Battery charging and discharging control system, charging method and power supply device

Abstract

The invention relates to a battery charging and discharging control system, a charging method and a power supply device. In the battery charging and discharging control system and the charging method, the SOC value of the battery is corrected before charging, charging is suspended and the SOC value is corrected when the SOC value of the battery is smaller than 100%, and whether charging of the battery continues or stops is selected according to whether the corrected SOC value reaches 100% or not. In addition, the SOH value and the battery capacity of the battery are corrected before charging or when charging is suspended according to the set interval of the number of charge-discharge cycles, and the SOC value is corrected again according to the corrected battery capacity when charging is suspended, so that the accuracy of the SOC value and the SOH value of the battery is improved, and the SOC value of the battery is improved. The battery capacity can be accurately estimated, the charging condition can be accurately set, the service life of the battery is prolonged, and the thermal runaway risk and the battery use risk are reduced. The power supply device comprises the battery charging and discharging control system.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a battery charging and discharging control system, a charging method and a power supply device. Background Art

[0002] With the development of new energy technologies, new power batteries such as lithium batteries have been deeply developed and widely used in recent years, and higher requirements have been put forward for battery charging control systems. Taking lithium batteries as an example, they have several characteristics: (1) The SOH (health state) value of the battery will decrease after exceeding a certain number of charging cycles, that is, the total power of the full charge will decrease; (2) Overcharging will shorten the battery life and increase the risk of use. In severe overcharging, thermal runaway may even occur; (3) When the SOC (state of charge) value is the same but the SOH value is different, the amount of power that the battery can charge and discharge is different, and the corresponding voltage is also different. Therefore, if the SOH value of the battery cannot be accurately evaluated and the battery is charged appropriately according to the SOH value, it is easy to cause overcharging; (4) As the use time increases, the internal resistance of the lithium battery will also increase. The increase in internal resistance not only affects the SOH value of the battery, but also increases the battery's own consumption and increases the risk of thermal runaway.

[0003] It can be seen that improving the accuracy of battery SOC and SOH values ​​is of great significance for accurately estimating battery capacity, reducing the risk of thermal runaway, extending battery life, and reducing the risk of battery use. At present, the industry proposes to use machine learning methods to estimate battery SOC and SOH, but machine learning methods have a large amount of calculations, the model is not mature enough, and the waiting time is long. Summary of the invention

[0004] In order to improve the accuracy of the battery SOC value and SOH value, accurately estimate the battery capacity, extend the battery life, reduce the risk of thermal runaway and reduce the risk of battery use, the present invention provides a battery charge and discharge control system and a charging method. The present invention also provides a power supply device.

[0005] In one aspect, the present invention provides a battery charge and discharge control system, the battery charge and discharge control system comprising:

[0006] a charging module, used to control a charging circuit to charge a battery, so that the SOC value of the battery increases from a first SOC value before charging to a second SOC value when charging is suspended, the second SOC value is less than 100%, the charging module is further used to continue charging the battery after the second SOC value is corrected and the corrected second SOC value is less than 100%, and stop charging when the SOC value of the battery reaches 100%; and

[0007] A data processing module is used to calibrate the first SOC value before charging the battery, and to calibrate the second SOC value when charging is suspended, and also to calibrate the SOH value and battery capacity of the battery before charging or when charging is suspended according to a set charge and discharge cycle interval, and to calibrate the second SOC value again according to the battery capacity calibrated when charging is suspended.

[0008] Optionally, the battery charging control system further includes:

[0009] The storage module is used to store the factory data of the battery and the data processed by the data processing module, wherein the factory data includes the relationship between the battery internal resistance and the SOH value and the relationship between the battery temperature and the battery capacity at different SOH values.

[0010] Optionally, the data processing module includes:

[0011] a first processing unit, configured to compare the SOC values ​​of the battery calculated by using the ampere-hour integration method and the open circuit voltage method respectively before charging the battery and when charging is suspended, so as to correct the corresponding first SOC value and second SOC value;

[0012] a second processing unit, configured to calculate, according to the set charge and discharge cycle interval, before charging the battery or when charging is suspended, a SOH value of the battery corresponding to a current battery capacity, correct the SOH value by using a relationship between the battery internal resistance and the SOH value, and correct the battery capacity according to a relationship between the battery temperature and the battery capacity at different SOH values; and

[0013] The first processing unit further calibrates the second SOC value according to the battery capacity calibrated by the second processing unit.

[0014] Optionally, the battery charging control system further includes:

[0015] The data acquisition and monitoring module is used to detect the battery temperature, the charging voltage and current, and the battery power during the battery charging process. When monitoring the battery power, based on the current battery power, the current battery temperature and the current SOH value, the current battery power is compared with the battery capacity corresponding to the current SOH value and the current battery temperature, so that the current battery power is less than the battery capacity corresponding to the current SOH value and the current battery temperature.

[0016] Optionally, the first processing unit is further used to calculate the current battery power and SOC value of the battery according to the charging voltage and current using the ampere-hour integration method, and calculate the current number of charge and discharge cycles of the battery according to the current battery power.

[0017] Optionally, when the ampere-hour integration method is used to calculate the SOC value of the battery, the battery capacity calculation that matches the current SOH value and the current battery temperature is selected by utilizing the relationship between the battery temperature and the battery capacity at different SOH values.

[0018] Optionally, the second processing unit calculates the SOH value corresponding to the current battery capacity of the battery by using the ratio of the current battery capacity of the battery to the initial battery capacity of the battery.

[0019] Optionally, the factory data further includes a plurality of initial battery capacities corresponding to different battery temperatures respectively; when calculating the SOH value corresponding to the current battery capacity, the initial battery capacity that best matches the battery temperature is selected for calculation.

[0020] Optionally, the factory data further includes the relationship between the number of battery charge and discharge cycles and the SOH value; the second processing unit further corrects the SOH value according to the current number of battery charge and discharge cycles and the relationship between the number of battery charge and discharge cycles and the SOH value.

