Coal mine security power supply underground load switching method and system

Abstract

The invention provides a coal mine security power supply underground load switching method and system, and relates to the technical field of power supply. The underground load switching method for the coal mine security power supply comprises the following steps: after a ground state monitoring unit determines that a ground substation is in a whole-substation power loss state, an intelligent control unit starts the security power supply; the power supply state monitoring unit monitors the operation state of the security power supply and evaluates to obtain the first real-time maximum output power of the security power supply; the intelligent control unit calculates first system available power according to the first real-time maximum output power and a preset safety coefficient; determining a target load based on the first system available power, the rated power corresponding to each underground load and a preset underground load priority; wherein the sum of the rated power of all the target loads is smaller than the first system available power, and the priority is used for indicating the importance sequence of the underground loads; and the load controller controls the switching system to supply power to the target load.

Description

Technical Field

[0001] This application relates to the technical field of power supply, and more specifically, to a method and system for switching underground loads in a coal mine safety power supply. Background Technology

[0002] Underground operations rely on a stable power supply, and underground substations are devices that supply power to underground loads (drainage pumps, ventilation fans, lighting equipment, production equipment, etc.). A power outage at an underground substation, meaning the power grid cannot provide power, directly threatens the safety of underground workers. Currently, an automatic backup power switching system can be installed to temporarily supply power to underground loads in the event of a substation power outage, thus ensuring the safety of underground workers.

[0003] Upon detecting a power failure, the automatic power switching system for emergency power supplies will supply power to all preset critical loads according to a pre-defined load list. If the emergency power supply is a fuel generator, this power supply strategy may fail to reach its rated power due to insufficient starter battery charge, fuel issues, ambient temperature, or altitude. If the emergency power supply is a renewable energy storage system (such as a battery), its maximum output power will dynamically change due to limitations in its remaining power. Therefore, with the current switching method of the automatic power switching system for emergency power supplies, the total power of critical loads may become excessive, causing the emergency power supply to shut down due to overload protection, resulting in a catastrophic situation of "power available but unable to save lives." Summary of the Invention

[0004] This application provides a method and system for switching underground loads of emergency power supply in coal mines to reduce the occurrence of situations where "there is power but no way to save lives".

[0005] In a first aspect, this application provides a method for switching underground loads in a coal mine emergency power supply system, applied to such a system. The system includes a surface substation and an underground substation. The surface substation includes an emergency power supply, a surface status monitoring unit, a power supply status monitoring unit, and an intelligent control unit. The underground substation includes a load controller. The method includes: after the surface status monitoring unit determines that the surface substation is in a state of total power failure, the intelligent control unit activates the emergency power supply; the emergency power supply provides emergency power to the underground substation, and the underground substation provides power to the underground loads; the power supply status monitoring unit monitors the operating status of the emergency power supply and evaluates its first real-time maximum output power; the intelligent control unit calculates a first system available power based on the first real-time maximum output power and a preset safety factor; a target load is determined based on the first system available power, the rated power corresponding to each underground load, and a preset underground load priority; wherein the sum of the rated power of all target loads is less than the first system available power, and the priority indicates the importance ranking of the underground loads; and the load controller controls the switching system to supply power to the target loads.

[0006] In this embodiment, after the ground condition monitoring unit determines that the ground substation is in a state of complete power failure and activates the backup power supply, it calculates the first system available power based on the first real-time maximum output power of the backup power supply and a preset safety factor. That is, the first system available power is less than or equal to the first real-time maximum output power. Based on this, when determining the target load using the first system available power, since the sum of the rated power of all target loads is less than the first system available power, the possibility of the backup power supply shutting down due to overload caused by excessive total load power can be reduced, thereby mitigating the catastrophic situation of "power available but unable to save lives." Furthermore, in this solution, the target load is determined by a preset underground load priority, meaning that power is prioritized for loads with higher priority, thus better ensuring the safety of underground personnel.

[0007] In conjunction with the technical solution provided in the first aspect above, in some possible implementations, the target load is determined based on the available power of the first system, the rated power corresponding to each of the downhole loads, and a preset downhole load priority. This includes: traversing each downhole load in descending order of priority; for each downhole load, determining whether the sum of the rated power of the downhole load and the cumulative demand power is less than the available power of the first system; wherein the cumulative demand power is the sum of the rated power of all currently determined loads that need to be switched; if the sum of the rated power of the downhole load and the cumulative demand power is less than or equal to the available power of the first system, the downhole load is determined to be a target load that needs to be switched; if the sum of the rated power of the downhole load and the cumulative demand power is greater than the available power of the first system, the downhole load is determined to be a load that does not need to be switched.

[0008] In this embodiment, each downhole load is traversed according to priority, and the sum of the final cumulative demand power is guaranteed to be less than or equal to the available power of the first system. This allows for the maximum utilization of the available power of the first system while prioritizing high-priority loads, thereby improving the utilization rate of the backup power supply.

[0009] In conjunction with the technical solution provided in the first aspect above, in some possible implementations, the security power supply includes multiple sub-power supplies, and the first real-time maximum output power of the security power supply is the sum of the real-time maximum output power of each of the sub-power supplies.

[0010] In this embodiment, multiple sub-power supplies are used for power supply, thereby improving the power supply capacity of the security power supply.

[0011] In conjunction with the technical solution provided in the first aspect above, in some possible implementations, after the load controller controls the switching system to supply power to the target load, the method further includes: the power status monitoring unit monitors the operating status of the backup power supply and evaluates and obtains the second real-time maximum output power of the backup power supply; the intelligent control unit calculates the second system available power based on the second real-time maximum output power and a preset safety factor; when the change between the second system available power and the first system available power meets preset conditions, the intelligent control unit determines a new target load based on the second system available power, the rated power corresponding to each of the downhole loads, the preset downhole load priority, and all currently powered target loads, or updates the existing target loads to designated loads that do not require power supply; the load controller controls the switching system to supply power to the new target load, or the load controller controls the switching system to stop supplying power to the designated load.

[0012] In this embodiment, since the power supply capacity of the backup power supply may fluctuate, by monitoring the real-time maximum output power of the backup power supply, and when the change in the available power of the second system compared to the available power of the first system meets preset conditions, a new target load is added, or the target load requiring power is reduced. Based on this, when the power supply capacity of the backup power supply is enhanced, its utilization rate can be improved. When the power supply capacity of the backup power supply is reduced, the total power of the target load requiring power can be reduced in a timely manner, thereby reducing the possibility of the backup power supply shutting down due to overload caused by excessive total load power, and improving the safety of this solution.

[0013] In conjunction with the technical solution provided in the first aspect above, in some possible implementations, the preset condition is: the available power of the second system is at least increased by a first value compared to the available power of the first system; the first value is the minimum rated power among all downhole loads that are not powered; the intelligent control unit determines a new target load based on the available power of the second system, the rated power corresponding to each downhole load, the preset downhole load priority, and all currently powered target loads, including: the intelligent control unit traverses each currently unpowered downhole load in descending order of priority; for each unpowered downhole load, it determines whether the sum of the rated power of the downhole load and the second cumulative demand power is less than the available power of the second system; wherein, the second cumulative demand power is the sum of the total power currently allocated to the target load and the rated power of all currently determined new target loads that need to be switched; if the sum of the rated power of the downhole load and the second cumulative demand power is less than or equal to the available power of the second system, the load is determined to be a new target load that needs to be switched; if the sum of the rated power of the load and the second cumulative demand power is greater than the available power of the second system, the load is determined to be a load that does not need to be switched.

