Electronic device and control method thereof

Abstract

An electronic device is provided with: a storage battery; a charging circuit that charges the storage battery; a load device that operates by power of the storage battery; a voltage sensor that detects a charging voltage and a discharging voltage of the storage battery; a current sensor that detects a charging current and a discharging current of the storage battery; and a control circuit. The control circuit calculates an internal resistance of the storage battery based on the charging voltage and the charging current, calculates an allowable power that indicates a maximum power that the load device can take from the storage battery based on the discharging voltage, the discharging current, and the internal resistance, and transmits a control signal to the load device so that the load device operates at a power lower than the allowable power.

Description

Technical Field

[0001] This disclosure relates to electronic devices and methods for controlling them. Background Technology

[0002] Portable personal computers and other electronic devices operate by power supplied by a battery that is equipped with or connected to them. Such electronic devices seek to control their power consumption so that they operate within the range of power that can be supplied by the battery.

[0003] Patent Document 1 discloses a technique for controlling the peak power of an electronic device comprising multiple processors operating as master devices and multiple devices operating as slave devices. When the electronic device of Patent Document 1 operates on power supplied by a battery, the processor is permitted to utilize the device when the total power consumption of the device is below a given value calculated based on the remaining battery capacity.

[0004] Prior technology documents

[0005] Patent documents

[0006] Patent Document 1: JP Japanese Patent Application Publication No. 2006-195945 Summary of the Invention

[0007] As batteries deteriorate with continued use, their power supply and overall electrical capacity decrease. Therefore, when calculating the battery's energy reserve based solely on its design specifications, battery deterioration makes it impossible to accurately calculate the power that can be supplied by the battery.

[0008] This disclosure provides an electronic device and a control method thereof that can control power consumption with higher precision than in the past.

[0009] An electronic device according to one aspect of this disclosure includes: a storage battery; a charging circuit for charging the storage battery; a load device operated by power from the storage battery; a voltage sensor for detecting the charging voltage and discharging voltage of the storage battery; a current sensor for detecting the charging current and discharging current of the storage battery; and a control circuit that calculates the internal resistance of the storage battery based on the charging voltage and the charging current, calculates a permissible power representing the maximum power that the load device can obtain from the storage battery based on the discharging voltage, the discharging current, and the internal resistance, and sends a control signal to the load device to cause the load device to operate at a power level below the permissible power.

[0010] The electronic device according to one aspect of this disclosure can control power consumption with higher precision than in the past. Attached Figure Description

[0011] Figure 1 This is a block diagram showing the structure of the electronic device 1 according to the embodiment.

[0012] Figure 2 It means Figure 1 A block diagram of the structure of the charging circuit 11.

[0013] Figure 3 It means by Figure 1 The flowchart of the charging control process executed by the control circuit 14.

[0014] Figure 4 This means that by repeating the execution Figure 3 The graph shows the calculation of the internal resistance Ra(1) to Ra(6) performed in steps S1 to S11.

[0015] Figure 5 This explains how to execute Figure 3 The graph shows the calculation of the internal resistance Ra(i) performed in steps S3 to S8.

[0016] Figure 6 It means Figure 3 The table of correction factors related to the temperature (Temp) of battery unit 12a used in step S8.

[0017] Figure 7 It means by Figure 1 The flowchart shows the discharge control process executed by the control circuit 14.

[0018] Figure 8 In order to be in Figure 7 The table used in step S24 to calculate the charging rate range Cd.

[0019] Figure 9 In order to be in Figure 7 The table used in step S25 determines the maximum power W1 that can be output from the battery pack 12.

[0020] Figure 10 It means by Figure 1 The flowchart of the interrupt handling executed by the control circuit 14. Detailed Implementation

[0021] Hereinafter, embodiments will be described in detail with appropriate reference to the accompanying drawings. However, sometimes necessary detailed descriptions are omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of substantially the same structures are sometimes omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art.

[0022] In addition, the inventors have provided drawings and the following description in order to enable those skilled in the art to fully understand this disclosure, but it is not intended to limit the subject matter set forth in the claims.

[0023] [Implementation Method]

[0024] [Structure of the Implementation Method]

[0025] Figure 1 This is a block diagram illustrating the structure of the electronic device 1 according to the embodiment. The electronic device 1 includes a battery pack 12 and operates using power supplied by the battery pack 12. The electronic device 1 can be, for example, a portable personal computer (e.g., a laptop computer, tablet computer), a mobile phone, etc. The electronic device 1 is connected to an AC power source 2 via an AC / DC converter 3. The AC / DC converter 3 converts the AC power supplied from the AC power source 2 into DC power and supplies it to the electronic device 1. The electronic device 1 operates using the power supplied from the AC / DC converter 3 and also charges the internal battery pack 12.

[0026] The electronic device 1 includes a charging circuit 11, a battery pack 12, a DC / DC converter 13, a control circuit 14, a switch SW, and a load device 20.

[0027] exist Figure 1 In the diagram, thick lines represent power lines, and thin lines represent signal lines.

[0028] The charging circuit 11 charges the battery pack 12 using power supplied from the AC / DC converter 3. The charging circuit 11 supplies power to the battery pack 12 with a voltage and a current that vary according to the charging rate of the battery pack 12, for example, in any of the constant current mode, constant voltage mode, and constant power mode.

