Cableless power supply and taking system for low-power-consumption equipment group of intelligent ventilation facility of coal mine

Abstract

The invention relates to a cable-free power supply and taking system for a low-power-consumption equipment group of an intelligent ventilation facility of a coal mine, and belongs to the technical field of power supply and taking of coal mine equipment. Aiming at the problems of cable redundancy, high failure rate and difficulty in maintenance of a traditional underground power supply system and low power density and lack of dynamic distribution of an existing non-contact power taking technology, the invention provides a one-cable multi-taking topological architecture: a non-contact electric energy picking module captures energy from a high-voltage cable through magnetic-electric double coupling; the electric energy conversion and hybrid energy storage module adopts a lithium titanate capacitor bank to realize long cycle life and rapid charging and discharging; the electric energy management unit dynamically distributes electric energy based on a priority algorithm; and the distributed equipment terminal accesses the system through wireless coupling. According to the invention, 15 devices are supported for power supply at a single point, and the operation and maintenance cost is reduced by 60%. According to the system, the cable-free power supply problem of an underground coal mine ventilation intelligent low-power-consumption equipment group can be solved, the intelligent transformation cost is greatly reduced, and the power supply safety and the intelligent level of coal mine ventilation facilities are remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power supply and power taking for coal mine equipment, and relates to a cableless power supply and power taking system for a low-power equipment group of intelligent ventilation facilities in coal mines. Background Art

[0002] With the in-depth promotion of the intelligent transformation of coal mines, a large number of low-power equipment (such as infrared sensors, light control sensors, alarms, position sensors, and communication modules, etc.) need to be supported for ventilation facilities. The number of associated devices for a single set of facilities has reached 5 to 15. However, the traditional power supply system adopts a centralized power supply mode of "one device, one cable", which has the following significant defects:

[0003] (1) Independent wiring of multiple devices results in intertwined underground cables, a sharp increase in the number of cable joints, a failure rate increase of more than 30%, and the joints are prone to moisture and corrosion, requiring frequent inspection one by one, seriously affecting the response speed of the ventilation system;

[0004] (2) Long-distance power transmission leads to line losses of 15% - 20%, and the power supply capacity of remote devices is insufficient;

[0005] (3) Dense cables are prone to short circuit and leakage risks in high-temperature, high-humidity, flammable and explosive environments, which does not meet the requirements of coal mine intrinsic safety;

[0006] (4) The dispersion of devices leads to a short maintenance cycle (monthly maintenance required), and the labor and material costs remain high.

[0007] Although existing non-contact power taking technologies attempt to solve some problems, their designs are mostly aimed at single devices or high-power scenarios, and have the following limitations:

[0008] A single power taking device cannot meet the collaborative power supply requirements of a multi-node equipment group (total power consumption ≤ 100W);

[0009] The magnetic field frequency of underground high-voltage power cables fluctuates (±5% - 15%), and the harmonic interference is complex. The output of existing induction devices is unstable, making it difficult to maintain continuous operation of the equipment;

[0010] There is a lack of an energy scheduling mechanism for low-power equipment groups, and it is impossible to dynamically switch the power supply mode according to the device priority, resulting in a high risk of power loss for key devices (such as air door controllers) when the cable is powered off.

[0011] Therefore, there is an urgent need for a systematic solution to achieve efficient cableless power supply for low-power equipment groups through topological architecture innovation and intelligent control strategies, while meeting the requirements of high reliability, high safety, and low maintenance cost in coal mine underground. Summary of the Invention

[0012] In view of this, the purpose of the present invention is to provide a cable-free power supply and retrieval system for a low-power device group of intelligent ventilation facilities in coal mines.

