Safety type intelligent explosion-proof lithium battery charger with double charging protection strategies

Abstract

The invention discloses a safety type intelligent explosion-proof lithium battery charger with double charging protection strategies. The safety type intelligent explosion-proof lithium battery charger comprises an explosion-proof charging gun and a charging module, the control panel is used for monitoring the single electric quantity voltage stage state of the mining explosion-proof lithium ion storage battery in real time and outputting a charging instruction matched with the single electric quantity voltage stage state according to a preset charging strategy; therefore, the charging module is controlled to provide a charging power supply for the explosion-proof charging gun according to the output voltage / current required by the electric quantity stage state; and meanwhile, the control panel is in communication connection with the BMS system, so that monitoring data of voltage monitoring of each single battery in the explosion-proof lithium ion storage battery by the BMS system can be obtained, and a current charging strategy is automatically adjusted according to an over-limit charging strategy. According to the invention, the purposes of dual charging protection of the mining explosion-proof lithium ion storage battery, improvement of the overall endurance and prolonging of the service life of the battery can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of charging technology for coal mine auxiliary transport lithium-ion transport equipment, and in particular to a safe intelligent explosion-proof lithium-ion charger with a dual charging protection strategy. Background Art

[0002] As explosion-proof new energy vehicles such as explosion-proof lithium-ion battery trackless rubber-tyred vehicles and explosion-proof lithium battery monorail crane locomotives have been fully promoted and applied in coal mines, customers' demand for charging explosion-proof lithium-ion battery vehicles underground in coal mines is becoming more and more urgent.

[0003] At present, the charging protection of explosion-proof chargers mainly adopts the following two methods: one is to charge the explosion-proof lithium-ion battery multiple times in a fast charging mode according to the requirements of the BMS. This method can easily lead to excessive voltage difference between the single cells of the lithium-ion battery power supply, reduce lithium ions, and easily lead to a significant drop in battery capacity, affecting the battery life; the second is to perform charging protection based on the total voltage of the battery box. When the required total voltage exceeds the total voltage of the battery box, overcharge protection is performed. This method is prone to the highest battery cell overvoltage and the BMS does not provide protection. When the overall voltage does not exceed the BMS required voltage (such as 365V), the single battery is in an overcharged state at most. Summary of the Invention

[0004] The purpose of the present invention is to provide a safe intelligent explosion-proof lithium battery charger with a dual charging protection strategy, aiming to solve the drawbacks of traditional explosion-proof chargers.

[0005] To solve the above problems, the present invention provides a safe intelligent explosion-proof lithium battery charger with a dual charging protection strategy, and its corresponding technical solutions include: A safe intelligent explosion-proof lithium battery charger with a dual charging protection strategy, which is used to charge explosion-proof lithium-ion batteries for mining, and is characterized by comprising: Explosion-proof charging gun, used to charge explosion-proof lithium-ion batteries for mining; The charging module is connected to the AC side through an AC contactor and is used to provide charging power to the explosion-proof charging gun according to the charging instructions output by the control board; The control board is connected to the charging module and the explosion-proof lithium-ion battery for mining. It is used to monitor the single cell power voltage stage state of the explosion-proof lithium-ion battery for mining, and output a charging instruction that matches the single cell power voltage stage state according to a preset charging strategy, thereby controlling the charging module to provide charging power to the explosion-proof charging gun according to the output voltage / current required by the single cell power voltage stage state; at the same time, the control board is communicatively connected to the BMS system, and can obtain monitoring data of the voltage monitoring of each single cell in the explosion-proof lithium-ion battery by the BMS system, and automatically adjust the current charging strategy according to the over-limit charging strategy.

