Emergency security power supply system of mine hoist and emergency control method of emergency security power supply system

Abstract

The invention relates to the technical field of mine electromechanical control, and provides a mine hoist emergency security power supply system and an emergency control method thereof. The system comprises a direct current collection bus; the AC end of the bidirectional converter is connected with the power grid, and the DC end is connected with the DC collection bus; the direct-current end of the four-quadrant frequency converter is connected with the direct-current collection bus, the alternating-current end of the motor side is connected with the mine hoist, and regenerative electric energy generated when the mine hoist is in a regenerative braking state is fed back to the direct-current collection bus; a fixed energy storage unit; the vehicle network interaction interface is connected with the direct current collection bus; and the energy management controller is used for controlling the fixed energy storage unit and / or the power battery to supply power to the mine hoist when the power grid fails. The bidirectional converter and a traditional frequency converter are deeply fused, the problems that a traditional emergency power supply is slow in response and complex in structure are fundamentally solved, and the safety requirement of emergency management is completely met.

Description

Technical Field

[0001] This application relates to the field of mining electromechanical control technology, and in particular to an emergency safety power supply system for a mine hoist and its emergency control method. Background Technology

[0002] Mine hoists are core equipment in mine production, consuming enormous amounts of energy. Traditional hoists use resistance to dissipate braking energy, resulting in energy waste and potential overheating. Furthermore, current regulations mandate that coal mine hoists be equipped with emergency power supplies to ensure the safe lifting of the cage to the mine shaft in the event of a main power grid failure, preventing major safety accidents. Current solutions often employ diesel generator sets or large-capacity UPS (Uninterruptible Power Supply), which suffer from slow response, high costs, cumbersome maintenance, and pollution.

[0003] Furthermore, while explosion-proof electric vehicles are becoming increasingly common in mining areas, possessing considerable onboard battery capacity, they are currently only used as transportation tools, and their potential as distributed mobile energy storage remains untapped. Therefore, there is an urgent need for a comprehensive solution that can simultaneously address energy conservation, emergency response, cost reduction, and integrate distributed energy resources within mining areas. Summary of the Invention

[0004] This application provides an emergency safety power supply system for mine hoists and its emergency control method, which deeply integrates a bidirectional converter with a traditional frequency converter, fundamentally solving the problems of slow response and complex structure of traditional emergency power supplies, and fully meeting the safety requirements of emergency management.

[0005] In a first aspect, embodiments of this application provide an emergency backup power supply system for a mine hoist, comprising: DC busbar; A bidirectional converter, wherein the AC terminal of the bidirectional converter on the grid side is connected to the power grid, and the DC terminal of the bidirectional converter is connected to the DC collecting bus; The four-quadrant frequency converter has its DC terminal connected to the DC busbar and its AC terminal on the motor side connected to the mine hoist, which is used to feed back the regenerative electrical energy generated by the mine hoist when it is in regenerative braking state to the DC busbar. A stationary energy storage unit is connected to the DC collecting bus. The vehicle-to-grid interface is connected to the DC bus and is used to connect the power battery of the mining electric vehicle to the DC bus. An energy management controller is connected to the bidirectional converter, the four-quadrant frequency converter, the stationary energy storage unit, and the vehicle-to-grid interface, respectively, and is used to control the stationary energy storage unit and / or the power battery to supply power to the mine hoist when the power grid fails.

[0006] In some embodiments, the bidirectional converter is used to supply power to a DC load and receive DC power fed back from the DC load to the grid; wherein the DC load includes the stationary energy storage unit, the power battery, and the mine hoist; The DC bus is equipped with multiple sets of switching switches corresponding to the DC load. The switching switches are controlled by the energy management controller and used to connect or disconnect the corresponding DC load.

[0007] In some embodiments, the stationary energy storage unit includes: A battery pack and a battery management system, wherein the battery management system is connected to the battery pack and the DC collector bus, respectively.

[0008] In some embodiments, the configured capacity of the battery pack is greater than or equal to a first product divided by a second product; wherein the first product is the product of the preset guaranteed load total power in the mine and the preset continuous power supply time, and the second product is the product of the system charge and discharge efficiency and the allowable discharge depth of the battery pack.

[0009] Secondly, embodiments of this application also provide an emergency control method for a mine hoist emergency backup power system, used to control the mine hoist emergency backup power system as described in the first aspect, the emergency control method comprising: Obtain the power grid status; When a grid fault is detected based on the grid status, the bidirectional converter is controlled to disconnect from the grid, and the stationary energy storage unit and / or the power battery are controlled to supply power to the mine hoist.

[0010] In some embodiments, after obtaining the power grid status, the method further includes: When the power grid is determined to be normal based on the power grid status, the status of the mine hoist is obtained. When the mine hoist is determined to be in regenerative braking state based on its status, the stationary energy storage unit and / or the power battery are controlled to absorb and store the regenerative electrical energy fed back to the DC collector bus via the four-quadrant frequency converter.

[0011] In some embodiments, before obtaining the status of the mine hoist, the method further includes: Obtain electricity price information and determine whether a hoist demand response command has been received; If the current electricity price is determined to be below peak based on the electricity price information, and no demand response instruction for the hoist has been received, the status of the mine hoist is obtained.

[0012] In some embodiments, after obtaining the power grid status, the method further includes: When the power grid is determined to be normal based on the power grid status, the stationary energy storage unit and / or the power battery are controlled according to the electricity price information to charge from the power grid during off-peak hours and discharge during peak hours.

[0013] In some embodiments, after determining that the power grid is normal based on the power grid status, the method further includes: Obtain electricity price information and hoist demand response instructions; When the electricity price is determined to be at its peak based on the electricity price information, the stationary energy storage unit and / or the power battery are controlled to discharge. Based on the electricity price information, if it is determined that the current electricity price is at a non-peak price, and based on the hoist demand response command, if it is determined that there is no hoist demand response, the status of the mine hoist is obtained. When the mine hoist is determined to be in a non-regenerative braking state based on its status, the stationary energy storage unit and / or the power battery are controlled to charge from the grid.

