Patent Publication Number: US-2022224142-A1

Title: Power supply circuit and power distribution method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Taiwan application no. 110100861, filed on Jan. 8, 2021. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND 
     Technical Field 
     The disclosure relates to a power supply circuit, and in particular, to a power supply circuit configured for a battery module. 
     Description of Related Art 
     Generally, at a regular temperature or a room temperature, when an adapter supplies power to a load of a system in a portable electronic device, the adapter simultaneously charges a battery module through the system. When the battery module is fully charged, the battery module is in a steady state. As the temperature of the system is at a high temperature due to a state of use of a user or the environment, the battery module is in a high-temperature steady state. To prevent the fully-charged battery module from swelling and aging caused by the high temperature, conventionally, when a system software detects that the battery module in the system is at the high temperature, the system is forced to be switched to the battery operation mode. That is, the power supply is provided for the load of the system by the battery module. In this case, the battery module discharges the power and sustain the system consumption, and thus cause a voltage of the battery module to decrease. 
     When the system is forced to be switched to the battery operation mode, a power management icon of the desktop on the screen also accordingly displays that the battery module is discharging the power and the user mistakes that the adapter is damaged and may thus replace the adapter. Furthermore, since the system is operated in the battery mode, to decrease the power consumption of the battery module, the system may decrease a current load amount of the operation (e.g. a central processing unit (CPU) is throttling to run). Therefore, the operation efficiency of the system in the battery mode is compromised. 
     SUMMARY 
     The disclosure is directed to a power supply circuit and a power distribution method thereof in which when a temperature and a power of a battery module are too high, an operation mode and a power management icon of an electronic device are not changed but the power of the battery module may still be consumed. 
     The power supply circuit of the disclosure is adapted to be coupled to an adapter, a battery module, and a load circuit. The power supply circuit includes a power supply line, a power input switch block, a power supply conversion block, and a power supply control block. The power supply line is coupled to the load circuit. The power input switch block is coupled to the adapter and the power supply line. The power input switch block receives an external power supply voltage from the adapter to provide a first power supply voltage to the power supply line. The first power supply voltage is provided to the load circuit through the power supply line. The power supply control block is coupled to the battery module. The power supply control block is configured to measure a battery temperature and a battery power of the battery module. When the battery temperature of the battery module is higher than a critical temperature and the battery power of the battery module is higher than or equal to a critical power, the power supply control block provides a conversion control signal. The power supply conversion block is coupled to the power supply control block, the battery module, and the power supply line and receives the conversion control signal. The power supply conversion block controls the battery module to provide a second power supply voltage in response to the conversion control signal. The second power supply voltage is provided to the load circuit through the power supply line. 
     The power distribution method of the power supply circuit of the disclosure includes the following steps. Based on that the power supply circuit is connected to an adapter, a battery power of a battery module is measured through a power supply control block of the power supply circuit. Based on that the battery power of the battery module is higher than or equal to a critical power, a battery temperature of the battery module is measured through the power supply control block of the power supply circuit. Based on that the battery temperature of the battery module is higher than a critical temperature, a battery voltage of the battery module is converted into a power supply voltage to a load circuit through a power supply conversion block. 
     Based on the above, in the power supply circuit and the power distribution method thereof of the embodiment of the disclosure, when the temperature and the power of the battery module are too high, the power supply control block controls the adapter and the battery module to supply the power simultaneously so that the battery module and the adapter are connected in parallel to simultaneously supply the power to the load circuit of the electronic device. Accordingly, the operation mode and the power management icon of the electronic device are not changed, but the power of the battery module may still be consumed. 