[0006] Furthermore, the charging module is connected to the positive terminal of the mining explosion-proof lithium-ion battery through a positive output circuit, and is connected to the negative terminal of the mining explosion-proof lithium-ion battery through a negative output circuit; the positive output circuit includes a fuse and a first DC contactor, one end of the fuse is connected to the positive pole of the charging module, and the other end is connected to the first DC contactor, and the other end of the first DC contactor is connected to the positive terminal of the mining explosion-proof lithium-ion battery and the control board; the negative output circuit includes a second DC contactor and a shunt, one end of the second DC contactor is connected to the negative pole of the charging module and the control board, and one end is connected to the shunt, and the other end of the shunt is connected to the negative terminal of the mining explosion-proof lithium-ion battery.

[0007] Furthermore, the aforementioned safe intelligent explosion-proof lithium battery charger also includes an auxiliary power supply, a control transformer, and an explosion-proof fan. The control transformer is connected to the AC side and outputs DC power through the AC input line to power the auxiliary power supply. The auxiliary power supply includes a first switching power supply and a second switching power supply. The input side of the first switching power supply is connected to the control transformer, and the output side is connected to the explosion-proof fan to power the explosion-proof fan; the input side of the second switching power supply is connected to the control transformer, and the output side is connected to the control board to power the control board; the input side of the explosion-proof fan is connected to the first switching power supply, and the explosion-proof fan dissipates heat for the charging module when the temperature exceeds the limit.

[0008] Furthermore, the cell power voltage stage state is determined according to the voltage difference between the highest cell voltage and the lowest cell voltage inside the mining explosion-proof lithium-ion battery in each new monitoring cycle, and is specifically divided into the following stage states: First stage state: When the pressure difference U 差 ≤ the first threshold; Second stage state: When the pressure difference U 差 >First threshold.

[0009] Furthermore, the charging strategy is to output a charging instruction that matches the single cell power voltage stage state of the mining explosion-proof lithium-ion battery according to the single cell power voltage stage state. The aforementioned charging instruction is: If the single cell voltage stage state is the second stage state, a normal charging command is output; If the cell voltage and power stage state is the first stage state, an adjustable charging command is output; The charging current I corresponding to the adjustable charging command 充 The calculation formula is I 充 =a / U 差 , where a is the current limiting coefficient.

[0010] Furthermore, the charging strategy is to output a charging instruction that matches the single cell power voltage stage state according to the single cell power voltage stage state of the mining explosion-proof lithium-ion battery. The aforementioned charging instruction is: If the single cell voltage stage state is the second stage state, a normal charging command is output; If the single cell power voltage stage state is the first stage state, it is confirmed to enter the pressure difference control cycle state, and the corresponding adjustable charging command is output in each cycle period until the current single cell power voltage stage state is the second stage state. The pressure difference control cycle state is: first, obtain the current pressure difference in the first stage state and output the adjustable charging command to make the mining explosion-proof lithium-ion battery in a fully charged state; secondly, record the time corresponding to the full charge state, and use the time as the timing base point to re-acquire the pressure difference U after meeting the time threshold. 差 And judge whether it belongs to the second stage state, if it is, exit this cycle process, otherwise output a new charging current I 充 ; The charging current I corresponding to the adjustable charging command 充 The calculation formula is I 充 =a / U 差 , where a is the current limiting coefficient.

[0011] Furthermore, the above-mentioned over-limit charging strategy includes real-time monitoring of the voltage value of each single battery in the lithium-ion battery power supply and outputting an active stop charging command at any voltage to cause the charging module to stop outputting power.

[0012] Furthermore, the above-mentioned over-limit charging strategy also includes real-time monitoring of the vehicle operating state. When the vehicle is in a special operating state, the voltage of each cell in the lithium-ion battery power source does not exceed the upper limit, that is, charging is stopped when the upper limit is met.

[0013] Furthermore, the safe intelligent explosion-proof lithium battery charger also includes an auxiliary power supply, a control transformer, and an explosion-proof fan. The control transformer is connected to the AC side and outputs DC power through the AC input line to power the auxiliary power supply. The auxiliary power supply includes a first switching power supply and a second switching power supply. The input side of the first switching power supply is connected to the control transformer, and the output side is connected to the explosion-proof fan to power the explosion-proof fan; the input side of the second switching power supply is connected to the control transformer, and the output side is connected to the control board to power the control board; the input side of the explosion-proof fan is connected to the first switching power supply, and the explosion-proof fan dissipates heat for the charging module when the temperature exceeds the limit.