[0014] In some embodiments, supplying power to the mine hoist includes: Prioritize controlling the mine hoist to operate in a safe mode to the designated position, while simultaneously controlling the fixed energy storage unit and / or the power battery to supply power to the ventilation and gas extraction equipment in the mine.

[0015] This application embodiment decomposes the traditional integrated frequency converter into independent functional units and reconstructs the system architecture with the DC collection bus as the core, achieving flexible energy scheduling and multi-path backup, greatly improving system reliability. Fixed energy storage units and mobile power batteries are directly connected to the DC collection bus, eliminating the start-up delay of traditional diesel generators and achieving millisecond-level emergency power switching, fully meeting the emergency power response requirements of mine safety regulations. Therefore, based on the architectural innovation of the DC collection bus, the problems of slow response and complex structure of traditional emergency power supplies are fundamentally solved, forming a complete, reliable, and efficient emergency backup power solution for mine hoists. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of an emergency safety power supply system for a mine hoist provided in an embodiment of this application.

[0018] Figure 2 This is a flowchart illustrating an emergency control method for an emergency safety power supply system for a mine hoist provided in this application.

[0019] Figure 3 This is a schematic diagram illustrating the specific process of an emergency control method for a mine hoist emergency safety power supply system provided in this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] This application relates to the field of integration and control technology of renewable energy and energy storage systems for mining electromechanical equipment, and provides an emergency backup power supply system for mine hoists and its emergency control method, that is, a method for utilizing renewable electrical energy of mine hoists as an emergency backup power supply. Figure 1 This is a schematic diagram of the structure of an emergency safety power supply system for a mine hoist provided in an embodiment of this application. Figure 1 As shown, the emergency backup power system for the mine hoist includes a DC busbar 1, a bidirectional converter 2, a four-quadrant frequency converter 3, a fixed energy storage unit 4, a vehicle-to-grid interface 5, and an energy management controller 6. The AC terminal of the bidirectional converter 2 on the grid side is connected to the power grid 7, and the DC terminal of the bidirectional converter 2 is connected to the DC busbar 1. The DC terminal of the four-quadrant frequency converter 3 is connected to the DC busbar 1, and the AC terminal on the motor side of the four-quadrant frequency converter 3 is connected to the mine hoist 8, used to feed back the regenerative energy generated by the mine hoist 8 when it is in regenerative braking state to the DC busbar 1. The fixed energy storage unit 4 is connected to the DC busbar 1. The vehicle-to-grid interface 5 is connected to the DC busbar 1, used to connect the power battery of the mining electric vehicle to the DC busbar 1. The energy management controller 6 is connected to the bidirectional converter 2, the four-quadrant frequency converter 3, the fixed energy storage unit 4, and the vehicle-to-grid interface 5 respectively, used to control the fixed energy storage unit 4 and / or the power battery to supply power to the mine hoist in the event of a grid failure.

[0022] Specifically, DC collector bus 1 refers to the core conductive bus in the system used to collect and distribute DC power, serving as the common DC voltage reference and energy exchange hub for the entire system. Bidirectional converter 2 refers to a power electronic device based on power conversion system technology capable of bidirectional conversion between AC and DC power; its AC side is connected to the power grid, and its DC side is connected to DC collector bus 1. Four-quadrant frequency converter 3 refers to a variable frequency drive device capable of enabling four-quadrant operation of the motor; its DC side is connected to DC collector bus 1, and its AC side is connected to the mine hoist motor; it can both drive the motor and feed back the electrical energy generated by the motor's regenerative braking to DC collector bus 1. Fixed energy storage unit 4 refers to a fixedly installed energy storage system that can be connected to DC collector bus 1 via a power conversion device. Vehicle-to-grid interface 5 refers to a bidirectional energy interaction interface used to connect the power battery of the mining electric vehicle to DC collector bus 1. Energy management controller 6 refers to an intelligent control system used to monitor the system's operating status and coordinate the control of its various components.

[0023] This application embodiment deeply integrates the bidirectional converter 2 of the energy storage system with the AC-DC-AC frequency converter of the drive system, changing the integrated structure of the traditional four-quadrant AC-DC-AC frequency converter in the AC drive system of the hoist. Specifically, it involves leading out a DC collecting bus 1 from the DC output side, responsible for the distribution and scheduling of the entire DC system's power. The traditional AC-DC-AC structure is replaced by two independent power units: the AC-DC bidirectional converter 2 based on PCS (Power Conversion System) technology and the four-quadrant DC-AC frequency converter. Grid AC power is connected through the grid-side AC terminal of the bidirectional converter 2, converted into stable DC power, and then transmitted to the DC collecting bus 1. This bidirectional converter 2 can both accept external power and feed excess power back to the grid.

[0024] The DC power on the DC bus 1 is supplied to the four-quadrant frequency converter 3, which inverts it into variable frequency AC power to drive the mine hoist. When the hoist is in regenerative braking mode, the four-quadrant frequency converter 3 rectifies the AC power generated by the motor into DC power and feeds it back to the DC bus 1. Specifically, the DC bus 1 is connected to the four-quadrant DC-AC frequency converter, which drives the mine hoist. The frequency converter feeds back the electrical energy generated by the hoist's braking and the lowering of heavy loads to the DC bus 1. When the hoist is lowering under heavy load, gravity will drive the motor, causing the motor speed to exceed its electrical synchronous speed. At this time, the motor becomes a generator. The driving conditions consume electrical energy, corresponding to the first and third quadrants. When a heavy object needs to be lifted, the four-quadrant frequency converter 3 receives an operating command. It draws DC power from its DC terminal, specifically from the DC bus 1. The inverter unit inside the four-quadrant frequency converter 3 converts the DC power into three-phase AC power with adjustable frequency and voltage. This precisely controlled AC power is then supplied to the mine hoist motor, driving it to operate at a predetermined speed and torque to complete the lifting task. Power generation occurs in the second and fourth quadrants. When a fully loaded cage needs to be lowered, the operator issues a lowering command. Gravity becomes the primary driving force, rotating the motor and putting it into power generation mode. The three-phase AC power generated by the motor enters the four-quadrant frequency converter 3. At this time, the inverter bridge inside the four-quadrant frequency converter 3 operates in rectification mode, converting the AC power into DC power. The converted DC power is then fed back to the DC bus 1, causing the bus voltage to rise, completing the process of converting gravitational potential energy into electrical energy and feeding it back to the DC bus 1.