[0029] The battery pack 12 includes multiple battery units 12a, a current sensor 12b, a voltage sensor 12c, a temperature sensor 12d, and a non-volatile memory 12e. Each battery unit 12a is a rechargeable and dischargeable secondary battery. The multiple battery units 12a are connected in series and / or in parallel, and together they have a given internal resistance Rd. The internal resistance Rd of the battery pack 12 is calculated by the control circuit 14 as described later. The current sensor 12b detects the current supplied from the charging circuit 11 to the battery pack 12 (hereinafter also referred to as the "charging current Ib" of the battery pack 12) and notifies the charging circuit 11 and the control circuit 14. In addition, the current sensor 12b detects the current supplied from the battery pack 12 to the load device 20 via the DC / DC converter 13 (hereinafter also referred to as the "discharging current Id" of the battery pack 12) and notifies the control circuit 14. Voltage sensor 12c detects the voltage across the positive and negative terminals of the battery pack 12 and notifies the charging circuit 11 and the control circuit 14. Hereinafter, the voltages of the battery pack 12 during charging and discharging will be referred to as the "charging voltage Vb" and "discharging voltage Vd" of the battery pack 12, respectively. Temperature sensor 12d detects the temperature of each battery unit 12a and notifies the control circuit 14. Non-volatile memory 12e stores the internal resistance Rd of the battery pack 12 calculated by the control circuit 14.

[0030] The battery pack 12 can be configured to be detachable from the electronic device 1, or it can be built into the electronic device 1.

[0031] Battery pack 12 is an example of a battery.

[0032] The switch SW selectively supplies either the power supplied from the AC / DC converter 3 or the power discharged from the battery pack 12 to the DC / DC converter 13 under the control of the control circuit 14.

[0033] DC / DC converter 13 generates one or more different DC voltages by means of power supplied from AC / DC converter 3 or power discharged from battery pack 12, and supplies the generated DC voltage to load device 20.

[0034] The control circuit 14 controls the operation of the charging circuit 11, the switch SW, and the central processing unit (CPU) 21 of the load device 20. The control circuit 14 may be, for example, a micro controller of the type called an EC (Embedded Controller) used in computers.

[0035] The load device 20 includes a central processing unit (CPU) 21, a memory 22, a storage device 23, a display device 24, an input device 25, and a communication interface (I / F) 26. The CPU 21 executes the program stored in the storage device 23 and controls the operation of the other components 22-26 of the load device 20. The memory 22 temporarily stores the programs and data required for the operation of the electronic device 1. The storage device 23 stores the programs and data required for the operation of the electronic device 1. The storage device 23 may include, for example, a solid-state drive or a hard disk drive. The display device 24 displays the results of the program executed by the CPU 21. The input device 25 accepts user input for controlling the operation of the electronic device 1. The input device 25 may include, for example, a keyboard and pointing devices. The communication interface 26 can communicatively connect to external devices via wired and / or wireless lines. The communication interface 26 may include interfaces such as USB (Universal Serial Bus) for connecting to peripheral devices.

[0036] CPU 21 has multiple performance states that operate at different power levels. These performance states can be, for example, Px performance states (x = 0, 1, ..., n) defined by the ACPI (Advanced Configuration and Power Interface) specification. Here, "n" is a predetermined maximum value dependent on CPU 21. In the P0 performance state, CPU 21 operates at its maximum performance and consumes the maximum power. In the P1 performance state, CPU 21 operates at a lower performance and consumes less power than in the P0 performance state. Subsequently, as the number of "Px" increases, the performance and power consumption of CPU 21 decrease, and in the Pn performance state, CPU 21 maintains an active state while operating at its lowest performance and consuming the minimum power.

[0037] CPU21 is an example of an arithmetic circuit.

[0038] Figure 2 It means Figure 1A block diagram of the structure of the charging circuit 11 is provided. The charging circuit 11 includes a DC / DC converter 31, a charging control circuit 32, a reference voltage source 33, and a comparator 34. The DC / DC converter 31 is, for example, a buck-boost type power converter including multiple switching elements, inductors, and pulse width modulation circuits. The charging control circuit 32 controls the operation of the DC / DC converter 31 based on the charging voltage Vb detected by the voltage sensor 12c and the charging current Ib detected by the current sensor 12b. Specifically, the charging control circuit 32 calculates the charging rate of the battery pack 12 based on the charging voltage Vb and the charging current Ib, and controls the switching frequency and duty cycle of each switching element of the DC / DC converter 31 to generate a desired voltage and a desired current corresponding to the charging rate. Furthermore, the charging control circuit 32 temporarily stops and resumes charging of the battery pack 12 according to the control signal from the control circuit 14. The reference voltage source 33 generates a reference voltage characterizing a given threshold voltage Vmin. The threshold voltage Vmin represents a low voltage that could potentially cause a transient interruption in electronic device 1. When the discharge voltage Vd detected by voltage sensor 12c becomes less than the threshold voltage Vmin, comparator 34 generates an interrupt signal and sends it to control circuit 14 and CPU 21.

[0039] Refer again Figure 1 The control circuit 14 calculates the internal resistance Rd of the battery pack 12 based on the charging voltage Vb and charging current Ib of the battery pack 12. The control circuit 14 also calculates the allowable power W, representing the maximum power that the CPU 21 can obtain from the battery pack 12, based on the discharging voltage Vd, discharging current Id, and internal resistance Rd of the battery pack 12. The control circuit 14 then sends a control signal to the CPU 21 to cause the CPU 21 to operate at a power level below the allowable power W.

[0040] Furthermore, when the discharge voltage Vd of the battery pack 12 decreases and there is a possibility of momentary power loss of the electronic device 1, the control circuit 14 corrects the internal resistance Rd to recalculate the allowable power W.

