Power supply device, power supply device control method, program and storage medium

Abstract

In a power supply device (10) and a method for controlling the power supply device (10), a first power conversion unit (60) is controlled on the basis of a first decrease characteristic such that a first output voltage decreases as a first output current increases. Also, a second power conversion unit (82) is controlled on the basis of a second decrease characteristic such that a second output voltage decreases as a second output current increases. The first decrease characteristic and the second diminishing characteristic are set so as to be different from each other.

Description

[Technical field]

[0001] The present invention relates to a power supply device, a control method for a power supply device, a program, and a storage medium. [Background technology]

[0002] International Publication No. 2020 / 235617 discloses a power output device including a power storage unit. The power output device converts DC power output from the power storage unit into AC power. The power output device outputs the converted AC power to the outside. Summary of the Invention

[0003] When power is supplied from two power output devices to a load, the two power output devices are connected in parallel to the load. When each of the two power output devices is operated at rated power, if the amount of charge in each power storage unit drops to a threshold value, each power storage unit needs to be replaced. In this case, power cannot be supplied from each power output device to the load during replacement of each power storage unit.

[0004] The present invention aims to solve the above-mentioned problems.

[0005] A first aspect of the present invention is a power supply device that outputs power to an outside, the power supply device comprising: a first power storage unit; a second power storage unit; a first power transmission path that connects the first power storage unit and a load connection unit to which a load is connected; a second power transmission path that connects the second power storage unit and the load connection unit; a first power conversion unit that is arranged on the first power transmission path and converts power supplied from the first power storage unit; a second power conversion unit that is arranged on the second power transmission path and converts power supplied from the second power storage unit; a first control unit that controls the first power conversion unit; and a second control unit that controls the second power conversion unit, The first storage unit and the second storage unit are connected in parallel to the load connection unit, and the first control unit controls the first power conversion unit based on a first step-down characteristic such that a first output voltage output from the first power conversion unit steps down as a first output current output from the first power conversion unit increases, and the second control unit controls the second power conversion unit based on a second step-down characteristic such that a second output voltage output from the second power conversion unit steps down as a second output current output from the second power conversion unit increases, and the first step-down characteristic and the second step-down characteristic are set to be different from each other.

[0006] A second aspect of the present invention is a power supply device including a second power storage unit connected in parallel to the first power storage unit to a load when a first power storage unit and a load are connected via a first power transmission path, the power supply device including a second power transmission path connecting the second power storage unit and the load, a power conversion unit arranged on the second power transmission path and converting power supplied from the second power storage unit, and a control unit controlling the power conversion unit, wherein when the first power storage unit outputs power based on a third step-down characteristic such that a first output current output from the first power transmission path steps down as a first output voltage output from the first power transmission path increases, the control unit controls the power conversion unit based on a fourth step-down characteristic such that a second output current output from the power conversion unit steps down as a second output voltage output from the power conversion unit increases, and the fourth step-down characteristic is set to be different from the third step-down characteristic.

[0007] A third aspect of the present invention is a method for controlling a power supply device that outputs power to an outside, the power supply device comprising: a first power storage unit; a second power storage unit; a first power transmission path connecting the first power storage unit and a load connection unit to which a load is connected; a second power transmission path connecting the second power storage unit and the load connection unit; a first power conversion unit that is arranged on the first power transmission path and converts power supplied from the first power storage unit; a second power conversion unit that is arranged on the second power transmission path and converts power supplied from the second power storage unit; and a control unit that controls the first power conversion unit and the second power conversion unit, The first power storage unit and the second power storage unit are connected in parallel to the load connection unit, and the control method includes a step of gradually decreasing a first output voltage output from the first power conversion unit as a first output current output from the first power conversion unit increases by controlling the first power conversion unit based on a first step-down characteristic, and a step of gradually decreasing a second output voltage output from the second power conversion unit as a second output current output from the second power conversion unit increases by controlling the second power conversion unit based on a second step-down characteristic different from the first step-down characteristic.

[0008] A fourth aspect of the present invention is a program for causing a computer to execute the power supply device control method according to the third aspect.

[0009] A fifth aspect of the present invention is a storage medium that stores the program according to the fourth aspect.

