Mining frequency converter and control system thereof

Abstract

The invention provides a mining frequency converter and a control system thereof, the mining frequency converter comprises a frequency converter cabinet body and a plurality of independent function modules, the plurality of independent function modules are drawer type structures, and are respectively connected with the frequency converter cabinet body through slideways; the plurality of independent function modules are divided into a plurality of loop groups according to voltage classes and loop functions, and when a fault of a certain loop group is detected, the power supply of the upper-level independent function module of the faulted loop group is cut off. Each module is of a drawer type structure, the modules are in butt joint with the interior of the cabinet body through the slideways, the corresponding drawer type modules can be independently dismantled for maintenance, normal continuous production of a coal mine is guaranteed, the volume of a large explosion-proof cavity is reduced by dividing a plurality of independent functional modules, and the explosion risk is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of mining electrical equipment, and in particular to a mining frequency converter and a control system thereof. Background Art

[0002] The coal mine integrated fluid supply system is specialized equipment used to load emulsions and clean water to a high-pressure state underground in coal mines. The entire system includes multiple pumping stations and filter stations, among other equipment. These devices require motors to drive them. Currently, frequency converters are used to drive the main motors of the emulsion pump station and the spray pump station, while the power frequency circuits of combination switches or combined frequency converters are used to drive other motors. This makes the entire power supply system complex and inconvenient to operate and maintain. Related technologies divide the frequency converter into flameproof chambers, dividing the entire machine into several larger flameproof chambers, such as a rectifier chamber, an inverter chamber, a first power frequency chamber, and a second power frequency chamber. While this reduces the complexity of the power supply system to a certain extent, if a fault occurs during operation and a component needs to be repaired, the entire machine must be shut down and opened for repair to avoid electric shock from misoperation. Furthermore, the components are highly interconnected, making quick and easy replacement impossible, thus interrupting coal mining operations. In severe cases, the entire machine must be brought up to the surface for repair. Summary of the Invention

[0003] The present invention provides a mine frequency converter and a control system thereof, which are used to solve the defects of a traditional mine frequency converter that causes the whole machine to stop when a fault occurs, cannot be quickly and conveniently replaced, and causes the coal mining production operation to be interrupted.

[0004] The present invention provides a mine frequency converter, comprising: A frequency converter cabinet and multiple independent functional modules, wherein the multiple independent functional modules are drawer-type structures and are respectively connected to the frequency converter cabinet through slides; The multiple independent functional modules are divided into multiple circuit groups according to voltage levels and circuit functions. When a fault is detected in a circuit group, the power supply of the upper-level independent functional module of the faulty circuit group is cut off.

[0005] According to the mining frequency converter provided by the present invention, the multiple independent functional modules include: multiple rectifier modules, multiple inverter modules, multiple power frequency output modules, multiple auxiliary power frequency modules and a control module; The multiple rectifier modules are arranged on the outer facade of the rectifier chamber, and the multiple inverter modules are arranged on the outer facade of the inverter chamber; the multiple power frequency output modules are arranged on the outer facade of the first power frequency chamber, and the multiple auxiliary power frequency modules are arranged on the outer facade of the second power frequency chamber; Each module forms an independent small explosion-proof chamber. Each independent small explosion-proof chamber is provided with slides on both sides. Each module can be pushed in and pulled out from each small explosion-proof chamber in a drawer structure. After pushing in, the outer surface of the module is locked, and when ready to be pulled out, it is unlocked from the outer surface of the module.

[0006] According to the mining frequency converter provided by the present invention, the multiple circuit groups include: a high-voltage frequency conversion circuit group, a main power frequency circuit group and an auxiliary power frequency circuit group; The high-voltage frequency conversion circuit group is used to control high-power equipment with a load change greater than a preset value to perform frequency conversion speed regulation; The main power frequency circuit group is used to control high-power equipment whose load variation is not greater than a preset value to operate at a fixed frequency; The auxiliary power frequency circuit group is used to control low-power auxiliary equipment to operate at a fixed frequency to assist the main power frequency circuit group.

[0007] According to the mining inverter provided by the present invention, an electrical motherboard made of insulating material is arranged inside the mining inverter, and the electrical motherboard integrates a power supply socket and a control communication socket; each independent functional module is connected to the electrical motherboard socket through a plug, and the internal wiring of the electrical motherboard is used for power transmission and signal communication between each independent functional module.

[0008] According to the mining frequency converter provided by the present invention, a Hall-type current sensor is provided on the wiring of the electrical motherboard. When the module is pulled out, the corresponding Hall-type current sensor triggers the control module to cut off the power supply of the upper level.

[0009] According to the mining frequency converter provided by the present invention, the multiple independent functional modules are embedded with temperature sensors, humidity sensors, vibration sensors and microprocessors. The temperature sensors, humidity sensors and vibration sensors are used to collect and upload operating parameters to the microprocessor in real time. The microprocessor analyzes the temperature, humidity and vibration acceleration data and sends the analysis results to the main control module. The main control module is also used to monitor the current values of the front and rear stages of each independent functional module in real time based on the current tree, and determine the fault location in combination with the preset current threshold range.