[0014] In this embodiment, if the available power of the second system is at least a first value greater than the available power of the first system, it indicates that a new target load can be added. Therefore, each unpowered downhole load is traversed in descending order of preset priority to determine the new target load. Simultaneously, the total power of all ultimately determined target loads must be less than the available power of the second system to ensure power supply safety.

[0015] In conjunction with the technical solution provided in the first aspect above, in some possible implementations, the preset condition is: the available power of the second system is less than the sum of the rated power of all the target loads; the intelligent control unit updates the existing target loads to designated loads that do not require power supply based on the available power of the second system, the rated power corresponding to each of the downhole loads, the preset downhole load priority, and all currently powered target loads, including: the intelligent control unit traverses all the target loads in order of priority from low to high; for each target load, it determines whether the difference between the third cumulative demand power and the rated power of the target load is less than or equal to the available power of the second system; wherein, the third cumulative demand power is the sum of the rated power of all the target loads minus the difference between the rated power of all currently determined designated loads; if the difference between the third cumulative demand power and the rated power of the target load is greater than the available power of the second system, the target load is determined to be a designated load that needs to be stopped from power supply, and the traversal operation continues; if the difference between the third cumulative demand power and the rated power of the load is less than or equal to the available power of the second system, the target load is determined to be a designated load that needs to be stopped from power supply, and the traversal operation stops.

[0016] In this embodiment, when the available power of the second system is less than the sum of the rated power of all target loads, in order to prevent the emergency power supply from shutting down due to overload caused by excessive total power of the target loads, it is necessary to identify some target loads as designated loads that need to have their power supply stopped, in order to reduce the total power demand of all target loads. By determining these loads using a priority-based approach, lower-priority target loads can be prioritized for power outages, ensuring the power supply to more important loads.

[0017] In conjunction with the technical solution provided in the first aspect above, in some possible implementations, the ground status monitoring unit determines whether the ground substation is in a state of complete power failure. This includes the ground status monitoring unit obtaining the voltage and current of the busbars in the incoming line cabinets of the ground substation and whether the bus tie switch is in an open state; and determining whether the conditions for determining complete power failure are met based on the voltage and current of the busbars in the incoming line cabinets and whether the bus tie switch is in an open state. The conditions for determining complete power failure include: the voltage of the busbars in the incoming line cabinets is less than a preset power failure standard voltage, which is determined according to the rated voltage of the busbars in the incoming line cabinets; the current of the busbars in the incoming line cabinets is less than or equal to a preset rated power failure standard current; and the bus tie switch in the incoming line cabinets is in an open state. When all the conditions for determining complete power failure are met, the ground substation is determined to be in a state of complete power failure.

[0018] Secondly, this application provides a coal mine emergency power supply underground load switching system, comprising: a surface substation and an underground substation. The surface substation includes an emergency power supply, a surface status monitoring unit, a power supply status monitoring unit, and an intelligent control unit. The underground substation includes a load controller. The surface status monitoring unit is used to determine that the surface substation is in a state of total power failure. Upon determining that the surface substation is in a state of total power failure, it sends a monitoring signal indicating a total power failure to the intelligent control unit. The intelligent control unit is used to activate the emergency power supply after receiving the monitoring signal indicating a total power failure. The emergency power supply is used to provide emergency power to the underground substation. The substation is used to supply power to the downhole load; the power status monitoring unit is used to monitor the operating status of the backup power supply and evaluate the first real-time maximum output power of the backup power supply; the intelligent control unit is also used to calculate the first system available power based on the first real-time maximum output power and a preset safety factor; the target load is determined based on the first system available power, the rated power corresponding to each downhole load, and a preset downhole load priority; wherein the sum of the rated power of all the target loads is less than the first system available power, and the priority is used to indicate the importance ranking of the downhole loads; the load controller is used to control the switching system to supply power to the target load.

[0019] In conjunction with the technical solution provided in the second aspect above, in some possible implementations, the backup power supply includes: a diesel generator set and a new energy power supply; the power status monitoring unit is specifically used to receive first real-time data sent by the diesel generator set, including its current maximum allowable output power, and to receive second real-time data sent by the new energy power supply, including its current maximum sustainable output power; calculate the sum of the current maximum allowable output power and the current maximum sustainable output power to obtain the first real-time maximum output power.

[0020] In conjunction with the technical solution provided in the second aspect above, in some possible implementations, the underground load switching system for coal mine safety power supply further includes: an underground status monitoring unit, used to detect the conduction status of the load switch corresponding to each underground load; the load controller is further used to determine whether the load switch corresponding to each target load is on based on the underground status monitoring unit, and when it is determined that the load switch corresponding to each target load is on, to send a feedback signal to the intelligent control unit indicating that the power supply to the target load is completed.

[0021] In conjunction with the technical solution provided in the second aspect above, in some possible implementations, the intelligent control unit further includes: a human-machine interaction module, used to respond to user operations and complete the configuration or modification of the rated power of the underground load; and used to display the working information, alarm information, and historical data of the coal mine safety power supply underground load switching system.

[0022] In conjunction with the technical solution provided in the second aspect above, in some possible implementations, the ground status monitoring unit is specifically used to obtain the voltage and current of the busbar in the incoming line cabinet of the ground substation and whether the bus tie switch is in an open state; and based on the voltage and current of the busbar in the incoming line cabinet and whether the bus tie switch is in an open state, determine whether the conditions for a complete power outage are met; the conditions for a complete power outage include: the voltage of the busbar in the incoming line cabinet is less than a preset power outage standard voltage, the preset power outage standard voltage is determined according to the rated voltage of the busbar in the incoming line cabinet; the current of the busbar in the incoming line cabinet is less than or equal to a preset rated power outage standard current; and the bus tie switch in the incoming line cabinet is in an open state; wherein, when all the conditions for a complete power outage are met, the ground substation is determined to be in a complete power outage state. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic flowchart illustrating the first method for switching underground loads of a coal mine safety power supply according to an embodiment of this application. Figure 2 This is a schematic flowchart illustrating a second method for switching underground loads of a coal mine safety power supply, as shown in an embodiment of this application. Figure 3 This is a structural block diagram of a first type of underground load switching system for coal mine safety power supply, as shown in an embodiment of this application. Figure 4 This is a structural block diagram of a second type of underground load switching system for coal mine safety power supply, as shown in an embodiment of this application. Detailed Implementation

[0025] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0026] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, relational terms such as "first," "second," etc., in the description of this application are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0027] The technical solution of this application will now be described in detail with reference to the accompanying drawings.

[0028] Please see Figure 1 , Figure 1 This is a schematic flowchart illustrating an underground load switching method for a coal mine safety power supply, as shown in an embodiment of this application. The following will be combined with... Figure 1 The steps involved are explained.