[0010] According to the present invention, the timing of replacement of the two power storage units does not overlap, so it is possible to continue supplying power to the load. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a configuration diagram of a power supply device according to this embodiment. [Diagram 2] FIG. 2 is a circuit diagram of the power device. [Diagram 3] FIG. 3 is a flowchart of the first embodiment. [Figure 4]FIG. 4 is a diagram showing the voltage-current characteristics of the base. [Diagram 5] FIG. 5 is a timing chart of the SOC in the first embodiment. [Figure 6] FIG. 6 is a diagram showing the first voltage-current characteristic and the second voltage-current characteristic. [Figure 7] FIG. 7 is a flowchart of the second embodiment. [Figure 8] FIG. 8 is a timing chart of the SOC in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] 1 is a configuration diagram of a power supply device 10 according to the present embodiment. The power supply device 10 includes a first power device 12 (power supply device), a second power device 14 (power supply device), a first power transmission path 16, and a second power transmission path 18.

[0013] The first power device 12 and the second power device 14 are power feeders capable of outputting power to the outside. The first power device 12 and the second power device 14 have the same external shape. The first power device 12 has a first housing 22 having a substantially rectangular parallelepiped shape. The second power device 14 has a second housing 24 having a substantially rectangular parallelepiped shape.

[0014] Each of the first power device 12 and the second power device 14 is capable of transmitting and receiving signals or information via wireless communication with the mobile terminal 26. The mobile terminal 26 is a portable device that can be operated by a user of the power supply device 10. The first power device 12 and the second power device 14 are capable of transmitting and receiving signals or information via wireless communication via the mobile terminal 26. Alternatively, signals or information may be transmitted and received directly between the first power device 12 and the second power device 14 via wireless communication.

[0015] The first power transmission path 16 electrically connects the first power device 12 and a load connection part 28 such as an AC outlet. The first power transmission path 16 is composed of two wires, a first positive electrode line 30 and a first negative electrode line 32. The second power transmission path 18 electrically connects the second power device 14 and the load connection part 28. The second power transmission path 18 is composed of two wires, a second positive electrode line 34 and a second negative electrode line 36. The first power device 12 and the second power device 14 are connected in parallel to the load connection part 28.

[0016] A load 38 is connected to the load connection section 28. The first power device 12 supplies a first output power to the load 38 via the first power transmission path 16 and the load connection section 28. The second power device 14 supplies a second output power to the load 38 via the second power transmission path 18 and the load connection section 28. The first output power and the second output power are AC powers.

[0017] Fig. 2 is a circuit configuration diagram of the first power device 12 and the second power device 14. The first power device 12 and the second power device 14 have the same configuration, including the circuit configuration. Fig. 2 illustrates the circuit configuration of one power device.

[0018] The first power device 12 includes a first power storage unit 40, a first DC / DC converter 42, a first inverter 44, a first CPU 46 (control unit, power storage amount acquisition unit, power consumption amount acquisition unit, calculation unit, first control unit, computer), a first filter 48, a first voltage sensor 50, a first current sensor 52, a first communication unit 54 (receiving unit), a first outlet 56, and a first parallel terminal 58. The first DC / DC converter 42 and the first inverter 44 configure a first power conversion unit 60. The first power storage unit 40, the first power conversion unit 60, the first CPU (Central Processing Unit) 46, the first filter 48, the first voltage sensor 50, the first current sensor 52, and the first communication unit 54 are housed inside a first housing 22 (see FIG. 1). The first outlet 56 and the first parallel terminal 58 are provided in the first housing 22.

[0019] The second power device 14 includes a second power storage unit 62, a second DC / DC converter 64, a second inverter 66, a second CPU 68 (control unit, power storage amount acquisition unit, power consumption amount acquisition unit, calculation unit, voltage acquisition unit, second control unit, computer), a second filter 70, a second voltage sensor 72, a second current sensor 74, a second communication unit 76 (receiving unit), a second outlet 78, and a second parallel terminal 80. The second DC / DC converter 64 and the second inverter 66 configure a second power conversion unit 82. The second power storage unit 62, the second power conversion unit 82, the second CPU 68, the second filter 70, the second voltage sensor 72, the second current sensor 74, and the second communication unit 76 are housed inside the second housing 24 (see FIG. 1). The second outlet 78 and the second parallel terminal 80 are provided in the second housing 24.

[0020] As described above, the first power device 12 and the second power device 14 have the same configuration, including the circuit configuration. Therefore, the configuration of the first power device 12 will be described as a representative example. Therefore, a detailed description of the second power device 14 will be omitted.

[0021] The first power storage unit 40 is a DC power source. The first power storage unit 40 is disposed (housed) inside the first housing 22 (see FIG. 1). The first power storage unit 40 is detachable from the first power device 12. The first power storage unit 40 is a mobile battery detachable from the first power device 12. The first power storage unit 40 is preferably, for example, a battery pack of a detachable lithium-ion battery.