[0041] CPU 21 operates selectively in one of a plurality of performance states according to the control signal from control circuit 14, so that CPU 21 operates at a power below the allowable power.

[0042] The control circuit 14 can also set a certain threshold power for the CPU 21 for the purpose of thermal management. For example, the threshold power of PL4 (Power Limit 4) used by Intel Core processors can be set to limit the operating frequency of the CPU 21 so as to prevent power spikes exceeding PL4.

[0043] [Implementation steps]

[0044] The control circuit 14 controls the operation of the electronic device 1 by performing the charging control process, discharging control process, and interrupt process described below.

[0045] [Charging control processing]

[0046] Figure 3 It means by Figure 1 The flowchart illustrates the charging control process executed by the control circuit 14. The battery pack 12 deteriorates with continuous use, resulting in an increase in its internal resistance Rd, which in turn reduces the power it can supply and the electrical strength it can generate. During the charging control process, the control circuit 14 measures the internal resistance Rd of the battery pack 12 while charging it.

[0047] In step S1, the control circuit 14 sets parameter i to 1. In this embodiment, in order to determine the internal resistance of the battery pack 12, the control circuit 14 continuously measures the internal resistance N times during the charging of the battery pack 12 and calculates the average of the multiple internal resistances. Parameter i is a parameter characterizing the number of times the internal resistance is measured.

[0048] In step S2, the control circuit 14 sets a threshold Th(i) for the charging rate of the battery pack 12. In this embodiment, the control circuit 14 measures the internal resistance Ra(i) of the battery pack 12 whenever the charging rate of the battery pack 12 reaches any of a predetermined set of thresholds Th(i).

[0049] Figure 4 This means that by repeating the execution Figure 3 The graph shows the calculation of the internal resistances Ra(1) to Ra(6) performed in steps S1 to S11. Figure 4 In the example, regarding the charging rate of battery pack 12, six thresholds are used: Th(1) = 65%, Th(2) = 70%, Th(3) = 75%, Th(4) = 80%, Th(5) = 85%, and Th(6) = 90%. That is, the multiple thresholds Th(i) are values ​​corresponding to the number of repetitions of steps S1 to S11 (parameter i: the number of times the internal resistance is measured). Here, the larger the parameter i, the larger the multiple thresholds Th(i). Figure 4 In the example, whenever the charging rate of the battery pack 12 reaches the threshold Th(1) to Th(6), the control circuit 14 measures the internal resistance Ra(1) to Ra(6) of the corresponding battery pack 12.

[0050] Refer again Figure 3In step S3, the control circuit 14 uses voltage sensor 12c to measure the charging voltage Vb of the battery pack 12 and current sensor 12b to measure the charging current Ib of the battery pack 12. The control circuit 14 can periodically measure the charging voltage Vb and charging current Ib, for example, at a frequency of tens to hundreds of milliseconds. In step S3, the control circuit 14 further calculates the charging rate of the battery pack 12 based on the charging voltage Vb. Since there is essentially a fixed relationship between battery voltage and charging rate, the charging rate can be estimated based on the voltage.

[0051] In step S4, the control circuit 14 determines whether the charging rate of the battery pack 12 has reached the threshold Th(i). If it is "yes", it proceeds to step S5; if it is "no", it returns to step S3.

[0052] In step S5, the control circuit 14 controls the charging circuit 11 to temporarily stop the charging of the battery pack 12.

[0053] In step S6, after a predetermined standby time of less than 1 second has elapsed since the charging of the battery pack 12 was stopped, the control circuit 14 uses the voltage sensor 12c to detect the voltage Va of the battery pack 12.

[0054] In step S7, the control circuit 14 uses the temperature sensor 12d to measure the temperature Temp of each battery unit 12a.

[0055] In step S8, the control circuit 14 calculates the internal resistance Ra(i) of the battery pack 12 based on the voltage Va, Vb, current Ib, and temperature Temp of the battery pack 12.

[0056] Figure 5 This explains how to execute Figure 3 The graph shows the calculation of the internal resistance Ra(i) performed in steps S3 to S8. Figure 5 The upper layer represents the voltage of the battery pack 12 detected by the voltage sensor 12c. Figure 5 The lower layer represents the current of the battery pack 12 detected by the current sensor 12b. Figure 5In the example, when the voltage of the battery pack 12 reaches the voltage Vb, the state of charge of the battery pack 12 reaches the threshold Th(i). Therefore, at time t1, the charging of the battery pack 12 is temporarily stopped, and the current of the battery pack 12 becomes zero. The control circuit 14 acquires the voltage Vb and the current Ib immediately before stopping the charging of the battery pack 12. Thereafter, after a standby time of 1 second has elapsed since stopping the charging of the battery pack 12, the control circuit 14 acquires the voltage Va of the battery pack 12 at time t2. The control circuit 14 calculates the internal resistance Ra(i) by dividing the potential difference between the voltage Vb and Va by the current Ib as in the following equation. In one example, the "immediately before" stopping the charging of the battery pack 12 refers to a time within 1 second from time t1.

[0057] Ra(i)=(Vb-Va) / Ib

[0058] The internal resistance of the battery pack 12 is characterized by a complex impedance Z=R+jX, and can be decomposed into a resistance component R and a reactance component X. If the contribution of the reactance component X in the calculation of the internal resistance is large, the calculated value of the internal resistance will become excessively large, and the power that can be supplied by the battery pack 12 will be estimated to be small. Therefore, it is sought to reduce the contribution of the reactance component X in the calculation of the internal resistance, and calculate the internal resistance specifically based on the resistance component R. The inventors of the present invention confirmed through experiments that by calculating the internal resistance Ra(i) based on the potential difference between the voltage Vb immediately before stopping the charging of the battery pack 12 and the voltage Va after a standby time of 1 second or less has elapsed since stopping the charging of the battery pack 12, the contribution of the reactance component X can be reduced, and the resistance component R can be specifically extracted.