[0021] Optionally, the battery charging control system further includes:

[0022] The discharge module is used to control a discharge circuit to make the battery discharge to the load; wherein, when preparing to charge the battery, a power source other than the battery is switched to discharge to the load until charging stops.

[0023] Optionally, the data processing module includes:

[0024] The third processing unit is used to calculate the SOC value of the battery by using the ampere-hour integration method when the battery is discharging.

[0025] In one aspect, the present invention provides a charging method, the charging method comprising:

[0026] Obtaining a first SOC value of the battery before charging and correcting the first SOC value, and correcting the SOH value and battery capacity of the battery according to a set charge and discharge cycle interval;

[0027] Charging the battery so that the SOC value of the battery increases from a first SOC value before charging to a second SOC value, and the second SOC value is less than 100%, and charging is suspended;

[0028] Correcting the second SOC value, and correcting the SOH value and battery capacity of the battery according to a set charge and discharge cycle interval, and then correcting the second SOC value again according to the corrected battery capacity; and

[0029] It is determined whether the corrected second SOC value reaches 100%. If not, the battery continues to be charged. When the SOC value of the battery reaches 100%, the charging is stopped.

[0030] Optionally, during charging of the battery, the current battery power is compared with the battery capacity corresponding to the current SOH value and the current battery temperature, so that the current battery power is smaller than the battery capacity corresponding to the current SOH value and the current battery temperature.

[0031] Optionally, when preparing to charge the battery, the battery stops supplying power to the load, and a power source other than the battery supplies power to the load; after charging the battery stops, the battery supplies power to the load.

[0032] In one aspect, the present invention provides a power supply device, comprising:

[0033] Batteries and rechargeable power supplies;

[0034] A charging circuit, wherein the charging power source is coupled to the battery through the charging circuit, and the charging circuit has a charging switch;

[0035] An internal resistance and open circuit voltage test circuit, comprising a test switch and a voltage divider resistor, wherein one end of the test switch is coupled to the positive electrode of the battery and the other end is coupled to one end of the voltage divider resistor, the other end of the voltage divider resistor is grounded, and the negative electrode of the battery is grounded; and

[0036] A controller coupled to the control end of the charging switch, the control end of the test switch and the positive terminal of the battery, the controller comprising a battery charge and discharge control system as described in any one of claims 1 to 11, the battery charge and discharge control system controls the on and off of the charging switch and the test switch, wherein when the test switch is turned on, the battery charge and discharge control system obtains the positive terminal voltage of the battery and calculates the internal resistance of the battery, and when the test switch is turned off, the battery charge and discharge system obtains the positive terminal voltage of the battery and uses it as the open circuit voltage of the battery.

[0037] Optionally, the power supply device further includes:

[0038] The discharge circuit is coupled to the battery to supply power to a load through the battery before the battery is charged.

[0039] Optionally, the controller includes a clock module; when the power supply device passes through a sleep period, the battery charge and discharge control system calculates the sleep duration according to the data of the clock module, calculates the current SOC value of the battery by using the ampere-hour integration method according to the sleep duration and the set sleep current, and calculates the current number of charge and discharge cycles of the battery.

[0040] In the battery charge and discharge control system and charging method provided by the present invention, before charging, the first SOC value of the battery is first corrected to improve the accuracy of the SOC value before charging, so as to facilitate accurate setting of charging conditions. When charging to a second SOC value less than 100%, charging is suspended, and the second SOC value is corrected. Whether to continue charging the battery or stop charging is selected according to whether the corrected second SOC value reaches 100%. While improving the accuracy of the second SOC value, compared with directly charging to 100%, overcharging can be effectively avoided, the risk of thermal runaway can be reduced, and the battery life can be extended. In addition, according to the set charge and discharge cycle interval, the SOH value and battery capacity of the battery are corrected before charging or when charging is suspended, and the second SOC value is corrected again according to the battery capacity corrected when charging is suspended, which can further improve the accuracy of the second SOC value. In addition, while improving the accuracy of the SOH value of the battery, it is convenient to accurately estimate the battery capacity, accurately set the charging conditions, extend the battery life, reduce the risk of thermal runaway, and reduce the risk of battery use.

[0041] The power supply device provided by the present invention includes the above-mentioned battery charge and discharge control system, and thus has the same or similar advantages as the above-mentioned battery charge and discharge control system and charging method. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a structural schematic diagram of a battery charging and discharging control system according to an embodiment of the present invention.

[0043] Figure 2 It is a schematic structural diagram of a power supply device according to an embodiment of the present invention.

[0044] Figure 3 It is a circuit connection diagram of a battery, an internal resistance and open circuit voltage test circuit, and an MCU in a power supply device according to an embodiment of the present invention.

[0045] Figure 4 Schematic diagram of main steps of the charging method according to an embodiment of the present invention.

[0046] Figure 5 It is a schematic flow chart of a charging method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The battery charge and discharge control system, method and device of the present invention are further described in detail below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer according to the following description. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0048] Figure 1 The structure of the battery charge and discharge control system is shown. Figure 1 The embodiment of the present invention relates to a battery charge and discharge control system 100, which at least includes a charging module 110 and a data processing module 120; the charging module 110 is used to control a charging circuit to charge a battery, so that the SOC value of the battery increases from a first SOC value before charging to a second SOC value when charging is suspended, and the second SOC value is less than 100%, and the charging module 110 is also used to continue charging the battery after the second SOC value is corrected and the corrected second SOC value is less than 100%, and stop charging when the SOC value of the battery reaches 100%; the data processing module 120 is used to correct the first SOC value before charging the battery, and correct the second SOC value when charging is suspended, and also correct the SOH value and battery capacity of the battery before charging or when charging is suspended according to the set charge and discharge cycle interval, and correct the second SOC value again according to the battery capacity corrected when charging is suspended.