[0022] At least one first power storage unit 40 may be attached to the first power device 12. When the first power device 12 includes a plurality of first power storage units 40, at least one of the plurality of first power storage units 40 may be detachable from the first power device 12. In this case, it is more preferable that the first power storage unit 40 is detachable from the first power device 12 without using a separate work tool or the like. That is, the first power storage unit 40 is configured so that it can be freely attached and detached from the first power device 12 without using a work tool or the like. In addition, "attaching and detaching from the first power device 12" includes a case where the first power storage unit 40 is attached to the first power device 12 and a case where the first power storage unit 40 is detached from the first power device 12. In the following description, a case where one first power storage unit 40 is detachable from the first power device 12 will be described.

[0023] The first power storage unit 40 is capable of outputting DC power based on a control signal from the first CPU 46. The first power storage unit 40 successively notifies the first CPU 46 of a state of charge (SOC), which is an amount of stored power.

[0024] The first power transmission path 16 connects the first power storage unit 40 and the load connection unit 28. The portion of the first power transmission path 16 inside the first power device 12 connects the first power storage unit 40 and the first outlet 56. The portion of the first power transmission path 16 outside the first power device 12 connects the first outlet 56 and the load connection unit 28.

[0025] In the portion of the first power transmission path 16 within the first power device 12, a first DC / DC converter 42, a first inverter 44, a first filter 48, a first voltage sensor 50, and a first current sensor 52 are arranged in this order from the first power storage unit 40 toward the first outlet 56. Of the first positive electrode line 30 and the first negative electrode line 32 of the first power transmission path 16, the portions between the first voltage sensor 50 and the first current sensor 52 and the first outlet 56 are connected to a first parallel terminal 58 via two wires 84.

[0026] The first DC / DC converter 42 converts the DC voltage of the first power storage unit 40 into a DC voltage of a desired value based on a control signal from the first CPU 46. The first inverter 44 converts the DC voltage converted by the first DC / DC converter 42 into a first output voltage based on a control signal from the first CPU 46. Therefore, the first power conversion unit 60 converts the DC voltage of the first power storage unit 40 into the first output voltage. The first output voltage is an AC voltage. The first filter 48 removes noise superimposed on the first output voltage converted by the first inverter 44.

[0027] The first voltage sensor 50 is disposed in a portion of the first power transmission path 16 between the first filter 48 and a connection point between the first power transmission path 16 and the two wires 84. One end of the first voltage sensor 50 is connected to the first positive electrode line 30. The other end of the first voltage sensor 50 is connected to the first negative electrode line 32. The first voltage sensor 50 sequentially detects the first output voltage that has passed through the first filter 48, and outputs the detection result to the first CPU 46.

[0028] The first current sensor 52 is disposed in a portion of the first positive electrode line 30 of the first power transmission path 16 between a connection point with one end of the first voltage sensor 50 and a connection point between the first positive electrode line 30 and one wiring 84. The first current sensor 52 sequentially detects the first output current flowing from the first inverter 44 to the load connection unit 28, and outputs the detection result to the first CPU 46. The first output current is an AC current.

[0029] The first CPU 46 is a computer that comprehensively controls each part of the first power device 12. The first CPU 46 realizes various functions by reading and executing programs stored in a memory 86 (storage medium). The functions of the first CPU 46 will be described later.

[0030] The first communication unit 54 transmits and receives signals or information via wireless communication with the mobile terminal 26. The first communication unit 54 also transmits and receives signals or information via wireless communication with the second power device 14 via the mobile terminal 26. Alternatively, the first communication unit 54 can directly transmit and receive signals or information with the second power device 14 via wireless communication.

[0031] In addition, in the above description of the circuit configuration, by replacing the word "first" with "second" and the word "second" with "first", the circuit configuration of the second power device 14 will be described.

[0032] The operation of the power supply device 10 configured as above will be described with reference to Figures 3 to 8. In explaining this operation, Figures 1 and 2 will also be referred to as necessary.

[0033] Here, a parallel operation in which power is output from both the first power device 12 and the second power device 14 to the load 38 will be described. Also, an operation when replacing the first power storage unit 40 and the second power storage unit 62 attached to the first power device 12 and the second power device 14 during parallel operation will be described. Specifically, a first embodiment in Figs. 3 to 6 and a second embodiment in Figs. 7 and 8 will be described. In both embodiments, the power supply device 10 operates to stagger the timing of replacement of the first power storage unit 40 and the second power storage unit 62 during parallel operation. Also, in both embodiments, a case in which the first CPU 46 is the main operator of the power supply device 10 will be described.

