Nickel-metal hydride battery pack charging and discharging management circuit and mining power supply system thereof

Abstract

The invention discloses a nickel-metal hydride battery pack charging and discharging management circuit and a mining power supply system thereof, and relates to the technical field of power electronics, the nickel-metal hydride battery pack charging and discharging management circuit comprises a charging and discharging management chip, an MCU, a battery information acquisition chip, a first MOS tube switch, a second MOS tube switch, a third MOS tube switch and a current sampling resistor, and the first MOS tube switch and the second MOS tube switch are connected in series in a charging and discharging main loop of a nickel-metal hydride battery pack; the MCU controls on and off of the MOS tube switch based on information acquired by the battery information acquisition chip so as to cooperate with the charging and discharging management chip to realize a complete charging process including trickle charging, constant-current charging and complementation charging, and judges that the nickel-metal hydride battery pack is fully charged and stops charging when detecting that the terminal voltage of the nickel-metal hydride battery pack falls back at a peak value; according to the invention, the battery charging and discharging management chip is combined with single-chip microcomputer control, conditions adaptive to the charging and discharging characteristics of the nickel-metal hydride battery are simulated, potential safety hazards in system operation are reduced, and the service life of the nickel-metal hydride battery pack is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power electronics, in particular to a nickel-hydrogen battery pack charging and discharging management circuit and its mining power supply system. BACKGROUND

[0002] Nickel-hydrogen batteries are widely used in mining power supply systems due to their high safety, environmental friendliness, and long cycle life. However, existing nickel-hydrogen battery charging and discharging management technology still has many shortcomings, limiting its further application in mining environments with high reliability and high safety.

[0003] Currently, the most special charging management chip for nickel-hydrogen batteries on the market only supports managing up to 16 strings of battery packs, and the functions are relatively simple, with most only having charging management functions and lacking path management capabilities. In addition, existing charging management chips mostly use constant current and constant voltage charging methods during charging, without fully considering the unique charging characteristics of nickel-hydrogen batteries, such as the voltage rise and subsequent drop phenomenon at the end of charging. If a lithium battery charging management chip is used to charge nickel-hydrogen batteries, due to the mismatch in charging characteristics, it can easily lead to problems such as the battery not being fully charged, overcharging and heating, which seriously affect the performance, service life and safety of the battery pack.

[0004] The common charging and discharging management scheme in the prior art usually uses a single-chip microcomputer to send a PWM wave to control a MOS tube to regulate the charging current, but this method is limited by the heat dissipation capacity of the MOS tube and is difficult to support large current charging. Moreover, the protection measures are relatively simple, usually only having basic protection functions such as overcurrent and overtemperature, which cannot meet the demand for high reliability and multiple safety protection of mining power supply systems.

[0005] However, mining power supply systems usually need to support multiple strings of battery packs (such as 3-20 strings) to meet different load power and endurance requirements. The existing chips have obvious shortcomings in terms of string support, path management, and charging strategy adaptation, and do not fully consider the unique charging characteristics of nickel-hydrogen batteries, making it difficult to adapt to the charging method of nickel-hydrogen batteries and unable to meet the application requirements in complex conditions. SUMMARY

[0006] In view of the shortcomings of the prior art that do not fully consider the unique charging characteristics of nickel-hydrogen batteries and are difficult to adapt to the charging method of nickel-hydrogen batteries, the present application proposes a nickel-hydrogen battery pack charging and discharging management circuit and its mining power supply system, which simulates the conditions that adapt to the charging and discharging characteristics of nickel-hydrogen batteries through the combination of a battery charging and discharging management chip and a single-chip microcomputer control method, thereby solving the problems existing in the prior art.

