Intelligent maintenance device for storage battery

Abstract

The invention discloses an intelligent maintenance device for a storage battery. The device comprises an EMI filter, a power factor compensation circuit, a rectification filter, an auxiliary power supply, a DC-DC converter, an electronic load and a control loop, the control loop comprises a processor module, a drive control module, an overvoltage protection module, an overcurrent protection module, a temperature protection module and the like. The working mode of the intelligent maintenance device for the storage battery is divided into a local mode and a remote control mode. In the local mode, the working state can be manually selected through a corresponding button, and in the remote control mode, the working state can be selected through a remote battery management system via a 433M communication module. In the two working modes, the local working mode is preferential. When the charger breaks down, the fault alarm circuit prompts a manager that the charger breaks down through the buzzer and the red light emitting diode. The device can accurately and quickly realize intelligent management of charging and discharging of the storage battery, so that daily charging maintenance of the storage battery can be realized, and repairable maintenance of the faulty storage battery can also be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of storage batteries, and particularly to an intelligent maintenance system for storage batteries. Background Art

[0002] As an important energy storage device and emergency uninterruptible power supply, the storage battery pack has the advantages of good reversibility, stable voltage characteristics, long service life, wide application range, rich raw materials, etc., and has been widely used in various industries. The storage battery maintenance devices in the prior art are often single charging devices or repair devices, and the working mode is relatively single, making it difficult to effectively and intelligently comprehensively maintain the storage battery. Summary of the Invention

[0003] The technical problem to be solved by the present invention is how to provide a device that can accurately and quickly realize intelligent control of the charging and discharging of the storage battery, so as to realize the daily charging maintenance of the storage battery and the repair maintenance of the faulty battery.

[0004] To solve the above technical problem, the technical solution adopted by the present invention is: an intelligent maintenance device for a storage battery, comprising: an EMI filtering circuit, the output end of the EMI filtering circuit is connected to the input end of a power factor compensation circuit, the output end of the power factor compensation circuit is connected to the input end of a rectifying and filtering circuit, one output end of the rectifying and filtering circuit is connected to the power supply terminal of a processor through an auxiliary power supply, the other output end of the rectifying and filtering circuit is connected to one input end of a DC-DC converter, the output end of the DC-DC converter is divided into two paths, the first path is connected to the input end of a reverse connection detection module, the second path is connected to the input end of a sampling and feedback module, the output end of the sampling and feedback module is respectively connected to the relevant sampling pins of the processor through an overcurrent protection circuit and an overvoltage protection circuit; the driving control output end of the processor is connected to the control input end of the DC-DC converter through a PWM control module; the output end of the reverse connection detection module is divided into three paths, the first path is connected to the reverse connection detection signal input end of the processor, the second path is connected to the processor through an electronic load, the third path is an output end of the maintenance system, and this output end is connected to one end of the storage battery; the auxiliary driving signal output end of the processor is respectively connected to the input ends of a negative pulse discharge module and a slow discharge module through an auxiliary driving module, and the output ends of the pulse discharge module and the slow discharge module are connected to the other end of the storage battery; the signal output end of a temperature protection circuit is connected to one signal input end of the processor; a wireless communication module is bidirectionally connected to the processor module, and is used for receiving control commands transmitted from a remote terminal and uploading the processing information of the system to the remote terminal.

[0005] The beneficial effects of adopting the above technical solutions are as follows: By setting corresponding charging and discharging modules and corresponding charge and discharge control strategies, this application can reduce the failure rate of the storage battery and extend its service life. In addition, through the wireless communication module, remote control can be achieved. When an abnormal situation is detected, an audible and visual alarm is given proximally and an alarm message is sent to the distal end through the wireless communication module, improving the safety of its use. Description of the Drawings

[0006] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0007] Figure 1 is the principle block diagram of the device according to the embodiment of the present invention; Figure 2 is the curve diagram of three-stage charging in the embodiment of the present invention; Figure 3 is the overall structure block diagram of the main circuit in the embodiment of the present invention; Figure 4 is the schematic diagram of the EMI filter circuit in the embodiment of the present invention; Figures 5a - 5d is the schematic diagram of the PWM control module in the embodiment of the present invention; Figure 6 is the schematic diagram of the overvoltage protection circuit in the embodiment of the present invention; Figure 7 is the schematic diagram of the overcurrent protection circuit in the embodiment of the present invention; Figure 8 is the schematic diagram of the control circuit in the embodiment of the present invention; Figures 9a - 9d is the schematic diagram of the auxiliary power supply in the embodiment of the present invention; Figure 10 is the schematic diagram of the electronic load in the embodiment of the present invention; Figure 11 is the schematic diagram of the auxiliary drive module in the embodiment of the present invention; Figure 12 is the positive and negative pulse repair waveform diagram in the embodiment of the present invention; Figure 13 is the schematic diagram of the positive and negative pulse circuit in the embodiment of the present invention; Figure 14 is the working principle diagram of the positive and negative pulse circuit in the embodiment of the present invention; Figure 15 is the positive and negative pulse waveform diagram in the embodiment of the present invention; Figure 16 is the circuit diagram of the wireless communication module E22-400T22S in the embodiment of the present invention; Figure 17 is the main program flow chart in the embodiment of the present invention; Figure 18 It is the flowchart of the main charging program in the embodiment of the present invention; Figure 19 It is the flowchart of the three-stage charging sub-program in the embodiment of the present invention; Figure 20 It is the flowchart of the fuzzy PID sub-program in the embodiment of the present invention; Figure 21 It is the flowchart of the discharge mode program in the embodiment of the present invention. Detailed implementation manners

[0008] Next, in combination with the accompanying drawings in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

[0009] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0010] Such as Figure 1As shown in the figure, an embodiment of the present invention discloses an intelligent battery maintenance device, including: an EMI filter circuit, the output end of the EMI filter circuit is connected to the input end of the power factor compensation circuit, the output end of the power factor compensation circuit is connected to the input end of the rectifier filter circuit, one output end of the rectifier filter circuit is connected to the power supply terminal of the processor through an auxiliary power supply, the other output end of the rectifier filter circuit is connected to one input end of the DC-DC converter, the output end of the DC-DC converter is divided into two paths, the first path is connected to the input end of the reverse connection detection module, and the second path is connected to the input end of the sampling feedback module. The output end of the sampling feedback module is connected to the relevant sampling pins of the processor through an overcurrent protection circuit and an overvoltage protection circuit respectively; the drive control output end of the processor is connected to the control input end of the DC-DC converter through a PWM control module; the output end of the reverse connection detection module is divided into three paths, the first path is connected to the reverse connection detection signal input end of the processor, the second path is connected to the processor through an electronic load, and the third path is an output end of the maintenance system, and this output end is connected to one end of the battery; the auxiliary drive signal output end of the processor is connected to the input ends of the negative pulse discharge module and the slow discharge module through an auxiliary drive module respectively, and the output ends of the pulse discharge module and the slow discharge module are connected to the other end of the battery; the signal output end of the temperature protection circuit is connected to a signal input end of the processor; the wireless communication module is bidirectionally connected to the processor module, and is used to receive control commands transmitted from a remote terminal and upload the processing information of the system to the remote terminal. The human-computer interaction module is bidirectionally connected to the processor, and is used to input control commands and display output data. The human-computer interaction module can use a keyboard and a display, and can also use a touch screen. In addition, the device may further include a fault alarm circuit, which is connected to the signal output end of the processor and is used to emit an audible and visual alarm signal under the control of the processor.