[0014] The implementation of the present invention will have the following beneficial effects: The present invention realizes dual charging protection for explosion-proof lithium-ion batteries for mining. For example, according to the voltage stage state of the single cell of the explosion-proof lithium-ion battery for mining, the appropriate charging strategy output is determined, and then the charging module is controlled to provide the explosion-proof charging gun with an active protection strategy of the charger with a "maintenance effect" according to the output voltage / current required by the power stage state, so that the voltage difference between the cells of the explosion-proof lithium-ion battery power supply is graded and low-current charging is performed, so as to achieve the purpose of maintaining the overall capacity without decreasing, improving the overall endurance and battery life, and benefiting the promotion and application of new energy vehicles in coal mines; for example, by setting an over-limit charging strategy based on the maximum voltage of the single cell of the explosion-proof lithium-ion battery power supply and the vehicle operating state, the current charging strategy is automatically adjusted to ensure that when the battery management system BMS fails to stop charging due to over-limit, the charger will actively stop, that is, the battery box BMS protection strategy, to achieve the effect of dual protection. At the same time, because the under-charge charging mode can be performed according to the operating conditions, the present invention can meet the normal operation of the vehicle under long downhill conditions. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0016] in: Figure 1 This is a schematic diagram of the overall circuit structure of a safe, intelligent, explosion-proof lithium battery charger according to an embodiment of the present invention. Figure 2 This is a circuit structure diagram of a charging strategy for a safe, intelligent, explosion-proof lithium battery charger according to an embodiment of the present invention; Figure 3 This is a circuit structure diagram of an embodiment of the present invention - a safe intelligent explosion-proof lithium battery charger over-limit charging strategy; Figure 4 This is a schematic diagram of a control table corresponding to the charging strategy of a safe intelligent explosion-proof lithium battery charger according to an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0018] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0019] In addition, the descriptions of "first", "second", etc. in the present invention are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the said features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0020] At present, new energy is being vigorously promoted in coal mines, and underground charging safety is particularly critical. In addition to using BMS to manage power supply for battery charging and other operating status monitoring, the charger's dual active protection for charging lithium-ion battery power (currently, lithium iron phosphate batteries are mostly used in underground coal mines) is an important guarantee to prevent overcharging of lithium battery boxes.

[0021] In other words, the essential technical problem addressed in this case is how to effectively achieve close integration and collaboration between the explosion-proof lithium-ion batteries (mine-grade), explosion-proof lithium-ion chargers, and BMS (Battery Management System), the core energy storage components of mining equipment systems, to jointly ensure the safety and reliability of power supply in special environments such as mines. In response to these requirements, the applicant's design concept includes improvements to the explosion-proof lithium-ion charger: the charger should feature intelligent control capabilities, enabling safe and efficient charging of the battery according to a preset algorithm and the ability to automatically stop charging in abnormal situations. Furthermore, the BMS (Battery Management System), serving as a bridge between the explosion-proof lithium-ion batteries and the explosion-proof lithium-ion charger, provides monitoring, management, and protection. While it can monitor various battery parameters (such as voltage, current, and temperature) in real time and use built-in logic to determine whether to allow the charger to continue charging or to implement other necessary protective measures (such as overvoltage, overcurrent, and overtemperature protection), it should also be considered in certain circumstances for the BMS to participate in the charging strategy to guide the charger to complete charging tasks more efficiently.