[0049] By utilizing the battery charge and discharge control system of the embodiment of the present invention, the accuracy of the SOC value and SOH value of the battery is improved. Moreover, when charging to a second SOC value less than 100%, the second SOC value is first corrected, and then the battery is selected to continue charging or stop charging according to whether the corrected second SOC value reaches 100%. This can improve the accuracy of the second SOC value while effectively avoiding overcharging compared to directly charging to an SOC value of 100%, thereby reducing the risk of thermal runaway and helping to extend the battery life. Moreover, by correcting the SOH value and battery capacity of the battery, and correcting the second SOC value again according to the battery capacity corrected when charging is suspended, the accuracy of the second SOC value can be further improved, which facilitates accurate estimation of the battery capacity and accurate control of the charging process, and helps to extend the battery life, reduce the risk of thermal runaway, and reduce the risk of battery use.

[0050] The battery charge and discharge control system 100 can be implemented in the form of hardware circuits, however, all or part of it can also be implemented in software, for example, in the form of a software program in conjunction with a device or equipment. The battery charge and discharge control system 100 can be implemented by hardware circuits and / or by a program set on a storage medium. The storage medium may include a hard disk, a random access memory (RAM), a flash memory, a programmable controller, an external storage medium, a storage device via a communication line, a register in a central processing unit (CPU), etc.

[0051] As an example, the battery charge and discharge control system 100 is implemented by a program written into a controller. The battery charge and discharge control system 100 is implemented by software at a low cost. As an example, a controller for the battery charge and discharge control system 100 and a battery whose charge and discharge is controlled by the battery charge and discharge control system 100 are set as part of a power supply device. The following embodiment first introduces the structure of the power supply device, and takes the use in the power supply device as an example to specifically describe the battery charge and discharge control system 100. It should be understood that the battery charge and discharge control system 100 of the present invention is not limited to application in the following embodiments. Figure 2 and Figure 3 In the power supply device shown, in other embodiments, the battery charge and discharge control system 100 and the battery whose charge and discharge is controlled by the battery charge and discharge control system 100 may also be arranged in a different device or may have a different circuit connection method.

[0052] Figure 2 The structure of the power supply device is shown. Figure 3 The circuit connection of the battery 10, the internal resistance and open circuit voltage test circuit, and the MCU used as a controller is shown. Figure 2 The power supply device includes a battery 10, a charging power source 20, a charging circuit 30, an internal resistance and open circuit voltage test circuit 40 and a controller. The power supply device may also include a discharge circuit 50 and a load 60.

[0053] Specifically, the battery 10 is a battery to be charged and discharged using the battery charge and discharge control system 100 of the embodiment of the present invention, for example, a lithium battery or a battery having the same or similar characteristics as a lithium battery (such as the four characteristics described in the background technology). The battery 10 of this embodiment is, for example, a lithium battery. The charging power supply 20 is used to provide electrical energy. Specifically, the charging power supply 20 is coupled to the battery 10 through the charging circuit 30 to facilitate charging the battery 10. The charging circuit 30 has a charging switch (not shown in the figure). By controlling the charging switch, the charging circuit 30 can be turned on to charge the battery 10 or turned off to suspend or stop charging.

[0054] The discharge circuit 50 is coupled to the battery 10 so as to supply power to the load 60 through the battery 10 before the battery 10 is charged. As an example, before the battery 10 is charged, the battery 10 is coupled to the discharge circuit 50 and supplies power to the load 60, and when the battery 10 is charged but charging has not yet started, the charging power source 20 supplies power to the load 60, and the charging power source 20 also supplies power to the load 60 during the charging of the battery 10 and during the charging pause, and after the charging stops, that is, when the SOC value of the battery 10 reaches 100%, the battery 10 supplies power to the load 60.

[0055] The internal resistance and open circuit voltage test circuit 40 is used to detect the internal resistance and open circuit voltage of the battery 10. Figure 3 As an example, the internal resistance and open circuit voltage test circuit 40 includes a test switch 41 (for example, a MOS transistor) and a voltage divider resistor R, one end of the test switch 41 is coupled to the positive electrode of the battery 10 and the other end is coupled to one end of the voltage divider resistor R, the other end of the voltage divider resistor R is grounded, and the negative electrode of the battery 10 is grounded.

[0056] In the power supply device, the controller is, for example, coupled to the control end of the charging switch, the control end of the test switch 41, and the positive terminal of the battery 10, so that the controller can turn on or off the charging switch and the test switch 41, and collect the voltage or current signal of the positive terminal of the battery 10, so as to control the charging circuit 30 to charge the battery 10 using the charging power supply 20, and control the internal resistance and open circuit voltage test circuit 40 to detect the internal resistance and open circuit voltage of the battery 10. Figure 2 and Figure 3 As shown, the controller includes, for example, an MCU, and the battery charge and discharge control system 100 can be stored in the MCU. The controller can also include a memory (not shown) connected to the MCU for communication, and the battery charge and discharge control system 100 can also be stored in the memory. When the battery charge and discharge control system 100 needs to obtain the internal resistance of the battery 10, a signal is sent to the control end of the test switch 41 through the GPIO port of the MCU to turn on the test switch 41. At this time, the battery 10, the test switch 41, and the voltage-dividing resistor R form a loop. By collecting the voltage signal or current signal at the positive end of the battery 10 at this time (collected by the ADC on the MCU), the voltage division of the battery internal resistance and the voltage-dividing resistor R with respect to the battery open circuit voltage can be obtained, and then the internal resistance value of the battery R can be calculated. When the battery charge and discharge control system 100 needs to obtain the open circuit voltage of the battery 10, a signal can be sent to the control end of the test switch 41 through the GPIO port of the MCU to turn off the test switch 41, and the above loop is disconnected. At this time, the voltage signal at the positive end of the battery 10 is collected to obtain the current open circuit voltage of the battery 10.