[0025] The fixed energy storage unit 4 is directly connected to the DC collection bus 1, serving as the main emergency backup power supply for the mine hoist. Simultaneously, the power battery of the mining electric vehicle is connected to the DC collection bus 1 via the vehicle-to-grid interface 5, forming a mobile emergency backup power supply. Alternatively, it can be understood that the DC collection bus 1, connected to the fixed energy storage unit 4 as the emergency backup power supply for the mine hoist, can also be used to connect the power battery of the mining electric vehicle, serving as a mobile battery for the backup power supply. The energy management controller 6 establishes a connection with the bidirectional converter 2, the four-quadrant frequency converter 3, the fixed energy storage unit 4, and the vehicle-to-grid interface 5 through a communication network, monitoring the system's operating status in real time and intelligently scheduling the distribution of electrical energy in the system. In the event of a grid failure, it immediately controls the fixed energy storage unit 4 and / or the connected power battery to supply power to the mine hoist.

[0026] Mine hoists are core equipment in mine production, consuming enormous amounts of energy and generating renewable energy during operation. Currently, most hoists use four-quadrant AC-DC-AC frequency converters to absorb renewable energy and feed it back to the grid, limiting their application. Bidirectional converters used for green energy grid connection employ similar AC-DC technology and power devices to AC-DC-AC frequency converters. Integrating these two technologies would not only meet the operational requirements of mine hoists but also provide multiple pathways for utilizing renewable energy, particularly facilitating easy and quick connection to energy storage batteries to provide a reliable emergency power source for the mine hoists.

[0027] Therefore, this embodiment of the application decomposes the traditional integrated frequency converter into independent functional units and reconstructs the system architecture with the DC collection bus 1 as the core, realizing flexible energy scheduling and multi-path backup, greatly improving the system reliability. The fixed energy storage unit 4 and the mobile power battery are directly connected to the DC collection bus 1, eliminating the start-up delay of the traditional diesel generator and achieving millisecond-level emergency power switching, fully meeting the emergency power response requirements of mine safety regulations. The design of the DC collection bus 1 enables optimized scheduling of hoist regenerative braking energy, fixed energy storage, mobile energy storage, and grid power on a unified platform, realizing cascaded utilization and efficient management of energy. The modular architecture design allows the system to easily expand energy storage capacity or add new energy access simply by adding corresponding interfaces to the DC collection bus 1, greatly improving the system's scalability. Each power unit is independently configured, and can be repaired or replaced individually in case of failure without affecting the normal operation of other units, significantly improving the system's maintainability and availability. In summary, this innovative architecture based on DC bus 1 fundamentally solves the problems of slow response and complex structure of traditional emergency power supplies, forming a complete, reliable, and efficient emergency power supply solution for mine hoists.

[0028] Furthermore, mine hoists are core equipment in mine production. During operation, they can feed the electrical energy generated by regenerative braking back to the power grid. Alternatively, the electrical energy generated by regenerative braking can be directly stored in emergency safety energy storage batteries. In the event of a sudden power outage, these batteries can quickly release energy, ensuring the normal operation of the auxiliary shaft hoist, evacuating underground workers to the surface for emergency rescue, and allowing the main shaft hoist to safely return to its position, achieving reliable interlocking and ensuring hoist safety. Compared to directly feeding the energy back to the grid, this energy storage method reduces the number of converter stages, resulting in higher energy utilization efficiency and greater flexibility.

[0029] In some embodiments, the bidirectional converter 2 is used to supply power to the DC load and receive DC power feedback from the DC load to the grid; wherein the DC load includes a fixed energy storage unit 4, a power battery and a mine hoist; the DC collection bus 1 is provided with multiple sets of switching switches corresponding to the DC load, and the switching switches are controlled by the energy management controller 6 and used to connect or disconnect the corresponding DC load.

[0030] Specifically, DC loads refer to the general term for equipment connected to the DC collector bus 1 that consumes or provides DC power. In this system, it specifically refers to the stationary energy storage unit 4, the power battery, and the mine hoist, with the mine hoist connected to the DC side via a four-quadrant frequency converter 3. Multiple switching switches refer to fast-acting devices installed on the DC collector bus 1, independently configured for different DC loads, enabling independent switching control of each DC load. That is, the bidirectional converter 2 uses multi-mode technology to provide DC power to the stationary energy storage unit 4, the power battery, and the mine hoist with different power requirements, and receives DC power feedback from these DC loads and inputs it into the grid. Multi-mode technology refers to the control technology that allows the bidirectional converter 2 to automatically switch between different operating modes according to system requirements, such as grid-connected rectification, grid-connected inverter, and off-grid operation.

[0031] Through advanced bidirectional converter 2 technology and intelligent switching configuration, refined management and flexible scheduling of DC loads are achieved. The bidirectional converter 2 operates in rectification mode, converting AC power from the grid into DC power to provide energy to various DC loads connected to the DC collector bus 1. Employing multi-mode control technology, it can automatically adapt to the power demand characteristics of different DC loads, providing stable and high-quality DC power to equipment with varying power requirements, such as fixed energy storage units 4, power batteries (i.e., mobile batteries), and mine hoists. When excess DC power is generated in the system, such as during regenerative braking of the hoist, or when energy storage units or power batteries feed back energy to the system, the bidirectional converter 2 operates in inverter mode, converting the DC power fed back from these loads into AC power that meets grid requirements, thus achieving energy feedback to the grid.