[0059] Figure 6 is a diagram showing Figure 3 a table of correction coefficients related to the temperature Temp of the battery unit 12a used in step S8. When the temperature Temp of each battery unit 12a fluctuates, the power that can be supplied by the battery pack 12 also fluctuates. Therefore, the control circuit 14 corrects the internal resistance Ra(i) based on the temperature Temp of the battery unit 12a. Specifically, the control circuit 14 multiplies the internal resistance Ra(i) by a correction coefficient k corresponding to the temperature Temp of each battery unit 12a at the time when the internal resistance Ra(i) is measured. In Figure 6 the example, the temperature Temp gradually increases in the order of T1<25 degrees<T2<T3. The correction coefficient k is set so that the internal resistance measured at each of the temperatures T1, T2, and T3 is converted into the internal resistance measured at the normal temperature of 25°C.

[0060] Referring again to Figure 3 , in step S9, after detecting the voltage Va, the control circuit 14 controls the charging circuit 11 to restart the charging of the battery pack 12 (refer to Figure 5 (Time t3). For example, the control circuit 14 can restart the charging of the battery pack 12 60 seconds after the charging of the battery pack 12 has been stopped.

[0061] In step S10, the control circuit 14 determines whether parameter i has reached a predetermined maximum value N. Figure 4 In the example, N=6), if "yes", proceed to step S12; if "no", proceed to step S11. In other words, in step S10, the control circuit 14 determines whether to calculate all internal resistances Ra(i) corresponding to all predetermined thresholds Th(i).

[0062] In step S11, the control circuit 14 increments parameter i by 1 and returns to step S2. The control circuit 14 obtains multiple internal resistances Ra(1) to Ra(N) by repeatedly pausing the charging of the battery pack 12 (step S5), calculating the internal resistance Ra(i) (step S8), and restarting the charging of the battery pack 12 (step S9).

[0063] In step S12, the control circuit 14 calculates the internal resistance Rm by averaging the internal resistances Ra(1) to Ra(N). For example, as Figure 4 As shown, when the internal resistance Ra(i) is measured 6 times during the charging of the battery pack 12, the average internal resistance Rm is calculated by the following formula.

[0064] Rm=[Ra(1)+Ra(2)+...+Ra(6)] / 6

[0065] The control circuit 14 can also determine whether the obtained internal resistances Ra(1) to Ra(N) are outliers before calculating the average internal resistance Rm. In this case, the control circuit 14 excludes the outlier internal resistances Ra(i) and calculates the internal resistance Rm by averaging the remaining internal resistances Ra(j) (1≤j≤N, i≠j).

[0066] Furthermore, the control circuit 14 presets a lower limit Rmin and an upper limit Rmax for the allowable internal resistance. If the calculated internal resistance Rm is less than the lower limit Rmin or greater than the upper limit Rmax, the value of the internal resistance Rm can be rounded. For example, if Rm > Rmax, the measured result can be set to Rm = Rmax for processing.

[0067] In step S13, the control circuit 14 reads the previously calculated internal resistance Rd from the non-volatile memory 12e as the internal resistance Rd(old).

[0068] In step S14, the control circuit 14 calculates the updated internal resistance Rd(new) by a moving average of the previously calculated internal resistance Rd(old) and the newly calculated internal resistance Rm. For example, when the previously calculated internal resistance Rd(old) is weighted by 3 / 4, the updated internal resistance Rd(new) is calculated by the following formula.

[0069] Rd(new)=Rd(old)×3 / 4+Rm×1 / 4

[0070] As described above, control circuit 14 uses the previously calculated internal resistance Rd(old), the weight of internal resistance Rd(old) (3 / 4), the newly calculated internal resistance Rm, and the weight of internal resistance Rm (1 / 4) to calculate a weighted moving average as the updated internal resistance Rd(new). In step S15, control circuit 14 saves the updated internal resistance Rd(new) as internal resistance Rd to non-volatile memory 12e and ends the process.

[0071] according to Figure 3 The charging control process can measure the internal resistance Rd of the battery pack 12 while charging the battery pack 12.

[0072] according to Figure 3 The charging control processing calculates the internal resistance Ra(i) based on the potential difference between the voltage Vb before charging of the battery pack 12 is about to stop and the voltage Va after a standby time of less than 1 second since charging of the battery pack 12 was stopped. This reduces the contribution of the reactance component X and specifically extracts the resistance component R. Therefore, according to Figure 3 The charging control processing can accurately measure the internal resistance Rd of the battery pack 12.

[0073] exist Figure 3 In the charging control process, a standby time is set from the time the charging of the battery pack 12 stops until the measured voltage Va, so that the resistive component R of the internal resistance Rd includes high-frequency components caused by electrolyte moving resistance, lead resistance, and charge moving resistance. The lower limit of the standby time is set to be greater than the duration of the load generated during control. The upper limit of the standby time is arbitrary, but if the standby time is increased, as mentioned above, the contribution of the reactance component X in the calculation of the internal resistance increases, thereby making the calculated value of the internal resistance too large, and the power that can be supplied by the battery pack 12 will be underestimated.

[0074] If electronic device 1 is connected to AC power supply 2 via AC / DC converter 3, then control circuit 14 can still operate even if the power supply to electronic device 1 is disconnected. Figure 3The charging control process is implemented. Therefore, even when the power supply to the electronic device 1 is disconnected, the battery pack 12 can be charged, and the internal resistance Rd of the battery pack 12 can be measured.

