Composite explosion-proof power supply control method and device

Abstract

The invention discloses a composite explosion-proof power supply control method and device, and belongs to the technical field of explosion-proof power supplies. A composite explosion-proof power supply control method comprises the following steps: detecting the running current of a locomotive and the temperature and residual electric quantity of a lead acid battery pack and a lithium ion battery pack; when the residual electric quantity of the lithium ion battery pack is smaller than the alarm threshold value, the first current threshold value serves as a judgment threshold value, when the residual electric quantity of the lithium ion battery pack is larger than the alarm threshold value, the second current threshold value serves as the judgment threshold value, and the second current threshold value is larger than the first current threshold value; when the locomotive operation current is smaller than the judgment threshold value, the locomotive operation state is regarded as a first operation state; when the locomotive operation current is larger than the judgment threshold value, the locomotive operation state is regarded as a second operation state; according to the invention, the lead-acid battery pack and the lithium ion battery pack are dynamically regulated and controlled according to the operation condition of the locomotive and the residual electric quantity of the lead-acid battery pack and the lithium ion battery pack, so that the working time of the battery device can be effectively prolonged.

Description

Technical Field

[0001] This invention relates to the field of explosion-proof power supply technology, and more specifically, to a composite explosion-proof power supply control method and device. Background Technology

[0002] Currently, explosion-proof power supply devices for underground mining electric locomotives mainly consist of lead-acid batteries or lithium-ion batteries. For safety reasons, the capacity of lithium-ion batteries should not be too large; the rated capacity of lithium-ion batteries used in transport vehicles does not exceed 230Ah. This is because the small capacity of lithium-ion batteries makes it difficult to meet usage requirements, and their safety is relatively low, while also being too expensive. Therefore, explosion-proof power supply devices for mines primarily use lead-acid batteries. Lead-acid batteries typically consist of two types: flooded batteries and maintenance-free batteries. Flooded batteries have a long service life, but require more maintenance and generate more hydrogen evolution, resulting in a complex casing design for the explosion-proof power supply device. Maintenance-free batteries are convenient to use and require less maintenance, but their grid alloys are not resistant to charging and discharging, leading to a shorter service life; therefore, their actual usage is relatively small.

[0003] A search revealed that Chinese patent CN101740803B discloses a hybrid battery with self-regulating function, consisting of a lead-acid battery and a lithium iron phosphate battery. This device fully utilizes the characteristics of both lead-acid and lithium iron phosphate batteries, enabling the hybrid battery to automatically adjust the discharge current of each branch without requiring any additional electronic circuitry. This ensures that the voltage of the two branches remains the same, and the lithium iron phosphate battery circuit prioritizes providing high-power discharge capability, avoiding damage caused by the high-current discharge of the lead-acid battery and extending its lifespan.

[0004] Existing composite power supplies do not consider the capacity limitations of lithium-ion batteries in mines, resulting in the lithium-ion batteries being depleted first. To maintain the locomotive's normal operation, the lead-acid batteries undergo deep discharge, severely impacting their lifespan. Therefore, we propose a composite explosion-proof power supply control method and device. Summary of the Invention

[0005] 1. Technical problems to be solved

[0006] The purpose of this invention is to provide a composite explosion-proof power supply control method and device to solve the problems mentioned in the background art.

[0007] 2. Technical Solution

[0008] This invention is achieved through the following technical solution:

[0009] A composite explosion-proof power supply control method includes the following steps:

[0010] S1. Detect the locomotive's operating current, as well as the temperature and remaining charge of the lead-acid battery pack and lithium-ion battery pack;

[0011] S2. When the remaining power of the lithium-ion battery pack is less than the alarm threshold, the first current threshold is used as the judgment threshold. When the remaining power of the lithium-ion battery pack is greater than the alarm threshold, the second current threshold is used as the judgment threshold. The second current threshold is greater than the first current threshold.