[0057] The power supply device may also include corresponding circuit components for collecting charging voltage, charging current, and discharging current, and a temperature sensor for sensing the temperature of the battery 10. As required, the controller may also collect real-time data required for the operation of the battery charge and discharge control system 100, such as charging voltage, charging current, discharging current, and the temperature of the battery 10, and send it to the battery charge and discharge control system 100. In addition, as required, the time data detected by the clock module in the controller, such as the MCU, may also be sent to the battery charge and discharge control system 100.

[0058] Reference Figures 1 to 3 In one embodiment, the battery charging control system 100 includes a storage module 130, which is used to store the factory data of the battery 10 and the data processed by the data processing module 120, so that the battery charging control system 100 can call or output it when it is working. The factory data refers to the data obtained from the battery supplier or battery manufacturer, which reflects the relevant characteristics of the battery or batteries of the same type and model. When the battery charging control system 100 is working, the factory data is used for data processing, which can reduce the amount of calculation and improve efficiency.

[0059] In this embodiment, the factory data at least includes the relationship between the battery internal resistance and the SOH value and the relationship between the battery temperature and the battery capacity at different SOH values. Optionally, the factory data also includes the relationship between the open circuit voltage and the SOC value at different SOH values, the relationship between the number of charge and discharge cycles and the SOH value, and the initial battery capacity data corresponding to different battery temperatures. The above factory data is as consistent as possible with the actual battery application scenario, temperature, power supply current, and battery continuous working time. In the factory data, the SOC value data can be denser and more continuous. Since the SOH value of the battery changes less after each charge and discharge, the SOH value can be continuous or discontinuous. In this embodiment, during the process of charging and discharging the battery 10 and before and after charging, the battery temperature and charging voltage at that time are also detected, and the number of battery charge and discharge cycles is recorded, so as to select more matching data in the factory data and determine whether the charging voltage meets the requirements.

[0060] By using the above-mentioned power supply device, the charging module 110 in the battery charge and discharge control system 100 can control the charging circuit 30 to charge the battery 10, so that the SOC value of the battery 10 increases from a first SOC value before charging to a second SOC value when charging is suspended, and after the second SOC value is corrected and the corrected second SOC value is less than 100%, the battery 10 continues to be charged, and when the SOC value of the battery 10 reaches 100%, the charging is stopped.

[0061] like Figure 1As shown, the battery charging control system 100 may also include a data acquisition and monitoring module 140. The data acquisition and monitoring module 140 is used to detect the battery temperature, the charging voltage and current, and monitor the current battery power during the charging process of the battery 10. When monitoring the battery power, based on the current battery power, the battery temperature and the current SOH value, the current battery power is compared with the battery capacity corresponding to the current SOH value and the current battery temperature (the battery capacity is, for example, obtained by using the relationship between the battery temperature and the battery capacity at different SOH values ​​in the factory data or using the battery capacity obtained by the most recent calibration), so that the current battery power is less than the battery capacity at the current SOH value and the current battery temperature to avoid overcharging. The battery temperature detected by the data acquisition and monitoring module 140 can be used by the data processing module 120 to calibrate the SOC value of the battery 10.

[0062] Reference Figure 1 The data processing module 120 in the battery charge and discharge control system 100 includes a plurality of processing units. The specific description is as follows.

[0063] The first processing unit 121 is used to compare the SOC values ​​of the battery 10 calculated by the ampere-hour integration method and the open circuit voltage method before charging the battery 10 and when charging is suspended, so as to correct the corresponding first SOC value before charging and the second SOC value when charging is suspended.

[0064] The ampere-hour integration method integrates the current charged into or out of the battery 10 with the time to obtain the current amount of electricity charged into or out of the battery 10, and obtains the current SOC value of the battery 10 according to the SOC value of the battery 10 at the initial moment. In the first processing unit 121, the relationship between the battery temperature and the battery capacity at different SOH values ​​in the factory data can be used to select the battery capacity that matches the current SOH value and the current battery temperature, so that the ampere-hour integration method can be used to calculate the SOC value of the battery 10 at the corresponding moment. In this embodiment, the first processing unit 121 is also used to calculate the current battery power and SOC value of the battery 10 according to the charging voltage and current collected by the data acquisition and monitoring module 140 using the ampere-hour integration method, and calculate the current number of charge and discharge cycles of the battery 10 according to the current battery power.

[0065] The open circuit voltage method determines the current SOC value based on the current open circuit voltage of the battery 10. The open circuit voltage can be used Figure 3 The internal resistance and open circuit voltage test circuit 40 and MCU shown are obtained. In order to reduce calculations, the corresponding relationship between the open circuit voltage and the SOC value under different SOH values ​​in the factory data can also be used to obtain the SOC value corresponding to the open circuit voltage method.

[0066] When comparing the SOC values ​​of the battery 10 calculated by the ampere-hour integration method and the open circuit voltage method, as an example, it can be determined whether the current difference between the two exceeds a set threshold value. If it does not exceed the set threshold value, the SOC value obtained by the ampere-hour integration method or the open circuit voltage method can be used as the corrected SOC value. If it exceeds the set threshold value, the SOC value obtained by the ampere-hour integration method or the open circuit voltage method is compensated accordingly according to the difference to obtain the corrected SOC value. For example, at the current SOH value, the SOC value calculated by the ampere-hour integration method is 100%, while the SOC value calculated by the open circuit voltage method is 98%. If the set threshold value is greater than or equal to 2%, no correction is required, and 100% or 98% is used as the corrected SOC value. If the set threshold value is less than 2%, 98% is compensated, and 99% is used as the corrected SOC value.

[0067] In this embodiment, the first SOC value of the battery 10 before charging is corrected, which can improve the accuracy of the SOC value before charging, and establish a basis for the accuracy of the SOC value during and after charging. In addition, the second SOC value of the battery 10 when charging is suspended is corrected, which can improve the accuracy of the second SOC value, facilitate further judgment on whether the battery 10 needs to continue charging and the amount of electricity to be charged when continuing charging, and help avoid overcharging.

