fault points. By directly utilizing the explosion-proof power supply of the integrated frequency converter itself, the explosion-proof consistency of the entire control circuit (from the controller to the relays to the valves) is ensured. The system has high integration, is easy to install, and complies with coal mine safety regulations, reducing the difficulty of engineering implementation and safety risks.

[0052] In some embodiments, the data communication unit connects to the mine's upper-level monitoring system via a CAN bus or industrial Ethernet. Employing standard industrial fieldbus or Ethernet communication, it offers strong anti-interference capabilities, reliable transmission, and high speed. It can seamlessly integrate with existing coal mine monitoring systems (such as KJ90X, KTC102, etc.) to achieve data fusion and avoid information silos. It provides a stable and high-speed data channel for remote ground monitoring, data analysis, and production scheduling.

[0053] In some embodiments, the data communication unit is further configured to receive remote instructions issued by the mine upper monitoring system, and the remote instructions include parameter configuration instructions and device status query instructions. Specifically, the data communication unit has the ability of two-way communication. In addition to uploading data, it can also analyze and execute the downlink instructions from the upper monitoring system. For example, receive and execute parameter configuration instructions; or respond to the device status query instructions and package and upload the current comprehensive system status information.

[0054] This embodiment realizes the remote intervention and management of underground equipment. Maintenance personnel can not only "observe" (monitor the status), but also "control" (configure parameters, query details). This greatly expands the management dimension and flexibility of the system, enabling a large number of underground maintenance tasks to be transferred to the ground, which is an important part of building an "unmanned and less manned" intelligent mine.

[0055] The present invention also proposes an intelligent cooling control method for a variable-frequency drive motor of a mining scraper conveyor, which is applied to the intelligent cooling control system for a variable-frequency drive motor of a mining scraper conveyor described in any one of the above embodiments, and includes the following steps: S1. System initialization, set the first preset temperature threshold T1 and the second preset temperature threshold T2, where T1 < T2; S2. Real-time collect the operating state signal and the motor winding temperature signal of the motor; S3. Judge the operating state of the motor; S4. If it is judged that the motor is in the forward rotation state or the reverse rotation state, output a cooling start instruction, control the explosion-proof electric stop valve to open, and return to step S2; S5. If it is judged that the motor is in the stop state, further judge whether the current motor winding temperature is lower than the first preset temperature threshold T1; S6. If the current motor winding temperature is lower than the first preset temperature threshold T1, output a cooling stop instruction, control the explosion-proof electric stop valve to close, and return to step S2; if the current motor winding temperature is not lower than the first preset temperature threshold T1, return to step S2; S7. Synchronously monitor whether the motor winding temperature reaches or exceeds the second preset temperature threshold T2; S8. If the motor winding temperature reaches or exceeds the second preset temperature threshold T2, control the frequency converter to stop and trigger an alarm.

[0056] Specifically, the control method of the present application is a procedural manifestation of the system operation. Step S1 is the preparation stage, setting control parameters. Steps S2-S6 constitute the main control loop, continuously collecting the status and temperature in a short cycle (such as ≤1 second) and executing the core logic: open the valve when running, and close the valve when the temperature is lower than T1 after stopping. Steps S7-S8 constitute an independent and high-priority protection monitoring thread. Once the temperature reaches or exceeds T2, immediately interrupt the main process and execute emergency shutdown and alarm. The two logics run in parallel to jointly ensure the safety of the motor.

[0057] The control method in this application concretizes the three-level coordinated strategy of "operation-priority cooling start-up, temperature-delayed shutdown, and over-temperature emergency protection" into executable program steps. Compared with single-condition control or open-loop control, this method achieves multi-condition, hierarchical intelligent decision-making, ensuring both timely and sufficient cooling, water conservation, and equipment safety protection. It is logically rigorous and has a comprehensive response.

[0058] In some embodiments, the sampling period for real-time acquisition in step S2 does not exceed 1 second. Specifically, in step S2, the programmable controller performs signal acquisition tasks in a fixed, periodic interrupt or scan manner. The sampling period is set to not exceed 1 second, for example, 500ms or 100ms. This means that the controller determines the motor's operating status and winding temperature at least once per second, and decides whether to output control commands based on the determination results.

[0059] In this embodiment, high-frequency sampling ensures the system's rapid perception of changes in external conditions. A response cycle of less than one second results in an extremely short delay from motor startup to cooling water valve opening, effectively addressing the rapid heat generation during the initial motor startup phase and preventing temperature accumulation due to excessively long control cycles. This significantly improves the real-time performance and accuracy of the control, which is crucial for ensuring the "instant cooling" effect.

[0060] In some embodiments, step S5a is further included between steps S5 and S6: determining whether the state of the motor winding temperature being lower than the first preset temperature threshold T1 has lasted for a preset stable time; if so, proceeding to step S6. Specifically, after determining in step S5 that the temperature is lower than T1, the valve closing command is not executed immediately, but a timer is started to continuously monitor the state of the temperature being lower than T1. Only when this state has been maintained for a preset stable time (e.g., 5 seconds or 8 seconds) is the valve closed executed in step S6. If the temperature fluctuates back above T1 during this period, the timer is reset to zero, and the system returns to the continuous cooling state.