[0012] S3. When the locomotive operating current is less than the judgment threshold, the locomotive operating state is regarded as the first operating state; when the locomotive operating current is greater than the judgment threshold, the locomotive operating state is regarded as the second operating state.

[0013] S4. If the locomotive is in the first operating state and the temperature of the lead-acid battery pack is less than the first temperature threshold, then the lead-acid battery pack shall be used for power supply.

[0014] S5. If the locomotive is in the second operating state and the temperature of the lithium-ion battery pack is lower than the second temperature threshold, then the lithium-ion battery pack shall be used for power supply.

[0015] As an optional solution to the technical solution of this application, in S2, the formula for calculating the second current threshold is as follows:

[0016] A1=A0[1+k(E pb -E li )]

[0017] In the formula, A0 is the first current threshold, A1 is the second current threshold, k is an empirical coefficient, and E pb E represents the remaining percentage of charge in the lead-acid battery pack. li This represents the remaining percentage of charge in the lithium-ion battery pack.

[0018] As an optional solution to the technical solution of this application, in S3, the first operating state is the locomotive moving smoothly, and the second operating state is the locomotive climbing a slope or being overloaded.

[0019] As an optional solution to the technical solution in this application, in S4, if the locomotive is in the first operating state and the temperature of the lead-acid battery pack is greater than the first temperature threshold, then a lithium-ion battery pack is used for power supply.

[0020] As an optional solution to the technical solution in this application, in S5, if the locomotive is in the second operating state and the temperature of the lithium-ion battery pack is greater than the second temperature threshold, then the lead-acid battery pack is used for power supply.

[0021] As an optional solution to the technical solution of this application, the first temperature threshold is 60 degrees Celsius and the second temperature threshold is 50 degrees Celsius.

[0022] As an optional solution to the technical solution in this application, in S4 or S5, if the temperature of the lead-acid battery pack is greater than the first temperature threshold and the temperature of the lithium-ion battery pack is greater than the second temperature threshold, then both the lead-acid battery pack and the lithium-ion battery pack will stop supplying power.

[0023] 3. Beneficial effects

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1) This application dynamically regulates the lead-acid battery pack and lithium-ion battery pack according to the locomotive operating conditions and the remaining power of the lead-acid battery pack and lithium-ion battery pack, thereby reducing the impact of high current on the lead-acid battery, improving the service life of the lead-acid battery, and extending the working time of the power supply device.

[0026] 2) By detecting the temperature of the lead-acid battery pack and the lithium-ion battery pack, this application can further dynamically regulate the lead-acid battery pack and the lithium-ion battery pack based on the temperature of the battery pack. This allows the application to not only increase the working time of the power supply device, but also to increase the safety of the power supply device and meet the needs of downhole operations. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the cover structure of a composite explosion-proof power supply device;

[0028] Figure 2 This is a schematic diagram of the enclosure structure of a composite explosion-proof power supply device;

[0029] Figure 3 This is a schematic diagram of the explosion-proof flexible conduit structure of a composite explosion-proof power supply device. Detailed Implementation

[0030] The technical solution of the present invention will now be clearly and completely described in conjunction with the accompanying drawings.

[0031] Example 1:

[0032] This invention provides a composite explosion-proof power supply control method, comprising the following steps:

[0033] S1. Detect the locomotive's operating current, as well as the temperature and remaining charge of the lead-acid battery pack and lithium-ion battery pack;

[0034] S2. When the remaining power of the lithium-ion battery pack is less than the alarm threshold, the first current threshold is used as the judgment threshold. When the remaining power of the lithium-ion battery pack is greater than the alarm threshold, the second current threshold is used as the judgment threshold. The second current threshold is greater than the first current threshold.

[0035] S3. When the locomotive operating current is less than the judgment threshold, the locomotive operating state is regarded as the first operating state; when the locomotive operating current is greater than the judgment threshold, the locomotive operating state is regarded as the second operating state.