[0032] Multiple sets of DC fast transfer switches are installed on the DC collection bus 1 for each DC load, forming a modular electrical connection structure. The energy management controller 6 monitors the operating status of each DC load and the system energy demand in real time, and controls the corresponding transfer switches. For example, specific DC loads can be flexibly connected or disconnected according to scheduling needs, the optimal power supply path can be quickly established in emergency situations, the load can be grouped and redundantly configured, and fault propagation can be prevented, thereby improving system reliability.

[0033] Therefore, through the multi-mode technology of the bidirectional converter 2 and the intelligent switching configuration of the DC collection bus 1, the system can flexibly adjust the power supply strategy according to real-time needs, adapting to changes in power demand under different operating conditions. Independent control of multiple sets of switching switches enables precise management of specific loads, avoiding a one-size-fits-all approach and improving energy utilization efficiency. The modular switch configuration provides redundancy backup capabilities; when a load fails, it can be quickly disconnected from the bus without affecting the normal operation of other loads. Intelligent switching control combined with the multi-mode operation of the bidirectional converter 2 allows the system to prioritize energy storage power supply during peak electricity price periods and charge during off-peak periods, optimizing operating costs. The grouped control switch configuration allows system maintenance to be performed by simply disconnecting the switches of the corresponding loads, without requiring a complete power outage, greatly improving system maintainability and availability.

[0034] In some embodiments, the stationary energy storage unit 4 includes a battery pack and a battery management system, with the battery management system connected to both the battery pack and the DC bus 1. Specifically, the battery management system monitors parameters such as battery pack voltage, current, and temperature, and performs balancing management to ensure safe battery operation. The battery management system uploads information such as the battery pack's state of charge and health status to the energy management controller 6 in real time, providing a basis for decision-making. Simultaneously, it achieves precise, efficient, and safe management of the stationary energy storage unit 4, ensuring the reliability of emergency power supply, extending the battery pack's lifespan, and laying the foundation for long-term stable system operation.

[0035] In some embodiments, the configured capacity of the battery pack is greater than or equal to a first product divided by a second product; wherein the first product is the product of the preset guaranteed load total power in the mine and the preset continuous power supply time, and the second product is the product of the system charge and discharge efficiency and the allowable discharge depth of the battery pack.

[0036] Specifically, the preset total power of the guaranteed load is the sum of the power of underground equipment that must be powered in emergency situations, such as hoists, ventilators, and gas drainage pumps, as required by regulations or determined by the mine's own safety needs. The preset continuous power supply time is the minimum continuous power supply time for emergency power as required by regulations or determined by the mine's own safety needs. The system charge / discharge efficiency is the efficiency of the entire process from the DC collector bus 1 into the battery pack and then back to the DC collector bus 1. The allowable depth of discharge is the maximum degree of battery discharge allowed to ensure battery life and safety.

[0037] This application sets the battery pack's configured capacity to be greater than or equal to the first product divided by the second product. The product of the preset total power of the underground mine's guaranteed load and the preset continuous power supply time is used to calculate the total energy the battery pack needs to provide in emergency situations. Due to limitations in system charging and discharging efficiency and the battery pack's permissible depth of discharge, the actual rated capacity of the fixed energy storage unit 4 must be greater than or equal to the first product divided by the second product to ensure that, after considering losses and battery protection, the mandatory requirements of the preset total power of the underground mine's guaranteed load and the preset continuous power supply time can still be met. This avoids the problems of insufficient capacity failing to meet safety requirements or excessive capacity causing wasted investment, ensuring that the system can reliably complete its tasks even in the most extreme circumstances, achieving an optimal balance between investment efficiency and safety assurance.

[0038] In some embodiments, the vehicle-to-grid interface 5 is a bidirectional charging pile, and the vehicle-to-grid interface 5 and the power battery of the electric vehicle constitute a mobile energy storage system.

[0039] Specifically, a bidirectional charging pile is a charging device with bidirectional power flow capability, capable of both charging vehicles and drawing power from them. The bidirectional charging pile communicates with and controls the charging and discharging of the mining electric vehicle's onboard battery management system. In other words, it establishes a connection with the mining electric vehicle's onboard battery management system, enabling it to access the vehicle's power battery and execute charging and discharging commands issued by the system. The bidirectional charging pile serves as a physical interface and communication gateway, connecting distributed mining electric vehicles to the system. When the energy management controller 6 needs to manage the power batteries of the mining electric vehicles, it sends instructions, such as discharge power and voltage demand instructions, to the on-board battery management system via the bidirectional charging pile. The on-board battery management system then executes operations based on the power battery status, achieving controlled flow of electrical energy. Thus, this application transforms the mining electric vehicle from a simple transportation tool into a mobile energy storage unit for the system, enabling dynamic expansion of energy storage and greatly enhancing the system's flexibility and redundancy. When the fixed energy storage capacity is insufficient, the vehicle's battery can be used to provide critical support, improving the reliability of the entire emergency safety system.

[0040] This application also provides an emergency control method for an emergency backup power supply system for a mine hoist. Figure 2 This is a flowchart illustrating an emergency control method for a mine hoist emergency backup power system provided in this application. The emergency control method for the mine hoist emergency backup power system is used to control the mine hoist emergency backup power system as described in the above embodiments, and can be executed by the energy management controller as described in the above embodiments. Figure 2 As shown, the emergency control method for the emergency backup power supply system of a mine hoist includes the following steps: Step 101: Obtain the power grid status.

[0041] Specifically, the power grid status includes electrical parameters such as voltage and frequency, which are used to determine whether the power grid is supplying power normally. The energy management controller continuously monitors the power grid status parameters.