[0007] The nickel-hydrogen battery pack charging and discharging management circuit comprises a charging and discharging management chip, a micro control unit (MCU), a battery information acquisition chip, a first MOS tube switch and a second MOS tube switch which are connected in series in a main charging and discharging loop of the nickel-hydrogen battery pack, a third MOS tube switch and a current sampling resistor; The power output end of the charging and discharging management chip is connected with the drain of the third MOS tube switch; the source of the third MOS tube switch is connected to the main charging and discharging loop of the nickel-hydrogen battery pack through the current sampling resistor; and the BGATE pin of the charging and discharging management chip is connected to the gate of the third MOS tube switch through a first resistor to control the on-off of the third MOS tube switch. The control pin of the MCU is connected to the gates of the first MOS tube switch and the second MOS tube switch through a driving module composed of a fourth MOS tube switch and a second resistor to control the on-off of the first MOS tube switch and the second MOS tube switch; the drains of the first MOS tube switch and the second MOS tube switch are interconnected, and the node after interconnection is connected with the drain of the third MOS tube switch; the source of the first MOS tube switch is connected with the power charging end of the charging and discharging management chip; and the source of the second MOS tube switch is connected with the positive electrode of the nickel-hydrogen battery pack. The voltage sampling end of the battery information acquisition chip is connected on the load side of the current sampling resistor to acquire the terminal voltage and loop current of the nickel-hydrogen battery pack; and the battery information acquisition chip is connected with the communication pin of the MCU through an IIC communication bus.

[0008] Further, the drain of the fourth MOS tube switch is connected with the gates of the first MOS tube switch and the second MOS tube switch through a shared coupling resistor; the gate of the fourth MOS tube switch is connected with the control pin PB12 of the MCU through a second resistor; and the source of the fourth MOS tube switch is grounded.

[0009] Further, the NTC temperature detection circuit comprises an NTC thermistor built in the battery pack and an external bias resistor; the NTC thermistor is electrically connected with the pin of the MCU through a fifth MOS tube switch and is electrically connected with the NTC pin of the charging and discharging management chip through the bias resistor to realize the over-temperature protection based on the temperature of the battery pack.

[0010] Further, the battery information acquisition chip adopts an INA226 chip and is connected with the communication pin of the MCU through an IIC communication interface.

[0011] The application further provides a mine power supply system based on the nickel-hydrogen battery pack charging and discharging management circuit, which comprises: An AC / DC module is used for converting external alternating current into direct current and supplying power for the nickel-hydrogen battery pack charging and discharging management circuit. A BMS master control board, a power input end of which is electrically connected with an output end of an AC / DC module, and a battery port of the BMS master control board is electrically connected with a nickel-hydrogen battery pack; wherein the BMS master control board comprises the nickel-hydrogen battery pack charging and discharging management circuit according to any one of claims 1 to 4, for controlling charging and discharging of the nickel-hydrogen battery pack, and the control process specifically comprises: trickle charging and constant current charging of the nickel-hydrogen battery pack by using the charging and discharging management chip; collecting voltage and current information of the nickel-hydrogen battery pack by using the battery information acquisition chip, and transmitting to the MCU; the MCU controls the conduction and turn-off of the first MOS tube switch and the second MOS tube switch based on the information collected by the battery information acquisition chip, so as to realize the complete charging process including trickle charging, constant current charging and make-up charging in cooperation with the charging and discharging management chip, and when the peak value of the nickel-hydrogen battery pack terminal voltage is detected to fall, it is judged to be full and the charging is stopped; A DC / DC output module, an input end of which is electrically connected with a load power supply end of the BMS master control board, for providing stable voltage DC output for the load.

[0012] Further, the MCU is specifically configured to: When the nickel-hydrogen battery pack terminal voltage is lower than the trickle charging voltage threshold, the first MOS tube switch and the second MOS tube switch are turned on, and the trickle charging stage is entered; When the nickel-hydrogen battery pack terminal voltage is higher than the trickle charging voltage threshold and lower than the constant current charging voltage threshold, the constant current charging stage is entered; When the nickel-hydrogen battery pack terminal voltage reaches or approaches the full voltage value, the voltage change is continuously monitored, and when the characteristic of voltage rising and then falling is captured, the make-up charging timing is triggered, and when the timing is over or during the timing, the voltage falling is detected again, the first MOS tube switch and the second MOS tube switch are turned off to stop charging.