     In order to make the aforementioned features and advantages of the disclosure comprehensible, embodiments accompanied with drawings are described in detail below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a system of an electronic device coupled to an adapter according to an embodiment of the disclosure. 
         FIG. 2  is a flow chart of a power distribution method of a power supply circuit according to an embodiment of the disclosure. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     To avoid a user mistaking that an adapter is damaged or replacing an adapter and to improve a user experience when a system is operated at a high temperature, a power supply distribution mechanism between the adapter back end and the system is adjusted. An adjustment is performed by using a current or an added set of a hardware voltage conversion line and a control circuit and applying an establishment of a control unit of system software. 
     When the system detects that a battery module in the system is in a high-temperature steady state and it is required to discharge a battery, a new power supply distribution mechanism activates a newly added system control unit to limit a power output to the system by the adapter. Furthermore, with regard to an unsatisfied part of a demand of an operation power of the system, a battery voltage may be boosted to be greater than or equal to an input voltage of the adapter through a power supply conversion circuit, and the converted battery voltage is connected to the adapter voltage in parallel. 
     When the power supplied to the system by the adapter is limited, the battery module supplies a small part of the power to the system to complement the power required for the system operation. Hence, the internal energy of the battery module may be consumed to lower the battery voltage. Furthermore, the new power supply distribution mechanism is not operated through a conventional battery discharging mode, instead, most of the power is output to the system by the adapter. Therefore, the operation efficiency of the system is not compromised. In addition, during a power discharging process of the battery module and the process of lowering the voltage, the system still detects that the adapter supplies the power, so the system state that the battery module continues returning is that the battery module is still fully charged (i.e. the power is 100%). Therefore, a power management icon of the desktop on the screen still displays that the adapter supplies the power, and the user is not aware that battery module abnormally discharges power. 
     According to the operation method above, a circuit operation of the system is further described below. The terms “a system” and “an electronic device” are used to describe the system of the disclosure and are interchangeable. They are not distinguished in particular below. 
       FIG. 1  is a schematic diagram of a system of an electronic device coupled to an adapter according to an embodiment of the disclosure. Referring to  FIG. 1 , in the embodiment, an electronic device  100  may be coupled to an adapter  10  to receive an external power supply voltage Vin from the adapter  10 . The electronic device  100  may be charged or operated by using the external power supply voltage Vin. 
     In the embodiment of the disclosure, the electronic device  100  includes a power supply circuit  101 , a battery module  180 , and a load circuit  190 . The power supply circuit  101  is adapted to be coupled to the adapter  10 , the battery module  180 , and the load circuit  190 . The power supply circuit  101  includes a power input switch block  110 , a power supply measurement block  120 , a power supply line  130 , a power supply control block  140 , a charging switch block  150 , a power supply conversion block  160 , and a discharging switch block  170 . 
     The power input switch block  110  is configured to be coupled to the adapter  10  and the power supply line  130 . The power input switch block  110  receives the external power supply voltage Vin (e.g. 19 volts) from the adapter  10  and provides a first power supply voltage VS 1  through the power supply line  130  to the load circuit  190  according to the external power supply voltage Vin. The power supply line  130  is coupled to the load circuit  190  to provide a system power supply voltage Vsys to the load circuit  190 . The first power supply voltage VS 1  may be substantially equal to the external power supply voltage Vin. The power supply measurement block  120  is configured to measure a current of the first power supply voltage VS 1  to provide a power supply indication signal Svi. 
     The power supply control block  140  is coupled to the power supply measurement block  120 , the power supply conversion block  160 , and the battery module  180 . The power supply control block  140  measures a battery temperature and a battery power of the battery module  180 . When the battery temperature of the battery module  180  is higher than a critical temperature (e.g. 45° C.) and the battery power of the battery module  180  is higher than or equal to a critical power (e.g. the power is 100%), the power supply control block  140  provides a conversion control signal Svt. 