[0011] The working modes of an intelligent battery maintenance device include a local mode and a remote control mode. In the local mode, the working state can be manually selected through corresponding buttons (switches), and can be selected as normal charging, emergency charging, pulse repair, and deep activation repair. In the remote control mode, the working state is selected through a remote communication module. In the two working modes, the local working mode has priority. When a fault occurs in the maintenance device, the fault alarm circuit uses a buzzer and a red light-emitting diode to prompt the management personnel that the charger has failed.

[0012] An intelligent battery maintenance device is built with a load unit, which is used for negative pulse discharge during fast charging to eliminate the polarization effect of the battery; the device uses a three-stage charging method to charge the load, which conforms to the charging characteristics of lead-acid batteries. The three stages are the constant current equalizing charge stage, the constant voltage current reduction stage, and the small current floating charge stage, also known as the floating charge stage.

[0013] The three-stage charging method, and the curve graph of three-stage charging is as Figure 2 shown: 1) Constant current equalizing charge stage. During the charging process, chemical reactions occur inside the storage battery and are converted into electrical energy, and its voltage will gradually increase. At the same time, the output value of the charger increases proportionally with the increase of the storage battery power to keep the charging battery unchanged. When the current in the circuit increases during the charging process, the charging circuit will automatically reduce the output voltage to prevent the current from increasing and keep the current unchanged. The formula for the output current value is as follows: Battery capacity (ampere-hour) × 1.2 (efficiency) ÷ 8 (hours) = charging current (ampere) Among them, 1.2 is a fixed value, and 8 refers to the charging time, which is stipulated by the standard and is also a fixed value.

[0014] 2) Constant voltage and decreasing current stage. When the charging voltage reaches the rated value on the lead-acid storage battery, the output voltage remains unchanged at this time, and the charging current gradually decreases according to the charging situation of the storage battery. The calculation formula for the charging voltage value is as follows: Number of cells (pieces) × single-cell voltage (V) = constant voltage charging voltage (V); among them, the number of cells refers to the number of charging cells of the lead-acid storage battery, and the single-cell voltage refers to the voltage of each cell of the lead-acid storage battery. Battery single-cell voltage (V) × number of cells of the battery (pieces) = constant voltage charging voltage (V); 3) Small current floating charge stage. The small current floating charge stage means that when the storage battery is basically full, the system will automatically control the output voltage according to the detected current in the circuit. At this time, the output voltage is stable and the current continues to decrease. The charging ends after about two hours.

[0015] The overall structure of the main circuit of the said device is as Figure 3 shown. It adopts high-frequency pulse width modulation technology and is equipped with a stable IGBT as the adjustment component, making this switching DC power supply have the characteristics of high conversion efficiency, stable voltage and current, high precision, good transient response, etc. The voltage and current are continuously adjustable, and it has protection functions such as input overvoltage, undervoltage, phase loss, output overvoltage, overcurrent, short circuit, constant current output voltage limit, overheating, etc. It mainly includes several parts such as EMI filter circuit, full-bridge rectifier circuit, DC / DC inverter circuit, LC filter circuit, PWM pulse width modulation circuit, etc. Single-phase alternating current is input, passes through the electromagnetic interference filter circuit, and then passes through full-bridge rectification and is sent to the DC / DC inverter circuit for inversion to obtain a high-frequency AC pulse voltage. Finally, it passes through the rectification and filter circuit to obtain a stable DC voltage and current, and the output voltage or current is controlled by the analog quantity given by the processor. In addition, this charging module has protection measures such as overvoltage, overcurrent, short circuit, temperature control, etc.

[0016] Selection of EMI filter circuit: When alternating current supplies voltage to a switching power supply, electromagnetic interference (EMI) will occur if corresponding measures are not taken. Radiation interference and conduction interference are two forms of electromagnetic interference. Radiation interference refers to the interference source coupling signals to another electrical network through the circuit working environment. There are many factors that can cause radiation interference. For example, when drawing a PCB and soldering a circuit board, many factors can become the radiation interference transmitting antennas, including component pins, frequency signal traces, and the pins of electronic components. Conduction interference refers to the interference generated by the interaction of signals on two electrical networks through a conductive medium.

[0017] Therefore, EMI filtering is essential in the design of switching power supplies and can play a role in avoiding electromagnetic interference. To suppress electromagnetic interference, it is first necessary to understand the necessary conditions for generating electromagnetic interference. There are three conditions for generating electromagnetic interference: the source of emission interference, the coupling path, and the receiver. Without any one of these three conditions, interference cannot be formed.

[0018] As Figure 4 shown, for the EMI filtering circuit, one input terminal of the EMI filtering circuit is divided into three paths. The first path is connected to one end of capacitor C24, the second path is connected to one end of capacitor C14, and the third path is connected to one input terminal of common-mode inductor L2; the other input terminal of the EMI filtering circuit is divided into three paths. The first path is connected to the other end of capacitor C24, the second path is connected to the other end of capacitor C14, and the third path is connected to the other input terminal of common-mode inductor L2; one output terminal of common-mode inductor L2 is divided into three paths. The first path is connected to one end of capacitor C16, the second path is grounded through capacitor C26, and the third path is the first output terminal of the EMI filtering circuit; the other output terminal of common-mode inductor L2 is divided into three paths. The first path is connected to the other end of capacitor C16, the second path is grounded through capacitor C25, and the third path is the second output terminal of the EMI filtering circuit.

[0019] After the alternating current is input, the electrolytic capacitor C24 with a capacitance of 470uf / 400V is first used for filtering. Since C24 has a large capacitance and the large parasitic inductance generated will affect the filtering efficiency, a small capacitor C14 is needed for secondary filtering. After filtering, it is supplied to the EMI circuit for filtering. EMI filtering is essentially a two-way low-pass filter and is also composed of two components, capacitors and inductors. EMI filtering can effectively suppress the external electromagnetic interference brought in on the AC power line, and it will not generate interference signals to the outside by itself. In the circuit, L2 is a common-mode inductor, which is composed of an iron core and copper wires. The copper wires on both sides have opposite directions but the same number of turns. When common-mode interference occurs, L2 will quickly generate a large inductive reactance to suppress the interference. C25, C26, and L2 together constitute the EMI common-mode filtering circuit.

[0020] DC-DC Inverter Circuit Design: The DC-DC inverter circuit is the core of the main circuit design of the charger. Selecting a suitable inverter structure form plays a crucial role in the performance and reliability of the charger. In current common switching power supply circuits, there are various inverter circuits, but the following five are the main common ones: single-ended forward, single-ended flyback, push-pull, half-bridge, and full-bridge converters.

[0021] According to the specific requirements of high current and high power output in this design, it is more appropriate to adopt a full-bridge inverter circuit for the DC-DC inverter circuit. The full-bridge inverter circuit consists of an IGBT full-bridge conversion circuit, a high-frequency transformer, and an output rectifier and filter circuit. IGBT is a device composed of a VDMOS and a bipolar transistor in combination. Its input terminal is a VDMOS, and its output terminal is a PNP transistor. It combines the advantages of these two devices. It has both the advantages of small device drive power and fast switching speed, and the advantages of low saturation voltage and large capacity of bipolar devices. Its characteristics are between those of power transistors and can work normally within dozens. It has been more and more widely used in modern power electronics technology and occupies a dominant position in high-power applications at higher frequencies. The full-bridge inverter circuit converts the rectified direct current into a high-frequency alternating current similar to a square wave with a frequency of 20KHz. The high-frequency transformer is responsible for stepping down the high-frequency alternating current output by the inverter circuit. The secondary rectifier circuit of the high-frequency transformer consists of two fast-recovery diodes, and its function is to rectify the high-frequency (20KHz) alternating square wave voltage coming from the high-frequency transformer. The output DC filter circuit consists of a filter capacitor (electrolytic capacitor) and a filter inductor, and filters out high-frequency and low-frequency interference after rectification through the filter circuit. The control method of the DC-DC inverter circuit is selected as the pulse width (PWM) modulation control method. The function of the DC-DC inverter circuit is to convert the input direct current into high-frequency alternating current in cooperation with the PWM pulses generated by the SG3525AN.