[0013] To achieve the above object, the present invention provides the following technical solutions:

[0014] A cable-free power supply and retrieval system for a low-power device group of intelligent ventilation facilities in coal mines, the system comprising:

[0015] A non-contact power pickup module, sleeved on the outer surface of a high-voltage power cable, and capturing the alternating magnetic field energy of the cable through a magnetic-electric double coupling mechanism;

[0016] A power conversion and hybrid energy storage module, connected to the non-contact power pickup module, including a wide-band resonance compensation circuit, a high-frequency rectification circuit, a DC / DC buck module, and a hybrid energy storage unit, for converting the picked-up electric energy into multi-level intrinsically safe DC voltages and dynamically storing them;

[0017] A power management unit, connected to the power conversion and hybrid energy storage module, and dynamically allocating electric energy and switching the power supply mode through an energy scheduling algorithm based on the device priority and real-time power consumption requirements;

[0018] A distributed low-power device terminal, accessing the system through a wireless coupling method, including a low-power device group embedded with a micro power repeater, and the terminal is built-in with a power consumption adaptive circuit and is communicatively connected to the power management unit.

[0019] Further, the non-contact power pickup module includes:

[0020] An openable and closable magnetic core, made of an iron-based nanocrystalline material, sleeved on the cable surface with an inner wall spacing of 3-15 mm;

[0021] A flexible electrode array, attached to the cable surface, and capturing high-frequency harmonic energy through capacitive coupling;

[0022] An electric field coupling antenna, cooperating with the magnetic core and the electrode array to form a magnetic-electric composite energy capture structure.

[0023] Further, the openable and closable magnetic core optimizes the magnetic circuit coupling efficiency by adjusting the opening and closing angle, and the surface is covered with a polyimide film encapsulation layer, with a temperature resistance range of -55°C to 200°C.

[0024] Further, the hybrid energy storage unit includes a lithium titanate capacitor bank and a thin-film lithium-ion battery bank, wherein the lithium titanate capacitor bank has a cycle life greater than 500,000 times and a charge and discharge response time less than 10 ms, and the battery bank maintains the device operation for ≥8 hours when the cable is powered off.

[0025] Further, the energy scheduling algorithm executes the following strategies:

[0026] Divide the device load into three priority levels: high, medium, and low.

[0027] When the energy storage power is lower than the first threshold, cut off the power supply to low-priority devices first.

[0028] When the energy storage power is lower than the second threshold, medium-priority devices enter the sleep mode or delay power supply and trigger the feedback correction mechanism to ensure the normal operation of high-priority devices first.

[0029] The real-time adjustable output current range is 0.1A to 5A to adapt to the switching of the device working mode.

[0030] Furthermore, the coverage radius of the distributed low-power device terminal is 10 meters, the single-point power taking ≥ 100W, and it supports powering 15 terminals with a single-device power ≤ 20W at the same time. Among them, the power of the air door controller is 20W, the power of the infrared sensor is 5W, the power of the light control sensor is 5W, the power of the opening and closing state detection module is 2W, and the power of the communication transmission module is 5W, and the power of the sound and light alarm module is 12W.

[0031] Furthermore, the power management unit is built-in with a LoRa communication module, and realizes the reporting of device power consumption data and the issuing of power commands within a range of 100 meters underground through the Modbus / TCP protocol.

[0032] Furthermore, the DC / DC buck module outputs multiple voltages of 12V / 15V / 18V / 24V, and maintains the output voltage volatility < 5% when the high-voltage cable voltage fluctuates by 5% - 15%.

[0033] Furthermore, the high-priority devices include an air door controller and a sound and light alarm, the medium-priority devices include an infrared sensor, a light control sensor, and a communication module, and the low-priority devices include an environmental monitoring sensor.

[0034] Furthermore, the micro power relay receives power through near-field coupling, and the power supply interface of the terminal device uses a wireless coupling coil to achieve plug-and-play access.

[0035] The beneficial effects of the present invention are as follows:

[0036] (1) Through the magnetic-electric double coupling mechanism and the "one cable, multiple power taking" topology, a single set of systems can cover an area with a radius of 10 meters, support the collaborative power supply of more than 15 low-power devices, reduce the cable laying length by more than 90%, and completely solve the problems of cable redundancy, high failure rate, and maintenance difficulties caused by the traditional "one device, one cable" mode.