[0029] in, Figure 1 The method for switching underground loads of the coal mine safety power supply shown is applied to the coal mine safety power supply underground load switching system. The system includes a surface substation and an underground substation. The surface substation includes a safety power supply, a surface status monitoring unit, a power status monitoring unit, and an intelligent control unit. The underground substation includes a load controller.

[0030] S100: After the ground condition monitoring unit determines that the ground substation is in a state of complete power failure, the intelligent control unit starts the backup power supply.

[0031] The emergency power supply is used to provide emergency power to the underground substation, which in turn supplies power to the underground load.

[0032] In one implementation, the ground condition monitoring unit determines whether a ground substation is in a state of complete power failure by: obtaining the voltage and current of the busbars in the incoming line cabinets of the ground substation and whether the bus tie switch is in the open state; and then determining whether the conditions for a complete power failure are met based on the voltage and current of the busbars in the incoming line cabinets and whether the bus tie switch is in the open state.

[0033] The criteria for determining a complete power outage can be set according to actual needs.

[0034] Optionally, the conditions for determining a complete power outage include: the voltage of the busbar in the incoming line cabinet is less than the preset power outage standard voltage, which is determined based on the rated voltage of the busbar in the incoming line cabinet; the current of the busbar in the incoming line cabinet is less than or equal to the preset rated power outage standard current; and the bus tie switch in the incoming line cabinet is in the open state.

[0035] Among them, if all the above-mentioned conditions for determining a complete power outage are met, the ground substation is determined to be in a state of complete power outage.

[0036] Optionally, the preset power failure standard voltage can be the product of the rated voltage of the bus in the incoming line cabinet and a first ratio.

[0037] The first percentage can be any value between 10% and 35%, such as 10%, 15%, 20%, 25%, 30%, 35%, etc. Taking a first percentage of 30% as an example, the preset power failure standard voltage can be 30% of the rated voltage of the bus in the incoming line cabinet.

[0038] Optionally, the preset rated power failure standard current can be set according to actual needs, for example, it can be set to 1% (or 0.1%, 1.5%) of the standard bus current. The standard bus current is the current value in the bus when the incoming cabinet can supply power normally. There is no limit to its specific value here.

[0039] One possible scenario is that when the current in the busbar of the incoming line cabinet is less than or equal to the preset rated power failure standard current, the current in the busbar of the incoming line cabinet is determined to be infinitely close to zero (no current).

[0040] Optionally, it can also be set that if the duration of all the above-mentioned conditions for total power outage exceeds a preset duration threshold, the ground substation is determined to be in a state of total power outage.

[0041] The preset duration threshold can be set according to actual needs. The preset duration threshold can be set to any value within the range of 0.5 to 3 seconds, such as 0.5 seconds, 1 second, 1.5 seconds, 2 seconds, 2.5 seconds, 3 seconds, etc. There is no specific limit to its value.

[0042] In one implementation, after the ground condition monitoring unit determines that the ground substation is in a state of complete power failure, the ground condition monitoring unit sends a monitoring signal indicating the complete power failure to the intelligent control unit. This allows the intelligent control unit to activate the backup power supply upon receiving the monitoring signal indicating the complete power failure.

[0043] In one implementation, the ground condition monitoring unit can be deployed on the high-voltage incoming cabinet or busbar of the ground substation to determine whether the ground substation is in a state of complete power failure.

[0044] Optionally, the ground condition monitoring unit can be equipped with a backup power supply, which can provide power in the event of a complete power outage, ensuring the normal operation of the ground condition monitoring unit after the power outage.

[0045] In one implementation, the intelligent control unit can be an electronic device with data processing capabilities, such as a computer or server.

[0046] Alternatively, the intelligent control unit can also be a processor with data processing capabilities integrated into the underground load switching system of the coal mine's safety power supply. For example, it can be a CPU (Central Processing Unit), NP (Network Processor), DSP (Digital Signal Processor), ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0047] S200: The power status monitoring unit monitors the operating status of the backup power supply and evaluates the first real-time maximum output power of the backup power supply.

[0048] In one implementation, if the backup power supply includes multiple sub-power supplies, the first real-time maximum output power of the backup power supply is the sum of the real-time maximum output power of each sub-power supply.

[0049] If the security power supply consists of only one power supply device, then the real-time maximum output power of that power supply device is the first real-time maximum output power.

[0050] Optionally, different sub-power sources can be of different types. Sub-power sources can be, for example, diesel generator sets, energy storage battery packs, wind turbines, solar power generation equipment, etc. There is no restriction on the specific type of sub-power source here.

[0051] In one implementation, the power status monitoring unit monitors the operating status of the backup power supply and evaluates and obtains the first real-time maximum output power of the backup power supply by: the power status monitoring unit receiving real-time data, including its own real-time maximum output power, sent by each sub-power supply; then calculating the sum of the maximum output power sent by each sub-power supply to obtain the first real-time maximum output power.

[0052] For ease of understanding, in one implementation, the backup power supply includes a diesel generator set and a new energy power source as an example. The power status monitoring unit receives first real-time data from the diesel generator set, including its current maximum permissible output power (i.e., the real-time maximum output power of the diesel generator set), and second real-time data from the new energy power source, including its current maximum sustainable output power (i.e., the real-time maximum output power of the new energy power source). The sum of the current maximum permissible output power and the current maximum sustainable output power is calculated to obtain the first real-time maximum output power.

[0053] Among them, new energy power sources can be, for example, energy storage battery systems, wind turbines, etc., and there are no restrictions on their specific types.

[0054] Optionally, the first real-time data may also include information such as the unit's operating status (running / stopped / faulty), output voltage, output current, and output frequency. The second real-time data may also include information such as the battery pack's total voltage, total current, remaining charge, and health status.

[0055] In this mode, the power status monitoring unit is also used to determine whether the diesel generator set and the renewable energy source are operating stably based on the first real-time data and the second real-time data. If it is determined that both the diesel generator set and the renewable energy source are operating stably, the sum of the current maximum allowable output power and the current maximum sustainable output power is calculated to obtain the first real-time maximum output power. In this mode, the calculated first real-time maximum output power is the real-time maximum output power under stable operating conditions of the backup power supply.

[0056] Optionally, after the power status monitoring unit receives real-time data including its own real-time maximum output power from each sub-power supply, the power status monitoring unit filters the power data (such as the current maximum allowable output power, the current maximum sustainable output power, etc.) in the received real-time data. Based on the filtered power data, the first real-time maximum output power is calculated.

[0057] Optionally, when the backup power supply includes a new energy storage system, after the power status monitoring unit receives real-time data on the current maximum sustainable output power and remaining power from the new energy storage system, if the remaining power is greater than or equal to a critical value, the current maximum sustainable output power is taken as the maximum output power of the new energy storage system. The maximum output power of the new energy storage system is used to subsequently calculate the real-time maximum output power of the backup power supply (e.g., the first real-time maximum output power, the second real-time maximum output power).

[0058] If the remaining power is less than the critical value, the product of the maximum sustainable output power and the preset limit coefficient will be used as the maximum output power of the new energy storage system. This extends the power supply time of the new energy storage system and protects it.

[0059] The specific value of the threshold can be set according to actual needs, but it must be less than the maximum storage capacity of the new energy storage system. For example, the threshold can be set to 50% (or 20%, 30%, 40%, 60%, 70%, etc.) of the maximum storage capacity of the new energy storage system. The preset limit coefficient is a positive number less than 1, and it can be set according to actual needs, such as 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, etc. The values ​​of the threshold and the preset limit coefficient are not limited to the examples given above.