[0022] PWM Control Module: The core control chip of the charging module uses SG3525AN. This chip has two output signals. Combined with the DC / DC full-bridge inverter circuit and overvoltage and overcurrent protection circuits, the designed charging module achieves the effect of intelligent, fast and stable charging. SG3525AN realizes this by controlling the current and then feeding back to the circuit to change the pulse width. The signal is compared using the internal input terminal and the internal error amplifier of the chip, and thus the duty cycle is changed. The reason for choosing this relatively traditional chip, SG3525AN, is that it has a dual-loop structure of current loop and voltage loop inside, which can improve the transient response characteristics, load regulation rate and voltage regulation rate. When the voltage in the circuit exceeds the rated voltage value, the soft start terminal will make the whole chip stop working, and then the charger stops working; when the current in the circuit is too large, it will also make SG3525AN stop working, and then the charger stops working.

[0023] As Figures 5a - 5d shown, the PWM control module includes an SG3525AN-type chip IC1. The U_OUT input terminal of the PWM control module is connected to one end of a resistor R67. The other end of the resistor R67 is divided into two paths. The first path is grounded through a resistor R70, and the second path is connected to one end of a resistor R68. The other end of the resistor R68 is divided into two paths. The first path is grounded through a capacitor C34, and the second path is connected to one end of a potentiometer W4. The other end of the potentiometer W4 is connected to one end of a resistor R69. The sliding end of the potentiometer W4 is grounded through a resistor R73. The other end of the resistor R69 is divided into two paths. The first path is connected to the inverting input terminal of an LM324-type amplifier U6B, and the second path is grounded through a resistor R71. The non-inverting input terminal of the U6B is grounded through a resistor R72. A diode D13 is connected in parallel between the inverting input terminal and the output terminal of the U6B. A capacitor C31 and a resistor R66 are connected in series and then connected in parallel with the diode D13; The UIN input terminal of the PWM control module is connected to one end of a resistor R65 through a resistor R64. A diode D12 is connected in parallel with the resistor R64. The other end of the resistor R65 is connected to the collector of a triode Q5, and the collector of the triode Q5 is connected to the inverting input terminal of the U6B. The base of the triode Q5 is connected to the non-inverting input terminal of the U6B; the base of the triode Q5 is connected to one end of a resistor R60. The output terminal of the U6B is connected to the cathode of a diode D14. The anode of the diode D14 is divided into two paths. The first path is connected to the other end of the resistor R60, and the second path is connected to the anode of a diode D11; The I_OUT input terminal of the PWM control module is sequentially connected to the non-inverting input terminal of the LM324 amplifier U6A through a resistor R46 and then a resistor R47. One end of the resistor R*1 and one end of the capacitor C23 are grounded. The other end of the resistor R*1 and the other end of the capacitor C23 are connected to the node between the resistor R46 and the resistor R47. The inverting input terminal of the U6A is divided into two paths. The first path is grounded through a capacitor C18, and the second path is grounded through a resistor R36. The resistor C19 and the resistor R39 are connected in parallel between the inverting input terminal of the U6A and the output terminal of the U6A. The output terminal of the U6A is divided into three paths. The first path is connected to one end of a resistor R44. The second path is grounded through a capacitor C26. The third path is connected to the non-inverting input terminal of the LM324 amplifier U6C through a resistor R57. The inverting input terminal of the U6C is divided into two paths. The first path is grounded through a resistor R63, and the second path is connected to the output terminal of the U6C through a resistor R62. The output terminal of the U6C is divided into four paths after passing through a resistor R59. The first path is grounded through a resistor R30. The second path is grounded through a potentiometer W3. The third path is connected to the sliding end of the potentiometer W3. The fourth path is the signal output terminal of the U6C; The output terminal of the U6C is connected to one end of a resistor R44. The other end of the resistor R44 is sequentially connected to the inverting input terminal of the LM324 amplifier U7A through a potentiometer W2 and then a resistor R45. The sliding end of the potentiometer W2 is grounded through a resistor R50. One end of a resistor R51 is connected to the inverting input terminal of the U7A, and the other end of the resistor R51 is grounded. The non-inverting input terminal of the U7A is grounded through a resistor R52. A diode D10 is connected in parallel between the inverting input terminal of the U7A and the output terminal of the U7A. A resistor R40 and a capacitor C17 are connected in series and then connected in parallel with the diode D10; The AIN input terminal of the PWM control module is sequentially connected to the collector of a transistor Q4 through a resistor R37 and then a resistor R38. The inverting input terminal of the U7A is connected to the collector of the transistor Q4. The non-inverting input terminal of the U7A is connected to the emitter of the transistor Q4. The output terminal of the U7A is connected to the cathode of a diode D11. The anode of the diode D11 is divided into two paths. The first path is connected to the base of the transistor Q4, and the second path is connected to one end of a resistor R48; The other end of the resistor R48 is divided into four paths. The first path is connected to the 2nd pin of the IC1 through the resistor R49. The second path is connected to the reference voltage Vref through the resistor R42. The third path is grounded through the resistor R43. The fourth path is grounded through the capacitor C20. The 1st pin of the IC1 is grounded successively through the resistor R41 and the capacitor C16. The 3rd and 4th pins of the IC1 are left floating. The 5th pin of the IC1 is divided into two paths. The first path is grounded through the capacitor C25. The second path is connected to the 7th pin of the IC1 through the resistor R54. The 6th pin of the IC1 is grounded through the resistor R56. The 8th pin of the IC1 is grounded through the capacitor C28. The 9th pin of the IC1 is connected to the node of the resistor R41 and the capacitor C16. The 10th pin of the IC1 is divided into two paths. The first path is grounded through the resistor R61. The second path is grounded through the capacitor C29. The 11th pin of the IC1 is connected to one end of the resistor R58, and the other end of the resistor R58 is the PWM_A output terminal. The 12th pin of the IC1 is grounded. The 13th pin of the IC1 is divided into two paths after passing through the resistor R55. The first path is connected to the +12V power supply. The second path is grounded through the capacitor C24. The 14th pin of the IC1 is connected to one end of the resistor R53, and the other end of the resistor R53 is the PWM_B output terminal. The 15th pin of the IC1 is connected to the +12V power supply. The 16th pin of the IC1 is divided into two paths. The first path is connected to the reference voltage Vref. The second path is grounded through the capacitor C21.

[0024] Overvoltage protection can, on the one hand, prevent the instantaneous high voltage from impacting the switching transistor and causing damage to the switching transistor, and on the other hand, also prevent the voltage from rising during the charging process and causing damage to the storage battery. The overvoltage protection circuit is as Figure 6 shown. In the figure, U5 is an optocoupler, and the selected chip is PC817. When the high-frequency circuit is working, it can generate high-frequency signals, and these signals will interfere with the normal operation of the low-frequency signals. The function of this circuit is exactly to effectively isolate the low-frequency circuit and the high-frequency circuit. Using an optocoupler can make the two combine well and at the same time shield the high-frequency signals. The function of the optocoupler in this circuit is that it forms a feedback circuit to feedback the corresponding control signals, which can achieve the function of voltage stabilization. And if the output exceeds the specified maximum voltage, it will trigger the feedback circuit and directly short-circuit the output to protect the subsequent load from harm.