[0010] According to the mining inverter provided by the present invention, the main control module is further used to monitor the current values of the front and rear stages of each independent functional module in real time based on the current tree, and determine the fault location in combination with the preset current threshold range, including: The main control module is configured with a spatiotemporal convolutional neural network hardware acceleration unit, which is used to perform microsecond sampling of the current waveform based on the spatiotemporal convolutional neural network to extract local features in the spatiotemporal dimension; perform early or late fusion of the spatiotemporal features of the current, temperature, and vibration data to generate a comprehensive feature vector; and locate the fault module and path based on the fused feature vector in combination with a pre-built fault tree model.

[0011] According to the mining frequency converter provided by the present invention, the spatiotemporal convolutional neural network includes: The spatiotemporal convolution layer is used to simultaneously extract the temporal and spatial features of the current wave through a three-dimensional convolution kernel; Pooling layer, used to reduce the dimension of feature maps and retain key failure mode information; The fully connected layer is used to output the fault probability distribution, map it to the fault tree nodes, and locate the fault module and path.

[0012] According to the mining frequency converter provided by the present invention, each independent functional module adopts a standardized interface design and is independently packaged. Each independent functional module is an independent unit with a unified standard mechanical interface and electrical interface.

[0013] The present invention also provides a control system for a mine frequency converter, comprising: a mine frequency converter as described in any one of the above items.

[0014] The present invention provides a mine-use frequency converter and its control system. The mine-use frequency converter includes a frequency converter cabinet and multiple independent functional modules. The multiple independent functional modules are drawer-type structures and are respectively connected to the frequency converter cabinet via slides. The multiple independent functional modules are divided into multiple circuit groups according to voltage level and circuit function. When a fault in a circuit group is detected, the power supply to the independent functional module of the upper level of the faulty circuit group is cut off. In the present invention, each module is a drawer-type structure, and the connection between the module and the interior of the cabinet is docked via slides. The corresponding drawer-type module can be removed separately for maintenance, ensuring normal and continuous production in the coal mine. In addition, by dividing the multiple independent functional modules, the volume of the large explosion-proof chamber is reduced, reducing the risk of explosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 This is one of the structural diagrams of the mining frequency converter provided by an embodiment of the present invention; Figure 2 Schematic diagram of a monomer module provided by an embodiment of the present invention; Figure 3 This is the second structural diagram of the mining frequency converter provided by the embodiment of the present invention; Figure 4 is a schematic diagram of an electrical wiring motherboard provided by an embodiment of the present invention; Figure 5This is a schematic diagram of module hot swapping provided by an embodiment of the present invention; Figure 6 This is a schematic diagram of current tree analysis provided by an embodiment of the present invention; Figure 7 It is a functional structure diagram of a mining inverter control system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0017] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0018] Figure 1 The flowchart of the mining frequency converter provided by the embodiment of the present invention is as follows: Figure 1 As shown, the mining frequency converter provided by the embodiment of the present invention includes: A frequency converter cabinet and multiple independent functional modules, wherein the multiple independent functional modules are drawer-type structures and are respectively connected to the frequency converter cabinet through slides; The multiple independent functional modules are divided into multiple circuit groups according to voltage levels and circuit functions. When a fault is detected in a circuit group, the power supply of the upper-level independent functional module of the faulty circuit group is cut off.

[0019] In an embodiment of the present invention, the plurality of independent functional modules include: a plurality of rectifier modules, a plurality of inverter modules, a plurality of power frequency output modules, a plurality of auxiliary power frequency modules and a control module; The multiple rectifier modules are arranged on the outer facade of the rectifier chamber, and the multiple inverter modules are arranged on the outer facade of the inverter chamber; the multiple power frequency output modules are arranged on the outer facade of the first power frequency chamber, and the multiple auxiliary power frequency modules are arranged on the outer facade of the second power frequency chamber; Each module forms an independent small explosion-proof chamber. Each independent small explosion-proof chamber is provided with slides on both sides. Each module can be pushed in and pulled out from each small explosion-proof chamber in a drawer structure. After pushing in, the outer surface of the module is locked, and when ready to be pulled out, it is unlocked from the outer surface of the module.

[0020] like Figure 2As shown, the independent functional modules are arranged on the front surfaces of the four explosion-proof chambers: the rectifier chamber, the inverter chamber, the first power frequency chamber, and the second power frequency chamber. Each module forms an independent small explosion-proof chamber, each of which is designed with slideways on both sides. Each module is designed as a drawer, with pluggable capabilities. Each module can be pushed in and pulled out of each small explosion-proof chamber like a drawer. After being pushed in, the module's outer surface can be locked and unlocked from the outside when ready to be pulled out.

[0021] Each module features a front handle for easy removal. Each module has a power plug and a control and communication plug on the side facing the interior of the explosion-proof chamber. Each sub-chamber has a power receptacle and a control and communication receptacle on the side facing the exterior of the explosion-proof chamber. Pushing the module in locks the power plug and receptacle, and the control and communication plug and receptacle together. Pulling the module out allows the power plug and receptacle to separate.

[0022] Traditionally, the inverter is divided into several larger explosion-proof chambers, such as the rectifier chamber, the inverter chamber, the first power frequency chamber, and the second power frequency chamber. Although this reduces the complexity of the power supply system to a certain extent, when a fault occurs during operation and a component needs to be repaired, in order to avoid electric shock due to misoperation, the entire machine must be powered off and shut down before the explosion-proof chamber is opened for maintenance. Moreover, the components are highly correlated and cannot be replaced quickly and conveniently, thereby interrupting coal mining operations. In severe cases, the entire machine needs to be lifted up to the surface for maintenance.