[0060] In one implementation, if the first real-time maximum output power calculated by the power status monitoring unit meets the alarm conditions, the power status monitoring unit issues an alarm and prohibits the switching operation.

[0061] Optionally, alarm conditions may include: the first real-time maximum output power is negative, or the first real-time maximum output power is less than the product of the total rated load of all downhole loads and the minimum proportional coefficient.

[0062] The minimum scaling factor can be set according to actual needs, such as 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, etc. The minimum scaling factor is not limited to the example given here.

[0063] To facilitate understanding of the specific processing logic of the power status monitoring unit described above, examples will be provided below.

[0064] The power status monitoring unit receives the first real-time data sent by the diesel generator in the backup power supply, and the second real-time data sent by the new energy storage system.

[0065] The current maximum output power in the first real-time data and the current maximum sustainable output power in the second real-time data are filtered.

[0066] Filtering can be expressed as: P filtered (t) = α P raw (t)+(1 α) P filtered (t 1) Where α is the filter coefficient (0 < α < 1), P filtered(t) represents the power value after filtering at time t, P filtered (t 1) represents the power value after filtering at time t-1, P raw This indicates the power value that needs to be filtered. P raw This could be the current maximum output power in the first real-time data or the current maximum sustainable output power in the second real-time data. Filtering can effectively suppress decision oscillations caused by signal jitter.

[0067] Optionally, for the current maximum output power P in the first real-time data gen_max_avail α can be set to 0.7. For the current maximum sustainable output power P in the second real-time data... ess_max_discharge You can set α = 0.3.

[0068] For diesel generators, when the generator is not in operation and is offline, determine the current maximum allowable output power P of the diesel generator. max_gen = 0.

[0069] When the diesel generator reports "running" status and its output voltage is greater than 0.9 times its rated output voltage (U>0.9 × U), rated U represents the output voltage of the diesel generator. rated (Indicates the rated output voltage of the diesel generator), determine the current maximum permissible output power P of the diesel generator. max_gen = min(P gen_max_avail , 0.2 × P gen_rated P gen_rated This indicates the rated output power of the diesel generator.

[0070] At this point, a test load can be connected to help stabilize the diesel generator under load.

[0071] After the diesel generator has been running stably for a preset period of time (e.g., 60 seconds), or after the real-time output power P of the diesel generator... gen >0.1 × P gen_rated Determine the current maximum permissible output power P of the diesel generator. max_gen = P gen_max_avail .

[0072] For new energy storage systems, if the remaining power of the new energy storage system is greater than or equal to a critical value, then the current maximum sustainable output power P will be... ess_max_discharge The maximum output power P of this new energy storage system max_ess .

[0073] If the remaining power is less than the critical value, the maximum sustainable output power P will be reduced. ess_max_discharge The product of the power output P and the preset limit coefficient (e.g., 0.5) is the maximum output power P of the new energy storage system. max_ess .

[0074] Calculate the first real-time maximum output power P of the backup power supply max_total = P max_gen + P max_ess .

[0075] In P max_total If the value is less than 5% of the total rated power of the backup power supply (rated power of the new energy storage system + rated output power of the diesel generator) or is negative, it is determined to be a failure of the capacity assessment, triggering an alarm and prohibiting load switching, waiting for operator intervention.

[0076] S300: The intelligent control unit calculates the first system available power based on the first real-time maximum output power and a preset safety factor. The target load is determined based on the first system available power, the rated power corresponding to each downhole load, and the preset downhole load priority.

[0077] Among them, the sum of the rated power of all target loads is less than the available power of the first system, and the priority is used to indicate the importance ranking of downhole loads.

[0078] The first system's available power is calculated based on the first real-time maximum output power and the preset safety factor, which is obtained by multiplying the first real-time maximum output power and the preset safety factor.

[0079] Optionally, the preset safety factor can be set according to actual needs, such as a positive number less than or equal to 1, such as 0.7, 0.75, 0.8, 0.85, 0.9, or 0.95. By setting a safety factor, a certain power margin can be provided for the backup power supply to prevent instantaneous overload.

[0080] In one implementation, the preset downhole load priority can be a priority ranking of all downhole loads.

[0081] When prioritizing loads, they can be ordered as follows: critical loads for life safety, critical loads for production safety and explosion protection, and auxiliary safety and protection loads. Among these, critical loads for life safety have the highest priority, while auxiliary safety and protection loads have the lowest priority.

[0082] Life-critical loads can be, for example, downhole loads such as the main drainage pump and the main ventilation fan.

[0083] Key loads for production safety and explosion protection can be, for example, underground loads such as local ventilation fans and gas extraction pumps.

[0084] Auxiliary safety and security loads can be, for example, downhole loads such as bottom lighting, safety monitoring systems, and dispatch telephones.

[0085] In one implementation, the intelligent control unit determines the target load based on the available power of the first system, the rated power corresponding to each downhole load, and a preset downhole load priority. This can be achieved by the intelligent control unit sequentially adding the rated power of each load in descending order of priority to obtain the cumulative required power. This continues until the cumulative required power is less than or equal to the available power of the first system, and the sum of the rated power of the next priority load and the cumulative required power is greater than the available power of the first system. Then, all loads prior to this next priority are determined as the target load.

[0086] For example, consider loads 1, 2, 3, and 4, with load 1 having a rated power of 10 kW, load 2 having a rated power of 15 kW, load 3 having a rated power of 5 kW, and load 4 having a rated power of 10 kW. The priority order from highest to lowest is load 1, load 2, load 3, and load 4. If the available power of the first system is 33 kW, then the rated power of loads 1, 2, and 3 is added together to obtain 30 kW. 30 kW is less than 33 kW, but 30 kW + 10 kW is greater than 33 kW. Therefore, loads 1, 2, and 3 are identified as the target loads requiring power supply. This example is for illustrative purposes only and should not be construed as a limitation of this application.

[0087] In one implementation, the intelligent control unit determines the target load based on the available power of the first system, the rated power corresponding to each downhole load, and the preset downhole load priority. Alternatively, the intelligent control unit may traverse each downhole load in descending order of priority.

[0088] For each downhole load, determine whether the sum of the rated power and the cumulative demand power of that downhole load is less than the available power of the first system. The cumulative demand power is the sum of the rated power of all currently determined loads that need to be switched.

[0089] If the sum of the rated power and the cumulative demand power of the downhole load is less than or equal to the available power of the first system, the downhole load is determined to be the target load that needs to be switched.

[0090] If the sum of the rated power and the cumulative demand power of the downhole load is greater than the available power of the first system, the downhole load is determined to be a load that does not need to be switched.

[0091] The initial value of the cumulative power demand is 0.

[0092] For example, taking the first system with an available power of 33KW and loads including load 1, load 2, load 3, and load 4 as an example, and the rated power of load 1 is 10KW, the rated power of load 2 is 15KW, the rated power of load 3 is 15KW, and the rated power of load 4 is 5KW, with the priority from high to low as load 1, load 2, load 3, and load 4.