[0036] S4. If the locomotive is in the first operating state and the temperature of the lead-acid battery pack is less than the first temperature threshold, then the lead-acid battery pack shall be used for power supply.

[0037] S5. If the locomotive is in the second operating state and the temperature of the lithium-ion battery pack is lower than the second temperature threshold, then the lithium-ion battery pack shall be used for power supply.

[0038] By employing the above method, based on the discharge characteristics of lithium-ion batteries and lead-acid battery packs, lead-acid battery packs can be used for power supply when the locomotive is moving smoothly, while lithium-ion battery packs can be used for power supply under conditions requiring higher output power, such as when the locomotive is climbing or overloaded. When the remaining charge of the lithium-ion battery pack is less than the alarm threshold, the power supply time of the lithium-ion battery pack can be reduced by increasing the judgment threshold, thus extending the service life of the lithium-ion battery pack. This allows the lead-acid battery pack to cover more operating conditions, while the lithium-ion battery pack only supplies power under conditions requiring higher output power, achieving a balanced control between battery life and locomotive travel.

[0039] In S2, the formula for calculating the second current threshold is as follows:

[0040] A1=A0[1+k(E pb -E li )]

[0041] In the formula, A0 is the first current threshold, A1 is the second current threshold, k is an empirical coefficient, and E pb E represents the remaining percentage of charge in the lead-acid battery pack. li This represents the remaining percentage of charge in the lithium-ion battery pack.

[0042] In this scheme, the lead-acid battery pack has a capacity of 500Ah, the lithium-ion battery pack has a capacity of 230Ah, the first current threshold is 25A, and the empirical coefficient is taken as 1.

[0043] By adopting the above control method, the second current threshold can adapt to changes in operating conditions. When the road conditions are rugged and the lithium-ion battery pack is consumed too quickly, the second current threshold is larger, which can effectively extend the service life of the composite battery and avoid the inability of a fixed control strategy to adapt to different operating conditions.

[0044] In S3, the first operating state is when the locomotive moves smoothly, and the second operating state is when the locomotive climbs a slope or is overloaded.

[0045] In S4, if the locomotive is in the first operating state and the temperature of the lead-acid battery pack is greater than the first temperature threshold, then the lithium-ion battery pack will be used for power supply.

[0046] In S5, if the locomotive is in the second operating state and the temperature of the lithium-ion battery pack is greater than the second temperature threshold, then the lead-acid battery pack will be used for power supply.

[0047] In S4 or S5, if the temperature of the lead-acid battery pack is greater than the first temperature threshold and the temperature of the lithium-ion battery pack is greater than the second temperature threshold, then both the lead-acid battery pack and the lithium-ion battery pack will stop supplying power.

[0048] Preferably, the first temperature threshold is 60 degrees Celsius, and the second temperature threshold is 50 degrees Celsius. Temperature control and remaining power control can effectively increase battery life and improve battery safety.

[0049] Example 2:

[0050] Please see Figures 1 to 3 This application provides a composite explosion-proof power supply device, which adopts a composite explosion-proof power supply control method described in Example 1, including a supercapacitor, a lead-acid battery pack, a lithium-ion battery pack and an explosion-proof power supply box. The explosion-proof power supply box is equipped with three independent battery boxes, and the supercapacitor, lead-acid battery pack and lithium-ion battery pack are respectively installed in the three independent battery boxes.