[0023] The mining inverter provided by the embodiment of the present invention includes an inverter cabinet and multiple independent functional modules. The multiple independent functional modules are of drawer-type structure and are respectively connected to the inverter cabinet through slides. The multiple independent functional modules are divided into multiple circuit groups according to voltage level and circuit function. When a fault in a circuit group is detected, the power supply of the upper-level independent functional module of the faulty circuit group is cut off. In the present invention, each module is of drawer-type structure, and the connection between the module and the interior of the cabinet is docked through a slide. The corresponding drawer-type module can be removed separately for maintenance, thereby ensuring normal and continuous production of the coal mine. In addition, by dividing the multiple independent functional modules, the volume of the large explosion-proof cavity is reduced, thereby reducing the risk of explosion.

[0024] Based on any of the above embodiments, Figure 3 As shown, the modules corresponding to each chamber are introduced separately.

[0025] (1) Rectification chamber The 1# and 2# input power sockets are installed on the outer wall of the rectifier chamber. The external power supply cable is introduced from the 1# and 2# input power sockets into the inverter rectifier chamber. The output end of the 1# input power socket is connected to the input end of the 1# disconnector. The 1# disconnector serves as module 1. The output end of the 2# input power socket is connected to the input end of the 2# disconnector. The 2# disconnector serves as module 2. The output end of the 1# disconnector is connected to the input end of the 1# fast-acting fuse, which is connected to the input end of the 1# vacuum contactor. The 1# fast-acting fuse and the 1# vacuum contactor are combined to form module 3. The output end of the 2# disconnector is connected to the input end of the 2# fast-acting fuse, which is connected to the input end of the 2# vacuum contactor. The 2# fast-acting fuse and the 2# vacuum contactor are combined to form module 4. The output end of the 1# vacuum contactor is connected to the input end of the rectifier unit (variable frequency AC / DC rectifier), and the rectifier unit (variable frequency AC / DC rectifier) is used as module 5; The output end of the rectifier unit (variable frequency AC / DC rectifier) is connected to the input end of the filter unit (variable frequency energy storage capacitor), and the filter unit (variable frequency energy storage capacitor) is used as module 6; (2) Inverter chamber The prior art uses several circuits to share one inverter. In the embodiment of the present invention, a larger inverter is divided into three separate single-phase inverters, thereby achieving modularization; the input ends of the 1# variable frequency inverter, the 2# variable frequency inverter, and the 3# variable frequency inverter are all connected to the output end of the filter unit of module 6, the output end of the 1# variable frequency inverter is connected to the input end of the 1# variable frequency output contactor, the output end of the 2# variable frequency inverter is connected to the input end of the 2# variable frequency output contactor, and the output end of the 3# variable frequency inverter is connected to the input end of the 3# variable frequency output contactor; the 1# variable frequency inverter and the 1# variable frequency output contactor are combined as module 7, the 2# variable frequency inverter and the 2# variable frequency output contactor are combined as module 8, and the 3# variable frequency inverter and the 3# variable frequency output contactor are combined as module 9.

[0026] (3) Main power frequency chamber The input terminals of the 1# main power frequency output contactor and the 2# main power frequency output contactor are connected to the output terminal of the 2# vacuum contactor (power frequency main contactor). The 1# main power frequency output contactor is used as module 10, and the 2# main power frequency output contactor is used as module 11. The input end of the 660V power frequency circuit transformer is connected to the output end of the 2# vacuum contactor (power frequency main contactor) to convert 3300V power frequency AC power to 660V power frequency AC power. The 660V power frequency circuit transformer serves as module 12. The input end of the 7# variable frequency output contactor and the input end of the 8# variable frequency output contactor are both connected to the output end of the 660V power frequency circuit transformer. The output end of the 7# variable frequency output contactor is connected to the input end of the 7# auxiliary power frequency output socket, and the output end of the 8# variable frequency output contactor is connected to the input end of the 8# auxiliary power frequency output socket, providing 660V power supply to the outside. The 7# variable frequency output contactor serves as module 13, and the 8# variable frequency output contactor serves as module 14. (4) Auxiliary power frequency chamber The input end of the 1140V power frequency circuit transformer is connected to the output end of the 2# vacuum contactor (power frequency main contactor) to convert the 3300V power frequency AC power into 1140V power frequency AC power. The 1140V power frequency circuit transformer serves as module 15; The input terminals of 1# auxiliary power frequency output contactor, 2# auxiliary power frequency output contactor, 3# auxiliary power frequency output contactor, 4# auxiliary power frequency output contactor, 5# auxiliary power frequency output contactor and 6# auxiliary power frequency output contactor are all connected to the output terminal of 1140V power frequency circuit transformer. The output terminal of 1# auxiliary power frequency output contactor is connected to the input terminal of 1# auxiliary power frequency output socket. The output terminal of 2# auxiliary power frequency output contactor is connected to the input terminal of 2# auxiliary power frequency output socket. The output terminal of 3# auxiliary power frequency output contactor is connected to the input terminal of 3# auxiliary power frequency output socket. The output terminal of 4# auxiliary power frequency output contactor is connected to the input terminal of 1# auxiliary power frequency output socket. Connect to the input end of the 4# auxiliary power frequency output socket, the output end of the 5# auxiliary power frequency output contactor is connected to the input end of the 5# auxiliary power frequency output socket, and the output end of the 6# auxiliary power frequency output contactor is connected to the input end of the 6# auxiliary power frequency output socket to provide 1140V power supply to the outside; use the 1# auxiliary power frequency output contactor as module 16, the 2# auxiliary power frequency output contactor as module 17, the 3# auxiliary power frequency output contactor as module 18, the 4# auxiliary power frequency output contactor as module 19, the 5# auxiliary power frequency output contactor as module 20, and the 6# auxiliary power frequency output contactor as module 21.