[0093] First, calculate that the sum of the rated power of load 1 and the initial value of the cumulative demand power (0KW) is 10KW. 10KW is less than the available power of the first system, which is 33KW. Therefore, load 1 is determined as the target load, and the cumulative demand power is updated to 10KW.

[0094] The sum of the rated power of load 2 and the initial value of the cumulative demand power (10KW) is calculated to be 25KW. 25KW is less than the available power of the first system, which is 33KW. Therefore, load 2 is determined as the target load, and the cumulative demand power is updated to 25KW.

[0095] The sum of the rated power of load 3 and the initial value of the cumulative demand power (25KW) is calculated to be 40KW. 40KW is greater than the available power of the first system, which is 33KW. Therefore, load 3 is determined not to be the target load, and the cumulative demand power remains at 25KW.

[0096] The sum of the rated power of load 4 and the initial value of the cumulative demand power (25KW) is calculated to be 30KW. 30KW is less than the available power of the first system, which is 33KW. Therefore, load 4 is determined as the target load, and the cumulative demand power is updated to 30KW.

[0097] Based on this, load 1, load 2, and load 4 are identified as target loads requiring power supply. This example is provided for ease of understanding and should not be construed as a limitation of this application.

[0098] In one implementation, all downhole loads are divided into N categories based on a preset downhole load priority, with different categories having different priorities. The intelligent control unit determines the target load based on the available power of the first system, the rated power corresponding to each downhole load, and the preset downhole load priority. Alternatively, it can calculate the total power demand for each load category, following a descending priority order. It then determines whether the total power demand for that load category is less than or equal to a decision power benchmark. If it is less than or equal to the decision power benchmark, all downhole loads in that category are determined to be target loads.

[0099] If the total demand power corresponding to this type of load is greater than the decision power benchmark, all downhole loads in this type of load are sorted in ascending order of rated power to obtain a first priority list. Each downhole load in the sorted first priority list is traversed in ascending order of rated power. If the sum of the rated power and the cumulative demand power of the downhole load is less than or equal to the available power of the first system, the downhole load is determined as the target load.

[0100] If the sum of the rated power and the cumulative demand power of the downhole load is greater than the available power of the first system, the downhole load is determined not to be the target load. In addition, other downhole loads with rated power greater than the downhole load in this category can also be determined not to be downhole loads.

[0101] For each type of load, the above-mentioned decision logic needs to be executed to obtain all target loads that need to be switched.

[0102] For ease of understanding, let P usable P represents the available power of the first system. max_total Let P represent the first real-time maximum output power, K represent the preset safety factor, and P represent the first real-time maximum output power. usable =P max_total ×K. The cumulative demand power P when no load switching is performed. allocated = 0. Airdrop switch instruction set S switch-on ={}.

[0103] In the preset downhole load priority, downhole loads are divided into N types of loads, where the smaller the value of N, the higher the priority. Each type of load includes at least one downhole load.

[0104] Calculate the total power demand for each type of load (i-th type) in descending order of priority. and decision power benchmark .in, = P usable -P allocated . . This represents the rated power of the j-th downhole load in the i-th load category, and n indicates that the i-th load category includes n downhole loads.

[0105] like ≤ If so, all downhole loads within that load category are identified as target loads. This means adding all downhole loads within that load category to the airdrop cutoff command set and updating P. allocated = P allocated + .

[0106] like > The downhole loads within this type of load are sorted according to their rated power from smallest to largest, resulting in a first priority list. The sorted first priority list is then iterated through in ascending order of rated power, provided that P... allocated + ( ) ≤ P usable The downhole load will be Join S switch on And update P allocated Until P allocated + ( ) > P usable Therefore, the remaining loads in this type of load can be directly identified as loads that do not need to be switched.

[0107] For example, P max_total = 800kW, safety factor K=0.8, then P usable The power is 640kW. If the load priority is: P1-main drainage (400kW), P2-local ventilation (250kW), P3-well bottom lighting (100kW).

[0108] If P1 is activated (400kW ≤ 640kW), the remaining usable power is 240kW; activating P2 requires 250kW, but since 250kW > 240kW, P2 is skipped; activating P3 requires 100kW, but 100kW ≤ 240kW, leaving 140kW of usable power. Therefore, the final target loads are P1 and P3.

[0109] S400: The load controller controls the switching system to supply power to the target load.

[0110] In one implementation, the load controller can be a multi-channel remote I / O (Input / Output) terminal or a dedicated PLC (Programmable Logic Controller). Each output circuit of the load controller controls the opening and closing coils of a load switch (e.g., a vacuum contactor) via an intermediate relay. Each output circuit logically corresponds to a downhole load. The load controller has communication capabilities, enabling it to feed back the final state (closed / open) of each switch to the intelligent control unit.

[0111] In one implementation, the load controller controls the switching system to supply power to the target load in the following way: the load controller sends a closing command to the load switch corresponding to each target load so that the load switch corresponding to the target load is closed.

[0112] When the load switch corresponding to the load is closed, the load can be supplied with power through the backup power supply.

[0113] Optionally, when it is necessary to send closing commands to the load switches corresponding to multiple target loads separately, the closing commands can be sent sequentially. A preset interval is set between two consecutive closing commands to prevent multiple load switches from closing simultaneously and impacting the backup power supply.

[0114] The preset interval duration can be set according to actual needs, such as 0.1 seconds, 0.5 seconds, 1 second, etc., and there is no limit to its specific duration.

[0115] Optionally, when sending closing commands sequentially, the order can be a priority order or a randomly generated order.

[0116] In one implementation, if the underground load switching system for coal mine safety power supply further includes an underground status monitoring unit, then the underground status monitoring unit can also detect the conduction status of the load switch corresponding to each underground load.

[0117] The load controller determines whether the load switch corresponding to each target load is turned on based on the downhole condition monitoring unit. When it is determined that the load switch corresponding to each target load is turned on, it sends a feedback signal to the intelligent control unit indicating that the power supply to the target load has been completed.

[0118] Optionally, if the downhole condition monitoring unit detects that the load switch corresponding to the specified target load is not conducting, it can send a load switch feedback signal to the load controller indicating that the load switch corresponding to the specified target load is not conducting. Upon receiving this load switch feedback signal, the load controller sends a closing command to the load switch corresponding to the specified target load again until the load switch corresponding to the specified target load is conducting (i.e., closed).

[0119] Alternatively, if the number of closing commands sent to the load switch corresponding to the specified target load exceeds a preset threshold, the intelligent control unit will be notified of the first information that the specified target load cannot be powered.

[0120] The downhole status detection unit detects whether power is being supplied to the target load, thereby reducing the possibility of power failure and wasted power.

[0121] Optionally, the downhole condition monitoring unit can also send information on whether each load is powered to the intelligent control unit, so that the intelligent control unit can determine which loads are powered based on the information.

[0122] Optionally, the downhole status monitoring unit can be deployed on the switchgear of the downhole substation to monitor the status of the load switch in the downhole substation, ensuring that the open and closed status of the load switch can be detected in real time before and after load control.

[0123] The switchgear in the underground substation includes load switches corresponding to each underground load.

[0124] Since the real-time maximum output power of the backup power supply may fluctuate, in one implementation, the power status monitoring unit monitors the operating status of the backup power supply and evaluates and obtains the second real-time maximum output power of the backup power supply.