[0022] like Figure 1-Figure 3The present invention proposes a safe intelligent explosion-proof lithium battery charger with a dual charging protection strategy, which is used to charge explosion-proof lithium-ion batteries for mining, and is characterized by comprising: Explosion-proof charging gun, used to charge explosion-proof lithium-ion batteries for mining; The charging module is connected to the AC side through an AC contactor and is used to provide charging power to the explosion-proof charging gun according to the charging instructions output by the control board; The control board is connected to the charging module and the explosion-proof lithium-ion battery for mining. It is used to monitor the single cell voltage stage state of the explosion-proof lithium-ion battery for mining, and output charging instructions that match the single cell voltage stage state according to a preset charging strategy, thereby controlling the charging module to provide charging power to the explosion-proof charging gun according to the output voltage / current required by the power stage state; at the same time, the control board is communicatively connected to the BMS system, and can obtain monitoring data of the voltage monitoring of each single cell in the explosion-proof lithium-ion battery by the BMS system, and automatically adjust the current charging strategy according to the over-limit charging strategy.

[0023] The working process of the above scheme is: The input AC power enters the charging module through the AC contactor. The charging module performs effective signal processing to suppress power supply interference (such as active PFC rectification and boosting to improve the power factor, reduce harmonic content and resist electromagnetic interference). It is then converted into the voltage and current required by the lithium-ion battery power box through the internal DC / DC module, and output to the explosion-proof lithium-ion battery power box through the DC contactor and explosion-proof charging gun.

[0024] Therefore, the explosion-proof charger has the function of intelligently charging the lithium-ion battery power supply and can provide power maintenance function for the explosion-proof lithium-ion battery. It is suitable for charging chambers underground in coal mines. The aforementioned power maintenance function includes monitoring the voltage data of each single cell and defining the maintenance charging mode triggering conditions to execute different charging strategies to achieve charging with maintenance function, thereby achieving the purpose of maintaining the lithium-ion battery power supply; and automatically adjusting the current charging strategy by setting the over-limit charging strategy based on the single cell maximum voltage of the explosion-proof lithium-ion battery power supply and the vehicle operating status, to ensure that when the battery management system BMS fails to issue a stop charging command due to over-limit of a single battery, the charger will actively stop, thereby achieving the effect of double protection.

[0025] In a further embodiment, the aforementioned safe intelligent explosion-proof lithium battery charger has an AC contactor, a charging module, a DC contactor, a control transformer, a switching power supply 1, a switching power supply 2, a control panel, a display screen and other components installed in an explosion-proof box, and the box adopts a bolt fastening structure. The explosion-proof charging gun, explosion-proof fan, and intrinsically safe keypad are all installed on the outside of the explosion-proof box. The display screen is used to provide an intuitive user interface, allowing the operator to view the current charging status, historical records and other information; the intrinsically safe keypad is installed on the door panel of the explosion-proof charger and is connected to the control panel. It mainly includes A gun start, A gun stop, B gun start, B gun stop, screen flip, charging maintenance key, emergency stop function key, etc. When the technician confirms that charging adaptive control is required, that is, when this charging maintenance key is pressed, the control panel determines the appropriate charging current through the internal charging strategy to output control commands to the charging module to adjust the charging behavior in real time. The input side of the AC contactor is connected to AC power, and the output side is connected to the charging module. The coil control point and feedback signal are connected to the main control board to achieve a closed-loop control effect; the input side of the charging module is connected to the AC contactor, and the output side is connected to the direct contactor.