     The power supply conversion block  160  is coupled to the power supply line  130 , the power supply control block  140 , and the battery module  180  and receives the conversion control signal Svt. The power supply conversion block  160  controls the battery module  180  to provide a second power supply voltage VS 2  to the load circuit  190  through the power supply line  130  in response to the conversion control signal Svt. The second power supply voltage VS 2  may be greater than or equal to the first power supply voltage VS 1  (equal to the external power supply voltage Vin). 
     When the battery temperature of the battery module  180  is higher than the critical temperature (e.g. 45° C.) and the battery power of the battery module  180  is higher than or equal to the critical power (e.g. the power is 100%), the power supply control block  140  provides the conversion control signal Svt to the power supply conversion block  160 . The power supply conversion block  160  controls the battery module  180  to provide the second power supply voltage VS 2  to the load circuit  190  through the power supply line  130  in response to the conversion control signal Svt. The power supply control block  140  controls a power of the second power supply voltage VS 2  provided to the power supply line  130  by the battery module  180  based on the power supply indication signal Svi. Accordingly, when the temperature and the power of the battery module  180  are too high, the adapter  10  and the battery module  180  may supply power simultaneously. That is, the battery module  180  and the adapter  10  are connected in parallel to supply the power simultaneously to the load circuit  190  of the electronic device  100 . Therefore, an operation mode and a power management icon of the electronic device  100  are not changed, but the power of the battery module  180  may still be consumed. 
     The charging switch block  150  is coupled between the battery module  180  and the power supply line  130 . When the charging switch block  150  is activated, the charging switch block  150  charges the battery module  180  by using the first power supply voltage VS 1  (i.e. the current system power supply voltage Vsys). The charging switch block  150  is activated when the electronic device  100  is coupled to the adapter  10  and the battery power of the battery module  180  is lower than the critical power. The charging switch block  150  is deactivated when the battery power of the battery module  180  is higher than or equal to the critical power. The discharging switch block  170  is coupled between the battery module  180  and the power supply line  130 . When the discharging switch block  170  is activated, a battery voltage VBT of the battery module  180  is converted into a third power supply voltage VS 3  (e.g. 12.6 to 19 volts) to the power supply line  130 . The discharging switch block  170  is activated when the electronic device  100  is not coupled to the adapter  10 . An operation of the charging switch block  150  and an operation of the discharging switch block  170  may be independent from the power supply control block  140 , which means that the charging switch block  150  and the discharging switch block  170  may not be controlled by the power supply control block  140 . 
     In the embodiment of the disclosure, when the conversion control signal Svt is not provided, which means that the battery voltage VBT of the battery module  180  is not converted into the second power supply voltage VS 2 , only the first power supply voltage VS 1  is provided to power supply line  130 , which means that the system power supply voltage Vsys is substantially the same as the first power supply voltage VS 1 . Therefore, the current of the first power supply voltage VS 1  (equal to the external power supply voltage Vin) is deemed a system total current corresponding to a load state of the load circuit  190  by the power supply control block  140 . Furthermore, when the conversion control signal Svt is provided, which means that the battery voltage VBT of the battery module  180  is converted into the second power supply voltage VS 2 , the first power supply voltage VS 1  and the second power supply voltage VS 2  are simultaneously provided to the power supply line  130 , which means that the current of the system power supply voltage Vsys is substantially equal to a total current of the first power supply voltage VS 1  and the second power supply voltage VS 2 . Therefore, a supply time of the conversion control signal Svt may be determined based on a system total current required for the load state of the load circuit  190  and a present current of the first power supply voltage VS 1  (equal to the external power supply voltage Vin). 
     Furthermore, the power supply control block  140  determines the current of the second power supply voltage VS 2  based on the system total current and the present current of the first power supply voltage VS 1 , and a discharging time of the battery module  180  discharging power from the critical power to a security power is calculated as the supply time according to the current of the second power supply voltage VS 2 . The security power (e.g. the power is 80% to 90%) is less than the critical power (e.g. the power is 100%). 