[0027] The input end of the 127V power frequency circuit transformer is connected to the output end of the 2# vacuum contactor (power frequency main contactor) to convert the 3300V power frequency AC power into 127V power frequency AC power. The 127V power frequency circuit transformer serves as module 22.

[0028] (5) Main control module The 1# main control module, 1# auxiliary control module, and 1# DSP module are used as module 23; the 2# main control module, 2# auxiliary control module, and 2# DSP module are used as module 24; In an embodiment of the present invention, the plurality of circuit groups include: a high-voltage frequency conversion circuit group, a main power frequency circuit group, and an auxiliary power frequency circuit group; The high-voltage frequency conversion circuit group is used to control high-power equipment with a load change greater than a preset value to perform frequency conversion speed regulation; The main power frequency circuit group is used to control high-power equipment whose load variation is not greater than a preset value to operate at a fixed frequency; The auxiliary power frequency circuit group is used to control low-power auxiliary equipment to operate at a fixed frequency to assist the main power frequency circuit group.

[0029] The embodiment of the present invention not only divides multiple independent functional modules, but also manages the associated logic between all modules based on the electrical connection relationship: first, all modules are grouped according to different voltage levels and different functional circuits; second, the situation where a superior module is associated with multiple subordinate modules is reduced; third, management software is designed to have a built-in power-off control function for the superior and subordinate modules of each module according to the electrical connection relationship when a module fails. The management software is designed to automatically cut off the power supply to the superior or multiple superior modules when a module is diagnosed as having a fault. Therefore, the embodiment of the present invention is not a simple modular design, but also realizes the automated safety management of all modules, ensuring that when a problem occurs in one module, the fault will not be transmitted to other modules.

[0030] Based on any of the above embodiments, an electrical motherboard made of insulating material is provided inside the mining inverter, and the electrical motherboard has integrated power supply sockets and control communication sockets; each independent functional module is connected to the electrical motherboard socket through a plug, and the internal wiring of the electrical motherboard is used for power transmission and signal communication between each independent functional module.

[0031] In an embodiment of the present invention, a Hall-type current sensor is provided on the wiring of the electrical motherboard. When the module is pulled out, the corresponding Hall-type current sensor triggers the control module to cut off the power supply of the upper level.

[0032] like Figure 4As shown, an electrical wiring motherboard is designed inside the explosion-proof cavity, covering the area of the four large explosion-proof chambers and shared by all the smaller ones. Each power supply and control communication socket is designed on the electrical wiring motherboard. Each module is designed with a power input terminal and a power output terminal, corresponding to two power supply sockets installed on the electrical motherboard. The output terminal of the upper-level module is connected to the input terminal of the lower-level module through wiring on the electrical motherboard. Each module is designed with a control communication interface, corresponding to a control communication socket for each module. The socket is installed on the electrical motherboard, and the control module is connected to the control communication ports of each module through wiring on the electrical motherboard.

[0033] like Figure 5 As shown, while the entire system remains powered on, Hall-effect current sensors are designed into the power wiring of the electrical motherboard. When a module is pulled out, the Hall-effect current sensors on the power wiring downstream of that module lose current sensing. At this point, the control unit automatically cuts off the output current to the module upstream of that module using a pre-set control program. This ensures that power is cut off to the upstream module when the module is plugged in or out, ensuring safe operation. Furthermore, the module's flameproof design includes a circular flameproof contact surface around the top contact, which mates with the circular flameproof surface of the housing. When the module is pulled out and the power plug is separated from the motherboard's power receptacle, the flameproof surface of the module contact remains in contact with the flameproof surface of the housing, and the contact length exceeds the safety requirements, ensuring explosion protection. Similarly, when the module is pushed in, the flameproof surfaces of the two contacts first come into contact. Only when the overlap distance exceeds the safety requirements does the metal conductive parts come into contact, thus ensuring effective explosion protection.

[0034] The embodiment of the present invention changes the traditional cable connection method between modules to an electrical motherboard connection method. All modules have their own plugs, and there are corresponding sockets on the electrical motherboard. The connection lines between the modules are fixed in the electrical motherboard. The electrical motherboard is made of insulating material, which reduces insulation failure, leakage and other problems caused by cable wear, reduces wiring workload, and improves the convenience of on-site maintenance.

[0035] Based on any of the above embodiments, each independent functional module adopts a standardized interface design and is independently packaged. Each independent functional module is an independent unit with a unified standard mechanical interface and electrical interface.