[0026] In a further embodiment, the aforementioned charging module is connected to the positive terminal of the mining explosion-proof lithium-ion battery through a positive output circuit, and is connected to the negative terminal of the mining explosion-proof lithium-ion battery through a negative output circuit; the positive output circuit includes a fuse and a first DC contactor, one end of the fuse is connected to the positive pole (DC+) of the charging module, and the other end is connected to the first DC contactor, and the other end of the first DC contactor is connected to the positive terminal of the mining explosion-proof lithium-ion battery and the control board, wherein the charging voltage and charging current output by the charging module are transmitted to the lithium-ion battery power supply through the fuse, and the fuse plays a voltage and voltage protection role in the output main circuit part. If the voltage is too high or the current exceeds the limit, the fuse blows and disconnects the output main circuit, thereby protecting the charging main circuit; the negative output circuit includes The system comprises a second DC contactor and a shunt. One end of the second DC contactor is connected to the negative electrode (DC-) of the charging module and the control board, and one end is connected to the shunt. The other end of the shunt is connected to the negative terminal of the mining explosion-proof lithium-ion battery. The negative electrode power (DC-) of the charging module flows to the shunt through the second DC contactor K2. The negative electrode power passing through the second DC contactor K2 is transmitted to the lithium-ion battery power supply through the shunt. The control board controls the switching of the first DC contactor K1 and the second DC contactor K2 between the on and off states as needed and feeds back the switching signal to the control board to form a closed-loop control. The above circuit design ensures that stable and reliable charging services can be provided to the battery under any circumstances, and can respond quickly to abnormalities to protect the safety of personnel and equipment. The specific working process is as follows: the control board is connected to the charging module via CAN communication, and the single-cell voltage stage state of the mining explosion-proof lithium-ion battery is monitored in real time. The charging instruction that matches the single-cell voltage stage state is output according to the preset charging strategy, so that the charging module converts the AC380V AC power into the voltage and current required by the lithium-ion battery power supply according to the charging instruction corresponding to the power stage state. At the same time, the control board interacts with the lithium-ion battery power supply via CAN communication. The control board and the electric meter adopt 485 communication connection to transmit the charging current, charging voltage, and charging metering power read by the electric meter to the control board (the electric meter collects the negative current of the DC- circuit (i.e., charging current) through the shunt, collects the charging voltage through the DC+ circuit, and the electric meter calculates the charging current, etc.); the lithium-ion battery power supply is connected to the control board and transmits the status monitoring data via CAN communication to complete the control process including protocol consistency confirmation, charging requirements, and full stop instruction control.

[0027] In a further embodiment, the charging module transmits status fault information to the control board via the CAN communication interface, enabling the control board to promptly respond to abnormal conditions and take necessary protective measures to ensure the safety and reliability of the entire charging system. This status fault information includes basic operating status information, such as the operating mode (currently in standby, charging, discharging, or other modes); input and output voltage / current information (AC 380V input voltage and converted DC output voltage, current value, and actual transmitted power); charging module temperature information, electrical parameters, fault alarms, and battery status. Temperature information includes the temperature of key components within the charging module (such as power elements and heat sinks), as well as the temperature of the surrounding environment; electrical parameters (information on voltage / current anomalies at the input and output ports); fault alarms (contactor failure, software errors, and communication failures) (CAN bus or other communication interface failures that affect data transmission); and battery status, such as SOC and internal cell voltage variations.

[0028] In a further embodiment, the start timing of the charging strategy with maintenance function can also be set. The "maintenance" button, that is, the function button, can be used for human intervention. For example, if a newly used mining explosion-proof lithium-ion battery does not require direct maintenance, this function can be considered for later use. Furthermore, the "maintenance" button is a self-locking switch connected to the control board. After pressing the button, the control board reads "1".

[0029] In a further embodiment, the single cell voltage stage state is determined according to the voltage difference between the highest single cell voltage and the lowest single cell voltage inside the mining explosion-proof lithium-ion battery in each new monitoring cycle, and is specifically divided into the following stage states: First stage state: When the pressure difference U 差 ≤ the first threshold; Second stage state: When the pressure difference U 差 >First threshold.

[0030] The first threshold value may be selected as 0.01V.

[0031] Correspondingly, the charging strategy is to output a charging instruction that matches the single cell voltage stage state according to the single cell voltage stage state of the mining explosion-proof lithium-ion battery, and then determine whether to enter the normal charging mode or the maintenance charging mode. The aforementioned charging instruction is: The charging strategy is to output a charging instruction that matches the single cell power voltage stage state according to the single cell power voltage stage state of the mining explosion-proof lithium-ion battery. The aforementioned charging instruction is: If the cell voltage stage state is the second stage state, a normal charging command is output; If the cell voltage stage state is the first stage state, an adjustable charging command is output; The charging current I corresponding to the adjustable charging command 充 The calculation formula is I 充 =a / U 差 , where a is the current limiting coefficient.