[0037] (2) Adopt iron-based nanocrystalline magnetic core and broadband resonance compensation technology to keep the output voltage volatility less than 5% when the voltage of the underground high-voltage cable fluctuates by 5% - 15%. The magnetoelectric composite design improves the electromagnetic environment adaptability and ensures stable power output under complex working conditions.

[0038] (3) Based on the equipment priority (high, medium, and low levels) and real-time power consumption requirements, dynamically allocate the energy storage power through the energy scheduling algorithm, and give priority to ensuring the continuous power supply of key equipment such as air door controllers and audible and visual alarms. After the cable power failure, the hybrid energy storage unit can maintain the equipment operation for more than 8 hours, and the power supply reliability is increased from 80% to 99%.

[0039] (4) The cycle life of the lithium titanate capacitor bank exceeds 500,000 times and the charge and discharge response time is less than 10 ms. Combined with thin-film lithium-ion batteries, it realizes seamless switching between the instantaneous high-power demand and continuous power supply of the equipment, and extends the full life cycle of the system.

[0040] (5) The electric energy pickup device is encapsulated with polyimide film, and the temperature resistance range covers -55°C to 200°C, meeting the coal mine explosion-proof standard; the terminal equipment is ready to use through wireless coupling. For new equipment, only need to bind the repeater, and the maintenance cycle is extended from once a month to once a quarter, and the operation and maintenance cost is reduced by more than 60%.

[0041] (6) The new magnetoelectric coupling material and high-frequency rectification technology achieve an electric energy conversion efficiency of 98%, reducing the line loss by more than 20% compared with the traditional power supply mode, meeting the development needs of coal mine intelligentization and greenization.

[0042] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following specification. Brief Description of the Drawings

[0043] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in detail preferably with reference to the accompanying drawings, where:

[0044] Figure 1 is the architecture diagram of the present invention;

[0045] Figure 2 is the architecture diagram of the energy management unit of the present invention;

[0046] Figure 3 is the circuit schematic diagram of the hybrid energy storage module of the present invention. Detailed Embodiments

[0047] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present invention schematically. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0048] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation to the present invention; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, which does not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0049] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only for illustrative purposes and should not be construed as a limitation to the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0050] Figure 1 is the architecture diagram of the present invention, showing the physical connection and signal flow of the non-contact power pickup module, the hybrid energy storage module, and the device terminal;

[0051] Figure 2 is the architecture diagram of the energy management unit of the present invention, including a priority algorithm logic, a LoRa communication module, and a human-machine interface.

[0052] Figure 3 is the circuit schematic diagram of the hybrid energy storage module of the present invention, clarifying the parallel structure of the lithium titanate capacitor bank and the thin-film battery, the bidirectional DC / DC module, and the protection circuit.

[0053] Embodiment 1: Magnetic-electric dual-coupling energy capture and broadband resonance compensation

[0054] Technical solution: Through the composite design of the magnetic core and the flexible electrode, the synergistic capture of the magnetic field of the high-voltage cable and the high-frequency harmonic energy is realized, and the power stability is improved by combining broadband resonance compensation.

[0055] 1. Core Installation and Parameter Configuration

[0056] Install an openable core (made of iron-based nanocrystals, with an inner diameter of 25 mm and an adjustable opening angle of 0° to 120°) on the surface of the high-voltage power cable (660V / 50Hz) at the underground air door. Set the distance between the inner wall of the core and the cable to 8 mm, and wrap the surface with a 0.2-mm-thick polyimide film (temperature-resistant up to 200°C).

[0057] Arrange a flexible electrode array (made of carbon fiber, with dimensions of 10 cm × 5 cm × 0.5 mm) at intervals of 50 cm along the axial direction of the cable. The capacitance coupling strength between the electrodes is 15 pF / m.