[0013] Further, the full voltage value is a nominal full voltage value set according to the number of battery strings.

[0014] Further, the parameter configuration circuit is configured outside the charging and discharging management chip; the charging output voltage of the nickel-hydrogen battery pack and the voltage threshold of the trickle charging are set by the parameter configuration circuit.

[0015] Further, a path management module is further included, for when external power supply is effective, the DC / DC output module is preferentially powered by the AC / DC module, and the nickel-hydrogen battery pack is charged; when the external power supply is invalid, the DC / DC output module is powered by the nickel-hydrogen battery pack.

[0016] The application provides a nickel-hydrogen battery pack charging and discharging management circuit and a mining power supply system thereof, which has the following beneficial effects: This invention utilizes a battery charge / discharge management chip combined with microcontroller control. By continuously monitoring the voltage changes at the NiMH battery pack terminals, it simulates conditions suitable for the charging and discharging characteristics of NiMH batteries (i.e., the voltage of a NiMH battery will first rise and then fall when it is almost fully charged). It then controls the first and second MOSFET switches to turn on or off for charging and discharging, rather than the traditional method of charging solely through a constant voltage and constant current process. This reduces safety hazards during system operation and extends the lifespan of the NiMH battery pack. Compared to the method of using a microcontroller to generate PWM waves to control the MOSFETs and adjust the battery pack charging current, this circuit combines a professional battery management chip with microcontroller control, further improving charging current and efficiency, and incorporating more protection measures. In case of charging abnormalities, it can automatically cut off the battery charging process. This circuit supports managing 3-20 NiMH battery packs and is compatible with devices operating at different DC voltages such as 12V / 18V / 24V. It can manage up to 20 battery packs, resulting in greater battery capacity and significantly improved overall backup time. Attached Figure Description

[0017] Figure 1 This is a system block diagram of a mining power supply system based on a nickel-metal hydride battery pack charge and discharge management circuit, as described in an embodiment of the present invention. Figure 2 This is an electrical connection diagram of the main functional components of the microcontroller (MCU) section and the nickel-metal hydride battery pack charge / discharge management circuit section in an embodiment of the present invention. Figure 3 This is an electrical connection diagram of the main components of the control section of the nickel-metal hydride battery pack charge and discharge management circuit in an embodiment of the present invention; Figure 4 This is a pin signal connection diagram of the MCU processing circuit in an embodiment of the present invention; Figure 5 This is a schematic diagram of the battery pack charge and discharge management circuit in an embodiment of the present invention; Figure 6 This is a schematic diagram of the charging and discharging management chip operating state control circuit in an embodiment of the present invention; Figure 7 This is a schematic diagram of the highest charging voltage configuration circuit for the charge / discharge management chip in an embodiment of the present invention; Figure 8 This is a schematic diagram of the battery pack information acquisition and control circuit in an embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0019] The application provides a nickel-hydrogen battery pack charging and discharging management circuit, which comprises a charging and discharging management chip (U2), a micro control unit (MCU) (U1), a battery information acquisition chip (U16), a first MOS tube switch Q14, a second MOS tube switch Q13, a third MOS tube switch (Q8) and a current sampling resistor (R99).

[0020] The power output end of the charging and discharging management chip (U2) is connected to the positive electrode of the nickel-hydrogen battery pack (BAT) through the third MOS tube switch (Q8) and the current sampling resistor (R99); the power output end of the charging and discharging management chip is connected with the drain electrode of the third MOS tube switch; the BGATE pin of the charging and discharging management chip (U2) is connected to the gate electrode of the third MOS tube switch (Q8) through a first resistor (R16) to control the on-off of the third MOS tube switch; the drain electrodes of the first MOS tube switch and the second MOS tube switch are interconnected, and the node after interconnection is connected with the drain electrode of the third MOS tube switch; the source electrode of the first MOS tube switch is connected with the power charging end of the charging chip; the source electrode of the third MOS tube switch is connected to the charging and discharging main circuit of the nickel-hydrogen battery pack through the current sampling resistor; the first MOS tube switch Q14 and the second MOS tube switch Q13 are connected in series in the charging and discharging main circuit of the nickel-hydrogen battery pack (BAT).