[0025] As Figure 6As shown, the overvoltage protection circuit includes operational amplifier U4B. One end of resistor R21 is the reference voltage input terminal. The other end of resistor R21 is divided into four paths. The first path is connected to the output terminal of U4B through capacitor C12. The second path is grounded through capacitor C10. The third path is grounded through resistor R36. The fourth path is connected to the inverting input terminal of U4B. The non-inverting input terminal of U4B is divided into four paths. The first path is connected to the DCOUT+ output terminal through resistor R35. The second path is grounded through capacitor C33. The third path is grounded through resistor R37. The fourth path is connected to the negative electrode of diode D22. The first path of the output terminal of U4B is connected to the positive electrode of diode D16. The second path is connected to the positive electrode of diode D22 through resistor R38. The negative electrode of diode D16 is connected to the positive electrode of the diode in optocoupler U5 through resistor R23. The collector of the triode in optocoupler U5 is the signal output terminal of the overvoltage protection circuit.

[0026] Overcurrent protection: When the current exceeds the set rated current value, the circuit will automatically cut off, as shown in Figure 7. When the charging circuit has overcurrent and overload, zener diode D15 will be broken down, and then the subsequent optocoupler U5 will generate isolation, turning off the continuous output of pulse signals by SG3525AN, causing the entire circuit to stop working.

[0027] As shown in Figure 7, the overcurrent protection circuit includes operational amplifier U4A. The input terminal of the overcurrent protection circuit is divided into two paths. The first path is sequentially connected to the inverting input terminal of U4A through resistor R17 and potentiometer A1. The second path is connected to the inverting input terminal of U4A through capacitor C8. The reference voltage Vref is connected to one end of resistor R19. The other end of resistor R19 is divided into two paths. The first path is connected to the inverting input terminal of U4A. The second path is sequentially connected to the output terminal of U4A through resistor R20 and capacitor C11. The inverting input terminal of U4A is connected to the power supply through capacitor C9. The non-inverting input terminal of U4A is grounded. The output terminal of U4A is connected to the positive electrode of diode D15. The negative electrode of diode D15 is the signal output terminal of the overcurrent protection circuit.

[0028] Output control circuit design: The processor controls the output voltage of the charging module through the DA given signal. The control circuit is as follows Figure 8As shown, the charging control circuit includes a resistor R11. One end of the resistor R11 is the control signal input terminal of the charging control circuit. The other end of the resistor R11 is divided into two paths. The first path is grounded through a capacitor C25, and the second path is connected to the non-inverting input terminal of an amplifier U2A of the TL062IDR type. The inverting input terminal of the U2A is connected to the output terminal of the U2A. The output terminal of the U2A is connected to the non-inverting input terminal of an amplifier U2B of the TL062IDR type. The inverting input terminal of the U2B is divided into two paths. The first path is grounded through a resistor R8, and the second path is connected to the output terminal of the U2B through a resistor R9. The 8th pin of the U2B is connected to a 12V power supply, and the 4th pin of the U2B is grounded. The output terminal of the U2B is divided into two paths. The first path is grounded through a capacitor C4, and the second path is connected to one end of a resistor R10. The other end of the resistor R10 is the control output terminal of the charging control circuit.

[0029] Further, as Figures 9a - 9d shown, the auxiliary power supply includes a power supply chip U2 of the UC3842AD8TR type. The 1st pin of the U2 is connected to the 2nd pin of the U2 through a resistor R8, and a capacitor C6 is connected in parallel with the resistor R8. The 2nd pin of the U2 is connected to the emitter of the triode in an optocoupler U3 through a resistor R9. The 3rd pin of the U2 is divided into three paths. The first path is connected to a current inspection signal terminal ISEN through a resistor R13, the second path is grounded through a capacitor C8, and the third path is connected to the 4th pin of the U2 through a capacitor C9. The 4th pin of the U2 is divided into two paths. The first path is connected to a reference voltage Vref through a resistor R16, and the second path is grounded through a capacitor C10. The 5th pin of the U2 is grounded. The 6th pin of the U2 is divided into two paths after passing through a resistor R14. The first path is connected to the gate of a field effect transistor Q1 of the KIA7N80H type, and the second path is connected through the source of the field effect transistor Q1. A diode D5 is connected in parallel with the resistor R14. The 7th pin of the U2 is divided into three paths. The first path is grounded through a capacitor E6, the second path is connected to a power supply VDD through a resistor R5, and the third path is connected to the collector of the triode in the optocoupler U3. The 8th pin of the U2 is divided into two paths. The first path is connected to the reference voltage Vref, and the second path is grounded through a capacitor C5. The power supply VDD is divided into several paths. The first path is grounded through a capacitor E3, the second path is connected to the negative electrode of a diode D3 through a capacitor CY1, the third path is connected to the negative electrode of the diode D3 through a resistor R2, and the fourth path is connected to one end of the first primary coil in a transformer T1. The positive electrode of the diode D3 is divided into two paths. The first path is connected to the drain of the field effect transistor Q1, and the second path is connected to the other end of the first primary coil in the transformer T1. The source of the field effect transistor Q1 is grounded. The collector of the triode in the optocoupler U3 is sequentially connected to one end of the second primary coil in the transformer T1 through a resistor R7 and a diode D4, and the other end of the second primary coil in the transformer T1 is grounded. One end of the first secondary coil in transformer T1 is connected to pin 1 of power supply chip U1 of type LM7805 after passing through diode D1, and capacitor C1 is connected in parallel with diode D1; pin 1 of U1 is divided into two paths, the first path is grounded through capacitor E1, and the second path is grounded through resistor R1; pin 2 of U1 is grounded; pin 3 of U1 is divided into three paths, the first path is grounded through capacitor E2, the second path is grounded through capacitor C2, and the third path is the +5V power output terminal; the other end of the first secondary coil in transformer T1 is grounded; One end of the second secondary coil in transformer T1 is divided into two paths after passing through diode D2, the first path is connected to one end of inductor L1, and the second path is grounded through capacitor E4, and capacitor C4 is connected in parallel with diode D2; the other end of inductor L1 is divided into four paths, the first path is grounded through capacitor E5, the second path is grounded through resistor R3, the third path is grounded through capacitor C3, and the fourth path is the +12V power output terminal; the other end of the second secondary coil in transformer T1 is grounded; The emitter of the triode in optocoupler U3 is grounded through resistor R19, and the positive pole of the diode in optocoupler U3 is divided into three paths after passing through resistor R10, the first path is connected to one end of resistor R11, the second path is connected to 12V power supply VCC, and the third path is connected to one end of resistor R12; the negative pole of the light-emitting diode in optocoupler U3 is divided into several paths, the first path is connected to pin 3 of voltage regulator tube U4 of type TL431, the second path is connected to the other end of resistor R11, the third path is connected to one end of resistor R15, the other end of resistor R15 is connected to the other end of resistor R12, one end of resistor R17, one end of resistor R18 and pin 1 of U4 after passing through capacitor C7, and the other ends of resistor R17, resistor R18 and pin 2 of U4 are grounded.

[0030] The activation of the storage battery requires a discharge process. The electronic load can safely consume power. Therefore, the electronic load is selected as the discharge object of the storage battery. The simplest electronic load consists of a circuit composed of a controllable switch (a bipolar transistor or a MOSFET tube) to adjust the required current value. The MOSFET operates at high speed and does not generate static power loss. The greatest advantage is in DC signals. The MOSFET gate impedance is infinite, equivalent to an open circuit. Theoretically, no DC current flows from the gate to the ground point of the circuit, forming a voltage-controlled device completely controlled by the gate voltage, which is more power-saving than the current-controlled bipolar transistor BJT and is easier to drive. Therefore, the designed DC electronic load uses MOSFET as its control device.