[0036] In an embodiment of the present invention, Figure 7Modules 7, 8, and 9 can be configured according to actual needs. 1, 2, or 3 frequency conversion output circuits can be flexibly selected according to actual customer needs. The three modules have unified design standards for external mechanical dimensions, mechanical interfaces, and electrical interfaces and can be interchanged. Modules 10 and 11 can be configured according to actual needs. 1, 2, or 3 main power frequency output circuits can be flexibly selected according to actual customer needs. The two modules have unified design standards for external mechanical dimensions, mechanical interfaces, and electrical interfaces and can be interchanged. Modules 13 and 14 can be configured according to actual needs. The modules can be configured as 1 or 2 660V auxiliary power frequency output circuits according to actual customer needs. The mechanical dimensions, mechanical interfaces and electrical interfaces of these two modules are designed to a unified standard and are interchangeable. Modules 16, 17, 18, 19, 20 and 21 can be configured as per actual needs. The modules can be configured as 1, 2, 3, 4, 5 or 6 1140V auxiliary power frequency output circuits according to actual customer needs. The mechanical dimensions, mechanical interfaces and electrical interfaces of these six modules are designed to a unified standard and are interchangeable.

[0037] The embodiment of the present invention can adapt to different systems and fault diagnosis requirements by adjusting the network structure and has good versatility.

[0038] In the traditional solution, the inverter is divided into several large explosion-proof cavities according to its first-level function, and then the components are arranged in several large explosion-proof cavities according to their functions. The modules are not strictly classified and arranged in the corresponding large explosion-proof cavities according to their functions. In addition, the components are not arranged separately in small explosion-proof cavities. When a component fails, the corresponding large explosion-proof cavity or even the entire machine must be powered off before maintenance. When the fault is serious, the faulty module cannot be replaced specifically, and the entire machine must be lifted up for maintenance, which will cause the entire machine to stop and affect the normal and continuous production of the coal mine.

[0039] In an embodiment of the present invention, a frequency converter for coal mines is designed with a modular architecture and a drawer-type structure, featuring pluggable modules, dynamic expansion capabilities, and standardized interfaces. The rectifier unit, inverter unit, control module, and protection module are designed as independent modules, each designed as a drawer-type structure, which can be easily withdrawn and installed. Hot-swappable replacement is supported, allowing faulty modules to be replaced without shutting down the system, reducing downtime for maintenance. The drawer-type modules can be removed for maintenance without power outages, and the power must be turned off via the panel before removal, reducing the volume of the large explosion-proof chamber and lowering the risk of explosion. Furthermore, the inverter has dynamic expansion capabilities, allowing for the flexible addition and removal of power modules based on the scale of the liquid supply system (such as the number of pump groups) to meet the needs of different coal mine scenarios. A standardized interface design is used to independently package each module, with each module designed as an independent unit with standardized mechanical and electrical interfaces, compatible with future technology upgrades and reducing system iteration costs.

[0040] Based on any of the above embodiments, the multiple independent functional modules are embedded with temperature sensors, humidity sensors, vibration sensors and microprocessors, and the temperature sensors, humidity sensors and vibration sensors are used to collect and upload operating parameters to the microprocessor in real time, and the microprocessor analyzes the temperature, humidity and vibration acceleration data and sends the analysis results to the main control module; The main control module is also used to monitor the current values of the front and rear stages of each independent functional module in real time based on the current tree, and determine the fault location in combination with the preset current threshold range.

[0041] In an embodiment of the present invention, each module is embedded with a remote I / O (Input / Output) module, which includes: a temperature sensor, a humidity sensor, a vibration sensor, a microprocessor, and a passive dry contact unit. The temperature sensor, humidity sensor, and vibration sensor respectively monitor the temperature, humidity, and vibration acceleration inside the module. The microprocessor is responsible for analyzing the collected temperature, humidity, and vibration acceleration data. When an abnormality is found in the data, the microprocessor sends a fault self-diagnosis message to the main control module and controls the passive dry contact to disconnect the power supply of the module.

[0042] In an embodiment of the present invention, the main control module is further configured to monitor the current values of the front and rear stages of each independent functional module in real time based on the current tree, and determine the fault location in combination with a preset current threshold range, including: The main control module is configured with a spatiotemporal convolutional neural network hardware acceleration unit, which is used to perform microsecond sampling of the current waveform based on the spatiotemporal convolutional neural network to extract local features in the spatiotemporal dimension; perform early or late fusion of the spatiotemporal features of the current, temperature, and vibration data to generate a comprehensive feature vector; and locate the fault module and path based on the fused feature vector in combination with a pre-built fault tree model.