[0075] [Discharge control processing]

[0076] Figure 7 It means by Figure 1 The flowchart shows the discharge control process executed by the control circuit 14. The discharge control process is executed to supply power from the battery pack 12 to the load device 20 when the power supply from the external AC power source 2 and the AC / DC converter 3 to the electronic device 1 stops.

[0077] In step S21, when the power supply from the external AC power source 2 and AC / DC converter 3 to the electronic device 1 stops, the control circuit 14 controls the switch SW to initiate the discharge from the battery pack 12. Alternatively, the control circuit 14 may start the discharge from the battery pack 12 when the electronic device 1 is powered on without being connected to the AC power source 2 and AC / DC converter 3.

[0078] In step S22, the control circuit 14 reads the internal resistance Rd from the non-volatile memory 12e.

[0079] In step S23, the control circuit 14 uses voltage sensor 12c to measure the discharge voltage Vd of battery pack 12, uses current sensor 12b to measure the discharge current Id of battery pack 12, and uses temperature sensor 12d to measure the temperature Temp of battery pack 12.

[0080] In step S24, the control circuit 14 determines which of the multiple charging rate ranges Cd is included based on the discharge voltage Vd and discharge current Id of the battery pack 12.

[0081] Figure 8 In order to be in Figure 7 The table used in step S24 to calculate the charging rate range Cd. Figure 8 In the example, Cd0 represents a charge rate of 0–49%, Cd50 represents a charge rate of 50–79%, and Cd80 represents a charge rate of 80–100%. The control circuit 14 determines which of the charge rate ranges Cd0, Cd50, and Cd80 is included in based on the discharge voltage Vd and the discharge current Id.

[0082] As mentioned above, there is essentially a fixed relationship between battery voltage and charging rate. Without a load, the charging rate can be estimated based on the voltage. However, under load, i.e., when a discharge current (or charging current) is flowing, the voltage shifts according to the magnitude of the current. Therefore, to determine the charging rate range Cd, the magnitude of the current must also be taken into account.

[0083] Refer again Figure 7 In step S25, the control circuit 14 determines the maximum power W1 that can be output from the battery pack 12 based on the charging rate range Cd and the temperature Temp of the battery pack 12. The maximum power W1 represents the maximum power that can be output from the battery pack 12 when the internal resistance Rd of the battery pack 12 is equal to the maximum value Rmax.

[0084] Figure 9 In order to be in Figure 7 The table used in step S25 determines the maximum power W1 that can be output from the battery pack 12. The control circuit 14 determines whether the maximum power W1 is 10W, 20W, 30W, 40W, or 45W based on the charging rate range Cd and the temperature Temp.

[0085] Refer again Figure 7 In step S26, the control circuit 14 calculates the allowable power W, which represents the maximum power that the CPU 21 can obtain from the battery pack 12, based on the maximum power W1 that can be output from the battery pack 12 and the internal resistance Rd of the battery pack 12, using the following formula.

[0086] W=(W1-W2)×((Rmax+Re) / (Rd+Re))+W2

[0087] Here, W2 represents the minimum power that must be output from the battery pack 12, including the power consumed by components other than the CPU 21 of the electronic device 1. Furthermore, Re represents the circuit resistance of the electronic device 1, excluding the internal resistance Rd of the battery pack 12.

[0088] As mentioned above, the maximum power W1 that can be output from the battery pack 12 is determined based on the charging rate range Cd of the battery pack 12, which in turn is determined based on the discharge voltage Vd and discharge current Id of the battery pack 12. Therefore, equivalently, the allowable power W is determined based on the discharge voltage Vd, discharge current Id, and internal resistance Cd of the battery pack 12. Furthermore, since the maximum power W1 that can be output from the battery pack 12 is determined based on the temperature Temp of the battery pack 12, the allowable power W is equivalently corrected by the temperature Temp.

[0089] In step S27, the control circuit 14 sets the allowable power W for the CPU 21. Thus, the CPU 21 is set to one of a plurality of operating states so that it receives only power below the allowable power W from the battery pack 12.

[0090] In step S28, the control circuit 14 uses voltage sensor 12c to measure the discharge voltage Vd of the battery pack 12, uses current sensor 12b to measure the discharge current Id of the battery pack 12, and uses temperature sensor 12d to measure the temperature Temp of the battery pack 12.

[0091] In step S29, the control circuit 14 determines whether any of the discharge voltage Vd, discharge current Id, and temperature Temp measured in step S28 has changed significantly from their previously measured values. If "yes," it returns to step S24; if "no," it returns to step S28. Here, "significant change" refers to... Figure 8 The table shows the extent to which the discharge voltage Vd or discharge current Id changes to require a change in the charging rate range Cd, or... Figure 9 The table shows the range of charging rate Cd or temperature Temp, and the extent to which a change in maximum power W1 is required.

[0092] according to Figure 7 Discharge control processing, through performing Figure 3 The charging control processing can set the allowable power of CPU 21 based on the measured internal resistance Rd of the battery pack 12. Therefore, based on the correct internal resistance Rd, the power consumption of CPU 21 can be controlled with higher precision than before.

[0093] [Interrupt Handling]

[0094] Figure 10 It means by Figure 1 The flowchart shows the interrupt handling process executed by the control circuit 14. The interrupt handling occurs when the electronic device 1 operates using power discharged from the battery pack 12 (i.e., Figure 7 (During the execution of the discharge control process), it is executed when the discharge voltage of the battery pack 12 decreases, which may cause a momentary interruption of the electronic device 1.