[0068] In this embodiment, the charging module 110 controls the charging circuit 30 to charge the battery 10, so that the SOC value of the battery 10 increases from the first SOC value before charging to the second SOC value when charging is suspended. Therefore, during the charging process, the first processing unit 121 can continuously calculate the real-time SOC value of the battery (for example, using the ampere-hour integration method) to determine whether the real-time SOC value of the battery reaches the second SOC value. When the second SOC value is reached, the charging module 110 controls the charging circuit 30 to disconnect, that is, suspend charging of the battery 10.

[0069] The first processing unit 121 calculates the battery power and the SOC value of the battery 10 during the charging process according to the charging voltage and current using the ampere-hour integration method, and calculates the current number of charge and discharge cycles of the battery 10 according to the battery power, wherein the calculated SOC value can be used to determine whether the SOC value of the battery 10 has reached the second SOC value, and the number of charge and discharge cycles can be used to estimate the SOH value of the battery 10. As an example, the current number of charge and discharge cycles of the battery 10 can be calculated according to the number of times the battery 10 is fully charged, for example, if the energy required to fully charge the battery 10 once is 1 kWh, and 10 kWh has been charged before, when 0.5 kWh is charged this time, the current number of charge and discharge cycles of the battery is 10.5.

[0070] The second processing unit 122 is used to calculate the SOH value of the battery 10 corresponding to the current battery capacity according to the set charge and discharge cycle interval before charging the battery 10 or when charging is suspended, and correct the SOH value using the relationship between the battery internal resistance and the SOH value in the factory data, and also correct the battery capacity according to the relationship between the battery temperature and the battery capacity at different SOH values.

[0071] Taking into account that the SOH value of the battery usually changes little after each charge and discharge, therefore, in this embodiment, the second processing unit 122 may calibrate the SOH value not before each charging or when charging is suspended, but may calibrate the SOH value by setting a more appropriate interval of charge and discharge cycles according to the specific situation (i.e., after completing one SOH value calibration, calibrate the SOH value again after a set number of charge and discharge cycles).

[0072] Specifically, the second processing unit 122 may calculate the SOH value of the battery 10 corresponding to the current battery capacity using the current battery capacity and the initial battery capacity of the battery 10. The SOH value of the battery 10 may be calculated by formula (1):

[0073] SOH=(Qn / Qd)*100% (1)

[0074] In formula (1), SOH represents the SOH value of the battery, Qn represents the current battery capacity, and Qd represents the initial battery capacity. In this embodiment, the factory data stored in the storage module 130 includes multiple initial battery capacities Qd corresponding to different battery temperatures. When calculating, the initial battery capacity Qd that best matches the actual battery temperature can be selected for calculation.

[0075] The second processing unit 122 uses the relationship between the battery internal resistance and the SOH value in the factory data to correct the SOH value calculated by formula (1). Specifically, before charging, the battery voltage is collected by the internal resistance and open circuit voltage test circuit 40 and the MCU, and the internal resistance of the battery 10 is calculated. Then, the SOH value closest to the calculated internal resistance is obtained according to the relationship between the battery internal resistance and the SOH value, and the SOH value calculated by formula (1) is compared with the SOH value obtained according to the relationship between the battery internal resistance and the SOH value to determine whether the difference between the two exceeds a set threshold. If the difference does not exceed the set threshold, the SOH value calculated by formula (1) or the SOH value obtained according to the relationship between the battery internal resistance and the SOH value is used as the corrected SOH value. If the difference exceeds the set threshold, the SOH value calculated by formula (1) or the SOH value obtained according to the relationship between the battery internal resistance and the SOH value is compensated accordingly to obtain the corrected SOH value.

[0076] The factory data in the storage module 130 may include the relationship between the number of charge and discharge cycles and the SOH value. When correcting the SOH value, the second processing unit 122 may calculate the SOH value of the battery 10 corresponding to the current battery capacity according to the number of charge and discharge cycles of the current battery 10 and the relationship between the number of charge and discharge cycles and the SOH value, and compare the SOH value with the SOH value calculated using the above formula (1) and / or the SOH value obtained according to the relationship between the battery internal resistance and the SOH value, so as to form a corrected SOH value.

[0077] After the SOH value of the battery 10 is corrected before charging, the current battery capacity can be further corrected according to formula (1) or the relationship between the battery temperature and the battery capacity at different SOH values ​​in the factory data. In this way, after charging starts, the corrected current battery capacity can be used to monitor the battery power and calculate the SOC value of the battery, which can improve the monitoring accuracy and the accuracy of the SOC value, and help avoid overcharging. After the SOH value of the battery 10 is corrected when charging is suspended, the current battery capacity can be further corrected according to formula (1) or the relationship between the battery temperature and the battery capacity at different SOH values ​​in the factory data. After that, the first processing unit 121 can further correct the second SOC value when charging is suspended according to the battery capacity corrected by the second processing unit 122 to further improve the accuracy of the second SOC value.

[0078] Reference Figure 1 The battery charging control system further includes a discharge module 150, which is used to control a discharge circuit (such as the discharge circuit 50 in the above-mentioned power supply device) to make the battery 10 discharge to the load 60; wherein, when preparing to charge the battery 10, it is switched in advance to discharge to the load 60 by a power source other than the battery 10 (such as the charging power source 20) until the charging is stopped, so as to avoid affecting the normal operation of the load 60 when the battery 10 is charged. When the battery 10 is discharged, the battery temperature, the charging voltage and current, and the current battery power can be detected by the data acquisition and monitoring module 140. The data processing module 120 may also include a third processing unit 123, which is used to calculate the SOC value of the battery 10 by using the ampere-hour integration method when the battery 10 is discharged. When calculating the SOC value of the battery 10, the third processing unit 123 may select the battery capacity matching the current SOH value and the current battery temperature according to the relationship between the battery temperature and the battery capacity at different SOH values ​​in the factory data, or may select the battery capacity calibrated at the last charge for calculation. In the battery charge and discharge control system 100 , the data collected by the data collection and detection module 140 and the SOC value and SOH value obtained by each processing unit in the data processing module 120 may be stored in the storage module 130 .