[0043] like Figure 6As shown, current sensors are placed at the upper and lower levels of each module to monitor the current of the previous and subsequent levels of each module. The built-in fault tree analysis module not only identifies abnormal faults such as short circuits and overloads, but also pre-analyzes and calculates the main and branch currents within the mining inverter's internal current tree. The loads carried by the inverter's left-side output interfaces (1#-3# inverter output sockets, 1#-2# power frequency output sockets, and 1#-8# auxiliary power frequency output sockets) all have rated power and rated current values. Based on the rated current values of each load, reverse reasoning is performed to calculate the normal current values at various points in the electrical motherboard. The actual current values during operation are monitored and analyzed in real time. If the current at a point in the current tree is abnormal after comparison with the upper and lower limits of the normal value, the power supply to the previous module is automatically cut off, ensuring that the fault does not propagate to the next level. Seamless switching of redundant modules is initiated, ensuring system stability during the switching of faulty modules through redundant design. For example, assuming that the 1# variable frequency output socket, 2# variable frequency output socket, and 3# variable frequency output socket are all equipped with a 500kW, 3300V variable frequency motor load, and the rated current of the motor is 106A, then the current monitoring point 1, current monitoring point 2, and current monitoring point 3 should all monitor a current of 106A. If any current exceeds ±10% of the rated current, an abnormal alarm will be activated. The current value monitored at current monitoring point 4 should be the sum of the three currents, 418A. Current monitoring point 5 should monitor 418A + the normal consumption current of the filter unit. Current monitoring point 6 should monitor the normal current consumption of 418A + filter unit + rectifier unit; current monitoring point 7 should monitor the normal current consumption of 418A + filter unit + rectifier unit + 1# vacuum contactor; current monitoring point 8 should monitor the normal current consumption of 418A + filter unit + rectifier unit + 1# fast fuse; determine the location of the fault based on the normal current of each level and automatically cut off the power supply of the previous level.

[0044] The embodiment of the present invention adopts a diagnostic solution based on the fusion of multimodal spatiotemporal features, performs microsecond-level high-frequency sampling on the current waveform, organizes the temperature sensors of each module into a dynamic temperature field for analysis, analyzes the vibration spectrum of each module, and adds microsecond-level timestamps to this information to achieve microsecond-level time alignment of the sensor data. This enables unified observation of the sensor data at the same microsecond-level time point and mining of their internal correlations.

[0045] In an embodiment of the present invention, the spatiotemporal convolutional neural network includes: The spatiotemporal convolution layer is used to simultaneously extract the temporal and spatial features of the current wave through a three-dimensional convolution kernel; Pooling layer, used to reduce the dimension of feature maps and retain key failure mode information; The fully connected layer is used to output the fault probability distribution, map it to the fault tree nodes, and locate the fault module and path.

[0046] The embodiment of the present invention adopts a spatiotemporal convolutional neural network algorithm to extract spatial structural features of the trunk and branch currents in the current tree, and extract temporal features of the current waveform in the current tree; extract spatial features of the temperature distribution space of each module, and extract temporal features of the temperature change over time of the dynamic temperature field; extract spatial features of the vibration position of each module, and extract temporal features of the vibration spectrum of each module. At the same time, the spatial structural information and temporal dependency of various sensor data, not limited to current, temperature, and vibration, are compared and analyzed. The specific method of implementing fault tree diagnosis by combining multimodal spatiotemporal feature fusion with a spatiotemporal convolutional neural network algorithm provided by the embodiment of the present invention is: (1) Data acquisition and preprocessing: Collect multimodal data such as vibration, temperature, and current from different sensors and other channels, and perform preprocessing such as denoising and normalization to ensure data quality.

[0047] (2) Multimodal spatiotemporal feature extraction: Using a spatiotemporal convolutional neural network, its convolution layer can extract local spatiotemporal features by sliding the convolution kernel in the time and space dimensions. The pooling layer is used to compress data and retain key features, and the spatiotemporal features of each modal data are extracted separately.

[0048] (3) Feature fusion: early fusion is used to directly splice multimodal data at the data layer; or late fusion is used to fuse the features extracted from each modality. Intermediate fusion can also be used to perform feature fusion operations at the middle layer of the network.

[0049] (4) Fault tree construction: A fault tree is constructed based on the system structure and fault logic relationship. The fused features are input into the trained spatiotemporal convolutional neural network, and the output results such as the probability of fault occurrence are mapped to each node of the fault tree to determine the cause and path of the fault.

[0050] (5) Model training and optimization: Use labeled fault and normal data, measure the difference between model prediction and true value with loss function, adjust network parameters through optimization algorithm, use cross-validation and other methods to prevent overfitting and improve model generalization ability.

[0051] The embodiments of the present invention can make more comprehensive use of information: multimodal data contains multiple aspects of information such as vibration and temperature, and the fusion of spatiotemporal features can fully consider the spatiotemporal characteristics of the system, avoid the limitations of single-modal data, and improve diagnostic accuracy. The spatiotemporal convolutional neural network can automatically extract complex spatiotemporal features without the need for manual feature design, can capture hidden fault modes and patterns in the data, and has good fault diagnosis effects on nonlinear and dynamic systems. It can process real-time data, monitor the system status in real time, detect early signs of faults, perform dynamic diagnosis, and adapt to changes during system operation. The fusion of multimodal data and spatiotemporal features makes the model more tolerant to noise and data loss. Even if there are problems with some data, other modalities and features can provide supplements to ensure diagnostic reliability.

[0052] In an embodiment of the present invention, the inverter also has a self-switching function for the variable frequency output circuit. When one of the variable frequency output circuits fails, it automatically disconnects that circuit and switches to one of the other two normal variable frequency output circuits. It also has a self-switching function for the main power frequency output circuit. When one of the power frequency output circuits fails, it automatically disconnects that circuit and switches to another normal main power frequency output circuit. It also has a self-switching function for the auxiliary power frequency output circuit. When one of the auxiliary power frequency output circuits fails, it automatically disconnects that circuit and switches to one of the other normal auxiliary power frequency output circuits.