[0058] 2. Dual-Mode Energy Harvesting

[0059] Magnetic field harvesting: The core couples with the alternating magnetic field of the cable, and the magnetic flux density is increased to 0.5 T, outputting an AC voltage of 127 V and a power of 80 W;

[0060] Electric field harvesting: The electrode array extracts the high-frequency harmonics (3 kHz) on the surface of the cable, outputting an AC voltage of 24 V and a power of 40 W;

[0061] The total output power is 120 W, covering an area with a radius of 12 meters.

[0062] 3. Wide-Frequency Resonant Compensation

[0063] The resonant circuit automatically adjusts the compensation capacitor (10 nF to 100 nF) and inductor (50 μH to 500 μH) according to the harmonic frequency (1 to 10 kHz), suppressing the voltage fluctuation to ±3%.

[0064] 4. Electric Energy Conversion

[0065] The high-frequency rectifier circuit (switching frequency of 100 kHz) converts the dual-mode alternating current into direct current, which is stepped down to intrinsically safe 12V / 10A output through the DC / DC module, and the conversion efficiency is ≥98%.

[0066] Application scenario: Suitable for areas with severe harmonic interference in underground cables (such as near frequency converters), solving the problem of insufficient power of single magnetic coupling.

[0067] Example 2: Hybrid Energy Storage Dynamic Allocation and Multi-Level Priority Control

[0068] Technical solution: Based on the hybrid energy storage of lithium titanate capacitors and lithium batteries, combined with a three-level priority algorithm to achieve dynamic power distribution.

[0069] 1. Energy Storage Module Configuration

[0070] The hybrid energy storage unit includes a lithium titanate capacitor bank (single capacitor capacity: 200 F, cycle life: 600,000 times, 10 capacitors in series) and a thin-film lithium battery bank (capacity: 2000 mAh, 3.7 V × 6 sets), which are connected in parallel through a bidirectional DC / DC module, and the total energy storage capacity is ≥ 500 Wh.

[0071] 2. Equipment priority classification

[0072] High priority: damper controller (20 W), audible and visual alarm (12 W) - continuous power supply;

[0073] Medium priority: infrared sensor (5 W), light control sensor (5 W), communication module (5 W) - sensors go into sleep mode or are allowed to be powered with a 10-second delay;

[0074] Low priority: environmental parameter monitoring sensor (2 W) - sensors go into sleep mode or power supply is interrupted.

[0075] 3. Dynamic allocation strategy

[0076] Normal mode: The power management unit continuously collects the device status. Power is preferentially supplied directly by the cable (12 V / 10 A), and the energy storage unit is in floating charge state;

[0077] Cable power outage: Switch to energy storage power supply and execute the following logic:

[0078] ① Initial stage: Maintain full-power operation of high-priority devices, and limit the power of medium-priority devices by 50%;

[0079] ② Energy storage power < 40%: Turn off low-priority devices, and medium-priority devices resume full power;

[0080] ③ Energy storage power < 20%: Trigger LoRa wireless alarm, and force high-priority devices to enter power-saving mode (power reduced by 30%), and maintain core function operation for ≥ 8 hours.

[0081] 4. Fast response mechanism

[0082] The lithium titanate capacitor bank responds to instantaneous high-power demands within 10 ms (such as a 30 A pulsed current required for emergency opening of the damper), avoiding large current damage to the lithium battery.

[0083] Application scenario: Suitable for high-risk areas with frequent cable power outages (such as near the mining face) to ensure continuous operation of key equipment.

[0084] Example 3: Wireless plug-and-play device access and adaptive power supply

[0085] Technical solution: Achieve terminal plug-and-play through near-field coupling and device management chip, and support adaptive power consumption adjustment.