[0042] Step 102: When a grid fault is detected based on the grid status, control the bidirectional converter to disconnect from the grid and control the fixed energy storage unit and / or the power battery connected through the vehicle-to-grid interface to supply power to the mine hoist.

[0043] Specifically, the energy management controller continuously monitors grid status parameters. Once it detects fault characteristics such as a sudden drop or disappearance of voltage, it immediately diagnoses the grid fault. After confirming the grid fault, it first commands the bidirectional converter to disconnect from the grid. This involves issuing a trip command to the bidirectional converter, causing its internal AC contactor or circuit breaker to quickly disconnect, thereby electrically isolating the system from the faulty grid and creating an islanded operation mode. This aims to prevent the system from feeding back power to the faulty grid, ensuring the safety of grid maintenance personnel, and avoiding any impact on the grid from the islanded system. Simultaneously, almost instantly, the stationary energy storage unit and / or power battery are activated to supply power to the mine hoist, seamlessly taking over power supply to the hoist from the grid.

[0044] This application enables a fully automatic, rapid, and seamless switching from power grid failure to emergency power activation. The entire process is completed within milliseconds to seconds, far exceeding the minute-level start-up time of diesel generators. This ensures the safety of personnel and equipment inside the cage and avoids the risk of hoist malfunction due to power outages.

[0045] In some embodiments, controlling the stationary energy storage unit and / or the power battery to supply power to the mine hoist includes: prioritizing the mine hoist to operate in a safe mode to a designated location, while simultaneously controlling the stationary energy storage unit and / or the power battery connected via the vehicle-to-grid interface to supply power to the ventilation equipment and gas extraction equipment in the mine.

[0046] Specifically, the safety mode is a dedicated operating procedure for the hoist, set up under emergency power supply conditions to ensure the safety of equipment and personnel. This may include reducing operating speed, limiting acceleration, and canceling unnecessary operations. The designated location is a pre-set safe stopping point for the cage according to safety regulations; this can be a pre-set safety platform at the wellhead or within the shaft. Ventilation equipment and gas extraction equipment are critical safety load equipment in coal mines, ensuring underground air circulation and preventing gas accumulation. Ventilation equipment may include, for example, main ventilation fans and local ventilation fans.

[0047] In emergency power supply mode, the energy management controller executes a priority-based power supply strategy. The highest priority instruction is to send a safe mode operation command to the hoist control system, controlling the hoist to move the cage to the preset designated position at a low speed and smoothly. Simultaneously, the energy management controller dispatches power in parallel, continuously supplying power to the underground ventilation and gas extraction equipment through the same emergency power supply network. This power supply process is synchronized with the power supply to the hoist, both being uniformly coordinated by the energy management controller to ensure that hoisting operations and underground environmental safety can be carried out simultaneously under limited emergency power. Therefore, this application achieves optimized and safest allocation of emergency power, not only solving the core problem of hoisting personnel and equipment to a safe position but also simultaneously ensuring the safety of the underground atmospheric environment, effectively preventing secondary disasters such as asphyxiation and gas explosions that may be caused by ventilation shutdowns and gas extraction interruptions. It upgrades the emergency protection of a single device, the hoist, to comprehensive protection of the entire mine's critical safety system, greatly improving the overall safety level of mine emergency management.

[0048] In some embodiments, after obtaining the grid status, the method further includes: when the grid is determined to be normal based on the grid status, obtaining the status of the mine hoist; when the mine hoist is determined to be in regenerative braking state based on the mine hoist status, controlling the fixed energy storage unit and / or the power battery connected through the vehicle-to-grid interface to absorb and store the regenerative electrical energy fed back to the DC collector bus via the four-quadrant inverter.

[0049] Specifically, regenerative braking occurs when the hoist is lowered under heavy load, and the motor, under the influence of gravity, exceeds the synchronous speed, operating as a generator to convert gravitational potential energy into electrical energy. The regenerative electrical energy is generated by the hoist motor during regenerative braking. When the power grid is normal and the hoist is in regenerative braking mode, the energy management controller detects an increase in the DC bus voltage due to energy feedback. At this time, the energy management controller does not feed energy back to the grid but prioritizes controlling the stationary energy storage unit and the power battery. Specifically, it controls the stationary energy storage unit to absorb and store the regenerative electrical energy fed back to the DC bus via the four-quadrant inverter, and controls the power battery to absorb and store the regenerative electrical energy fed back to the DC bus via the four-quadrant inverter through the bidirectional charging pile, thus absorbing and storing the regenerative electrical energy on the DC bus.

[0050] Therefore, this application converts the braking energy that would otherwise be consumed or directly fed back to the grid into valuable chemical energy for storage and use. Taking 40 heavy-load descents of the hoist per day for regenerative braking as an example, with each regenerative braking recovering 15 kWh of energy, the daily recovered energy reaches 600 kWh, resulting in considerable annual electricity savings. This not only generates direct energy-saving benefits but also avoids thermal pollution from braking resistors, achieving green operation.

[0051] In some embodiments, before obtaining the status of the mine hoist, the method further includes: obtaining electricity price information and determining whether a hoist demand response instruction has been received; if the current electricity price is determined to be at a non-peak price based on the electricity price information and no hoist demand response instruction has been received, the mine hoist status is obtained, i.e., determining whether the hoist is in a re-braking power generation state.

[0052] Specifically, electricity price information refers to the time-of-use (TOU) price signals released by the power grid, which can be divided into different time periods such as peak, flat, and off-peak. The hoist demand response command is a signal issued by the hoist system itself indicating that it is about to or is currently performing a hoisting task. Determining that there is no hoist demand response based on the hoist demand response command is equivalent to a non-peak electricity price, such as during nighttime. Determining that there is hoist demand response based on the hoist demand response command is equivalent to a peak electricity price, such as during daytime mining operations. Before determining whether to perform energy recovery, the energy management controller checks the electricity price and hoist operating demand. The condition of a non-peak electricity price and a corresponding hoist demand response (i.e., no hoisting task) avoids increasing costs by charging during periods of high electricity prices. Energy recovery mode is only allowed to be activated when the electricity price is non-peak and there is no hoisting task.