[0051] The explosion-proof power supply box consists of a cover and a body. The cover is a composite cover welded from 5mm hot-rolled steel plate, while the body is welded from 6mm hot-rolled steel plate. Two partitions inside the box divide it into three battery compartments. Ventilation holes are located on the upper side of the body to prevent hydrogen accumulation, and drainage holes are located at the bottom to allow liquids entering the power supply unit to drain promptly. The body and cover are connected by hinges. The composite cover structure ensures the cover will not be damaged by accidental impacts during use. Vent slots on the cover allow hydrogen generated during battery operation to drain promptly, ensuring the hydrogen concentration inside the explosion-proof power supply unit does not exceed 2% (by volume), guaranteeing proper ventilation and gas dissipation. The cover is welded from steel plate, and a lock is installed between the cover and the body, requiring a special tool to open. The inner and outer surfaces of the enclosure are coated with acid-resistant insulating plastic powder. The average thickness of the plastic layer on the inner surface of the enclosure is 1.4mm (not less than 1mm), and the thickness of the plastic layer on the outer surface of the enclosure is 1.3mm (not less than 0.7mm).

[0052] The lead-acid battery pack contains four-terminal valve-regulated maintenance-free cells, each with its own conductivity capable of handling independent circuit current. It uses ABS battery cases and covers, with positive and negative plates employing a plate structure and the grid cast from lead-calcium alloy. Fully sealed flexible connecting wires are used, with no exposed conductive parts. The cells are connected in series by welding to prevent sparking and reduce contact resistance, ensuring safe operation and unobstructed circuitry. Each cell has an vent valve on top, with an opening pressure of 5 kPa.

[0053] Preferably, each individual cell in the lead-acid battery pack is equipped with a three-way valve at its electrolyte filling port. An explosion-proof hose is installed inside the battery box containing the lead-acid battery pack. Multiple three-way valves are connected in series on the explosion-proof hose, with the end of the hose extending out of the battery box and fitted with an explosion-proof plug. The length of the explosion-proof hose extending out of the battery box is no less than 500mm. By installing three-way valves at the electrolyte filling ports of the individual cells in the lead-acid battery pack, internal moisture loss from the battery is prevented, achieving a maintenance-free effect and reducing the workload of lead-acid battery maintenance.

[0054] The lithium-ion battery pack has a square structure, consisting of a high-strength explosion-proof shell and lithium iron phosphate cells. The surface of the lithium-ion battery pack is insulated, and internal protection circuits and pressure valves are installed to prevent safety hazards caused by excessive internal pressure and short circuit faults, thereby increasing the safety performance of lithium-ion batteries.

[0055] The supercapacitor uses a high-capacity wound capacitor with an internal fast-acting fuse for overcurrent protection. It employs an explosion-proof or increased safety structure, protected by a stainless steel casing and filled with explosion-proof rubber to prevent internal faults from causing external explosions. During locomotive startup, the maximum instantaneous current can reach 1C5A, but the duration is short, only about 10 milliseconds. Based on the capacity of the composite explosion-proof power supply device, the supercapacitor specifications are calculated based on a 1C5A instantaneous current, a duration of 10 milliseconds, and 10-15 start-stop cycles. This avoids the impact of large currents on the composite explosion-proof power supply device, improving its safety.

[0056] Preferably, the supercapacitor is 48V 60F. The supercapacitor only provides instantaneous starting current. When the vehicle starts, the supercapacitor begins to work, carrying a large instantaneous current for approximately 10 milliseconds during discharge. After the vehicle is powered on, the supercapacitor disconnects and no longer provides the power required for vehicle operation. Therefore, selecting a smaller supercapacitor facilitates installation within the explosion-proof power supply device and fully utilizes its high-current discharge advantage, reducing the impact of the large current during vehicle startup on the explosion-proof power supply device and improving safety.

[0057] Once the vehicle starts and begins operation, power is supplied according to the composite explosion-proof power supply control method described in Example 1. The discharge timing of the lead-acid battery pack and lithium-ion battery pack is dynamically adjusted based on the vehicle's operating conditions, battery charge status, and temperature. Specifically, when the vehicle is traveling at a constant speed and smoothly, the power management system controls the lead-acid battery pack to supply power and drive the vehicle, while also monitoring the remaining battery charge in real time. When the vehicle is in conditions requiring higher output power, such as climbing or overload, the power management system switches to supply power from the lithium-ion battery pack.