[0053] The existing technology lacks overall fault monitoring of the entire mining inverter. When a fault occurs, it only automatically identifies typical abnormal faults and passively cuts off the faulty components, but does not manage the fault points in a tree-like association. This makes it easy for electric shock accidents to occur during maintenance and it is also easy for the fault to be transmitted to the next level.

[0054] In the embodiment of the present invention, sensors and microprocessors are embedded in each module to monitor parameters such as temperature, vibration, and current in real time. A built-in fault tree analysis module not only identifies abnormal faults such as short circuits and overloads, but also monitors and analyzes the internal current tree of the mining inverter in real time. A diagnostic solution that integrates multimodal spatiotemporal features is adopted, combined with a spatiotemporal convolutional neural network algorithm to identify faults. When an abnormal current occurs somewhere in the current tree, the power supply to the upper-level module is automatically cut off to ensure that the fault will not be transmitted to the upper level, and seamless switching of redundant modules is initiated. The redundant design ensures system stability when switching faulty modules.

[0055] The mining inverter provided by the embodiments of the present invention utilizes a technical approach that divides the overall inverter system into several submodules. This offers advantages such as hot-swappable module replacement without downtime and dynamic module expansion capabilities based on actual needs. It also features module self-diagnosis, enabling precise location of inverter internal faults and localizing them to the module, preventing them from spreading. It also implements current tree analysis and fault handling. High-speed intelligent communication links are established between the modules. Based on a custom communication protocol, the modules can share operating status information and fault diagnosis data in real time. The main control module, acting as the "central nervous system," dynamically adjusts control strategies based on feedback from each module. For example, in the event of a sudden load change, the inverter module rapidly transmits current change information to the control module. The control module immediately optimizes the vector control algorithm and coordinates the rectifier module to adjust the DC bus voltage, ensuring smooth motor operation and effectively avoiding the risk of equipment downtime due to fluctuating operating conditions. Specifically designed for the high-temperature environments found underground in mines, a special composite heat pipe material is used, boasting a thermal conductivity approximately 30% higher than traditional heat pipes, enabling more rapid transfer of internal module heat to the heat sink fins. At the same time, the structure of the heat sink fins has been optimized through fluid dynamics simulations, increasing the contact area with air within a limited space. Combined with the forced air cooling system, the temperature of key components of the inverter remains below the normal operating threshold even in ambient temperatures as high as 45°C, ensuring continuous and stable operation of the equipment. The uniquely designed multi-layer protective casing comprises, from the inside out, an explosion-proof buffer layer, a waterproof sealing layer, and a dust-proof and wear-resistant layer. The explosion-proof buffer layer utilizes a new energy-absorbing material that effectively absorbs energy from gas explosions and protects the internal modules. The waterproof sealing layer utilizes a polymer sealant and a special sealing process to ensure an IP68 protection rating in water-spraying or water-logged environments. The dust-proof and wear-resistant layer utilizes high-strength, wear-resistant plastic to resist erosion by dust particles.

[0056] During the initial operation of the inverter, an embodiment of the present invention can automatically collect the operating parameters of the driven motor under different operating conditions (such as startup, acceleration, full load, and no-load) and establish a personalized operating condition model. During subsequent operation, the speed regulation strategy is optimized in real time based on this model to achieve efficient operation of the motor across the entire operating range. Taking an underground scraper conveyor as an example, the algorithm's optimized speed regulation reduces equipment energy consumption by approximately 25% compared to traditional control methods, while also extending the equipment's service life. Advanced fault prediction and self-diagnosis algorithms are introduced, and by real-time monitoring of multi-dimensional parameters such as voltage, current, temperature, and vibration of each module, big data analysis and machine learning techniques are used to predict potential fault risks in advance. When abnormal trends are detected, early warning information is promptly issued and operating parameters are automatically adjusted. If necessary, a backup module is activated or a safety shutdown procedure is executed, reducing equipment failure rates by approximately 40% and providing strong support for safe mine production.

[0057] The control system of the mine frequency converter provided by the present invention is described below. The control system of the mine frequency converter described below and the mine frequency converter described above can be referred to each other.

[0058] The present invention also provides a control system for a mine frequency converter, comprising: a mine frequency converter as described in any one of the above items.

[0059] In the mining sector, the increasing demand for automated and intelligent equipment places extremely high demands on the performance and reliability of mining inverters. Traditional inverters, when faced with the complex and harsh environment of mines, have exposed numerous drawbacks, such as difficult maintenance, poor functional scalability, and difficulty adapting to the precise speed regulation required under diverse operating conditions. To overcome these challenges, the R&D team invested significant effort and ultimately successfully applied for this invention patent, aiming to provide a highly adaptable and innovative modular inverter solution for mines.

[0060] Based on the actual needs of coal mine integrated fluid supply systems, the VFD output circuits within these systems are categorized according to the motors they drive. These circuits include variable frequency output circuits, main power frequency output circuits, and auxiliary power frequency output circuits. Depending on the specific configuration of the integrated fluid supply system in different coal mines, the number of variable frequency output circuits is typically 1-4, with a power range of 200kW-1000kW; the number of power frequency output circuits is typically 1-3, with a power range of 200kW-1000kW; and the number of auxiliary power frequency circuits is typically 2-16, with a power range of 0.5kW-15kW.