[0021] The first control pin (PB12) of the core MCU (U1) is connected to the gate electrodes of the first MOS tube switch Q14 and the second MOS tube switch Q13 through a driving circuit (the fourth MOS tube switch Q19 and a second resistor R163) and a coupling resistor R172 to control the on-off of the first MOS tube switch and the second MOS tube switch. The drain electrode of the fourth MOS tube switch is connected with the gate electrodes of the first MOS tube switch and the second MOS tube switch through a shared coupling resistor; the gate electrode of the fourth MOS tube switch is connected with the control pin PB12 of the MCU through a second resistor, and the source electrode of the fourth MOS tube switch is grounded.

[0022] The voltage sampling end of the battery information acquisition chip (U16) is connected on the load side of the current sampling resistor (R99), and the current sampling end is connected across the two ends of the current sampling resistor (R99) to collect the terminal voltage and loop current of the nickel-hydrogen battery pack (BAT); the battery information acquisition chip (U16) is connected with the communication pins (PC4 and PC5) of the core MCU (U1) through an IIC communication bus.

[0023] The core MCU (U1) is configured to output a control signal to the first control pin (PB12) to drive the first MOS tube switch Q14 and the second MOS tube switch Q13 to be turned on or turned off according to the terminal voltage and loop current collected by the battery information acquisition chip (U16).

[0024] Based on the above nickel-hydrogen battery pack charging and discharging management circuit, the application proposes a mine power supply system supporting 3-20 string nickel-hydrogen battery pack charging and discharging management, comprising: The AC / DC module is used for converting external alternating current into direct current and supplying power for the nickel-hydrogen battery pack charging and discharging management circuit.

[0025] The power supply input end of the BMS master control board is electrically connected with the output end of the AC / DC module, and the battery port of the BMS master control board is electrically connected with the nickel-hydrogen battery pack; wherein the BMS master control board comprises the nickel-hydrogen battery pack charging and discharging management circuit, which is used for controlling the charging and discharging of the nickel-hydrogen battery pack, and the control process specifically comprises: trickle charging and constant current charging the nickel-hydrogen battery pack by using the charging and discharging management chip; collecting voltage and current information of the nickel-hydrogen battery pack by using the battery information acquisition chip and transmitting the information to the MCU; controlling the conduction and turn-off of the first MOS tube switch and the second MOS tube switch based on the information collected by the battery information acquisition chip, so as to realize the complete charging process including trickle charging, constant current charging and make-up charging in cooperation with the charging and discharging management chip, and stop charging when the peak value of the nickel-hydrogen battery pack end voltage is detected.

[0026] The input end of the DC / DC output module is electrically connected with the load power supply end of the BMS master control board, and is used for providing stable voltage direct current output for the load.

[0027] As shown in Figure 1 , when the external power supply is effective (power frequency 127V~220V alternating current), the AC / DC module works normally, the AC / DC module generates 24V direct current power, and the BMS (battery management system) master control board is powered. The BMS board card is connected with the screen (displaying the running state of the system), the DC / DC output module (direct current voltage output, connected with the load end), the nickel-hydrogen battery pack (as a backup power supply) and the battery pack mechanical switch and other functional units.