[0079] When the load 10 is not working, that is, the power supply device is in a dormant period, if the battery 10 is not in a charging state and is still supplying power to the load 60, the battery 10 is in a slower discharging state, but the discharge current may not be detected (for example, a car or an electronic cigarette including the above-mentioned power supply device when not in use). At this time, the SOC value of the battery 10 and the specific values ​​of the number of charge and discharge cycles will change slowly. In order to improve the accuracy of the SOC value and SOH value of the battery 10, the battery charge and discharge control system 100 can also calculate the SOC value and the number of charge and discharge cycles of the battery 10 after the power supply device has passed the dormant period. As an example, the controller (such as the MCU therein) includes a clock module (including a timer). During the sleep period, the clock module always keeps working and can detect the start and end time of the sleep period; when the power supply device passes a sleep period, that is, when the sleep period ends, the MCU is awakened, and the battery charge and discharge control system 100 can use the data acquisition and detection module 140 to collect data from the clock module, use the data processing module to calculate the sleep duration, and can use the set sleep current (this current is usually very small and stable, so it can be set according to empirical data), according to the sleep duration and the set sleep current, use the ampere-hour integration method to calculate the amount of electricity discharged by the battery 10 during the sleep period and the current SOC value, and can calculate the current number of charge and discharge cycles. After obtaining the amount of electricity discharged by the battery 10, the remaining battery power can be further obtained, and the battery power, SOC value, and charge and discharge cycle number stored before the sleep period are replaced by the remaining power, SOC value, and charge and discharge cycle number of the battery 10 after the sleep period, respectively, which can improve the accuracy of the battery data.

[0080] Figure 4 and Figure 5 The main steps and processes of the charging method according to an embodiment of the present invention are respectively shown. Figure 4 and Figure 5 The embodiment of the present invention also relates to a charging method, which is used to charge a battery. The charging method can be executed by a computer processor in the form of computer instructions, or by using multiple functional modules of the computer. Therefore, a computer with computing functions, a charging module, etc. can be provided to complete the above-mentioned charging method. In this embodiment, the charging method is implemented, for example, by using the above-mentioned battery charging and discharging control system 100 and a power supply device.

[0081] Reference Figure 5In one embodiment of the present invention, before step S1, the charging module 110 of the battery charge and discharge control system 100 can be used to determine whether a charging instruction is received or whether an automatic charging condition is met (such as determining whether the current SOC value of the battery 10 is lower than a set value). If the corresponding charging instruction is received or the automatic charging condition is met, the data acquisition and monitoring module 140 can be used to detect the charging voltage output by the charging power source 20, and the charging module 110 can be used to determine whether the charging voltage meets the charging requirement (for example, determine whether the charging voltage is within a set range and is not too high or too low). If the charging requirement is not met (such as the judgment result is "No"), the charging module 110 does not control the charging switch on the charging circuit 30 to be turned on, and reminds the user of the risk, and then continues to detect the charging voltage and determine whether the charging requirement is met until the charging requirement is met (such as the judgment result is "Y"), and the charging module 110 is ready to control the charging switch to be turned on, so as to use the charging power source 20 and the charging circuit 30 to charge the battery 10. It should be noted that, in the subsequent charging process, the charging module 110 still detects whether the charging voltage output by the charging power source 20 in real time meets the charging requirements. If not, the charging switch is turned off and the user is reminded of the risk.

[0082] After the charging voltage meets the requirement, the battery 10 is ready to be charged. When the battery is connected to the load 60, in order to ensure the normal operation of the load 60, the power supply of the load 60 is switched to a power source other than the battery (such as the charging power source 20).

[0083] Afterwards, refer to Figure 4 and Figure 5 , execute step S1: obtain the first SOC value of the battery 10 before charging and correct the first SOC value, and correct the SOH value and battery capacity of the battery 10 according to the set charge and discharge cycle interval. In this process, the open circuit voltage and internal resistance of the battery 10 can be detected, so that the SOC value of the battery 10 can also be calculated by the open circuit voltage method, and the SOH value can be corrected by using the relationship between the battery internal resistance and the SOH value in the factory data. Step S1 can be implemented by the above-mentioned battery charge and discharge control system 100 and the power supply device, for example, the data acquisition and monitoring module 140 collects the corresponding data, and the data processing module 120 compares the SOC values ​​of the battery 10 calculated by the ampere-hour integration method and the open circuit voltage method respectively, so as to correct the corresponding first SOC value, and calculate the SOH value of the battery 10 corresponding to the current battery capacity, and correct the SOH value by using the relationship between the battery internal resistance and the SOH value in the factory data, and correct the battery capacity according to the relationship between the battery temperature and the battery capacity under different SOH values. The specific implementation process can refer to the description of the above embodiment.

[0084] Next, refer to Figure 4 and Figure 5 , execute step S2: charge the battery 10 so that the SOC value of the battery 10 increases from a first SOC value before charging to a second SOC value, and the second SOC value is less than 100%, and the charging is suspended.

[0085] Step S2 can be implemented using the above-mentioned battery charge and discharge control system 100 and the power supply device. For example, during the charging process, the above-mentioned data acquisition and monitoring module 140 can be used to detect the temperature, charging voltage and current of the battery 10, and monitor the real-time battery power, etc. By monitoring the real-time battery power, the real-time battery power is compared with the battery capacity corresponding to the current SOH value and the current battery temperature (the battery capacity is, for example, obtained by using the relationship between the battery temperature and the battery capacity at different SOH values ​​described in the factory data or the battery capacity obtained by the most recent calibration), so that the real-time battery power does not exceed the battery capacity corresponding to the current SOH value and the current battery temperature, so as to avoid overcharging.