[0053] Therefore, by introducing electricity price and operational demand as prerequisites, this application makes energy recovery operations more intelligent and economical, prevents uneconomical behavior that may result from recycling during peak electricity price periods, and optimizes the overall operational economy of the system without affecting core production safety.

[0054] In some embodiments, after obtaining the grid status, the method further includes: when the grid is determined to be normal based on the grid status, controlling the stationary energy storage unit and / or the power battery connected through the vehicle-to-grid interface to charge from the grid during off-peak hours and discharge during peak hours based on the electricity price information.

[0055] Specifically, off-peak electricity prices, which are the periods when grid electricity prices are lowest, typically occur at night. Peak electricity prices, which are the periods when grid electricity prices are highest, typically occur during the day. When the grid is operating normally, the energy management controller executes a strategy of buying low and selling high based on preset clock and electricity price information. During off-peak hours at night, the controller controls stationary energy storage units and / or power batteries connected via vehicle-to-grid interfaces to draw power from the grid and store low-cost energy. During peak hours during the day, the controller controls stationary energy storage units and / or power batteries connected via vehicle-to-grid interfaces to discharge to the system's DC bus, replacing the need to purchase high-priced electricity from the grid to supply power to the mine load.

[0056] Therefore, this application utilizes the peak-valley electricity price difference for arbitrage, generating significant economic benefits for the system and effectively shortening the project's investment payback period. Simultaneously, discharging electricity during peak hours also alleviates the power grid's supply pressure, thus playing a role in peak shaving.

[0057] In some embodiments, after determining that the power grid is normal based on the power grid status, the method further includes: acquiring electricity price information and hoist demand response instructions; when determining that the current electricity price is at a peak price based on the electricity price information, controlling the fixed energy storage unit and / or the power battery connected through the vehicle-to-grid interface to discharge; when determining that the current electricity price is at a non-peak price based on the electricity price information and determining that there is no hoist demand response based on the hoist demand response instructions, acquiring the mine hoist status; and when determining that the mine hoist is in a non-regenerative braking state based on the mine hoist status, controlling the fixed energy storage unit and / or the power battery connected through the vehicle-to-grid interface to charge from the power grid.

[0058] Specifically, during peak electricity prices or when a grid demand response command is received, the energy management controller instructs stationary energy storage units and / or power batteries connected via the vehicle-to-grid interface to discharge, achieving peak shaving and valley filling. During off-peak electricity prices and when there is no demand response, the energy management controller checks the hoist status to determine whether to recover energy. If the hoist is also not in a braking state, the energy management controller instructs stationary energy storage units and / or power batteries connected via the vehicle-to-grid interface to charge from the grid during off-peak hours to replenish energy.

[0059] Therefore, this application maximizes the system's economic benefits by integrating various profit and energy-saving models, such as peak-valley arbitrage, demand response, and energy recovery, into a single intelligent decision-making framework. This enables the system to automatically find and execute the optimal operating strategy, maximizing return on investment and demonstrating a high degree of intelligence and economy. For example, in the power battery or bidirectional charging pile scheduling step, the energy management controller prioritizes electric vehicles with higher remaining state of charge (SOC) for discharging and reserves a minimum charge level for vehicles performing emergency tasks.

[0060] Figure 3 This is a schematic diagram illustrating the specific process of an emergency control method for a mine hoist emergency safety power supply system provided in this application. Figure 3 As shown, the emergency control method for the emergency backup power supply system of a mine hoist specifically includes the following steps: Step 201: System startup.

[0061] Step 202: The energy management controller monitors the power grid status in real time.

[0062] Specifically, the energy management controller can also monitor electricity price information, whether it has received demand response commands from the hoist, and the remaining power of the battery packs in the vehicle's power battery and stationary energy storage unit in real time.

[0063] Step 203: Determine if the power grid is normal. If yes, proceed to step 209; if no, proceed to step 204.

[0064] Step 204: Enter emergency mode.

[0065] Step 205: Disconnect the power grid.

[0066] Step 206: Control the discharge of stationary energy storage units and / or power batteries.

[0067] Step 207: Prioritize power supply to critical loads and control the safe operation of the hoist.

[0068] Step 208: Emergency procedure ends.

[0069] Step 209: Determine whether the electricity price is at its peak or whether a demand response instruction has been received. If yes, proceed to step 210; otherwise, proceed to step 212.

[0070] Specifically, if the current electricity price is determined to be below peak based on the electricity price information, and no hoist demand response command has been received, the status of the mine hoist is obtained. Under other conditions, step 212 is executed.

[0071] Step 210: Enter discharge mode.

[0072] Step 211: Control the discharge of the stationary energy storage unit and schedule the discharge of the available power battery.

[0073] Step 212: Determine if the hoist is in generator mode. If yes, proceed to step 213; otherwise, proceed to step 215.

[0074] Step 213: Enter energy recovery mode.

[0075] Step 214: Control the regenerative energy to prioritize charging the stationary energy storage unit and the connected power battery.

[0076] Step 215: Enter charging mode.

[0077] Step 216: Control the charging of stationary energy storage units and power batteries during off-peak electricity price periods.

[0078] Step 217, process loop.

[0079] Specifically, the aforementioned process is executed cyclically back to step 202.

[0080] Figure 3The flowchart shown illustrates the core control logic of an energy management controller, such as an Energy Management System (EMS). The system continuously monitors its operating status and, based on the highest priority criterion of whether the power grid is functioning normally, decides whether to enter emergency mode or normal mode. In normal mode, the energy management controller further intelligently switches between discharge mode (peak shaving or demand response), energy recovery mode (regenerative braking), and charging mode (off-peak charging) based on electricity price signals and the hoist's operating status, forming an efficient closed-loop control.