[0034] First, a first embodiment will be described with reference to Figures 3 to 6. In the first embodiment, a case in which the SOC of first power storage unit 40 is lower than the SOC of second power storage unit 62 will be described.

[0035] In step S1 of FIG. 3, a user of the power supply device 10 (see FIG. 1) operates the mobile terminal 26 to instruct execution of parallel operation. The user operates the mobile terminal 26 to execute the operation mode (specification mode) of the first embodiment. The mobile terminal 26 transmits an instruction signal for instructing execution of the operation mode of the first embodiment to the first power device 12 and the second power device 14 based on the user's operation content (request). The first communication unit 54 (see FIG. 2) of the first power device 12 receives the instruction signal and outputs it to the first CPU 46. The second communication unit 76 of the second power device 14 receives the instruction signal and outputs it to the second CPU 68. The user's request also includes a share (allocation ratio) of the output power supplied from the first power storage unit 40 and the second power storage unit 62 to the load 38.

[0036] In step S2, the first CPU 46 executes the operation mode based on the instruction signal. A map 88 is stored in the memory 86 of the first CPU 46. As shown in Fig. 4, this map 88 is a map of voltage-current characteristics (first step-down characteristic (third step-down characteristic), first drooping characteristic) that represents the relationship between the effective value (V) of the output voltage and the effective value (I) of the output current.

[0037] In this map 88, the vertical axis represents the effective value of the output voltage, and the horizontal axis represents the effective value of the output current. In the following description, for convenience, the "effective value of the output voltage" may be referred to as the "output voltage," and the "effective value of the output current" may be referred to as the "output current."

[0038] This map 88 has a decreasing characteristic (first decreasing characteristic) in which the output voltage gradually decreases as the output current increases. This map 88 also has a drooping characteristic (first drooping characteristic) in which the output voltage suddenly decreases when the output current is equal to or greater than a threshold Ith0 (third predetermined value). The drooping characteristic is provided to protect the power supply device 10 (power device) from an overcurrent.

[0039] The first CPU 46 controls the first power conversion unit 60 based on this map 88 so that desired values ​​of the first output voltage and first output current are output. Specifically, the first CPU 46 sets target values ​​of the first output voltage and the first output current based on the map 88. The first CPU 46 outputs a control signal to the first power conversion unit 60 according to the target values.

[0040] Note that a map 88 having a plurality of voltage-current characteristics with different decrement characteristics and droop characteristics may be stored in the memory 86. In this case, the first CPU 46 may select an appropriate voltage-current characteristic from the plurality of voltage-current characteristics, and set the target values ​​of the first output voltage and the first output current by referring to the selected voltage-current characteristic.

[0041] The first DC / DC converter 42 converts the DC voltage of the first power storage unit 40 into a DC voltage of a desired value based on the control signal. The first inverter 44 converts the DC voltage converted by the first DC / DC converter 42 into a first output voltage based on the control signal. This starts supplying the first output power (first output voltage, first output current) from the first power device 12 to the load 38. When the first output power is active power, the first output power is the product of the effective value of the first output voltage, the effective value of the first output current, and a power factor.

[0042] The first voltage sensor 50 detects the first output voltage and outputs the detection result to the first CPU 46. The first current sensor 52 detects the first output current and outputs the detection result to the first CPU 46. Therefore, the first CPU 46 can perform feedback control so that the first output voltage and the first output current become target values.

[0043] The first CPU 46 notifies the second power device 14 that the first power device 12 has started executing the operating mode via the first communication unit 54. The second communication unit 76 of the second power device 14 receives the notification from the first CPU 46 and outputs it to the second CPU 68.

[0044] The second CPU 68 executes the operation mode based on the notification from the first CPU 46. A map 88 is also stored in the memory 86 of the second CPU 68. This map 88 is the same as the map 88 stored in the memory 86 of the first CPU 46 (see FIG. 4).

[0045] As described above, the first power device 12 and the second power device 14 are connected in parallel to the load connection unit 28. The first power device 12 supplies the first output voltage to the load 38. Therefore, the first output voltage is also supplied to the second outlet 78 of the second power device 14. The second voltage sensor 72 detects the first output voltage and outputs the detection result to the second CPU 68. Alternatively, the first CPU 46 may notify the second CPU 68 of the detection result of the first voltage sensor 50 via the first communication unit 54.