[0032] Preferably, the charging strategy is to output a charging instruction that matches the single cell power voltage stage state according to the single cell power voltage stage state of the mining explosion-proof lithium-ion battery. The aforementioned charging instruction is: If the single cell voltage stage state is the second stage state, a normal charging command is output; If the single cell power voltage stage state is the first stage state, it is confirmed to enter the pressure difference control cycle state, and the corresponding adjustable charging command is output in each cycle period until the current single cell power voltage stage state is the second stage state. The pressure difference control cycle state is: first, obtain the current pressure difference in the first stage state and output the adjustable charging command to make the power of the mining explosion-proof lithium-ion battery in the full charge state; secondly, record the time corresponding to the full charge state, and use the time as the timing base point to re-acquire the pressure difference U after the time threshold is met. 差 And judge whether it belongs to the second stage state, if it is, exit this cycle process, otherwise recalculate the new charging current I according to the current voltage difference 充 , and output adjustable charging commands; if the battery box is fully charged and has been standing for 3 hours, the charger detects that the voltage difference is still too large, and then performs charging control again, repeating the cycle several times until the voltage difference of the battery box cells is controlled within a certain range; The charging current I corresponding to the adjustable charging command 充 The calculation formula is I 充 =a / U 差 , where a is the current limiting coefficient, a is a constant (can be modified in the settings interface, the default value is 0.2), such as the voltage difference is 0.01V, the charging current is 20A, when the voltage difference is 0.02V, the charging current is 10A, the control board limits the output current of the charging module to be smaller, and vice versa, the specific applicant's practice in the first stage state charging current and voltage difference control logic table, as shown in the attached Figure 4 And Table 1 below, Table 1

[0033] In a further embodiment, the above-mentioned over-limit charging strategy includes real-time monitoring of the voltage value of each single battery in the lithium-ion battery power supply and outputting an active stop charging command to cause the charging module to stop outputting power when any voltage exceeds the limit by 3.5V, so as to ensure that when the battery management system BMS fails to issue a stop charging command due to overvoltage of a single battery, the charger can actively stop charging, greatly increasing the risk of charging the lithium-ion battery power supply.

[0034] In a further embodiment, the above-mentioned over-limit charging strategy also includes real-time monitoring of the vehicle's operating status. When the vehicle is in a special operating state, the voltage of each cell in the lithium-ion battery power supply does not exceed the upper limit value, that is, charging is stopped when the upper limit value is met. That is, by setting the upper limit value of the cell voltage, it can be satisfied that the lithium-ion battery power supply is not fully charged. For example, when an explosion-proof lithium battery transport vehicle (trackless rubber-wheeled vehicle, monorail crane vehicle) is heavily loaded downhill, energy feedback causes the battery to charge. If it is fully charged, the lithium-ion battery power supply cannot be fed back, and the vehicle cannot travel normally at this time. For example, if the maximum cell voltage is set to 3.45V to stop, it can be not fully charged, which meets the normal operation of the vehicle under long downhill conditions.

[0035] In a further embodiment, the aforementioned control board is connected to a display screen, and through RS232 communication, the charging status, charging current, charging voltage, BMS data (including the highest single cell voltage of the battery), fault status information, and each module information are sent to the display screen for display. The display screen can write the single cell charging stop protection value and can perform parameter settings, module grouping, power settings, factory settings, etc.

[0036] In a further embodiment, the aforementioned control board is connected to the BMS system via a CAN communication interface for data exchange (start / stop control, etc.). The BMS system monitors various parameters of each battery - E1 to E100 batteries (such as E1 to E100 single cell voltage, current, temperature, etc.) in real time to collect and monitor data in real time to ensure safe, stable and long-life operation of the batteries.