[0125] The intelligent control unit calculates the second system's available power based on the second real-time maximum output power and a preset safety factor. When the change in the second system's available power relative to the first system's available power meets preset conditions, the intelligent control unit determines a new target load based on the second system's available power, the rated power corresponding to each downhole load, preset downhole load priorities, and all currently powered target loads, or updates the existing target loads to designated loads that do not require power.

[0126] The load controller controls the switching system to supply power to the new target load, or the load controller controls the switching system to stop supplying power to the designated load.

[0127] Optionally, the power status monitoring unit can periodically monitor the operating status of the backup power supply and obtain the second real-time maximum output power.

[0128] The monitoring cycle can be set according to actual needs, such as once per second, once every 10 seconds, once every 30 seconds, once per minute, etc. There are no restrictions on it here.

[0129] In one implementation, when the load controller acquires a new target load, the load controller sends a closing command to the load switch corresponding to the new target load, so that the load switch corresponding to the new target load is closed.

[0130] Optionally, when the load controller detects a specified load that requires power to be cut off, the load controller sends an opening command to the load switch corresponding to the specified load to disconnect the load switch and stop the power supply.

[0131] Optionally, if the preset condition is: the available power of the second system is at least increased by a first value compared to the available power of the first system.

[0132] The intelligent control unit determines new target loads based on the available power of the second system, the rated power of each downhole load, preset downhole load priorities, and all currently powered target loads. The method may be as follows: The intelligent control unit iterates through each currently unpowered downhole load in descending order of priority. For each unpowered downhole load, it determines whether the sum of its rated power and the second cumulative demand power is less than the available power of the second system; where the second cumulative demand power is the sum of the total power currently allocated to target loads and the rated power of all newly identified target loads requiring switching.

[0133] If the sum of the rated power of the downhole load and the second cumulative demand power is less than or equal to the available power of the second system, the load is determined to be a new target load that needs to be switched.

[0134] If the sum of the rated power of the load and the second cumulative demand power is greater than the available power of the second system, the load is determined to be a load that does not need to be switched.

[0135] Optionally, the specific value of the first value can be set according to actual needs. For example, the first value can be the minimum rated power among all downhole loads that are not powered.

[0136] Alternatively, the first value can be the product of the available power of the first system and a preset growth rate. For example, the preset growth rate could be 5%, 10%, 15%, etc.

[0137] For example, taking a first system with an available power of 28KW and a second system with an available load of 33KW, the loads include load 1, load 2, load 3, and load 4. The rated power of load 1 is 10KW, the rated power of load 2 is 15KW, the rated power of load 3 is 15KW, and the rated power of load 4 is 5KW. The priority from high to low is load 1, load 2, load 3, and load 4.

[0138] If the current target load is load 1 and load 2, then the currently unpowered underground loads are load 3 and load 4. That is, the first value is 5KW. The second system's available power of 33KW is 5KW higher than the first system's available power of 28KW, thus meeting the preset conditions.

[0139] Based on priority, for load 3, the sum of the rated power of load 3 and the second cumulative demand power (25KW) is 40KW, which is greater than 33KW. Therefore, load 3 is a load that does not need to be switched.

[0140] For load 4, the sum of the rated power of load 4 and the second cumulative demand power (25KW) is 30KW, which is less than 33KW. Therefore, load 4 is the new target load.

[0141] The examples provided are for illustrative purposes only and should not be construed as limiting the scope of this application.

[0142] Optionally, if the preset condition is: the available power of the second system is less than the sum of the rated power of all target loads.

[0143] The intelligent control unit updates existing target loads to designated loads that do not require power supply, based on the available power of the second system, the rated power corresponding to each downhole load, the preset downhole load priority, and all currently powered target loads. This can be achieved by the intelligent control unit iterating through all target loads in ascending order of priority. For each target load, it determines whether the difference between the third cumulative demand power and the rated power of that target load is less than or equal to the available power of the second system; where the third cumulative demand power is the sum of the rated power of all target loads minus the difference between the rated power of all currently determined designated loads.

[0144] If the difference between the third cumulative demand power and the rated power of the target load is greater than the available power of the second system, the target load is determined to be a designated load that needs to be shut down, and the traversal operation continues.

[0145] If the difference between the third cumulative demand power and the rated power of the load is less than or equal to the available power of the second system, the target load is determined to be the designated load for which power supply needs to be stopped, and the traversal operation is stopped.

[0146] For example, taking a first system with an available power of 33KW and a second system with an available load of 29KW, the loads include load 1, load 2, load 3, and load 4 as an example. The rated power of load 1 is 10KW, the rated power of load 2 is 15KW, the rated power of load 3 is 5KW, and the rated power of load 4 is 15KW. The priority from high to low is load 1, load 2, load 3, and load 4.

[0147] If the current target loads are load 1, load 2, and load 3, then the currently unpowered underground load is load 4. This means the sum of the rated power of the target loads is 30KW. The available power of the second system is 29KW. Therefore, the preset condition that the available power of the second system is less than the sum of the rated power of all target loads is met.

[0148] Based on priority, for load 3, the difference between the third cumulative power demand and the rated power of load 3 is 25KW, which is less than 29KW. Therefore, load 3 is determined to be the designated load that needs to be shut down, and the traversal operation is stopped.

[0149] The examples provided are for illustrative purposes only and should not be construed as limiting the scope of this application.

[0150] Optionally, if the preset condition is: the available power of the second system is less than the available power of the first system, and the absolute value of the difference between the available power of the second system and the available power of the first system is greater than or equal to a second value. The intelligent control unit determines the new target load based on the available power of the second system, the rated power corresponding to each downhole load, the preset downhole load priority, and all currently powered target loads. The method may be as follows: the intelligent control unit iterates through each currently unpowered downhole load in descending order of priority. For each unpowered downhole load, it determines whether the sum of the rated power of that downhole load and the second cumulative demand power is less than the available power of the second system; wherein, the second cumulative demand power is the sum of the total power currently allocated to the target loads and the rated power of all currently determined new target loads that need to be switched.

[0151] The specific value of the second value can be set according to actual needs. For example, the second value can be a pre-set fixed value.

[0152] Alternatively, the second value can be the product of the available power of the first system and a preset reduction ratio. For example, the preset reduction ratio could be 5%, 10%, 15%, etc.

[0153] To facilitate understanding of the above-mentioned method for switching underground loads in coal mine safety power supplies, the following will combine... Figure 2 Let's illustrate with examples.

[0154] like Figure 2 As shown, the ground condition monitoring unit first determines whether the ground substation is in a state of complete power outage. If it is not in a state of complete power outage, monitoring continues.

[0155] In the event of a complete power outage, the ground-based status monitoring unit sends a monitoring signal representing the power outage to the intelligent control unit.

[0156] Upon receiving a monitoring signal indicating a complete power outage, the intelligent control unit activates the emergency power supply.

[0157] The power status monitoring unit monitors the operating status of the backup power supply and evaluates the first real-time maximum output power of the backup power supply.

[0158] The intelligent control unit calculates the first system available power based on the first real-time maximum output power and the preset safety factor; and determines the target load based on the first system available power, the rated power corresponding to each downhole load, and the preset downhole load priority.