[0031] Such as Figure 10As shown, the electronic load includes several load units with the same structure. The input end of the load unit is divided into two paths. The first path is grounded through resistor R9, and the second path is connected to the non-inverting input end of amplifier U1A of type LM324 after passing through resistors R1, R2, and R3 in sequence. One end of capacitor C1 is grounded, and the other end of capacitor C1 is connected to the node between resistor R1 and resistor R2. One end of capacitor C2 is grounded, and the other end of capacitor C2 is connected to the node between resistor R2 and resistor R3. One end of resistor R10 is grounded, and the other end of resistor R10 is connected to the non-inverting input end of the U1A. One end of capacitor C3 is grounded, and the other end of capacitor C3 is connected to the non-inverting input end of the U1A. One end of resistor R15 is divided into two paths. The first path is grounded through capacitor C10, and the second path is connected to the inverting input end of the U1A through resistor R13. One end of capacitor C7 is connected to the non-inverting input end of the U1A, and the other end of capacitor C7 is connected to the output end of the U1A. The output end of the U1A is connected to the gate of field effect transistor Q1 of type RFP260N through resistor R7. The drain of the Q1 is connected to the power supply. The source of the Q1 is divided into two paths. The first path is grounded through resistor RS1, and the second path is connected to the other end of the resistor R15.

[0032] As Figure 11 shown, the auxiliary drive module includes resistor R7. The other end of the resistor R7 is divided into two paths. The first path is grounded through capacitor C2, and the second path is connected to the non-inverting input end of amplifier U1A of type TL062IDR. The inverting input end of the U1A is connected to the output end of the U1A. The output end of the U1A is connected to the non-inverting input end of amplifier U1B of type TL062IDR. The inverting output end of the U1B is grounded through resistor R3. The 4th pin of the U1B is grounded. The 8th pin of the U1B is divided into three paths. The first path is connected to the +12V power supply, the second path is grounded through capacitor C22, and the third path is grounded through capacitor C23. One end of resistor R4 is connected to the inverting input end of the U1B, and the other end of resistor R4 is connected to the output end of the U1B. The output end of the U1B is divided into five paths. The first path is grounded through capacitor C1, the second path is connected to pin 1 of connector JP1 through resistor R1, the third path is connected to pin 1 of connector JP2 through resistor R2, the fourth path is connected to pin 1 of connector JP3 through resistor R5, and the fifth path is connected to pin 1 of connector JP4 through resistor R6. The 2nd pins of the JP1 - JP4 are grounded. The JP1 - JP4 are the control signal output ends of the auxiliary drive module.

[0033] Repair circuit design: During the use of lead-acid batteries, problems such as capacity decline or even failure and scrapping may occur. The main failure modes include: grid oxidation and corrosion, shedding of positive plate active material, irreversible sulfation, etc. These failure modes affect and coexist with each other. Due to its high incidence and irreversibility, irreversible sulfation has become the most common cause of battery failure. Plate sulfation means that when the battery is over-discharged or charged unsaturated for a long time, the active material on the battery plate will gradually turn into large and hard lead sulfate crystals and adhere to the surface of the plate. The large lead sulfate crystals adhere to the micropores of the active material, preventing the sulfuric acid solution from penetrating deeply and the current from transmitting, and the internal resistance of the battery becomes larger. This causes the charge and discharge performance of the battery to deteriorate severely, the battery capacity is restricted, and the conventional charging method cannot convert the lead sulfate crystals into lead dioxide and lead, resulting in a significant reduction in the active material generated on the plate, making the battery discharge much less than the normal value and greatly reducing the battery life. It can be seen that the sulfation of the battery plate has a great impact on the battery performance, and in severe cases, the battery may even be scrapped in advance. Research shows that about 70-80% of the faults in current batteries are caused by plate sulfation.

[0034] In order to restore the capacity decline of lead-acid batteries caused by sulfation and extend the battery life, it is necessary to turn the lead sulfate crystals inside the battery back into active substances that can participate in chemical reactions. There is an urgent need to design an intelligent maintenance device to repair the batteries with capacity decline. Currently, the common repair methods for batteries are water treatment method, overcharge repair method, automatic constant voltage charging and repeated charge and discharge method, and pulse repair method. The pulse rapid charging method can not only improve the charging efficiency of the battery, but also the positive and negative pulses can also improve the performance of the batteries with sulfation to a certain extent.

[0035] The pulsed current can accelerate the balance speed of the electrolyte inside the battery. Under the action of the pulse, the lead sulfate crystals will participate in the reduction reaction and turn back into lead and sulfuric acid, thus dissolving the lead sulfate. When the pulse wave continuously acts on the positive and negative electrodes of the battery, the oxidation-reduction reaction inside the battery will proceed intermittently, disturbing the relatively static environment required for the formation of lead sulfate crystals, thereby preventing the irreversible sulfation of lead-acid batteries. The positive and negative pulse repair waveforms are as Figure 12 shown.

[0036] The repair principle is: for all materials with poor conductivity, there is a maximum voltage value that they can withstand, which we call the minimum breakdown voltage. If the externally applied voltage value is greater than this critical value, the insulating material will be broken down and become a conductor. The positive and negative pulse repair waveforms make use of this principle. During the positive pulse, a larger voltage value is applied to both ends of the lead-acid battery. This voltage can break up the lead sulfate crystals that have been formed and attached to the plates, turning them into lead sulfate that can participate in the charging reaction during charging, thereby increasing the capacity of the lead-acid battery. However, this will cause an area near the plates during the dissolution process. The lead sulfate concentration in this area is relatively high. Lead sulfate solutions with a high concentration are prone to recrystallization problems, which will hinder the further dissolution of lead sulfate crystals. On the other hand, the applied voltage is relatively high. Due to the existence of a certain amount of internal resistance in the lead-acid battery, the temperature of the lead-acid battery will rise, and in severe cases, it will cause thermal runaway of the lead-acid battery. In order to reduce the concentration of lead sulfate solution in this area and prevent thermal runaway, we add a negative pulse to the repair waveform. The essence of the negative pulse is to discharge the lead-acid battery for a short time. During the discharge process, it will absorb the heat generated during charging and reduce the concentration of the lead sulfate solution.

[0037] The schematic diagram of the positive and negative pulse circuit designed for a battery intelligent maintenance device is shown in Figure 13, in which DC is the 13.8V DC voltage output by the flyback power supply circuit; R is the battery discharge resistor; Q1 and Q2 are positive and negative pulse control switch tubes respectively; and the battery is a lead-acid battery to be repaired.

[0038] The working principle of the circuit is shown in Figure 14. The positive and negative pulse waveforms generated by the circuit are shown in Figure 15. We stipulate that the direction of the current when the battery is charged is the positive direction.

[0039] (1) During the t0-t1 phase, the switch tube Q1 is turned on and Q2 is turned off, and the 13.8V DC power charges the battery. At this time, the circuit generates a positive pulse, and the duration of the positive pulse is t1-t0.

[0040] (2) During the t1-t2 phase, the switch tubes Q1 and Q2 are both in the off state. At this time, the circuit stops working and does not generate any waveform. The pause time is t2-t1.

[0041] (3) In the t2-t3 stage, the switch Q2 is turned on and Q1 is turned off. The battery discharges to the resistor R through Q2. At this time, the circuit generates a negative pulse with a duration of t3-t2.