[0028] As shown in Figure 2 , the main functional device electrical connection diagram of the single-chip microcomputer MCU part and the nickel-hydrogen battery pack charging and discharging management circuit part; the U1 unit (MCU) issues instructions through the pin PB12, is electrically connected with the gate electrode of the tube Q19 through R163, the MCU can control the working state of the tube Q19, the drain electrode of the tube Q19 is electrically connected with the gate electrode of the tube Q14 / Q13 through the resistor R172, and then the working state (saturation, cut-off state) of the tube Q14 / Q13 can be controlled, Figure 2The middle signal VBAT represents the battery pack terminal voltage. The resistance R99 is a charging and discharging circuit sampling resistance, the U1 unit (MCU) pin PC4 / PC5 is electrically connected with U16 (INA226 chip), which is an IIC communication line, and the information such as the battery pack voltage and current collected by the U16 chip can be obtained. The resistances R100 / R100 play a filtering role in signal collection. The U1 unit (MCU) pin PE6 is electrically connected with the gate of the fifth MOS tube switch (tube Q18) through the resistance R135, and the drain of the tube Q18 is directly connected with the internal NTC resistance of the battery pack, and is electrically connected with the NTC pin of the U2 unit (LTC4020 chip) through the resistance R30, so that when the temperature of the battery pack is too high (caused by overcharging of the battery pack), the chip LTC4020 stops the charging action of the battery pack, and the safety of the system operation is increased. The resistance R30 is used as a biasing resistance, and the temperature threshold when the charging action is stopped can be adjusted. When R30 is 0 ohm, the temperature threshold is 40 DEG C.

[0029] The U2 unit (LTC4020 chip) pin BGATE is electrically connected with the gate of the tube Q8 through the resistance R16, so that the U2 chip can control the working state of Q8, and the trickle charging and constant current charging actions of the battery pack can be realized. The source of the tube Q8 is electrically connected with the load end through the resistances R19 / R164, and the resistances R19 / R164 are connected in parallel to set the charging current resistance, Figure 3 The middle set value is about 1.4A. The resistances R14 / R22 play a filtering role in signal collection.

[0030] System operation logic: when the external power supply is effective, the AC / DC module starts to work, the BMS board card is powered after being powered, and the nickel-hydrogen battery pack is charged through the path management function of the on-board charging and discharging management chip LTC4020. When the battery pack reaches the full power condition (depending on the set logic), the charging action is automatically stopped, and the BMS board card does not affect the power supply to the load.

[0031] When the external power supply is invalid, the BMS board card will execute the action in time, and immediately switches to the battery pack power supply mode to ensure the uninterrupted power supply of the load end. If the external power supply has not been effective before the battery pack is discharged to the output cutoff, the system will stop outputting when the battery pack reaches the discharge output cutoff voltage. If the external power supply is reactivated before the battery pack reaches the discharge cutoff output voltage, the system will switch to the AC / DC module to supply power to the load, and at the same time, the nickel-hydrogen battery pack is charged.

[0032] The application takes a battery pack of 20 strings of nickel-hydrogen batteries (the charging current is set to 1.4A) as an example: When the BMS system external power supply is effective, the LTC4020 chip and INA216 chip detect the battery pack state (mainly voltage information), and start to prepare for charging the battery pack. When the battery pack terminal voltage is less than the trickle charging voltage threshold (i.e. 23.375V), the LTC4020 chip controls the tube Q8 to work in the linear region, and the MCU controls the tube Q13 / Q14 to work in the saturation region, at this time the battery pack will be charged in a trickle current (size in 0.5A~0.6A) way. The charging process will be the battery pack voltage rising, when the terminal voltage exceeds 23.375V, the system charges the battery pack in a constant current (size 1.4A) way. This constant current value is related to R19 / R164, Figure 3 R19 / R164 is in parallel, the equivalent resistance is 35mΩ, and the constant current value is I cs =50 / 35A≈1.4A. Here, two resistors are connected in parallel, which can effectively avoid the situation that a single resistor overheats due to large current. The constant current charging process accounts for the largest proportion of the entire charging process. Since the charging process of the nickel-hydrogen battery has the phenomenon of voltage rising first and then falling, it cannot be controlled by the charging chip alone, and the single-chip microcomputer MCU needs to be used for joint control to achieve the best charging effect. For example, according to Figure 7 R57 / R59 resistance value, the whole machine output voltage (i.e. battery pack charging voltage) is set to 28.75V (i.e. Vout=2.5V*(R57 / R59+1)), which needs to be slightly higher than the nickel-hydrogen battery pack charging cutoff voltage (20 battery pack full voltage nominal value is 28V), so as to ensure that the battery pack can be reliably fully charged. The MCU obtains the battery pack terminal voltage, charging current and other information by communicating with the chip INA226. By detecting the battery pack terminal voltage, when the voltage rises and then falls around 28V (for example, the battery pack terminal voltage decreases from 28.5V to 28.2V), it can be judged that the battery pack has been fully charged, at this time the MCU can control the tube Q13 / Q14 to work in the cutoff state and stop the charging action. At the same time, the battery charging current collected can be integrated to calculate the energy charged into the battery.