[0061] In this embodiment, the stability of the valve closing judgment is increased by adding step S5a, preventing malfunctions. After the motor stops, the winding temperature may fluctuate slightly due to thermal inertia or uneven local heat dissipation. This "delayed confirmation" mechanism can effectively filter out these brief, non-trend-like temperature rise signals, preventing the valve from closing erroneously before the temperature has truly stabilized below the safe threshold, thus ensuring sufficient and reliable cooling.

[0062] In some embodiments, step S8 further includes recording fault-related data. When step S8 triggers over-temperature protection, the programmable controller creates a fault record in its internal memory or external storage medium while simultaneously controlling a shutdown alarm. This record includes at least a "over-temperature fault" type identifier and a timestamp of the fault occurrence.

[0063] In some embodiments, step S8 further includes uploading the recorded fault-related data to the mine's upper-level monitoring system via a data communication unit. Specifically, after completing local recording, the system immediately uploads the newly generated fault record data packet to the mine's upper-level monitoring system via the data communication unit, according to the agreed communication protocol format, either proactively or in response to a query. Upon receiving the data, the upper-level computer software can parse, display, display pop-up alarms, and archive it. This enables remote real-time reporting of fault information, allowing the ground dispatch center to be aware of abnormal conditions in underground equipment immediately without waiting for reports from underground personnel. This significantly shortens fault response time, facilitates remote participation of ground technical personnel in fault diagnosis and emergency response command, and improves the safety management level and emergency response efficiency of the entire production system.

[0064] In some embodiments, fault-related data includes the fault type, the time of fault occurrence, the motor winding temperature at the time of fault occurrence, and the motor operating status. Specifically, fault-related data is a structured collection of information. In addition to the fault type and the time of occurrence, it also includes the specific value of the motor winding temperature collected at the moment the fault occurred, as well as the motor's operating status at that time (such as forward rotation, reverse rotation, or stop). This data is packaged together to form a complete fault log.

[0065] This embodiment provides multi-dimensional fault context information. A single fault type is insufficient for comprehensive problem analysis. Combining the specific temperature value and equipment status at the time of the fault allows for a more accurate reconstruction of the fault scenario. For example, whether it was a slow temperature rise to overheating during heavy-load operation or an abnormal temperature rise after a light-load shutdown is crucial for determining the nature of the fault (overload, cooling failure, sensor failure, etc.), making fault diagnosis more accurate and efficient.

[0066] The technical solution of this application is further explained below by describing a specific embodiment:

[0067] Taking a mining scraper conveyor driven by a 3300V / 1000kW variable frequency drive as an example. A PT100 temperature sensor is pre-installed in the motor windings, and the signal is connected to the AI ​​module of the programmable controller within the drive unit. The controller obtains the inverter's operating status flags through internal data interaction. A mining explosion-proof electric shut-off valve is installed on the pipeline before the motor cooling water inlet, driven by a mining intrinsically safe intermediate relay. The relay coil is controlled by the controller's DO point Q0.0, and the valve power supply is taken from the controller's built-in explosion-proof 24VDC output. The controller is connected to the mine's industrial ring network via an Ethernet module and communicates with the ground-based KJ90X monitoring system.

[0068] The system initializes upon power-up, and T1=40℃ and T2=60℃ are remotely set via the monitoring system. The controller collects temperature and status data at 200ms intervals. Upon receiving a start command, the motor begins forward rotation, and the controller immediately sets Q0.0, turning on the cooling water. At the end of production, the motor stops, and the controller continues to monitor the temperature. When the temperature drops below 40℃ and stabilizes for 5 seconds, the controller resets Q0.0 and shuts off the cooling water. During operation or shutdown, if the winding temperature reaches 60℃ for any reason, the controller immediately sends an emergency stop signal to the inverter via the DO point and triggers a local audible and visual alarm via another DO point. Simultaneously, it stores a record containing "over-temperature fault," time, temperature value (e.g., 65℃), and status (e.g., "forward rotation") locally and uploads it to the ground. The ground monitoring screen immediately displays the alarm and fault details.

[0069] Other configurations and operations of the intelligent cooling control system and method for the variable frequency drive motor of a mining scraper conveyor according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0070] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is 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.

[0071] 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. An intelligent cooling control system for a variable frequency drive motor of a mining scraper conveyor, characterized by, include: The variable frequency integrated unit includes a motor body, a frequency converter, and a programmable controller integrated inside the variable frequency integrated unit. The programmable controller is configured to collect motor winding temperature signals and motor operating status signals, the motor operating status signals including forward rotation, reverse rotation, and stop. The cooling water control unit includes an explosion-proof electric shut-off valve installed on the motor cooling water inlet pipe, and a control relay connected to the programmable controller for driving the explosion-proof electric shut-off valve to open and close. The data communication unit is configured to upload the motor winding temperature signal, the motor operating status signal, the status information and fault information of the explosion-proof electric shut-off valve to the mine's upper-level monitoring system. The programmable controller has embedded intelligent control logic and is configured to perform the following operations: When the motor is detected to be rotating in the forward or reverse direction, the explosion-proof electric shut-off valve is controlled to open. When the motor is detected to be in a stopped state and the motor winding temperature is lower than the first preset temperature threshold, the explosion-proof electric shut-off valve is controlled to close. When the temperature of the motor winding is detected to reach or exceed the second preset temperature threshold, the inverter is controlled to stop and an alarm is triggered. The second preset temperature threshold is greater than the first preset temperature threshold.