[0061] In the embodiment of the present invention, Figure 7 As shown, there are 3 main frequency conversion output circuits, and the power of each main frequency conversion output circuit is 500kW; there are 2 main power frequency output circuits, and the power of each main power frequency output circuit is 500kW; there are 8 auxiliary power frequency output circuits, and the power of each auxiliary power frequency output is 5kW.

[0062] It should be noted that the inverter provided by the embodiments of the present invention can be widely used in various aspects of underground mining, transportation, ventilation, drainage, etc. In large-scale coal mines, it provides stable power and precise speed regulation for core equipment such as coal mining machines and scraper conveyors, facilitating efficient coal mining; in metal mine ventilation systems, it ensures energy-saving operation of ventilators and protects underground air quality; and in various mine drainage systems, it reliably responds to changes in water inflow and ensures mine safety.

[0063] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0064] Through the description of the above embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the relevant technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A mine frequency converter, characterized in that: include: A frequency converter cabinet and multiple independent functional modules, wherein the multiple independent functional modules are drawer-type structures and are respectively connected to the frequency converter cabinet through slides; The multiple independent functional modules are divided into multiple circuit groups according to voltage levels and circuit functions. When a fault is detected in a circuit group, the power supply of the upper-level independent functional module of the faulty circuit group is cut off.

2. The mining frequency converter according to claim 1, characterized in that: The multiple independent functional modules include: multiple rectifier modules, multiple inverter modules, multiple power frequency output modules, multiple auxiliary power frequency modules and a control module; The multiple rectifier modules are arranged on the outer facade of the rectifier chamber, and the multiple inverter modules are arranged on the outer facade of the inverter chamber; the multiple power frequency output modules are arranged on the outer facade of the first power frequency chamber, and the multiple auxiliary power frequency modules are arranged on the outer facade of the second power frequency chamber; Each module forms an independent small explosion-proof chamber. Each independent small explosion-proof chamber is provided with slides on both sides. Each module can be pushed in and pulled out from each small explosion-proof chamber in a drawer structure. After pushing in, the outer surface of the module is locked, and when ready to be pulled out, it is unlocked from the outer surface of the module.

3. The mine frequency converter according to claim 1, characterized in that: The multiple circuit groups include: a high-voltage frequency conversion circuit group, a main power frequency circuit group and an auxiliary power frequency circuit group; The high-voltage frequency conversion circuit group is used to control high-power equipment with a load change greater than a preset value to perform frequency conversion speed regulation; The main power frequency circuit group is used to control high-power equipment whose load variation is not greater than a preset value to operate at a fixed frequency; The auxiliary power frequency circuit group is used to control low-power auxiliary equipment to operate at a fixed frequency to assist the main power frequency circuit group.

4. The mining frequency converter according to claim 1, characterized in that: An electrical motherboard made of insulating material is arranged inside the mining inverter, and a power supply socket and a control communication socket are integrated on the electrical motherboard; each independent functional module is connected to the electrical motherboard socket through a plug, and the internal wiring of the electrical motherboard is used for power transmission and signal communication between each independent functional module.

5. The mining frequency converter according to claim 4, characterized in that: A Hall-type current sensor is provided on the wiring of the electrical motherboard. When the module is pulled out, the corresponding Hall-type current sensor triggers the control module to cut off the power supply of the upper level.

6. The mine frequency converter according to claim 2, characterized in that: The multiple independent functional modules are embedded with temperature sensors, humidity sensors, vibration sensors and microprocessors. The temperature sensors, humidity sensors and vibration sensors are used to collect and upload operating parameters to the microprocessor in real time. The microprocessor analyzes the temperature, humidity and vibration acceleration data and sends the analysis results to the main control module. The main control module is also used to monitor the current values of the front and rear stages of each independent functional module in real time based on the current tree, and determine the fault location in combination with the preset current threshold range.

7. The mine frequency converter according to claim 6, characterized in that: The main control module is also used to monitor the current values of the front and rear stages of each independent functional module in real time based on the current tree, and determine the fault location based on the preset current threshold range, including: The main control module is configured with a spatiotemporal convolutional neural network hardware acceleration unit, which is used to perform microsecond sampling of the current waveform based on the spatiotemporal convolutional neural network to extract local features in the spatiotemporal dimension; perform early or late fusion of the spatiotemporal features of the current, temperature, and vibration data to generate a comprehensive feature vector; and locate the fault module and path based on the fused feature vector in combination with a pre-built fault tree model.

8. The mine frequency converter according to claim 7, characterized in that: The spatiotemporal convolutional neural network comprises: The spatiotemporal convolution layer is used to simultaneously extract the temporal and spatial features of the current wave through a three-dimensional convolution kernel; Pooling layer, used to reduce the dimension of feature maps and retain key failure mode information; The fully connected layer is used to output the fault probability distribution, map it to the fault tree nodes, and locate the fault module and path.

9. The mine frequency converter according to claim 1, characterized in that: Each independent functional module adopts a standardized interface design and is independently packaged. Each independent functional module is an independent unit with unified standard mechanical and electrical interfaces.

10. A control system for a mine frequency converter, characterized in that: It includes the mining frequency converter as described in any one of claims 1 to 9.

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