[0081] In summary, the system is described as follows: The four-quadrant frequency converter is the drive controller for the motor, and its DC collector bus serves as the system's energy hub, capable of feeding regenerative energy back to the grid or the DC collector bus. A stationary energy storage system is connected to the DC collector bus. Bidirectional charging piles are deployed in the mining area to connect to the explosion-proof electric mining vehicles, possessing the ability to communicate with and control the charging and discharging of the onboard battery management system. One or more bidirectional charging piles are used to connect to the explosion-proof electric mining vehicles. The energy management controller, acting as the system's brain, connects to the four-quadrant frequency converter, the stationary energy storage system, and the bidirectional charging piles. The energy management controller is configured to perform the following operations: The system performs mode control, automatically switching between various operating modes such as energy recovery, peak shaving and valley filling, emergency backup, and V2G (Vehicle-to-Grid) dispatching, based on grid status, electricity price signals, load demand, and battery state of charge. It also performs emergency management, monitoring grid voltage in real time and immediately disconnecting the grid connection upon detecting a power outage. This involves controlling the discharge of stationary energy storage systems and / or electric vehicles connected to bidirectional charging piles to provide emergency power for the hoist and critical underground loads, and controlling the hoist to execute safety lifting or shutdown procedures. Furthermore, it performs coordination optimization, coordinating the charging and discharging of stationary energy storage systems and electric vehicle clusters to participate in grid demand response or achieve optimal system operating economy. In summary, the energy management controller connects to the four-quadrant frequency converter, stationary energy storage system, and bidirectional charging piles: scheduling the charging and discharging of stationary energy storage systems and electric vehicles connected via bidirectional charging piles, and switching to emergency mode during grid failures, allowing the stationary energy storage system and / or electric vehicles to provide emergency power for the hoist and critical underground loads.

[0082] In summary, the method is described as follows: In the multi-mode operation, when the power grid is normal, the energy management controller controls the stationary energy storage system to perform peak shaving and valley filling and recover and boost the driving energy. When a grid demand response signal is received or the system is in a peak electricity price period, the energy management controller can schedule connected electric vehicles to discharge to the system through bidirectional charging piles or the stationary energy storage system. When a power outage is detected, the stationary energy storage system immediately enters emergency mode to prioritize power supply to critical loads. In the multi-mode operation, the control system performs energy recovery and peak shaving and valley filling when the power grid is normal, and seamlessly switches to emergency power supply mode when the power grid fails. In the V2G scheduling step, the stationary energy storage system obtains information such as the vehicle type and remaining battery power of the connected vehicles through communication with the bidirectional charging piles, and generates a charging and discharging scheduling plan for the vehicle cluster based on current system needs, such as demand control, emergency redundancy, and peak-valley arbitrage, and sends instructions to each bidirectional charging pile for execution. The stationary energy storage system obtains the battery status information of the connected electric vehicles and generates a charging and discharging scheduling plan to optimize the economic operation of the system or provide emergency power support. In the emergency capacity configuration step, the minimum energy capacity of the stationary energy storage system is calculated and determined based on the required continuous power supply time and total power of the downhole critical loads.

[0083] The technical solution of this application will be described again below with specific embodiments.

[0084] For example, in a coal mine auxiliary shaft hoisting system with a depth of 450 meters, a single 800kW hoist is used for personnel and material transportation. An energy storage device serves as an emergency power source for the hoist, and batteries from electric trackless rubber-wheeled vehicles act as distributed power sources. In the fixed energy storage configuration step, a 1MW / 1.2MWh lithium iron phosphate battery energy storage system is configured to provide continuous power for one hour. In the V2G configuration step, five 120kW bidirectional charging piles are installed in the mine parking area to provide intelligent charging and discharging for 20 trackless rubber-wheeled vehicles, each with approximately 200kWh of power.

[0085] The hoist drive uses an 800kW four-quadrant frequency converter with a DC bus voltage of 700V. During heavy-load lowering and power generation, when a fully loaded cage weighing approximately 15 tons needs to be lowered, the operator issues a lowering command. At this time, the gravitational potential energy of the heavy-load cage becomes the primary power source, driving the motor to rotate. This causes the motor's actual speed to exceed the synchronous speed corresponding to the frequency converter's output frequency, and the motor enters power generation mode.

[0086] In generator mode, the hoist motor becomes a generator, producing three-phase AC power. In rectifier mode, the generated AC power is converted to DC power by the inverter bridge on the output side of the four-quadrant frequency converter, which operates in rectifier mode, and is then delivered to the DC collector bus, causing the bus voltage to rise. The energy management system monitors the DC collector bus voltage in real time. At this time, the energy management system prioritizes controlling the stationary energy storage system to operate in charging mode, storing the electrical energy on the DC collector bus into the battery pack. Under this braking condition, the 800kW hoist can continuously generate 550kW to 600kW of power, with a single descent lasting approximately 90 seconds, recovering approximately 15kWh of electrical energy. If the stationary energy storage is nearing full charge, the energy management system can intelligently dispatch electric mining trucks connected to the bidirectional charging pile at the wellhead for charging, transferring the regenerated energy to the mobile energy storage unit to avoid energy waste.

[0087] One day, a sudden power grid failure caused a blackout throughout the mine. The energy management system detected a sharp drop in grid voltage within 20ms and immediately issued a command to disconnect the grid contactor using the bidirectional converter. Simultaneously, it switched the stationary energy storage system to off-grid inverter mode to power the hoist. Subsequently, the energy management system sent a safety command to the hoist control system. At this point, the stationary energy storage system, acting as an emergency power source, supplied power to the control and drive circuits of the hoist's frequency converter, controlling the hoist to smoothly lift the cage running in the mine to the nearest safe platform in a low-speed, safe mode. To extend the backup time, the energy management system, through the dispatch system, called a nearby electric command vehicle with high remaining battery power to the bidirectional charging station. Once connected, the vehicle acted as a mobile power source, feeding back power to the system's DC bus via the bidirectional charging station, providing additional energy support for safe hoisting.