[0095] As mentioned above, when the discharge voltage Vd detected by the voltage sensor 12c becomes smaller than the threshold voltage Vmin, the charging circuit 11 generates an interrupt signal and sends it to the control circuit 14 and the CPU 21.

[0096] Interrupt signals, for example, could be the ProChot signal used by Intel Core processors. The ProChot signal is asserted when the processor is at high temperature, causing the processor to transition to the Pn behavior state. By using the ProChot signal, CPU 21 transitions to a state of minimum power consumption while maintaining an active state and operating at its lowest performance level, thus avoiding momentary interruptions in electronic device 1.

[0097] In step S31, the control circuit 14 receives an interrupt signal from the charging circuit 11.

[0098] In step S32, the control circuit 14 reads the internal resistance Rd from the non-volatile memory 12e.

[0099] In step S33, the control circuit 14 corrects the internal resistance Rd by a predetermined correction factor larger than 1, such as 1.05, so that the internal resistance Rd increases.

[0100] In step S34, the control circuit 14 saves the corrected internal resistance Rd to the non-volatile memory 12e.

[0101] In step S35, the control circuit 14 uses voltage sensor 12c to measure the discharge voltage Vd of the battery pack 12, uses current sensor 12b to measure the discharge current Id of the battery pack 12, and uses temperature sensor 12d to measure the temperature Temp of the battery pack 12.

[0102] In step S36, control circuit 14 and Figure 7 Similarly, in step S24, the discharge voltage Vd and discharge current Id of the battery pack 12 are used to determine which of the multiple charge rate ranges Cd the charge rate is included in.

[0103] In step S37, control circuit 14 and Figure 7 Similarly, in step S25, the maximum power W1 that can be output from the battery pack 12 is determined based on the charging rate range Cd and the temperature Temp of the battery pack 12.

[0104] In step S38, control circuit 14 and Figure 7 Similarly, in step S26, the allowable power W representing the maximum power that the CPU 21 can obtain from the battery pack 12 is calculated based on the maximum power W1 that can be output from the battery pack 12 and the internal resistance Rd of the battery pack 12.

[0105] In step S39, the control circuit 14 sets the allowable power W for the CPU 21. As a result, the CPU 21 ends the Pn performance state that started corresponding to the prochot signal and sets itself to one of a plurality of performance states, so that it obtains only power below the allowable power W from the battery pack 12.

[0106] After step S39 is executed, control circuit 14 returns to Figure 7 Discharge control processing.

[0107] By calculating the internal resistance Rd to be smaller than its actual value, the CPU21 will be set to a value larger than its actual allowable power W. According to... Figure 10 The interrupt handling mechanism can recalculate the allowable power W by correcting the internal resistance Rd when the discharge voltage of the battery pack 12 decreases, which may cause a momentary interruption of the electronic device 1. This can control the power consumption of the CPU 21 with high precision while avoiding the momentary interruption of the electronic device 1.

[0108] [Effects of the implementation method, etc.]

[0109] The electronic device 1 disclosed herein includes: a battery pack 12; a charging circuit 11 for charging the battery pack 12; a load device 20 that operates using power from the battery pack 12; a voltage sensor 12c for detecting the charging voltage and discharging voltage of the battery pack 12; a current sensor 12b for detecting the charging current and discharging current of the battery pack 12; and a control circuit 14. The control circuit 14 calculates the internal resistance of the battery pack 12 based on the charging voltage and charging current, calculates a permissible power representing the maximum power that the load device 20 can obtain from the battery pack 12 based on the discharging voltage, discharging current, and internal resistance, and sends a control signal to the load device 20 to cause the load device 20 to operate at a power level below the permissible power.

[0110] In this way, by setting the allowable power of the load device 20 based on the measured internal resistance Rd of the battery pack 12, power consumption can be controlled with higher precision than in the past.

[0111] According to the electronic device 1 of one aspect of this disclosure, the control circuit 14 can also control the charging circuit 11 during the charging of the battery pack 12, thereby temporarily stopping the charging of the battery pack 12. In this case, the control circuit 14 detects the charging voltage (first voltage) of the battery pack 12 before the charging of the battery pack 12 is about to be stopped. Furthermore, the control circuit 14 detects the second voltage of the battery pack 12 after a predetermined standby time of less than one second since the charging of the battery pack 12 was stopped. Furthermore, the control circuit 14 detects the charging current, i.e., the first current, before the charging of the battery pack 12 is about to be stopped. Furthermore, the control circuit 14 calculates the internal resistance by dividing the potential difference between the first and second voltages by the first current. Furthermore, after the detection of the second voltage, the control circuit 14 controls the charging circuit 11 to restart the charging of the battery pack 12.

[0112] In this way, by calculating the internal resistance Ra(i) based on the potential difference between the voltage Vb before the charging of the battery pack 12 is about to stop and the voltage Va after a standby time of less than 1 second since the charging of the battery pack 12 is stopped, the internal resistance Rd of the battery pack 12 can be measured with high precision.

[0113] According to the electronic device 1 of one aspect of this disclosure, the control circuit 14 can also obtain multiple internal resistances by repeatedly pausing the charging of the battery pack 12, calculating the internal resistances, and restarting the charging of the battery pack 12. In this case, the control circuit 14 calculates the allowable power based on the discharge voltage, the discharge current, and the average of the multiple internal resistances.

[0114] In this way, by calculating the average of multiple internal resistances, the internal resistance Rd of the battery pack 12 can be measured with high precision.