[0086] During the charging process, the data processing module 140 can be used to calculate the amount of electricity charged into the battery 10, i.e., the real-time battery electricity and the real-time SOC value of the battery 10, using the ampere-hour integration method. When the real-time SOC value of the battery reaches the set second SOC value (such as 95%), the charging module 110 can be used to disconnect the charging switch on the charging circuit 30, i.e., suspend charging of the battery 10. During the charging process, the data processing module 140 can also be used to calculate the current number of charge and discharge cycles of the battery 10 based on the real-time battery electricity. The current number of charge and discharge cycles, SOC value, SOH value, temperature and other data can all be detected or calculated and stored. In this embodiment, the second SOC value is less than 100% to avoid the problem of overcharging due to the insufficient accuracy of the real-time SOC value calculated during the charging process.

[0087] Afterwards, refer to Figure 4 and Figure 5, execute step S3, correct the second SOC value, and correct the SOH value and battery capacity of the battery 10 according to the set charge and discharge cycle interval, and then correct the second SOC value again according to the corrected battery capacity. Step S3 can be implemented by the above-mentioned battery charge and discharge control system 100 and power supply device. For example, the data acquisition and monitoring module 140 can be used to collect the open circuit voltage and internal resistance of the battery 10, and the data processing module 120 compares the SOC values ​​of the battery 10 calculated by the ampere-hour integration method and the open circuit voltage method respectively to correct the corresponding second SOC value, and calculates the SOH value of the battery 10 corresponding to the current battery capacity according to the set charge and discharge cycle interval, and corrects the SOH value using the relationship between the battery internal resistance and the SOH value in the factory data, and corrects the battery capacity according to the relationship between the battery temperature and the battery capacity at different SOH values, and then further corrects the second SOC value again according to the corrected battery capacity. The specific implementation process of step S3 can refer to the description of the above embodiment.

[0088] Next, refer to Figure 4 and Figure 5 , execute step S4: determine whether the second SOC value after correction reaches 100% (i.e. determine whether the second SOC value after correction is greater than or equal to 100%, i.e. determine whether the battery 10 is fully charged). If not, continue to charge the battery 10. When the SOC value of the battery 10 reaches 100%, stop charging. When the second SOC value after correction is less than 100% and the battery 10 continues to be charged, the real-time SOC value can be calculated using the ampere-hour integration method. When the calculated SOC value reaches 100%, stop charging. When stopping charging, disconnect the charging switch on the charging circuit 30 and switch to the battery 10 to charge the load 60. In addition, when the SOC value of the battery 10 is greater than 100% after correction and stops charging, set the SOC value of the battery 10 to 100%. In addition, information indicating that the battery power is 100 or the battery is fully charged can be output. The current SOC value, charge and discharge cycle number, power level and other data of the battery can be stored in the storage module 130, and the required data can also be output through a display as needed, and the charging is completed.

[0089] In the battery charge and discharge control system and charging method described in the above embodiment, before charging, the first SOC value of the battery 10 is first corrected to improve the accuracy of the SOC value before charging, so as to facilitate accurate setting of charging conditions. When charging to a second SOC value less than 100%, charging is suspended, and the second SOC value is corrected. Whether to continue charging or stop charging the battery 10 is selected according to whether the corrected second SOC value reaches 100%. While improving the accuracy of the second SOC value, compared with directly charging to 100%, overcharging can be effectively avoided, the risk of thermal runaway can be reduced, and the battery life can be extended. In addition, the SOH value and battery capacity of the battery 10 are corrected before charging or when charging is suspended according to the set charge and discharge cycle interval, and the second SOC value is corrected again according to the battery capacity corrected when charging is suspended, which can further improve the accuracy of the second SOC value. In addition, while improving the accuracy of the battery's SOH value, it is convenient to accurately estimate the battery capacity, accurately set the charging conditions, extend the battery life, reduce the risk of thermal runaway, and reduce the risk of battery use.

[0090] In other embodiments of the present invention, the aforementioned battery charge and discharge control system 100 or power supply device can also be used in a vehicle, so as to utilize the battery charge and discharge control system 100 to charge the battery in the vehicle, and the battery can be a power source or an auxiliary power source, such as a lithium battery.

[0091] The vehicle may be an electric bicycle, an electric car, a hybrid car, a fuel car, etc. The vehicle may include a battery management system (BMS), and the battery management system may include the battery charge and discharge control system 100, which can improve the accuracy of the battery SOC value and SOH value while controlling the battery charge and discharge, so as to accurately estimate the battery capacity, extend the battery life, reduce the risk of thermal runaway and reduce the risk of battery use, and improve the quality of the vehicle.

[0092] In other embodiments of the present invention, the aforementioned battery charge and discharge control system 100 or power supply device can also be used in an electronic cigarette, so as to charge the battery in the electronic cigarette by using the battery charge and discharge control system 100, and the battery is, for example, a lithium battery. By charging the battery by using the battery charge and discharge control system 100, the accuracy of the battery SOC value and SOH value can be improved while controlling the battery charge and discharge, so as to accurately estimate the battery capacity, extend the battery service life, reduce the risk of thermal runaway, and reduce the risk of battery use, thereby improving the quality of the electronic cigarette.

[0093] It should be noted that the embodiments in this specification are described in a progressive manner, and each part focuses on the differences from the previous part. The same and similar parts between the parts can be referenced to each other.

[0094] The above description is only a description of the preferred embodiment of the present invention, and is not any limitation on the scope of rights of the present invention. Any technical personnel in this field can make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A battery charge and discharge control system, characterized in that: include: a charging module, used to control a charging circuit to charge a battery, so that the SOC value of the battery increases from a first SOC value before charging to a second SOC value when charging is suspended, the second SOC value is less than 100%, the charging module is further used to continue charging the battery after the second SOC value is corrected and the corrected second SOC value is less than 100%, and stop charging when the SOC value of the battery reaches 100%; and A data processing module is used to calibrate the first SOC value before charging the battery, and to calibrate the second SOC value when charging is suspended, and also to calibrate the SOH value and battery capacity of the battery before charging or when charging is suspended according to a set charge and discharge cycle interval, and to calibrate the second SOC value again according to the battery capacity calibrated when charging is suspended.