[0159] The load controller controls the switching system to supply power to the target load.

[0160] The power status monitoring unit continuously monitors the operating status of the backup power supply and evaluates the second real-time maximum output power of the backup power supply.

[0161] The intelligent control unit calculates the available power of the second system based on the second real-time maximum output power and the preset safety factor.

[0162] When the change in available power of the second system relative to available power of the first system meets preset conditions, the intelligent control unit determines a new target load or updates the existing target load to a designated load that does not require power supply, based on the available power of the second system, the rated power corresponding to each downhole load, the preset downhole load priority, and all currently powered target loads.

[0163] The load controller controls the switching system to supply power to the new target load, or the load controller controls the switching system to stop supplying power to the designated load.

[0164] Figure 2 The specific implementation methods of each step shown have been clearly described above, and will not be repeated here for the sake of brevity.

[0165] Based on the same technical concept, this application also provides a coal mine safety power supply underground load switching system, such as... Figure 3 As shown, the underground load switching system for coal mine safety power supply includes a surface substation and an underground substation. The surface substation includes a safety power supply 110, a surface status monitoring unit 120, a power status monitoring unit 130, and an intelligent control unit 140. The underground substation includes a load controller 210.

[0166] The ground status monitoring unit 120 is used to determine whether the ground substation is in a state of complete power failure; if it is determined that the ground substation is in a state of complete power failure, it sends a monitoring signal representing the complete power failure to the intelligent control unit 140.

[0167] The intelligent control unit 140 is used to activate the emergency power supply 110 after receiving a monitoring signal indicating a complete power outage; the emergency power supply 110 is used to provide emergency power to the underground substation, which in turn provides power to the underground load.

[0168] The power status monitoring unit 130 is used to monitor the operating status of the backup power supply 110 and evaluate the first real-time maximum output power of the backup power supply 110.

[0169] The intelligent control unit 140 is also used to calculate the first system available power based on the first real-time maximum output power and the preset safety factor; and to determine the target load based on the first system available power, the rated power corresponding to each downhole load, and the preset downhole load priority; wherein the sum of the rated power of all target loads is less than the first system available power, and the priority is used to indicate the importance ranking of the downhole loads.

[0170] The load controller 210 is used to control the switching system to supply power to the target load.

[0171] The specific implementation methods and execution logic of the security power supply 110, ground status monitoring unit 120, power status monitoring unit 130, intelligent control unit 140, and load controller 210 have been clearly described above, and will not be repeated here for the sake of brevity.

[0172] In one implementation, the backup power supply 110 may include a diesel generator set and a new energy power source. In this implementation, the power status monitoring unit 130 is specifically used to receive first real-time data sent by the diesel generator set, including its current maximum allowable output power, and to receive second real-time data sent by the new energy power source, including its current maximum sustainable output power; calculate the sum of the current maximum allowable output power and the current maximum sustainable output power to obtain the first real-time maximum output power.

[0173] In one implementation, such as Figure 4 As shown, the underground load switching system for coal mine safety power supply also includes an underground status monitoring unit 220, which is used to detect the conduction status of the load switch corresponding to each underground load.

[0174] The load controller 210 is also used to determine whether the load switch corresponding to each target load is turned on based on the downhole condition monitoring unit 220, and when it is determined that the load switch corresponding to each target load is turned on, to send a feedback signal to the intelligent control unit 140 indicating that the power supply to the target load is completed.

[0175] The specific execution logic of the downhole condition monitoring unit 220 has been clearly described above, and will not be repeated here for the sake of brevity.

[0176] In one implementation, the intelligent control unit 140 further includes a human-machine interface module. The human-machine interface module is used to respond to user operations, configure or modify the rated power of the underground load, and display the working information, alarm information, and historical data of the coal mine safety power supply underground load switching system.

[0177] The operational information of the underground load switching system for coal mine safety power supply may include the operational status of the target load currently being supplied with power, as well as an overview of the system's status.

[0178] Users can also use this human-computer interaction module to perform operations such as querying historical data.

[0179] The human-computer interaction module can also be used to display information such as animated demonstrations of the load switching process.

[0180] Optionally, the human-machine interaction module can be a touch screen, which allows users to configure or modify the rated power of the underground load, and display the working information, alarm information, and historical data of the underground load switching system for coal mine safety power supply through operation on the touch screen.

[0181] Alternatively, the human-computer interaction module can be a combination of input devices (such as keyboards, mice, etc.) and a display.

[0182] The implementation of the human-computer interaction module is not limited to the method exemplified here.

[0183] In one implementation, the ground status monitoring unit 120 is specifically used to obtain the voltage, current and bus tie switch of the bus in the incoming line cabinet of the ground substation from the incoming line cabinet; and to determine whether the judgment condition of power outage of the entire substation is met based on whether the voltage, current and bus tie switch of the bus in the incoming line cabinet are in the open state.

[0184] The conditions for determining a complete power outage include: the voltage of the busbar in the incoming line cabinet is less than the preset power outage standard voltage, which is determined based on the rated voltage of the busbar in the incoming line cabinet; the current of the busbar in the incoming line cabinet is less than or equal to the preset rated power outage standard current; and the bus tie switch in the incoming line cabinet is in the open state. When all the conditions for determining a complete power outage are met, the ground substation is determined to be in a state of complete power outage.

[0185] In one embodiment, the underground load switching system for coal mine safety power supply also includes a switch cabinet. The switch cabinet is used to receive power from the mains grid and use the mains grid power to supply power to the underground load.

[0186] The underground load switching system for coal mine safety power supply provided in this application has the same implementation principle and technical effect as the aforementioned underground load switching method for coal mine safety power supply. For the sake of brevity, any parts not mentioned in the device embodiment can be referred to the corresponding content in the aforementioned underground load switching method for coal mine safety power supply.

[0187] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for switching underground loads in a coal mine safety power supply, characterized in that, An application is made to an underground load switching system for emergency power supply in coal mines. The system includes a surface substation and an underground substation. The surface substation includes an emergency power supply, a surface status monitoring unit, a power status monitoring unit, and an intelligent control unit. The underground substation includes a load controller. The method includes: After the ground status monitoring unit determines that the ground substation is in a state of complete power failure, the intelligent control unit activates the emergency power supply; the emergency power supply is used to provide emergency power to the underground substation, and the underground substation is used to supply power to the underground load; The power status monitoring unit monitors the operating status of the backup power supply and evaluates the first real-time maximum output power of the backup power supply. The intelligent control unit calculates the first system available power based on the first real-time maximum output power and a preset safety factor; and determines the target load based on the first system available power, the rated power corresponding to each downhole load, and a preset downhole load priority; wherein the sum of the rated power of all the target loads is less than the first system available power, and the priority is used to indicate the importance ranking of the downhole loads; The load controller controls the switching system to supply power to the target load.

2. The method according to claim 1, characterized in that, The target load is determined based on the available power of the first system, the rated power corresponding to each downhole load, and the preset downhole load priority, including: Each downhole load is traversed in descending order of priority; For each downhole load, determine whether the sum of the rated power and the cumulative demand power of the downhole load is less than the available power of the first system; wherein, the cumulative demand power is the sum of the rated power of all currently determined loads that need to be switched; If the sum of the rated power of the downhole load and the cumulative demand power is less than or equal to the available power of the first system, the downhole load is determined to be the target load that needs to be switched. If the sum of the rated power of the downhole load and the cumulative demand power is greater than the available power of the first system, the downhole load is determined to be a load that does not need to be switched.