[0086] 1. The terminal is deployed inside the windshield controller (power consumption 18W), with a miniature power relay (a wireless coupling coil with a diameter of 30mm and a working frequency of 13.56MHz) embedded, and the effective transmission distance is 10 meters.

[0087] The device management chip (STM32F103) is pre - set with the Modbus / TCP protocol, supporting power consumption data reporting (accuracy ±1%) and instruction reception (response time < 10ms).

[0088] 2. Wireless access and power supply

[0089] Device binding: When adding an infrared sensor (5W), bring the repeater close to the pickup module for 3 seconds to complete wireless pairing.

[0090] Adaptive adjustment:

[0091] When the sensor is in sleep mode, the chip reports a power consumption of 0.1W, and the system output current automatically drops to 0.01A.

[0092] When the sensor is activated, the power consumption rises to 5W, and the system increases the current to 0.4A within 50ms, with the voltage fluctuation < 2%.

[0093] 3. Exception handling

[0094] When a device short - circuit (current > 5A) is detected, the solid - state relay cuts off the circuit within 2ms and uploads the fault code through LoRa (e.g., E01 indicates over - current).

[0095] The maintenance personnel remotely send a reset instruction, and the system attempts to restart 3 times (with an interval of 10 seconds). After failure, the device is marked as offline.

[0096] Application scenario: Suitable for areas where devices are dispersed and nodes need to be frequently added or deleted (such as ventilation roadways), simplifying the operation and maintenance process.

[0097] Example 4: Voltage fluctuation resistance and intrinsic safety protection

[0098] Technical solution: Through dynamic resonance compensation and explosion - proof structure design, it adapts to the complex underground electromagnetic environment.

[0099] 1. Voltage fluctuation suppression

[0100] When the voltage of the high - voltage cable fluctuates by ±15% (660V → 561V ~ 759V), the broadband resonance circuit automatically adjusts the inductance value (±10%) and capacitance value (±15%) to maintain the output of the DC / DC module at 12V ± 0.5V (volatility < 5%).

[0101] 2. Explosion - proof design

[0102] The magnetic core and the electrode array are encapsulated with double insulation: the inner layer is a polyimide film (0.2 mm), and the outer layer is a flame-retardant silicone rubber (with a thickness of 1 mm and an oxygen index ≥ 28%);

[0103] The cable joint adopts a cast-sealing explosion-proof structure (compliant with the ExdIMa standard), and the inside is filled with epoxy resin (temperature-resistant up to 150 °C) to prevent the electric arc from igniting the gas.

[0104] 3. Fault isolation and recovery

[0105] When overvoltage (>15 V) or over-temperature (>85 °C) is detected, the protection circuit disconnects the main circuit within 5 ms and activates the lithium titanate capacitor bank for temporary power supply (to maintain the operation of key equipment for 30 seconds);

[0106] After the fault is eliminated, the system automatically detects the environmental safety (such as the gas concentration < 0.5%), restores the power supply and records the event log.

[0107] Application scenario: It is applicable to the extreme underground environment with high gas concentration, high temperature and high humidity to ensure the intrinsic safety of the system.

[0108] 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 them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the present technical solution, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A cable-free power supply and retrieval system for a low-power device group of intelligent ventilation facilities in coal mines, characterized in that: The system includes: A non-contact power pickup module, which is sleeved on the outer surface of the high-voltage power cable and captures the alternating magnetic field energy of the cable through a magnetic-electric double coupling mechanism; A power conversion and hybrid energy storage module, connected to the non-contact power pickup module, including a broadband resonance compensation circuit, a high-frequency rectification circuit, a DC / DC buck module and a hybrid energy storage unit, for converting the picked-up power into multi-level intrinsically safe DC voltages and dynamically storing them; A power management unit, connected to the power conversion and hybrid energy storage module, dynamically allocates power and switches the power supply mode based on device priorities and real-time power consumption requirements through an energy scheduling algorithm; Distributed low-power device terminals, which are accessed to the system through a wireless coupling method, including a low-power device group embedded with a micro power relay. The terminals are built-in with a power consumption adaptive circuit and are communicatively connected to the power management unit.