2. The intelligent cooling control system for the variable frequency drive motor of a mining scraper conveyor according to claim 1, characterized in that, The motor winding temperature signal is acquired by a PT100 temperature sensor installed inside the motor body, and the output signal of the PT100 temperature sensor is connected to the temperature acquisition interface of the programmable controller.

3. The intelligent cooling control system for the variable frequency drive motor of a mining scraper conveyor according to claim 1, characterized in that, The programmable controller obtains the motor operating status signal by reading the internal operating status flag bit. The state of the operating status flag bit is determined based on the inverter's operating enable signal or external start / stop control command.

4. The intelligent cooling control system for the variable frequency drive motor of a mining scraper conveyor according to claim 1, characterized in that, The first preset temperature threshold is no greater than 40℃, and the second preset temperature threshold is no less than 60℃.

5. The intelligent cooling control system for the variable frequency drive motor of a mining scraper conveyor according to claim 1, characterized in that, The first preset temperature threshold and the second preset temperature threshold can be remotely configured and modified through the mine's upper-level monitoring system.

6. The intelligent cooling control system for the variable frequency drive motor of a mining scraper conveyor according to claim 1, characterized in that, The control relay is an intrinsically safe intermediate relay for mining, and its control terminal is connected to the digital output port of the programmable controller.

7. The intelligent cooling control system for the variable frequency drive motor of a mining scraper conveyor according to claim 1, characterized in that, The explosion-proof electric shut-off valve is a mining explosion-proof electric shut-off valve, and its control power supply is provided by the intrinsically safe or explosion-proof power supply provided by the frequency converter unit.

8. The intelligent cooling control system for the variable frequency drive motor of a mining scraper conveyor according to claim 1, characterized in that, The data communication unit is connected to the mine's upper-level monitoring system via a CAN bus or industrial Ethernet.

9. The intelligent cooling control system for the variable frequency drive motor of a mining scraper conveyor according to claim 1, characterized in that, The data communication unit is also configured to receive remote commands issued by the mine's upper-level monitoring system, including parameter configuration commands and equipment status query commands.

10. An intelligent cooling control method for a variable frequency drive motor of a mining scraper conveyor, applied to the intelligent cooling control system for a variable frequency drive motor of a mining scraper conveyor as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. System initialization: Set the first preset temperature threshold T1 and the second preset temperature threshold T2, where T1 <T2; S2. Real-time acquisition of motor operating status signals and motor winding temperature signals; S3. Determine the operating status of the motor; S4. If it is determined that the motor is in forward or reverse rotation, output a cooling start command to control the explosion-proof electric shut-off valve to open, and return to step S2. S5. If it is determined that the motor is in a stopped state, then it is further determined whether the current motor winding temperature is lower than the first preset temperature threshold T1. S6. If the current motor winding temperature is lower than the first preset temperature threshold T1, output a cooling shutdown command to control the explosion-proof electric shut-off valve to close, and return to step S2; if the current motor winding temperature is not lower than the first preset temperature threshold T1, return to step S2. S7. Simultaneously monitor whether the temperature of the motor winding reaches or exceeds the second preset temperature threshold T2; S8. If the temperature of the motor winding reaches or exceeds the second preset temperature threshold T2, the inverter is controlled to stop and an alarm is triggered.

11. The intelligent cooling control method for a variable frequency drive motor of a mining scraper conveyor according to claim 10, characterized in that, In step S2, the sampling period for real-time acquisition does not exceed 1 second.

12. The intelligent cooling control method for a variable frequency drive motor of a mining scraper conveyor according to claim 10, characterized in that, Between steps S5 and S6, there is also step S5a: determining whether the state of the motor winding temperature being lower than the first preset temperature threshold T1 has lasted for a preset stable time; if so, proceed to step S6.

13. The intelligent cooling control method for a variable frequency drive motor of a mining scraper conveyor according to claim 10, characterized in that, Step S8 also includes: recording fault-related data.

14. The intelligent cooling control method for a variable frequency drive motor of a mining scraper conveyor according to claim 13, characterized in that, Step S8 further includes: uploading the recorded fault-related data to the mine's upper-level monitoring system via the data communication unit.

15. The intelligent cooling control method for a variable frequency drive motor of a mining scraper conveyor according to claim 14, characterized in that, The fault-related data includes the fault type, the time of fault occurrence, the motor winding temperature at the time of fault occurrence, and the motor operating status.

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