[0042] (4) During the t3-t4 period, Q1Q2 are both in the off state, and the circuit does not generate a waveform until the next cycle begins. The rest period is t4-t3.

[0043] Communication Module Design: Select the wireless serial port module (UART) - E22-400T22S LoRa wireless module based on the SX1268 radio frequency chip of SEMTECH Corporation. The E22-400T22S adopts a new generation of LoRa spread spectrum technology. Compared with the traditional SX1278 solution, the SX1268 solution has a longer transmission distance, faster speed, lower power consumption, smaller size, and has multiple transmission methods. It operates in the frequency band of (410.125~493.125 MHz) (default 433.125 MHz). The main features of the E22-400T22S wireless module are as follows: (1) Develop a new LoRa spread spectrum modulation technology based on SX1268, bringing a longer communication distance and stronger anti-interference ability; (2) Wireless parameter configuration can be performed. By wirelessly sending instruction data packets, the parameters of the wireless module can be remotely configured or read; (3) The parameters are saved when the power is off, and the module will work according to the set parameters after power-on; (4) Industrial-grade standard design, supporting long-term use at -40~+85°C; (5) Dual antennas are available (IPEX / stamp holes), which is convenient for users' secondary development and beneficial for integration.

[0044] The circuit diagram of E22-400T22S is shown in Figure 16. M0 and M1 cooperate to determine the four working modes of the module. RXD is the TTL serial port input end, connected to the TXD of the single-chip microcomputer. TXD is the TTL serial port output end, connected to the RXD of the single-chip microcomputer. Data is transmitted with the STM32 single-chip microcomputer through RXD and TXD. AUX is used to indicate the working state of the module, and NAST is the module reset pin.

[0045] The software part is the brain of the intelligent maintenance device, the core to achieve efficient charging and discharging of the battery, and the key element to constitute the intelligent maintenance device.

[0046] 1) Main Program Design The main tasks implemented by the main program include: initializing the entire system after power-on, identifying the communication interface, detecting the battery polarity during power-on. If the battery is reversely connected, the next operation will be stopped. If there is no problem with the physical connection, the real-time interrupt is enabled, the system working mode is selected, the mode subroutine is jumped to for execution, and after completion, it returns to the main program. The interface identification functions include the analog quantity detection function (ADC_function), the wireless communication function (Wifi_function), and the serial port communication function (Uart_function), which are used to detect the information using analog quantity as the identification method in the interface, and read the battery firmware information and real-time status in the interface using the communication method respectively. The called data monitoring program performs real-time detection on parameters such as the battery and charging current at the battery end, and synchronously sends the voltage and current parameters to the serial port screen for display through serial port communication; at the same time, the voltage and current parameters are synchronously sent to the handheld device for display and recording through the 433MHz wireless communication module. The flowchart of the charging main program is as Figure 17 shown.

[0047] Design of the charging mode program: 1) Design of the charging mode main program: After receiving the charging mode command, the main program jumps to the charging program, reads the battery information, determines the charging method, sets the parameters, and executes the charging command. The charging program calls the data monitoring program to collect signals such as the input voltage and current of the storage battery in real time and calculate the error and its change rate. The control system uses a fuzzy PID controller to adjust the control parameters online, and adjusts the charging output voltage and current through the voltage loop regulator and the current loop regulator to keep the battery in a better charging state at all times; if there is no fault, it judges the charging stage and the battery state, enters the loop of the main program, and calls the corresponding subroutine at any time according to the charging needs. The software subroutine is called according to the requirements of the main program to implement the corresponding functions and automatically returns to the main program after execution. When a fault occurs during the charging process, the protection subroutine responds and takes corresponding alarm and protection measures. The flowchart of the charging main program is as Figure 18 shown: 2) Design of the three-stage charging subroutine: The three-stage charging first uses a constant current of 1C for charging (that is, a current that is one time the battery system capacity). When the voltage value reaches the rated voltage of the battery, it enters the constant voltage charging mode. In the constant voltage charging mode, the current slowly decreases. When the current decreases to 0.1A, it no longer decreases, and the constant voltage charging is completed. After the constant current and constant voltage charging are completed, the terminal voltage of the storage battery may have reached the charging requirement, but at this time the storage battery is not fully charged. Continue to charge with a small current of 0.1A for 2 hours to complete the charging. The flowchart of the three-stage charging subroutine is as Figure 19 shown: 3) Design of Fuzzy PID Subroutine: To improve the output accuracy, response speed, and stability of the charging system, a regulator needs to be added. In practical applications, the conventional PID controller has a simple structure and is easy to implement. However, since its parameters cannot be adjusted online, it is difficult to coordinate the contradiction between rapidity and stability, and the control effect is not ideal. The fuzzy PID controller takes the error e of the controlled quantity and the error change rate ec as inputs, makes decisions through fuzzy reasoning, and adjusts the three parameters of PID , , in real time online, so that the sampling signal can achieve precise control and achieve the purpose of rapid charging. In this design, the fuzzy PID subroutine reads the voltage and current collected by the data monitoring program in real time, calculates the input variables e and ec, and determines the duty cycle and phase shift angle of the output PWM waveform through fuzzy processing, so as to adjust the magnitude of the output voltage or current. The program design flowchart is as shown in Figure 20 .

[0048] Design of Discharge Mode Program: After receiving the discharge mode command, the main program jumps to the discharge program, reads the battery information, sets the discharge current, and executes the discharge command. When the discharge voltage reaches the discharge cut-off voltage, the discharge ends. The discharge mode program flowchart is as shown in Figure 21 .

Claims

1. A battery intelligent maintenance device, characterized in that include: An EMI filter circuit, wherein the output end of the EMI filter circuit is connected to the input end of the power factor compensation circuit, the output end of the power factor compensation circuit is connected to the input end of the rectifier filter circuit, one output end of the rectifier filter circuit is connected to the power supply end of the processor via an auxiliary power supply, the other output end of the rectifier filter circuit is connected to an input end of a DC-DC converter, the output end of the DC-DC converter is divided into two paths, the first path is connected to the input end of the reverse connection detection module, and the second path is connected to the input end of the sampling feedback module, the output end of the sampling feedback module is connected to the relevant sampling pins of the processor via a current protection circuit and an overvoltage protection circuit; the drive control output end of the processor is connected to the DC-DC converter via a PWM control module The output end of the reverse connection detection module is divided into three paths, the first path is connected to the reverse connection detection signal input end of the processor, the second path is connected to the processor via the electronic load, and the third path is an output end of the maintenance system, which is connected to one end of the battery; the auxiliary drive signal output end of the processor is connected to the input ends of the negative pulse discharge module and the slow discharge module respectively through the auxiliary drive module, and the output ends of the pulse discharge module and the slow discharge module are connected to the other end of the battery; the signal output end of the temperature protection circuit is connected to a signal input end of the processor; the wireless communication module is bidirectionally connected to the processor module, and is used to receive the control command transmitted from the remote terminal, and upload the processing information of the system to the remote terminal.

2. A battery intelligent maintenance device as claimed in claim 1, characterized in that: The system further comprises a human-computer interaction module, which is bidirectionally connected to the processor and is used for inputting control commands and displaying output data.