2. The cable-free power supply and retrieval system for the low-power equipment group of intelligent ventilation facilities in coal mines according to claim 1, characterized in that: The non-contact power pickup module includes: An openable and closable magnetic core, made of iron-based nanocrystalline material, sleeved on the cable surface with an inner wall spacing of 3-15 mm; A flexible electrode array, attached to the cable surface, capturing high-frequency harmonic energy through capacitive coupling; An electric field coupling antenna, which cooperates with the magnetic core and the electrode array to form a magnetic-electric composite energy capture structure.

3. The cable-free power supply and retrieval system for the low-power equipment group of intelligent ventilation facilities in coal mines according to claim 2, characterized in that: The openable and closable magnetic core optimizes the magnetic circuit coupling efficiency by adjusting the opening and closing angles, and its surface is covered with a polyimide film encapsulation layer, with a temperature resistance range of -55°C to 200°C.

4. The cable-free power supply and retrieval system for low-power equipment groups of intelligent ventilation facilities in coal mines according to claim 1, characterized in that: The hybrid energy storage unit includes a lithium titanate capacitor bank and a thin-film lithium-ion battery bank. The lithium titanate capacitor bank has a cycle life greater than 500,000 times and a charge and discharge response time less than 10 ms. The battery bank can maintain the device operation for ≥8 hours when the cable power is cut off.

5. The cable-free power supply and retrieval system for the low-power equipment group of intelligent ventilation facilities in coal mines according to claim 1, characterized in that: The energy scheduling algorithm executes the following strategies: Dividing the device loads into three levels of priorities: high, medium, and low; When the energy storage level is lower than the first threshold, cutting off the power supply to low-priority devices first; When the energy storage level is lower than the second threshold, delaying the power supply to medium-priority devices and triggering a feedback correction mechanism to ensure the normal operation of high-priority devices first; Adjusting the output current range in real time to be 0.1 A to 5 A to adapt to the switching of the device working mode.

6. The cable-free power supply and retrieval system for low-power equipment groups of intelligent ventilation facilities in coal mines according to claim 1, characterized in that: The coverage radius of the distributed low-power device terminals is 10 meters, the single-point power pickup is ≥100 W and it supports powering 15 terminals with a single-device power ≤20 W at the same time. Among them, the power of the air door controller is 20 W, the power of the infrared sensor is 5 W, the power of the light control sensor is 5 W, the power of the opening and closing state detection module is 2 W, and the power of the communication transmission module is 5 W, and the power of the sound and light alarm module is 12 W.

7. The cable-free power supply and retrieval system for low-power equipment groups of intelligent ventilation facilities in coal mines according to claim 1, characterized in that: The power management unit is built-in with a LoRa communication module, and realizes the reporting of device power consumption data and the issuance of power commands within a range of 100 meters underground through the Modbus / TCP protocol.

8. The cableless power supply and retrieval system for low-power equipment groups of intelligent ventilation facilities in coal mines according to claim 1, wherein: The DC / DC buck module outputs multi-level voltages of 12V / 15V / 18V / 24V, and maintains the output voltage volatility <5% when the high-voltage cable voltage fluctuates by 5% to 15%.

9. The cable-free power supply and retrieval system for low-power equipment group of intelligent ventilation facilities in coal mines according to claim 5, characterized in that: The high-priority devices include an air door controller and a sound and light alarm, the medium-priority devices include an infrared sensor, a light control sensor and a communication module, and the low-priority devices include an environmental monitoring sensor.

10. The cable-free power supply and retrieval system for the low-power equipment group of intelligent ventilation facilities in coal mines according to claim 1, characterized in that: The micro power repeater receives power through near-field coupling, and the power supply interface of the terminal device is realized by a wireless coupling coil for plug-and-play access.

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