[0033] When the external power supply is invalid, the MCU detects this state and immediately turns on the tube Q13 / Q14 to switch to the battery pack supplying power to the load.

[0034] The application supports management of 3-20 series nickel-hydrogen battery packs, and the management system can be adapted to devices with different direct-current working voltages such as 12V / 18V / 24V, the number of battery pack series can be managed to 20 series, the capacity of the battery pack is larger, and the overall backup time is significantly improved; through the battery charging and discharging management chip combined with the single-chip microcomputer control mode, the conditions suitable for the charging and discharging characteristics of the nickel-hydrogen battery (that is, when the nickel-hydrogen battery is fully charged, the voltage will first rise and then fall) are simulated, instead of the traditional constant voltage and constant current charging process, the safety hidden danger in system operation is reduced, and the service life of the nickel-hydrogen battery pack is prolonged. Compared with the way that the single-chip microcomputer sends out a PWM wave to control a MOS tube to regulate the charging current of the battery pack, the circuit adopts a combination of a professional battery management chip and a single-chip microcomputer control mode, which can further improve the charging current and charging efficiency, and more protection measures are added, and in the case of abnormal charging, the action of charging the battery can be automatically cut off; the battery pack management circuit adds the functions of active and passive control of energy output, and in the case of abnormal circuit (such as battery pack overheating) or battery pack energy will be exhausted, the battery pack will stop supplying power to the load, which further reduces the risk of system operation.

[0035] The design of the hardware circuit of the application comprises: The core MCU processing circuit: the BMS board uses STM32F407ZET6 as the core MCU to process the information of the whole system and control the state of the circuit. By monitoring the battery pack power, voltage, current and other information, the corresponding charging action is performed. When the nickel-hydrogen battery pack is connected to the BMS system from a deep discharge state, it will go through trickle charging, constant current charging and nickel-hydrogen battery supplement charging in turn. The trickle and constant current charging processes are completed by using the LTC4020 charging management chip; the supplement charging process relies on collecting real-time information data of the battery pack, combining the MCU running algorithm to control the charging process, and the phenomenon of the battery pack terminal voltage rising and then falling will appear in the process, which is used as the basis for judging the fullness of the battery pack. When the inflection point of the battery pack terminal voltage appears, the MCU logic algorithm controls the Q13 and Q14 MOS tubes in the to close the charging action of the nickel-hydrogen battery pack, thereby completing the whole nickel-hydrogen battery pack charging process. In the MCU algorithm, the charging protection logic is added, and the battery pack overcharging is prevented through the timing mechanism. Figure 2

[0036] ​Battery pack charge / discharge management circuit: Based on the LTC4020 chip, and combined with MCU logic control and the use of peripheral MOSFETs, the charge / discharge management path of the NiMH battery pack is further optimized, resulting in a healthier charge / discharge process. MOSFET (P-type) Q11 acts as an electronic switch for output control, and is electrically connected to the MCU's PC13 (pin 7) via MOSFET Q12; MOSFET (P-type) Q13 / Q14 act as electronic switches for battery pack charge / discharge control, and are electrically connected to the MCU's PB12 (pin 51) via MOSFET Q19. Figure 2 R30 is the NTC (NTC thermistor) protection bias resistor, designed to expand the temperature measurement range of the NTC resistor within the battery pack. Adding R30 can increase the NTC's operating value (e.g., if the default is 40℃, then R30 should be 0Ω), but it cannot be increased indefinitely. Pin 5 (PE6) of the microcontroller (MCU) is electrically connected to transistor Q18 via resistor R135, thereby controlling the voltage division at the NTC. This allows for more flexible control of the charging management process. If the NTC voltage division is too low, it indicates a low resistance value, meaning the battery pack temperature is too high, and charging should be stopped.