     In addition, during a supply time when the second power supply voltage VS 2  is supplied, when the battery temperature is lower than the critical temperature and the battery power is less than the critical power, the power supply control block  140  may stop providing the conversion control signal Svt, which means that the power supply control block  140  stops converting the battery voltage VBT into the power supply voltage. 
     In the embodiment of the disclosure, when the power input switch block  110  is coupled to the adapter  10  or receives the external power supply voltage Vin, the charging switch block  150  may be turned on and the discharging switch block  170  is turned off. When the power input switch block  110  is not coupled to the adapter  10  or does not receive the external power supply voltage Vin, the charging switch block  150  may be turned off and the discharging switch block 
     According to the above, in the embodiment of the disclosure, the power supply control block  140  is configured to manage a power source (including a power source of the adapter  10  and a power source of the battery module  180 ) supplied to the load circuit  190  of the electronic device  100 . The power supply control block  140  activates a management mechanism at the timing when the following conditions are all satisfied: 1. The battery module in the electronic device  100  is in a high-temperature environment (e.g. 45° C.); 2. The battery module  180  is in a steady state in the electronic device  100  and is fully charged (i.e. the power is 100%); 3. The adapter  10  is coupled to the electronic device  100  and supplies the power to the load circuit  190 . 
     When the power supply control block  140  activates the management mechanism, the power supplied to the load circuit  190  originally by the adapter  10  is simultaneously supplied to the load circuit  190  by double power sources of the external power supply voltage Vin of the adapter  10  and the battery voltage VBT connected in parallel. The power supply control block  140  simultaneously controls the power source of the adapter  10  and the power source of the battery module  180 . The power sources of the adapter  10  and the battery module  180  are simultaneously supplied to the load circuit  190  at different rations. In addition, when the adapter  10  supplies the power to the load circuit  190 , the power supply control block  140  also discharges some energy of the fully charged battery module  180  which is at the high temperature to the load circuit  190 . Therefore, a security concern of the battery module  180  caused by the high temperature is avoided and the electronic device  100  functions normally without being affected by the high temperature. 
     Furthermore, the power source management mechanism of the power supply control block  140  functions as the following. When the power supply control block  140  detects that the temperature of the fully charged battery module  180  in the electronic device  100  is too high, a power supply measurement unit is activated first to measure and calculate a power currently consumed by the load circuit  190 . Next, energy required to be discharged by the battery module  180  is calculated by the power supply control block  140  based on 100% power capacity specifications of the battery module  180  at a regular temperature (e.g. 20° C.) and a high temperature (e.g. 45° C.). Then, the power supply control block  140  controls the power supply conversion block  160  to boost the battery voltage VBT to be greater than or equal to the external power supply voltage Vin output by the adapter  10 . 
     Furthermore, a power supply path of the battery module  180  and a power supply path of the adapter  10  are connected in parallel to generate a double power source framework connected in parallel, and a power output to the electronic device  100  by the adapter  10  is limited through the power supply control block  140  and the power supply measurement block  120 . Power amounts supplied to the load circuit  190  of the electronic device  100  by the battery module  180  and the adapter  10  are simultaneously adjusted by the power supply control block  140 . Last, the power supply control block  140  calculates the energy required to be discharged by the battery module  180  to estimate a time of the battery module  180  supplying the power to the load circuit  190 . When the battery temperature decreases or the power of the battery module  180  reaches a security range limited in a battery specification, the power supply control block  140  is switched to a state in which only the adapter  10  supplies the power to the load circuit  190  through the power input switch block  110 . 
     For example, a specification of the adapter  10  is 19V/60W, and the specification of the battery module  180  is a battery module with three batteries connected in series and one battery connected in parallel, a regular temperature capacity of 11.1V/6 Ah/66.6 Wh with 100% power, a high-temperature capacity of 11.1V/5.4 Ah/60 Wh with 100% power, and with the critical temperature, for example, 45° C. A conversion power of the battery module  180  may be calculated according to the equations (1) to (3): 
     