[0037] In a further embodiment, the aforementioned control board monitors in real time the CC1 (constant current / constant voltage control) status of the charging module during the charging process, the CAN communication connection status, the auxiliary power supply (switching power supply) control status, the gun line temperature acquisition status (monitoring the temperature of the charging gun cable to prevent safety hazards caused by overheating, so as to record temperature change trends for subsequent analysis and optimization of charging strategies), and the charging gun electromagnetic lock control and feedback status to ensure that the charging gun is firmly connected to the vehicle or other equipment. At the same time, it provides connection status feedback, such as detecting the communication signal connecting the explosion-proof charging gun and the explosion-proof lithium-ion battery power supply, CC1 and PE are 500Ω, CC2 and PE are 1kΩ, and after the gun insertion signal is confirmed, the communication signal is confirmed to be normal; thereby, the control board can effectively manage and protect the entire charging system, ensuring its safe and reliable operation in various environments.

[0038] In a further embodiment, the aforementioned safe intelligent explosion-proof lithium battery charger also includes an auxiliary power supply, a control transformer, and an explosion-proof fan. The control transformer is connected to the AC side and the output is AC220V through the AC incoming line, and the output is used to supply power to the auxiliary power supply. The auxiliary power supply includes a first switching power supply 1 and a second switching power supply 2. The input side of the first switching power supply 1 is connected to the control transformer, and the output side is connected to the explosion-proof fan to supply power to the explosion-proof fan at a voltage of DC24V; the input side of the second switching power supply 2 is connected to the control transformer, and the output side is connected to the control board to supply power to the control board at a voltage of DC12V; the input side of the explosion-proof fan is connected to the first Switching power supply 1 and explosion-proof fan dissipate heat for the charging module when the temperature exceeds the limit; the control panel is connected to the second switching power supply 2 and the intrinsically safe button. The second switching power supply 2 supplies power to the control panel, and the intrinsically safe button sends a switching signal to the control panel. In addition, the control panel also has functions such as insulation detection, reverse connection protection, electromagnetic lock control, and card swiping control. It transmits the protection signals of the charging module (AC overvoltage, undervoltage, phase loss, output overvoltage, undervoltage, overtemperature) and real-time signals (voltage, current, power, temperature) to the background monitoring software in real time. Through the built-in software algorithm, the background monitoring software adjusts the current, voltage, and power limit of the module output.

[0039] The above disclosure is merely a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A safe intelligent explosion-proof lithium battery charger with a dual charging protection strategy, the explosion-proof charger is used to charge explosion-proof lithium-ion batteries for mining, characterized in that: include: Explosion-proof charging gun, used to charge explosion-proof lithium-ion batteries for mining; The charging module is connected to the AC side through an AC contactor and is used to provide charging power for the explosion-proof charging gun according to the charging instructions output by the control board; The control board is connected with the charging module and the explosion-proof lithium-ion battery for mining, and is used to monitor the single cell power voltage stage state of the explosion-proof lithium-ion battery for mining, and output a charging instruction matching the single cell power voltage stage state according to a preset charging strategy, thereby controlling the charging module to provide charging power to the explosion-proof charging gun according to the output voltage / current required by the single cell power stage state; at the same time, the control board is communicatively connected with the BMS system, and can obtain the monitoring data of the voltage monitoring of each single cell in the explosion-proof lithium-ion battery by the BMS system, and automatically adjust the current charging strategy according to the over-limit charging strategy.

2. The safe intelligent explosion-proof lithium battery charger with dual charging protection strategy as claimed in claim 1 is characterized in that: The charging module is connected to the positive terminal of the mining explosion-proof lithium-ion battery through a positive output circuit, and is connected to the negative terminal of the mining explosion-proof lithium-ion battery through a negative output circuit; the positive output circuit includes a fuse and a first DC contactor, one end of the fuse is connected to the positive electrode of the charging module, and the other end is connected to the first DC contactor, and the other end of the first DC contactor is connected to the positive terminal of the mining explosion-proof lithium-ion battery and the control board; the negative output circuit includes a second DC contactor and a shunt, one end of the second DC contactor is connected to the negative electrode of the charging module and the control board, and one end is connected to the shunt, and the other end of the shunt is connected to the negative terminal of the mining explosion-proof lithium-ion battery.