[0037] Charge / discharge management parameter configuration circuit: Before using this system, parameters such as the number of battery cells in the NiMH battery pack and the charging current must be determined. This allows for adjustment of the LTC4020 configuration resistor to adapt to battery packs with different cell numbers. This invention uses a 20-cell NiMH battery pack (charging current set to 1.4A) as an example. (The circuit is described below.) Figure 7 Based on the resistance values ​​of resistors R57 / R59, the overall output voltage (i.e., the battery pack charging voltage) is set at 28.75V (Vout = 2.5V * (R57 / R59 + 1)). This voltage needs to be slightly higher than the charging cutoff voltage of the NiMH battery pack (the nominal full-charge voltage of a 20-cell battery pack is 28V) to ensure reliable full charging. Based on the resistance values ​​of resistors R62 / R65, the trickle charging voltage range is set when the battery pack terminal voltage is less than 23.375V (Vmin = 2.125V * (R62 / R65 + 1)). Capacitor C40 is the longest charging timer capacitor, providing an extra layer of protection for the overall battery charging process.

[0038] Battery pack information acquisition and control circuit: The INA226 chip is used to acquire real-time voltage and current information of the battery pack, and the gate of MOSFET Q13 / Q14 is controlled to make MOSFET Q13 / Q14 work in the saturation or cutoff region, thereby achieving the purpose of controlling the charging and discharging of the battery pack. Figure 8 The positive terminal of the battery pack is electrically connected to chip U16 (pin 9 VIN+) through R100; pin 51 (PB12) of chip U1 MCU is electrically connected to the gate of transistor Q19 through R163; transistor Q19 is electrically connected to the gate of transistors Q13 / Q14 through resistor R172.Figure 8 Battery pack information acquisition and control circuit.

[0039] The above description is merely preferred embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can make equivalent substitutions or changes according to the technical scheme and the inventive concept of the present application within the technical scope disclosed by the present application, which should be covered by the protection scope of the present application.

Claims

1. A charge-discharge management circuit for a nickel-hydrogen battery pack, characterized by comprising: Comprise: The charge and discharge management chip, micro control unit MCU, battery information acquisition chip, first MOS tube switch and second MOS tube switch, third MOS tube switch and current sampling resistance which are connected in series in the main circuit of the nickel hydrogen battery pack charge and discharge; The power output end of the charge and discharge management chip is connected with the drain of the third MOS tube switch; the source of the third MOS tube switch is connected to the main circuit of the nickel hydrogen battery pack through the current sampling resistance; the BGATE pin of the charge and discharge management chip is connected to the gate of the third MOS tube switch through the first resistance to control its on-off; The control pin of the MCU is connected to the gate of the first MOS tube switch and the second MOS tube switch through the driving module composed of the fourth MOS tube switch and the second resistance respectively to control its on-off; the drain of the first MOS tube switch and the second MOS tube switch is interconnected, and the node after interconnection is connected with the drain of the third MOS tube switch; the source of the first MOS tube switch is connected with the power charging end of the charge and discharge management chip; the source of the second MOS tube switch is connected with the positive electrode of the nickel hydrogen battery pack; The voltage sampling end of the battery information acquisition chip is connected on the load side of the current sampling resistance for collecting the terminal voltage and loop current of the nickel hydrogen battery pack; the battery information acquisition chip is connected with the communication pin of the MCU through IIC communication bus.