3. The method according to claim 1, characterized in that, The security power supply includes multiple sub-power supplies, and the first real-time maximum output power of the security power supply is the sum of the real-time maximum output power of each of the sub-power supplies.

4. The method according to claim 1, characterized in that, After the load controller controls the switching system to supply power to the target load, the method further includes: The power status monitoring unit monitors the operating status of the backup power supply and evaluates and obtains the second real-time maximum output power of the backup power supply. The intelligent control unit calculates the second system available power based on the second real-time maximum output power and the preset safety factor; When the change in the available power of the second system relative to the available power of the first system meets a preset condition, the intelligent control unit determines a new target load or updates the existing target load to a designated load that does not require power supply, based on the available power of the second system, the rated power corresponding to each of the downhole loads, the preset downhole load priority, and all currently powered target loads. The load controller controls the switching system to supply power to the new target load, or the load controller controls the switching system to stop supplying power to the designated load.

5. The method according to claim 4, characterized in that, The preset condition is that the available power of the second system is at least increased by a first value compared to the available power of the first system; The intelligent control unit determines a new target load based on the available power of the second system, the rated power corresponding to each of the downhole loads, the preset downhole load priorities, and all currently powered target loads, including: The intelligent control unit traverses each currently unpowered downhole load in descending order of priority; For each unpowered downhole load, determine whether the sum of the rated power of the downhole load and the second cumulative demand power is less than the available power of the second system; wherein, the second cumulative demand power is the sum of the total power currently allocated to the target load and the rated power of all newly identified target loads that need to be switched on. If the sum of the rated power of the downhole load and the second cumulative demand power is less than or equal to the available power of the second system, the load is determined to be a new target load that needs to be switched. If the sum of the rated power of the load and the second cumulative demand power is greater than the available power of the second system, the load is determined to be a load that does not need to be switched.

6. The method according to claim 4, characterized in that, The preset condition is that the available power of the second system is less than the sum of the rated power of all the target loads; The intelligent control unit updates the existing target loads to designated loads that do not require power supply, based on the available power of the second system, the rated power corresponding to each of the downhole loads, the preset downhole load priorities, and all currently powered target loads. The intelligent control unit traverses all the target loads in order of priority from low to high; For each target load, determine whether the difference between the third cumulative demand power and the rated power of the target load is less than or equal to the available power of the second system; wherein, the third cumulative demand power is the sum of the rated power of all target loads minus the difference between the rated power of all currently determined specified loads; If the difference between the third cumulative demand power and the rated power of the target load is greater than the available power of the second system, the target load is determined to be a designated load that needs to be shut down, and the traversal operation continues. If the difference between the third cumulative demand power and the rated power of the load is less than or equal to the available power of the second system, the target load is determined to be the designated load for which power supply needs to be stopped, and the traversal operation is stopped.

7. The method according to claim 1, characterized in that, The ground condition monitoring unit determines whether the ground substation is in a state of complete power outage, including: The ground status monitoring unit obtains the voltage, current and bus tie switch status of the bus in the incoming line cabinet of the ground substation from the incoming line cabinet; and determines whether the conditions for a complete power outage are met based on the voltage, current and bus tie switch status of the bus in the incoming line cabinet and whether the conditions for a complete power outage are met. The criteria for determining a complete power outage include: The voltage of the busbar in the incoming line cabinet is less than the preset power failure standard voltage, which is determined based on the rated voltage of the busbar in the incoming line cabinet. The current in the busbar of the incoming line cabinet is less than or equal to the preset rated power failure standard current. The bus tie switch in the incoming line cabinet is in the open state; Specifically, if all the conditions for determining a complete power outage are met, the ground substation is determined to be in a state of complete power outage.

8. A coal mine safety power supply underground load switching system, characterized in that, include: The substation includes a surface substation and an underground substation. The surface substation includes a backup power supply, a surface status monitoring unit, a power status monitoring unit, and an intelligent control unit. The underground substation includes a load controller. The ground status monitoring unit is used to determine whether the ground substation is in a state of complete power failure; if it is determined that the ground substation is in a state of complete power failure, it sends a monitoring signal representing the complete power failure to the intelligent control unit. The intelligent control unit is used to activate the emergency power supply after receiving a monitoring signal indicating a complete power outage; the emergency power supply is used to provide emergency power to the underground substation, and the underground substation is used to supply power to the underground load; The power status monitoring unit is used to monitor the operating status of the backup power supply and evaluate the first real-time maximum output power of the backup power supply. The intelligent control unit is further configured to calculate the first system available power based on the first real-time maximum output power and a preset safety factor; and to determine the target load based on the first system available power, the rated power corresponding to each of the downhole loads, and a preset downhole load priority; wherein the sum of the rated power of all the target loads is less than the first system available power, and the priority is used to indicate the importance ranking of the downhole loads; The load controller is used to control the switching system to supply power to the target load.

9. The underground load switching system for coal mine safety power supply according to claim 8, characterized in that, The backup power supply includes: diesel generator sets and new energy power sources; The power status monitoring unit is specifically used to receive first real-time data, including its current maximum allowable output power, sent by the diesel generator set, and second real-time data, including its current maximum sustainable output power, sent by the new energy power source; calculate the sum of the current maximum allowable output power and the current maximum sustainable output power to obtain the first real-time maximum output power.

10. The underground load switching system for coal mine safety power supply according to claim 8, characterized in that, The underground load switching system for coal mine safety power supply also includes: The downhole condition monitoring unit is used to detect the conduction status of the load switch corresponding to each downhole load; The load controller is further configured to determine whether the load switch corresponding to each target load is turned on based on the downhole status monitoring unit, and when it is determined that the load switch corresponding to each target load is turned on, to send a feedback signal to the intelligent control unit indicating that the power supply to the target load is completed.

11. The underground load switching system for coal mine safety power supply according to claim 8, characterized in that, The intelligent control unit also includes: The human-machine interaction module is used to respond to user operations, configure or modify the rated power of the underground load, and display the working information, alarm information, and historical data of the underground load switching system for coal mine safety power supply.

12. The underground load switching system for coal mine safety power supply according to claim 8, characterized in that, The ground status monitoring unit is specifically used to obtain the voltage, current and bus tie switch status of the bus in the incoming line cabinet of the ground substation from the incoming line cabinet; and to determine whether the conditions for a complete power outage are met based on the voltage, current and bus tie switch status of the bus in the incoming line cabinet and whether the conditions for a complete power outage are met. The criteria for determining a complete power outage include: The voltage of the busbar in the incoming line cabinet is less than the preset power failure standard voltage, which is determined based on the rated voltage of the busbar in the incoming line cabinet. The current in the busbar of the incoming line cabinet is less than or equal to the preset rated power failure standard current. The bus tie switch in the incoming line cabinet is in the open state; Specifically, if all the conditions for determining a complete power outage are met, the ground substation is determined to be in a state of complete power outage.

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