[0115] According to one aspect of the electronic device 1 disclosed herein, the control circuit 14 can calculate a moving average of a previously calculated internal resistance and a newly calculated internal resistance. In this case, the control circuit 14 calculates the allowable power based on the discharge voltage, discharge current, and the moving average of the internal resistance.

[0116] In this way, by calculating the moving average of the internal resistance, the internal resistance Rd of the battery pack 12 can be measured with high precision.

[0117] According to one aspect of the electronic device 1 disclosed herein, the electronic device 1 may further include a temperature sensor 12d for detecting the temperature of the battery pack 12. In this case, the control circuit 14 adjusts the internal resistance and allowable power based on the temperature of the battery pack 12.

[0118] In this way, by adjusting the internal resistance and allowable power based on the temperature of the battery pack 12, power consumption can be controlled with high precision.

[0119] According to one aspect of the electronic device 1 disclosed herein, the control circuit 14 can correct the internal resistance by a predetermined correction factor larger than 1, thereby increasing the internal resistance, if the discharge voltage becomes less than a predetermined threshold. In this case, the control circuit 14 calculates the allowable power based on the discharge voltage, the discharge current, and the corrected internal resistance.

[0120] In this way, by correcting the internal resistance Rd and recalculating the allowable power W, the power consumption of the load device 20 can be controlled with high precision while avoiding the instantaneous interruption of the electronic device 1.

[0121] According to one aspect of the electronic device 1 disclosed herein, the load device 20 may include arithmetic circuitry.

[0122] As a result, the power consumption of the CPU21 and other computing circuits can be controlled with greater precision than in the past.

[0123] According to one aspect of the electronic device 1 disclosed herein, the arithmetic circuit can have multiple performance states that operate at different power levels. In this case, the control circuit 14 selectively operates in one of the multiple performance states according to a control signal, so that the arithmetic circuit operates at a power level below the allowable power.

[0124] As a result, the power consumption of the CPU21 and other computing circuits can be controlled with greater precision than in the past.

[0125] The present disclosure discloses a method for controlling an electronic device 1 that controls an electronic device having a battery pack 12 and a load device operated by power from the battery pack 12. The method includes the steps of: calculating the internal resistance of the battery pack 12 based on its charging voltage and charging current; calculating a permissible power representing the maximum power the load device can obtain from the battery pack 12 based on its discharging voltage, discharging current, and internal resistance; and controlling the load device to operate at a power level below the permissible power.

[0126] In this way, by setting the allowable power of the load device 20 based on the measured internal resistance Rd of the battery pack 12, power consumption can be controlled with higher precision than in the past.

[0127] [Other Implementation Methods]

[0128] As described above, embodiments have been illustrated as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited to this and can also be applied to embodiments with appropriate modifications, substitutions, additions, omissions, etc. Furthermore, new embodiments can be made by combining the constituent elements described in the above embodiments.

[0129] Therefore, other implementation methods are illustrated below.

[0130] The control circuit 14 is not limited to the CPU 21, and can control any computing circuit having multiple performance states that operate with different power levels. The computing circuit can be, for example, a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), or a FPGA (Field Programmable Gate Array).

[0131] exist Figure 1 In the example, when the discharge voltage Vd becomes less than the threshold voltage Vmin, the charging circuit 11 generates an interrupt signal and sends it to the control circuit 14 and the CPU 21. Alternatively, the control circuit 14 may have a reference voltage source that generates a reference voltage characterizing the threshold voltage Vmin, and when the discharge voltage Vd becomes less than the threshold voltage Vmin, the control circuit 14 generates an interrupt signal and sends it to the CPU 21.

[0132] It can also be used in accordance with the specifications of each battery unit, 12A. Figure 6 The different temperatures (Temp) and correction factors (k) are shown. Furthermore, it can also be used according to the specifications of each 12A battery unit. Figure 8 Other charging rate ranges Cd are shown. Furthermore, it can also be used with [specifications] corresponding to the specifications of each battery unit 12. Figure 9 The different ranges and numbers of other maximum power W1 are shown.

[0133] exist Figure 6 In the example, a table of temperature (Temp) and correction factor (k) is used to correct the internal resistance Ra(i) of the battery pack 12, but the control circuit 14 can also use certain calculations instead of the table to correct the internal resistance Ra(i). Furthermore, in Figure 8 In the example, a table of discharge voltage Vd and discharge current Id is used to determine the charging rate range Cd, but control circuit 14 can also replace the table and use certain formulas to calculate the charging rate range Cd. Furthermore, in Figure 9In the example, a table of charging rate range Cd and temperature Temp is used to determine the maximum power W1, but the control circuit 14 can also use certain formulas instead of the table to calculate the maximum power W1.

[0134] The current sensor 12b and the voltage sensor 12c can also be located outside the battery pack 12.

[0135] When the battery pack 12 is built into the electronic device 1 without being detached, the internal resistance of the battery pack 12 can be stored in the non-volatile memory inside the control circuit 14.

[0136] As described above, embodiments have been illustrated as examples of the technology in this disclosure. For this purpose, accompanying drawings and detailed descriptions are provided.

[0137] Therefore, the constituent elements described in the accompanying drawings and detailed description include not only those necessary to solve the problem, but also those not necessary for solving the problem, in order to illustrate the above-described technology. Therefore, the mere presence of these non-essential constituent elements in the accompanying drawings and detailed description should not be interpreted as a direct indication that these non-essential constituent elements are necessary.