       
         
           
             
               
                 
                   
                     P 
                     
                       Batt 
                       , 
                       K 
                     
                   
                   = 
                   
                     
                       P 
                       
                         Total 
                         , 
                         K 
                       
                     
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                         P 
                         
                           total 
                           , 
                           
                             k 
                             - 
                             1 
                           
                         
                       
                       ⁢ 
                       
                         exp 
                         
                           
                             - 
                             Δ 
                           
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           
                             T 
                             / 
                             λ 
                           
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   1 
                   ) 
                 
               
             
             
               
                 
                   
                     Δ 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     T 
                   
                   = 
                   
                     
                       T 
                       
                         K 
                         - 
                         1 
                       
                     
                     - 
                     
                       T 
                       H 
                     
                   
                 
               
               
                 
                   ( 
                   2 
                   ) 
                 
               
             
             
               
                 
                   Ut 
                   = 
                   
                     
                       
                         Q 
                         k 
                       
                       - 
                       
                         Q 
                         safe 
                       
                     
                     
                       P 
                       
                         Batt 
                         , 
                         K 
                       
                     
                   
                 
               
               
                 
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     A discharging power P Batt,K  of the battery module  180 =a total consumption power P total,K  of the load circuit  190 −a power P total,K-1 exp −ΔT/λ  of the adapter  10 . λ, is a constant which is used to adjust a change amount of ΔT. K represents a current state, and K−1 represents a previous measurement state. ΔT=a current battery temperature T K —a critical temperature T H . When the battery temperature is higher, AT is greater, and it is more likely to limit a power provided by the adapter  10 . A discharging time Ut of the battery module  180 =(A current capacity Q k —a set security capacity Q safe )/a current discharging power PBatt,K of the battery module  180 . 
     Furthermore, assuming that when the battery temperature is measured 50° C., a discharging mechanism of the battery module  180  is activated. If a load amount required for a current operation of the electronic device  100  is 50W, it may be obtained from the equation 1: if λ, is set to 10, an output power provided to the electronic device  100  by the adapter  10  is limited to 30W and the rest of 20W is provided by the battery module  180 . If the battery module  180  is fully charged, it may be obtained from the equation 2 that it takes approximately 19.8 minutes to discharge the battery module  180  to the security capacity, Ut=(66.6 Wh-60 Wh)/20 W=19.8. 
       FIG. 2  is a flow chart of a power distribution method of a power supply circuit according to an embodiment of the disclosure. Referring to  FIG. 2 , the power distribution method of the power supply circuit in the embodiment includes the following. In step S 200 , it is determined whether a power supply circuit is connected to an adapter. When the power supply circuit is connected to the adapter, in step S 201 , it is determined (or measured) whether a battery power of a battery module is higher than or equal to a critical power through a power supply control block. When the battery power of the battery module is not higher than or equal to the critical power, in step S 212 , the adapter supplies power normally to an electronic device. When the battery power of the battery module is higher than or equal to the critical power, in step S 202 , it is determined (or measured) whether a battery temperature of the battery module is higher than a critical temperature through the power supply control block of the power supply circuit. 
     When the battery temperature of the battery module is not higher than the critical temperature, in step S 212 , the adapter supplies the power normally to the electronic device. When the battery temperature of the battery module is higher than the critical temperature, in step S 203 , the power supply control block is activated. Next, in step S 204 , the power supply control block calculates a load state of a load circuit through a measurement of the power supply measurement block of the power supply circuit and a system total current required in the load state of the load circuit. That is, a power P_load of the load circuit=an output voltage Vout_adapter of the adapter x an output current Tout adapter of the adapter. In step S 205 , the power supply control block calculates a discharging power of the battery module. In step S 206 , the power supply control block controls a power supply conversion block to convert a battery voltage of the battery module into a power supply voltage having a limited power to the load circuit. In step S 207 , the power supply control block limits an output power of the adapter and simultaneously adjusts the discharging power of the battery module. In step S 208 , the power supply control block estimates a discharging time of the battery module. 
     Next, in step S 209 , it is determined (or measured) whether the battery temperature of the battery module is lower than or equal to the critical temperature through the power supply control block. When the battery temperature of the battery module is not lower than the critical temperature, in step S 210 , it is determined whether the discharging time of the battery module is completed through the power supply control block. When the battery temperature of the battery module is not lower than the critical temperature, in step S 211 , the power supply control block controls the power supply conversion block to disconnect the battery module and a power supply line. When the discharging time of the battery module is not completed, returning to step S 207  to continue battery module discharging. When the discharging time of the battery module is completed, in step S 211 , the power supply control block controls the power supply conversion block to disconnect the battery module and the power supply line. After step S 211 , step S 212  is executed. The sequence of steps S 200  to S 212  is for description, and the disclosure is not limited thereto. Furthermore, with regard to the details of steps S 200  to S 212 , the embodiment of  FIG. 1  may be referred to, and they are not repeated here. 
     In summary of the above, in the power supply circuit and the power distribution method thereof of the embodiment of the disclosure, when the temperature and the power of the battery module are too high, the power supply control block controls the adapter and the battery module to supply the power simultaneously so that the battery module and the adapter are connected in parallel to simultaneously supply the power to the load circuit of the electronic device. Accordingly, the operation mode and the power management icon of the electronic device are not changed, but the power of the battery module may still be consumed. 
     Although the disclosure has been described with reference to the above embodiments, they are not intended to limit the disclosure. It will be apparent to one of ordinary skill in the art that modifications to the described embodiments may be made without departing from the spirit and the scope of the disclosure. Accordingly, the scope of the disclosure will be defined by the attached claims and their equivalents and not by the above detailed descriptions.