2. The charge and discharge management circuit for a Ni-MH battery pack according to claim 1, wherein The drain of the fourth MOS tube switch is connected with the gate of the first MOS tube switch and the second MOS tube switch through a shared coupling resistance; the gate of the fourth MOS tube switch is connected with the control pin PB12 of the MCU through the second resistance, and the source of the fourth MOS tube switch is grounded.

3. The charge and discharge management circuit for a Ni-MH battery pack according to claim 1, wherein, Further comprising NTC temperature detection circuit; the NTC temperature detection circuit comprises NTC thermistor built-in battery pack and external bias resistance, the NTC thermistor is electrically connected with the pin of the MCU through the fifth MOS tube switch, and is electrically connected with the NTC pin of the charge and discharge management chip through the bias resistance, for realizing over-temperature protection based on the temperature of the battery pack.

4. The charge and discharge management circuit for a Ni-MH battery pack according to claim 1, wherein, The battery information acquisition chip adopts INA226 chip and is connected with the communication pin of the MCU through IIC communication interface.

5. A mine power supply system based on the nickel-hydrogen battery pack charge-discharge management circuit of claim 1, characterized in that, Comprise: AC / DC module for converting external alternating current into direct current and providing power for the nickel hydrogen battery pack charge and discharge management circuit; A BMS master control board, a power input end of which is electrically connected with an output end of an AC / DC module, and a battery port of the BMS master control board is electrically connected with a nickel-hydrogen battery pack; wherein the BMS master control board comprises the nickel-hydrogen battery pack charge-discharge management circuit as claimed in any one of claims 1 to 4, for controlling charge-discharge of the nickel-hydrogen battery pack, and the control process specifically comprises: trickle charging and constant current charging of the nickel-hydrogen battery pack by the charge-discharge management chip; collecting voltage and current information of the nickel-hydrogen battery pack by the battery information collection chip, and transmitting to the MCU; the MCU controls the turn-on and turn-off of the first MOS switch and the second MOS switch based on the information collected by the battery information collection chip, to realize the complete charging process including trickle charging, constant current charging and make-up charging in cooperation with the charge-discharge management chip, and judges to be full and stops charging when detecting that the nickel-hydrogen battery pack terminal voltage appears peak drop; A DC / DC output module, an input end of which is electrically connected with a load power supply end of the BMS master control board, for providing stable voltage DC output for the load.

6. The mine power supply system based on the charging and discharging management circuit of the nickel-hydrogen battery pack according to claim 5, characterized in that, The MCU is specifically configured to: When the nickel-hydrogen battery pack terminal voltage is lower than the trickle charging voltage threshold, the first MOS switch and the second MOS switch are turned on to enter the trickle charging stage; When the nickel-hydrogen battery pack terminal voltage is higher than the trickle charging voltage threshold and lower than the constant current charging voltage threshold, the constant current charging stage is entered; When the nickel-hydrogen battery pack terminal voltage reaches or approaches the full voltage value, the voltage change is continuously monitored, and when the characteristic of voltage rising and then falling is captured, the make-up charging timing is triggered, and when the voltage falls again after or during the timing ends, the first MOS switch and the second MOS switch are turned off to stop charging.

7. The mine power supply system based on the charging and discharging management circuit of the nickel-hydrogen battery pack according to claim 6, characterized in that, The full voltage value is a nominal full voltage value set according to the number of battery strings.

8. The mine power supply system based on the charging and discharging management circuit of the nickel-hydrogen battery pack according to claim 5, characterized in that, The charge-discharge management chip is externally configured with a parameter configuration circuit; the charge output voltage of the nickel-hydrogen battery pack and the voltage threshold of the trickle charging are set through the parameter configuration circuit.

9. The mine power supply system based on the charging and discharging management circuit of the nickel-hydrogen battery pack according to claim 5, characterized in that, Further comprising a path management module, for when external power supply is effective, the DC / DC output module is preferentially powered by the AC / DC module, and the nickel-hydrogen battery pack is charged; when the external power supply fails, the DC / DC output module is powered by the nickel-hydrogen battery pack.

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