[0138] Furthermore, the above-described embodiments are used to illustrate the technology disclosed herein, and therefore, various changes, substitutions, additions, omissions, etc., can be made within the scope of the claims or their equivalents.

[0139] Industrial availability

[0140] The electronic device according to one aspect of this disclosure can control power consumption with higher precision than in the past, thereby improving the availability of the electronic device.

[0141] Explanation of reference numerals in the attached figures

[0142] 1. Electronic device

[0143] 2 AC power supply

[0144] 3 AC / DC converter

[0145] 11 Charging Circuit

[0146] 12 Battery Packs

[0147] 12A battery unit

[0148] 12b Current Sensor

[0149] 12c voltage sensor

[0150] 12D temperature sensor

[0151] 12e Non-volatile memory

[0152] 13 DC / DC converters

[0153] 14 Control Circuit

[0154] 20 Load devices

[0155] 21. Central Processing Unit (CPU)

[0156] 22 Memory

[0157] 23 Storage devices

[0158] 24 Display devices

[0159] 25 Input devices

[0160] 26 Communication connection (I / F)

[0161] 31 DC / DC converter

[0162] 32 Charging control circuit

[0163] 33 Reference Voltage Source

[0164] 34 comparators

[0165] SW switch.

Claims

1. An electronic device comprising: Storage battery; A charging circuit for charging the battery; A load device that operates using the power of the battery; A voltage sensor for detecting the charging and discharging voltages of the battery; A current sensor for detecting the charging and discharging current of the battery; and Control circuit, The control circuit performs the following processing: The internal resistance of the battery is calculated based on the charging voltage and the charging current. The allowable power, representing the maximum power that the load device can obtain from the battery, is calculated based on the discharge voltage, the discharge current, and the internal resistance. A control signal is sent to the load device to cause the load device to operate at a power level below the allowable power. During the charging of the battery, the charging circuit is controlled to temporarily stop the charging of the battery. The charging voltage, i.e., the first voltage, is detected just before the charging of the battery is about to stop. The second voltage of the battery is detected after a predetermined standby time of less than one second elapsed since charging of the battery was stopped. The first current is detected just before the charging of the battery is about to stop. The internal resistance is calculated by dividing the potential difference between the first voltage and the second voltage by the first current. After the second voltage is detected, the charging circuit is controlled to recharge the battery. The charging rate of the battery is calculated based on the charging voltage. Determine whether the charging rate has reached the threshold. When it is determined that the charging rate has reached the threshold, the charging circuit is controlled to temporarily stop the charging of the battery.

2. The electronic device according to claim 1, wherein, The control circuit performs the following processing: Multiple internal resistances are obtained by repeatedly pausing the charging of the battery, calculating the internal resistance, and restarting the charging process. The allowable power is calculated based on the discharge voltage, the discharge current, and the average of the plurality of internal resistances.

3. The electronic device according to claim 2, wherein, The control circuit performs the following processing: The charging rate of the battery is calculated based on the charging voltage. Determine whether the charging rate has reached a threshold corresponding to the number of repetitions. When it is determined that the charging rate has reached a threshold corresponding to the number of repetitions, the charging circuit is controlled to temporarily stop the charging of the battery.

4. The electronic device according to any one of claims 1 to 3, wherein, The control circuit performs the following processing: Calculate the moving average of the previously calculated internal resistance and the calculated internal resistance. The allowable power is calculated based on the discharge voltage, the discharge current, and the moving average.

5. The electronic device according to any one of claims 1 to 3, wherein, The control circuit performs the following processing: A weighted moving average is calculated using the previously calculated internal resistance, the weight of the previously calculated internal resistance, the calculated internal resistance, and the weight of the calculated internal resistance. The allowable power is calculated based on the discharge voltage, the discharge current, and the weighted moving average.

6. The electronic device according to any one of claims 1 to 3, wherein, The electronic device also includes: A temperature sensor that detects the temperature of the battery. The control circuit adjusts the internal resistance and the allowable power based on the temperature of the battery.

7. The electronic device according to any one of claims 1 to 3, wherein, The control circuit performs the following processing: If the discharge voltage becomes less than a predetermined threshold, The internal resistance is corrected by a predetermined correction factor greater than 1, thereby increasing the internal resistance. The allowable power is calculated based on the discharge voltage, the discharge current, and the corrected internal resistance.

8. The electronic device according to any one of claims 1 to 3, wherein, The load device includes a computing circuit.

9. The electronic device according to claim 8, wherein, The arithmetic circuit has multiple performance states that operate at different power levels. The control signal is used to selectively operate in one of the multiple performance states so that the arithmetic circuit operates at a power level below the allowable power.

10. A method for controlling an electronic device, comprising a battery and a load device operated by power from the battery. The control method for the electronic device includes the following steps: The internal resistance of the battery is calculated based on its charging voltage and charging current. The allowable power, representing the maximum power that the load device can obtain from the battery, is calculated based on the battery's discharge voltage, discharge current, and internal resistance. Control the load device so that the load device operates at a power below the allowable power; When the battery is being charged, the charging of the battery is temporarily stopped; The charging voltage, i.e., the first voltage, is detected just before the charging of the battery is about to stop; The second voltage of the battery is detected after a predetermined standby time of less than 1 second since the charging of the battery was stopped; The first current is the charging current just before the charging of the battery is about to stop. The internal resistance is calculated by dividing the potential difference between the first voltage and the second voltage by the first current; After the second voltage is detected, the battery is recharged. The charging rate of the battery is calculated based on the charging voltage; Determine whether the charging rate has reached the threshold; and When it is determined that the charging rate has reached the threshold, the charging of the battery is temporarily stopped.

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