3. A battery intelligent maintenance device as claimed in claim 1, characterized in that: The EMI filter circuit, one input end of the EMI filter circuit is divided into three paths, the first path is connected to one end of the capacitor C24, the second path is connected to one end of the capacitor C14, and the third path is connected to an input end of the common-mode inductor L2; another input end of the EMI filter circuit is divided into three paths, the first path is connected to the other end of the capacitor C24, the second path is connected to the other end of the capacitor C14, and the third path is connected to the other input end of the common-mode inductor L2; an output end of the common-mode inductor L2 is divided into three paths, the first path is connected to one end of the capacitor C16, the second path is grounded via the capacitor C26, and the third path is the first output end of the EMI filter circuit; another output end of the common-mode inductor L2 is divided into three paths, the first path is connected to the other end of the capacitor C16, the second path is grounded via the capacitor C25, and the third path is the second output end of the EMI filter circuit.

4. A battery intelligent maintenance device as claimed in claim 1, characterized in that: The PWM control module includes a SG3525AN chip IC1, the U_OUT input end of the PWM control module is connected to one end of a resistor R67, the other end of the resistor R67 is divided into two paths, the first path is grounded via a resistor R70, and the second path is connected to one end of a resistor R68, the other end of the resistor R68 is divided into two paths, the first path is grounded via a capacitor C34, and the second path is connected to one end of a potentiometer W4, the other end of the potentiometer W4 is connected to one end of a resistor R69, the sliding end of the potentiometer W4 is grounded via a resistor R73, the other end of the resistor R69 is divided into two paths, the first path is connected to the inverting input end of an LM324 amplifier U6B, the second path is grounded via a resistor R71, the non-inverting input end of the U6B is grounded via a resistor R72, a diode D13 is connected in parallel between the inverting input end of the U6B and the output end of the U6B, and a capacitor C31 is connected in series with a resistor R66 and then connected in parallel with the diode D13; The UIN input terminal of the PWM control module is connected to one end of the resistor R65 via the resistor R64, the diode D12 is connected in parallel with the resistor R64, the other end of the resistor R65 is connected to the collector of the transistor Q5, and the collector of the transistor Q5 is connected to the inverting input terminal of the U6B, and the base of the transistor Q5 is connected to the non-inverting input terminal of the U6B; the base of the transistor Q5 is connected to one end of the resistor R60, the output terminal of the U6B is connected to the cathode of the diode D14, and the anode of the diode D14 is divided into two paths, the first path is connected to the other end of the resistor R60, and the second path is connected to the anode of the diode D11; The I_OUT input terminal of the PWM control module is connected to the in-phase input terminal of the LM324 amplifier U6A through resistors R46 and R47 in sequence, one end of the resistor R*1 and one end of the capacitor C23 are grounded, the other end of the resistor R*1 and the other end of the capacitor C23 are connected to the node between the resistor R46 and the resistor R47, the inverting input terminal of the U6A is divided into two paths, the first path is grounded through the capacitor C18, and the second path is grounded through the resistor R36, the resistor C19 and the resistor R39 are connected in parallel between the inverting input terminal of the U6A and the output terminal of the U6A, and the U The output end of 6A is divided into three paths, the first path is connected to one end of the resistor R44, the second path is grounded via the capacitor C26, the third path is connected to the non-inverting input end of the LM324 amplifier U6C via the resistor R57, the inverting input end of the U6C is divided into two paths, the first path is grounded via the resistor R63, the second path is connected to the output end of the U6C via the resistor R62, the output end of the U6C is divided into four paths after passing through the resistor R59, the first path is grounded via the resistor R30, the second path is grounded via the potentiometer W3, the third path is connected to the sliding end of the potentiometer W3, and the fourth path is the signal output end of the U6C; The output end of U6C is connected to one end of resistor R44, the other end of resistor R44 is connected to the inverting input end of LM324 amplifier U7A via potentiometer W2 and resistor R45 in sequence, the sliding end of potentiometer W2 is grounded via resistor R50, one end of resistor R51 is connected to the inverting input end of U7A, and the other end of resistor R51 is grounded; the in-phase input end of U7A is grounded via resistor R52; diode D10 is connected in parallel between the inverting input end of U7A and the output end of U7A; resistor R40 is connected in series with capacitor C17 and then connected in parallel with diode D10; The AIN input end of the PWM control module is connected to the collector of the transistor Q4 through resistors R37 and R38 in sequence, the inverting input end of U7A is connected to the collector of the transistor Q4, the non-inverting input end of U7A is connected to the emitter of the transistor Q4, the output end of U7A is connected to the cathode of the diode D11, and the anode of the diode D11 is divided into two paths, the first path is connected to the base of the transistor Q4, and the second path is connected to one end of the resistor R48; The other end of the resistor R48 is divided into four paths, the first path is connected to the 2nd pin of the IC1 through the resistor R49, the second path is connected to the reference voltage Vref through the resistor R42, the third path is connected to the ground through the resistor R43, and the fourth path is connected to the ground through the capacitor C20; the 1st pin of the IC1 is connected to the ground after passing through the resistor R41 and the capacitor C16 in sequence; the 3rd and 4th pins of the IC1 are suspended; the 5th pin of the IC1 is divided into two paths, the first path is connected to the ground through the capacitor C25, and the second path is connected to the 7th pin of the IC1 through the resistor R54; the 6th pin of the IC1 is connected to the ground through the resistor R56; the 8th pin of the IC1 is connected to the ground through the capacitor C28; the 9th pin of the IC1 is connected to the node of the resistor R41 and the capacitor C16; the 1st pin of the IC1 Pin 0 is divided into two paths, the first path is grounded through resistor R61, and the second path is grounded through capacitor C29; Pin 11 of the IC1 is connected to one end of resistor R58, and the other end of the resistor R58 is the PWM_A output end; Pin 12 of the IC1 is grounded; Pin 13 of the IC1 is divided into two paths after passing through resistor R55, the first path is connected to the +12V power supply, and the second path is grounded through capacitor C24; Pin 14 of the IC1 is connected to one end of the resistor R53, and the other end of the resistor R53 is the PWM_B output end; Pin 15 of the IC1 is connected to the +12V power supply; Pin 16 of the IC1 is divided into two paths, the first path is connected to the reference voltage Vref, and the second path is grounded through capacitor C21.

5. A battery intelligent maintenance device as claimed in claim 1, characterized in that: The overvoltage protection circuit includes an operational amplifier U4B, one end of a resistor R21 is a reference voltage input end, the other end of the resistor R21 is divided into four paths, the first path is connected to the output end of the U4B via a capacitor C12, the second path is grounded via a capacitor C10, the third path is grounded via a resistor R36, and the fourth path is connected to the inverting input end of the U4B; The in-phase input terminal of U4B is divided into four paths, the first path is connected to the DCOUT+ output terminal via resistor R35, the second path is grounded via capacitor C33, the third path is grounded via resistor R37, and the fourth path is connected to the cathode of diode D22; the first path of the output terminal of U4B is connected to the anode of diode D16, and the second path is connected to the anode of diode D22 via resistor R38; the cathode of diode D16 is connected to the anode of the diode in the optical coupler U5 via resistor R23, and the collector of the transistor in the optical coupler U5 is the signal output terminal of the overvoltage protection circuit.

6. A battery intelligent maintenance device as claimed in claim 1, characterized in that: The overcurrent protection circuit includes an operational amplifier U4A, and the input end of the overcurrent protection circuit is divided into two paths. The first path is connected to the inverting input end of U4A after passing through resistor R17 and potentiometer A1 in sequence, and the second path is connected to the inverting input end of U4A after passing through capacitor C8; the reference voltage Vref is connected to one end of resistor R19, and the other end of resistor R19 is divided into two paths, the first path is connected to the inverting input end of U4A, and the second path is connected to the output end of U4A after passing through resistor R20 and capacitor C11 in sequence; the reverse input end of U4A is connected to the power supply through capacitor C9; the in-phase input end of U4A is grounded; the output end of U4A is connected to the positive pole of diode D15, and the negative pole of diode D15 is the signal output end of the overcurrent protection circuit.