[0088] The hoist operates approximately 100 cycles per day, with about 40 of those cycles being heavy-load power generation. It can recover approximately 600 kWh of energy daily. The system fully meets mandatory requirements, has a fast response time, and provides reliable power supply, avoiding potential personal safety risks and significant economic losses caused by power outages. Combined with the cost savings from peak shaving and valley filling, it demonstrates significant economic and technological advantages.

[0089] In summary, this application utilizes a single system to simultaneously address three major issues: energy recovery, demand management, and emergency power supply. It complies with regulatory requirements and avoids redundant investment. Employing energy storage batteries as an emergency power source offers rapid response, eliminates the start-up delays and failure risks associated with diesel generator sets, and is zero-emission. By profiting from peak-valley pricing and reducing demand-based electricity costs, the investment payback period can be significantly shortened. The innovative integration of mining electric vehicles into microgrid resources enables dynamic expansion of energy storage, greatly enhancing the system's flexibility and redundancy. Global optimized scheduling is achieved through an energy management controller, improving the intelligence and reliability of mine energy management.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. An emergency backup power supply system for mine hoists, characterized in that, include: DC busbar; A bidirectional converter, wherein the AC terminal of the bidirectional converter on the grid side is connected to the power grid, and the DC terminal of the bidirectional converter is connected to the DC collecting bus; The four-quadrant frequency converter has its DC terminal connected to the DC busbar and its AC terminal on the motor side connected to the mine hoist, which is used to feed back the regenerative electrical energy generated by the mine hoist when it is in regenerative braking state to the DC busbar. A stationary energy storage unit is connected to the DC collecting bus. The vehicle-to-grid interface is connected to the DC bus and is used to connect the power battery of the mining electric vehicle to the DC bus. An energy management controller is connected to the bidirectional converter, the four-quadrant frequency converter, the stationary energy storage unit, and the vehicle-to-grid interface, respectively, and is used to control the stationary energy storage unit and / or the power battery to supply power to the mine hoist when the power grid fails.

2. The emergency safety power supply system for mine hoists according to claim 1, characterized in that, The bidirectional converter is used to supply power to the DC load and receive DC power fed back from the DC load to the grid; wherein, the DC load includes the stationary energy storage unit, the power battery and the mine hoist; The DC bus is equipped with multiple sets of switching switches corresponding to the DC load. The switching switches are controlled by the energy management controller and used to connect or disconnect the corresponding DC load.

3. The emergency safety power supply system for mine hoists according to claim 1, characterized in that, The stationary energy storage unit includes: A battery pack and a battery management system, wherein the battery management system is connected to the battery pack and the DC collector bus, respectively.

4. The emergency safety power supply system for mine hoists according to claim 3, characterized in that, The configured capacity of the battery pack is greater than or equal to the first product divided by the second product; wherein, the first product is the product of the preset guaranteed load total power in the mine and the preset continuous power supply time, and the second product is the product of the system charging and discharging efficiency and the allowable discharge depth of the battery pack.

5. An emergency control method for an emergency backup power supply system for a mine hoist, characterized in that, The emergency control method for controlling the emergency backup power system of a mine hoist as described in any one of claims 1-4 includes: Obtain the power grid status; When a grid fault is detected based on the grid status, the bidirectional converter is controlled to disconnect from the grid, and the stationary energy storage unit and / or the power battery are controlled to supply power to the mine hoist.

6. The emergency control method for the emergency safety power supply system of a mine hoist according to claim 5, characterized in that, After obtaining the power grid status, the process also includes: When the power grid is determined to be normal based on the power grid status, the status of the mine hoist is obtained. When the mine hoist is determined to be in regenerative braking state based on its status, the stationary energy storage unit and / or the power battery are controlled to absorb and store the regenerative electrical energy fed back to the DC collector bus via the four-quadrant frequency converter.

7. The emergency control method for the emergency backup power system of a mine hoist according to claim 6, characterized in that, Before obtaining the status of the mine hoist, the process also includes: Obtain electricity price information and determine whether a hoist demand response command has been received; If the current electricity price is determined to be below peak based on the electricity price information, and no demand response instruction for the hoist has been received, the status of the mine hoist is obtained.

8. The emergency control method for the emergency safety power supply system of a mine hoist according to claim 5, characterized in that, After obtaining the power grid status, the process also includes: When the power grid is determined to be normal based on the power grid status, the stationary energy storage unit and / or the power battery are controlled according to the electricity price information to charge from the power grid during off-peak hours and discharge during peak hours.

9. The emergency control method for the emergency safety power supply system of a mine hoist according to claim 8, characterized in that, After determining that the power grid is normal based on the power grid status, the process further includes: Obtain electricity price information and hoist demand response instructions; When the electricity price is determined to be at its peak based on the electricity price information, the stationary energy storage unit and / or the power battery are controlled to discharge. Based on the electricity price information, if it is determined that the current electricity price is at a non-peak price, and based on the hoist demand response command, if it is determined that there is no hoist demand response, the status of the mine hoist is obtained. When the mine hoist is determined to be in a non-regenerative braking state based on its status, the stationary energy storage unit and / or the power battery are controlled to charge from the grid.

10. The emergency control method for the emergency safety power supply system of a mine hoist according to claim 5, characterized in that, The supply of power to the mine hoist includes: Prioritize controlling the mine hoist to operate in a safe mode to the designated position, while simultaneously controlling the fixed energy storage unit and / or the power battery to supply power to the ventilation and gas extraction equipment in the mine.

Images