2. The battery charge and discharge control system according to claim 1, characterized in that: Also includes: The storage module is used to store the factory data of the battery and the data processed by the data processing module, wherein the factory data includes the relationship between the battery internal resistance and the SOH value and the relationship between the battery temperature and the battery capacity at different SOH values.

3. The battery charge and discharge control system according to claim 2, characterized in that: The data processing module comprises: a first processing unit, configured to compare the SOC values ​​of the battery calculated by using the ampere-hour integration method and the open circuit voltage method respectively before charging the battery and when charging is suspended, so as to correct the corresponding first SOC value and second SOC value; a second processing unit, configured to calculate, according to the set charge and discharge cycle interval, before charging the battery or when charging is suspended, a SOH value of the battery corresponding to a current battery capacity, correct the SOH value by using a relationship between the battery internal resistance and the SOH value, and correct the battery capacity according to a relationship between the battery temperature and the battery capacity at different SOH values; and The first processing unit further calibrates the second SOC value according to the battery capacity calibrated by the second processing unit.

4. The battery charge and discharge control system according to claim 3, characterized in that: Also includes: The data acquisition and monitoring module is used to detect the battery temperature, the charging voltage and current, and the battery power during the battery charging process. When monitoring the battery power, based on the current battery power, the current battery temperature and the current SOH value, the current battery power is compared with the battery capacity corresponding to the current SOH value and the current battery temperature, so that the current battery power is less than the battery capacity corresponding to the current SOH value and the current battery temperature.

5. The battery charge and discharge control system according to claim 4, characterized in that: The first processing unit is further used to calculate the current battery power and SOC value of the battery according to the charging voltage and current using the ampere-hour integration method, and calculate the current number of charge and discharge cycles of the battery according to the current battery power.

6. The battery charge and discharge control system according to claim 5, characterized in that: When the ampere-hour integration method is used to calculate the SOC value of the battery, the battery capacity calculation that matches the current SOH value and the current battery temperature is selected by utilizing the relationship between the battery temperature and the battery capacity at different SOH values.

7. The battery charge and discharge control system according to claim 3, characterized in that: The second processing unit calculates a SOH value corresponding to the current battery capacity of the battery by using a ratio of the current battery capacity of the battery to the initial battery capacity of the battery.

8. The battery charge and discharge control system according to claim 7, characterized in that: The factory data also includes a plurality of initial battery capacities corresponding to different battery temperatures respectively; when calculating the SOH value corresponding to the current battery capacity, the initial battery capacity that best matches the battery temperature is selected for calculation.

9. The battery charge and discharge control system according to claim 3, characterized in that: The factory data also includes the relationship between the number of battery charge and discharge cycles and the SOH value; the second processing unit also corrects the SOH value according to the current number of battery charge and discharge cycles and the relationship between the number of battery charge and discharge cycles and the SOH value.

10. The battery charge and discharge control system according to claim 2, characterized in that: Also includes: The discharge module is used to control a discharge circuit to make the battery discharge to the load; wherein, when preparing to charge the battery, a power source other than the battery is switched to discharge to the load until charging stops.

11. The battery charge and discharge control system according to claim 10, characterized in that: The data processing module comprises: The third processing unit is used to calculate the SOC value of the battery by using the ampere-hour integration method when the battery is discharging.

12. A charging method, characterized in that: include: Obtaining a first SOC value of the battery before charging and correcting the first SOC value, and correcting the SOH value and battery capacity of the battery according to a set charge and discharge cycle interval; Charging the battery so that the SOC value of the battery increases from a first SOC value before charging to a second SOC value, and the second SOC value is less than 100%, and charging is suspended; Correcting the second SOC value, and correcting the SOH value and battery capacity of the battery according to a set charge and discharge cycle interval, and then correcting the second SOC value again according to the corrected battery capacity; as well as It is determined whether the corrected second SOC value reaches 100%. If not, the battery continues to be charged. When the SOC value of the battery reaches 100%, the charging is stopped.

13. The charging method according to claim 12, characterized in that: During the process of charging the battery, the current battery power is compared with the battery capacity corresponding to the current SOH value and the current battery temperature, so that the current battery power is smaller than the battery capacity corresponding to the current SOH value and the current battery temperature.

14. The charging method according to claim 12, characterized in that: When preparing to charge the battery, the battery stops supplying power to the load, and a power source other than the battery supplies power to the load. After charging the battery stops, the battery supplies power to the load.

15. A power supply device, characterized in that: include: Batteries and rechargeable power supplies; A charging circuit, wherein the charging power source is coupled to the battery through the charging circuit, and the charging circuit has a charging switch; An internal resistance and open circuit voltage test circuit, comprising a test switch and a voltage divider resistor, wherein one end of the test switch is coupled to the positive electrode of the battery and the other end is coupled to one end of the voltage divider resistor, the other end of the voltage divider resistor is grounded, and the negative electrode of the battery is grounded; as well as A controller coupled to the control end of the charging switch, the control end of the test switch and the positive terminal of the battery, the controller comprising a battery charge and discharge control system as described in any one of claims 1 to 11, the battery charge and discharge control system controls the on and off of the charging switch and the test switch, wherein when the test switch is turned on, the battery charge and discharge control system obtains the positive terminal voltage of the battery and calculates the internal resistance of the battery, and when the test switch is turned off, the battery charge and discharge system obtains the positive terminal voltage of the battery and uses it as the open circuit voltage of the battery.

16. The power supply device according to claim 15, characterized in that: Also includes: The discharge circuit is coupled to the battery to supply power to a load through the battery before the battery is charged.

17. The power supply device according to claim 15, characterized in that: The controller includes a clock module; when the power supply device passes through a sleep period, the battery charge and discharge control system calculates the sleep duration according to the data of the clock module, calculates the current SOC value of the battery by using the ampere-hour integration method according to the sleep duration and the set sleep current, and calculates the current number of charge and discharge cycles of the battery.

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