7. A battery intelligent maintenance device as claimed in claim 1, characterized in that: The charging control circuit includes a resistor R11, one end of the resistor R11 is the control signal input end of the charging control circuit, and the other end of the resistor R11 is divided into two paths, the first path is grounded via a capacitor C25, and the second path is connected to the non-inverting input end of a TL062IDR amplifier U2A, the inverting input end of U2A is connected to the output end of U2A, the output end of U2A is connected to the non-inverting input end of a TL062IDR amplifier U2B, the inverting input end of U2B is divided into two paths, the first path is grounded via a resistor R8, and the second path is connected to the output end of U2B via a resistor R9; the 8th pin of U2B is connected to a 12V power supply, and the 4th pin of U2B is grounded; the output end of U2B is divided into two paths, the first path is grounded via a capacitor C4, and the second path is connected to one end of a resistor R10, and the other end of the resistor R10 is the control output end of the charging control circuit.

8. The battery intelligent maintenance device according to claim 1, characterized in that: The auxiliary power supply includes a UC3842AD8TR type power supply chip U2, the pin 1 of the U2 is connected to the pin 2 of the U2 via a resistor R8, and a capacitor C6 is connected in parallel with the resistor R8; the pin 2 of the U2 is connected to the emitter of the transistor in the photocoupler U3 via a resistor R9; The 3rd pin of U2 is divided into three paths, the first path is connected to the current detection signal terminal ISEN through the resistor R13, the second path is grounded through the capacitor C8, and the third path is connected to the 4th pin of U2 through the capacitor C9; the 4th pin of U2 is divided into two paths, the first path is connected to the reference voltage Vref through the resistor R16, and the second path is grounded through the capacitor C10; the 5th pin of U2 is grounded; the 6th pin of U2 is divided into two paths after the resistor R14, the first path is connected to the gate of the KIA7N80H field effect transistor Q1, and the second path is connected to the source of the field effect transistor Q1; the diode D5 is connected in parallel with the resistor R14; the 7th pin of U2 is divided into three paths, the first path is grounded through the capacitor E6, the second path is connected to the power supply VDD through the resistor R5, and the third path is connected to the collector of the transistor in the photocoupler U3; the 8th pin of U2 is divided into two paths, the first path is connected to the reference voltage Vref, and the second path is grounded through the capacitor C5; The power supply VDD is divided into several paths, the first path is connected to the ground through the capacitor E3, the second path is connected to the cathode of the diode D3 through the capacitor CY1, the third path is connected to the cathode of the diode D3 through the resistor R2, and the fourth path is connected to one end of the first primary coil in the transformer T1; the anode of the diode D3 is divided into two paths, the first path is connected to the drain of the field effect transistor Q1, and the second path is connected to the other end of the first primary coil in the transformer T1; the source of the field effect transistor Q1 is grounded; the collector of the transistor in the photocouple U3 is connected to one end of the second primary coil in the transformer T1 through the resistor R7 and the diode D4 in sequence, and the other end of the second primary coil in the transformer T1 is grounded; One end of the first secondary coil in the transformer T1 is connected to the pin 1 of the LM7805 power chip U1 through the diode D1, and the capacitor C1 is connected in parallel with the diode D1; the pin 1 of the U1 is divided into two paths, the first path is grounded through the capacitor E1, and the second path is grounded through the resistor R1; the pin 2 of the U1 is grounded; the pin 3 of the U1 is divided into three paths, the first path is grounded through the capacitor E2, the second path is grounded through the capacitor C2, and the third path is the +5V power output terminal; the other end of the first secondary coil in the transformer T1 is grounded; One end of the second secondary coil in the transformer T1 is divided into two paths after passing through the diode D2, the first path is connected to one end of the inductor L1, the second path is grounded through the capacitor E4, and the capacitor C4 is connected in parallel with the diode D2; the other end of the inductor L1 is divided into four paths, the first path is grounded through the capacitor E5, the second path is grounded through the resistor R3, the third path is grounded through the capacitor C3, and the fourth path is the +12V power supply output end; the other end of the second secondary coil in the transformer T1 is grounded; The emitter of the triode in the photocoupler U3 is grounded via resistor R19, and the anode of the diode in the photocoupler U3 is divided into three paths after passing through resistor R10, the first path is connected to one end of the resistor R11, the second path is connected to the 12V power supply VCC, and the third path is connected to one end of the resistor R12; the cathode of the light-emitting diode in the photocoupler U3 is divided into several paths, the first path is connected via pin 3 of the TL431 voltage regulator U4, the second path is connected to the other end of the resistor R11, and the third path is connected to one end of the resistor R15. The other end of the resistor R15 is connected to the other end of the resistor R12, one end of the resistor R17, one end of the resistor R18, and pin 1 of the U4 respectively via capacitor C7, and the other end of the resistor R17, the other end of the resistor R18, and pin 2 of the U4 are grounded.

9. A battery intelligent maintenance device as claimed in claim 1, characterized in that: The auxiliary driving module includes a resistor R7, the other end of which is divided into two paths, the first path is grounded via a capacitor C2, the second path is connected to the non-inverting input terminal of a TL062IDR amplifier U1A, the inverting input terminal of U1A is connected to the output terminal of U1A, the output terminal of U1A is connected to the non-inverting input terminal of a TL062IDR amplifier U1B, and the inverting output terminal of U1B is grounded via a resistor R3; the 4th pin of U1B is grounded; the 8th pin of U1B is divided into three paths, the first path is connected to a +12V power supply , the second path capacitor C22 is grounded, and the third path capacitor C23 is grounded; one end of the resistor R4 is connected to the inverting input end of the U1B, and the other end of the resistor R4 is connected to the output end of the U1B; the output end of the U1B is divided into five paths, the first path capacitor C1 is grounded, the second path resistor R1 is connected to pin 1 of the connector JP1, the third path resistor R2 is connected to pin 1 of the connector JP2, the fourth path resistor R5 is connected to pin 1 of the connector JP3, and the fifth path resistor R6 is connected to pin 1 of the connector JP4. Pins 2 of JP1- JP4 are grounded, and JP1- JP4 are control signal output ends of the auxiliary drive module.

10. The battery intelligent maintenance device according to claim 1, characterized in that: The electronic load includes a plurality of load units with the same structure. The input end of the load unit is divided into two paths. The first path is grounded through a resistor R9, and the second path is connected to the in-phase input end of the LM324 amplifier U1A after passing through resistors R1, R2, and R3 in sequence; one end of the capacitor C1 is grounded, and the other end of the capacitor C1 is connected to the node between the resistors R1 and R2; one end of the capacitor C2 is grounded, and the other end of the capacitor C2 is connected to the node between the resistors R2 and R3; one end of the resistor R10 is grounded, and the other end of the resistor R10 is connected to the in-phase input end of the U1A; one end of the capacitor C3 is grounded, The other end of capacitor C3 is connected to the non-inverting input terminal of U1A; one end of resistor R15 is divided into two paths, the first path is grounded via capacitor C10, and the second path is connected to the inverting input terminal of U1A via resistor R13, one end of capacitor C7 is connected to the non-inverting input terminal of U1A, the other end of capacitor C7 is connected to the output terminal of U1A, the output terminal of U1A is connected to the gate of RFP260N field effect transistor Q1 via resistor R7, the drain of Q1 is connected to the power supply, the source of Q1 is divided into two paths, the first path is grounded via resistor RS1, and the second path is connected to the other end of resistor R15.

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