3. The safe intelligent explosion-proof lithium battery charger with dual charging protection strategy as claimed in claim 1 is characterized in that: The single cell voltage stage state is determined according to the voltage difference between the highest single cell voltage and the lowest single cell voltage in the mining explosion-proof lithium-ion battery in each new monitoring cycle, and is specifically divided into the following stage states: The first stage state: When the pressure difference U 差 ≤ the first threshold; The second stage state: When the pressure difference U 差 >First threshold.

4. The safe intelligent explosion-proof lithium battery charger with dual charging protection strategy as claimed in claim 3 is characterized in that: The charging strategy is to output a charging instruction that matches the single cell power voltage stage state according to the single cell power voltage stage state of the mining explosion-proof lithium-ion battery. The aforementioned charging instruction is: If the single cell voltage stage state is the second stage state, a normal charging command is output; If the single cell power voltage stage state is the first stage state, an adjustable charging command is output; The charging current I corresponding to the adjustable charging command 充 The calculation formula is I 充 =a / U 差 , where a is the current limiting coefficient.

5. The safe intelligent explosion-proof lithium battery charger with dual charging protection strategy as claimed in claim 3, characterized in that: The charging strategy is to output a charging instruction that matches the single cell power voltage stage state according to the single cell power voltage stage state of the mining explosion-proof lithium-ion battery. The aforementioned charging instruction is: If the single cell voltage stage state is the second stage state, a normal charging command is output; If the single cell power voltage stage state is the first stage state, it is confirmed to enter the pressure difference control cycle state, and the corresponding adjustable charging command is output in each cycle period until the current single cell power voltage stage state is the second stage state. The pressure difference control cycle state is: first, obtain the pressure difference in the current first stage state and output an adjustable charging command to make the mining explosion-proof lithium-ion battery in a fully charged state; secondly, record the time corresponding to the full charge state, and use the time as the timing base point to re-acquire the pressure difference U after the time threshold is met. 差 And determine whether it belongs to the second stage state, if it is, exit this cycle process, otherwise output a new charging current I 充 ; The charging current I corresponding to the adjustable charging command 充 The calculation formula is I 充 =a / U 差 , where a is the current limiting coefficient.

6. The safe intelligent explosion-proof lithium battery charger with dual charging protection strategy as claimed in claim 1, characterized in that: The above-mentioned over-limit charging strategy includes real-time monitoring of the voltage value of each single battery in the lithium-ion battery power supply and outputting an active stop charging command to make the charging module stop outputting electrical energy when any voltage exceeds the limit.

7. The safe intelligent explosion-proof lithium battery charger with dual charging protection strategy as claimed in claim 1, characterized in that: The above-mentioned over-limit charging strategy also includes real-time monitoring of the vehicle's operating status. When the vehicle is in a special operating state, the voltage of each single cell in the lithium-ion battery power source does not exceed the upper limit value, that is, charging is stopped when the upper limit value is met.

8. The safe intelligent explosion-proof lithium battery charger with dual charging protection strategy as claimed in claim 1, characterized in that: The safe intelligent explosion-proof lithium battery charger also includes an auxiliary power supply, a control transformer, and an explosion-proof fan. The control transformer is connected to the AC side and outputs DC power through the AC incoming line to supply power to the auxiliary power supply. The auxiliary power supply includes a first switching power supply and a second switching power supply. The input side of the first switching power supply is connected to the control transformer, and the output side is connected to the explosion-proof fan to supply power to the explosion-proof fan. The input side of the second switching power supply is connected to the control transformer, and the output side is connected to the control board to supply power to the control board; the input side of the explosion-proof fan is connected to the first switching power supply, and the explosion-proof fan dissipates heat for the charging module when the temperature exceeds the limit.

Images