[0058] Dynamically adjusting the lead-acid battery pack and lithium-ion battery pack according to the locomotive's operating conditions can effectively extend the low-current operating time of the lead-acid battery pack, reduce the impact of high current on the lead-acid battery, improve the service life of the lead-acid battery, and extend the working time of the power supply unit.

Claims

1. A composite explosion-proof power supply control method, characterized in that: Includes the following steps: S1. Detect the locomotive's operating current, as well as the temperature and remaining charge of the lead-acid battery pack and lithium-ion battery pack; S2. When the remaining power of the lithium-ion battery pack is less than the alarm threshold, the first current threshold is used as the judgment threshold. When the remaining power of the lithium-ion battery pack is greater than the alarm threshold, the second current threshold is used as the judgment threshold. The second current threshold is greater than the first current threshold. S3. When the locomotive operating current is less than the judgment threshold, the locomotive operating state is regarded as the first operating state; When the locomotive operating current is greater than the judgment threshold, the locomotive operating state is regarded as the second operating state; S4. If the locomotive is in the first operating state and the temperature of the lead-acid battery pack is less than the first temperature threshold, then the lead-acid battery pack shall be used for power supply. S5. If the locomotive is in the second operating state and the temperature of the lithium-ion battery pack is lower than the second temperature threshold, then the lithium-ion battery pack shall be used for power supply.

2. The composite explosion-proof power supply control method according to claim 1, characterized in that: In S2, the formula for calculating the second current threshold is as follows: A1=A0[1+k(E pb -E li )] In the formula, A0 is the first current threshold, A1 is the second current threshold, k is an empirical coefficient, and E pb E represents the remaining percentage of charge in the lead-acid battery pack. li This represents the remaining percentage of charge in the lithium-ion battery pack.

3. The composite explosion-proof power supply control method according to claim 1, characterized in that: In S3, the first operating state is the locomotive moving smoothly, and the second operating state is the locomotive climbing a slope or being overloaded.

4. The composite explosion-proof power supply control method according to claim 1, characterized in that: In S4, if the locomotive is in the first operating state and the temperature of the lead-acid battery pack is greater than the first temperature threshold, then the lithium-ion battery pack will be used for power supply.

5. The composite explosion-proof power supply control method according to claim 1, characterized in that: In S5, if the locomotive is in the second operating state and the temperature of the lithium-ion battery pack is greater than the second temperature threshold, then the lead-acid battery pack will be used for power supply.

6. The composite explosion-proof power supply control method according to claim 1, characterized in that: The first temperature threshold is 60 degrees Celsius, and the second temperature threshold is 50 degrees Celsius.

7. The composite explosion-proof power supply control method according to claim 1, characterized in that: In S4 or S5, if the temperature of the lead-acid battery pack is greater than the first temperature threshold and the temperature of the lithium-ion battery pack is greater than the second temperature threshold, then both the lead-acid battery pack and the lithium-ion battery pack will stop supplying power.

8. A composite explosion-proof power supply device, employing a composite explosion-proof power supply control method as described in any one of claims 1-7, characterized in that: It includes a supercapacitor, a lead-acid battery pack, a lithium-ion battery pack, and an explosion-proof power supply box. The explosion-proof power supply box contains three independent battery boxes, and the supercapacitor, lead-acid battery pack, and lithium-ion battery pack are respectively housed in the three independent battery boxes.

9. A composite explosion-proof power supply device according to claim 8, characterized in that: Each individual cell in the lead-acid battery pack is equipped with a three-way valve at its liquid filling port. The battery box containing the lead-acid battery pack is equipped with an explosion-proof hose. Multiple three-way valves are connected in series on the explosion-proof hose. The end of the explosion-proof hose extends out of the battery box and is equipped with an explosion-proof plug.

10. A composite explosion-proof power supply device according to claim 9, characterized in that: The explosion-proof flexible hose extends out of the battery box by no less than 500 mm.

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