[0046] The second CPU 68 sets target values ​​for the second output voltage and the second output current based on the map 88. In this case, the second CPU 68 sets the target values ​​so that the first output voltage and the second output voltage are equal. The second CPU 68 outputs a control signal according to the target values ​​to the second power conversion unit 82.

[0047] The second DC / DC converter 64 converts the DC voltage of the second power storage unit 62 into a DC voltage of a desired value based on the control signal. The second inverter 66 converts the DC voltage converted by the second DC / DC converter 64 into a second output voltage based on the control signal. This starts supplying the second output power (second output voltage, second output current) from the second power device 14 to the load 38. When the second output power is active power, the second output power is the product of the effective value of the second output voltage, the effective value of the second output current, and the power factor.

[0048] The second voltage sensor 72 detects the second output voltage and outputs the detection result to the second CPU 68. The second current sensor 74 detects the second output current and outputs the detection result to the second CPU 68. Therefore, the second CPU 68 can perform feedback control so that the second output voltage and the second output current become target values.

[0049] In this manner, a parallel operation is started in which the first output power is supplied from the first power device 12 to the load 38, and the second output power is supplied from the second power device 14 to the load 38. At the beginning of the parallel operation, the first power conversion unit 60 and the second power conversion unit 82 are controlled based on the same first voltage-current characteristic. Therefore, the amount of power shared by the first power device 12 and the second power device 14 with respect to the load 38 (shared power) is equal.

[0050] In addition, in the parallel operation, the first power conversion unit 60 and the second power conversion unit 82 are controlled so that the first output voltage and the second output voltage are equal. That is, in the parallel operation, a synchronization process is performed to match the first output voltage and the second output voltage. In the parallel operation, the second power device 14 may synchronize the first output voltage and the second output voltage by the following method.

[0051] The second CPU 68 controls the second power conversion unit 82 so that a first state quantity correlated with the frequency of the second output voltage and a second state quantity correlated with the phase of the second output voltage match the first output voltage. The second CPU 68 also controls the second power conversion unit 82 so that a third state quantity correlated with the amplitude of the second output voltage matches the first output voltage.

[0052] The first state quantity is a physical quantity related to the frequency of the first output voltage and the second output voltage. Specifically, the first state quantity is the frequency, period, or wavelength of the first output voltage and the second output voltage. The second state quantity is a physical quantity related to the phase of the first output voltage and the second output voltage. The phase of the first output voltage and the second output voltage may be the second state quantity. The third state quantity is a physical quantity related to the amplitude of the first output voltage and the second output voltage. Specifically, the third state quantity refers to the magnitude of the voltage at a predetermined phase of the first output voltage and the second output voltage. The amplitude of the first output voltage and the second output voltage may be the third state quantity.

[0053] In step S3, the first CPU 46 acquires the current state of charge (SOC) from the first power storage unit 40. The second CPU 68 acquires the current state of charge (SOC) from the second power storage unit 62. The second CPU 68 notifies the first CPU 46 of the SOC of the second power storage unit 62 via the second communication unit 76. This allows the first CPU 46 to acquire the SOC of each of the first power storage unit 40 and the second power storage unit 62.

[0054] In step S4, the first CPU 46 identifies one of the first and second power storage units 40 and 62 that has a lower SOC. Specifically, the first CPU 46 identifies that the SOC of the first power storage unit 40 is lower than the SOC of the second power storage unit 62. Next, the first CPU 46 decides to promote the supply of the first output power from the first power storage unit 40 to the load 38. That is, the first CPU 46 decides to stagger the timing of replacement of the first power storage unit 40 and the second power storage unit 62, and to replace the first power storage unit 40 first.

[0055] Fig. 5 is a timing chart showing the change over time in the SOC of first power storage unit 40 (see Fig. 2) and second power storage unit 62. In Fig. 5, the change over time in the SOC of first power storage unit 40 is indicated by a solid line, and the change over time in the SOC of second power storage unit 62 is indicated by a dashed dotted line. Time point t1 is the time point immediately after the start of parallel operation.

[0056] Because the SOC of first power storage unit 40 is lower than the SOC of second power storage unit 62, first CPU 46 changes the voltage-current characteristics used for controlling first power conversion unit 60. Specifically, as shown in Fig. 6, first CPU 46 (see Fig. 2) changes the voltage-current characteristics used for controlling first power conversion unit 60 from the first voltage-current characteristics (first step-down characteristic, first drooping characteristic) shown by the solid line to the second voltage-current characteristics (second step-down characteristic (fourth step-down characteristic), second drooping characteristic) shown by the dashed dotted line.

[0057] The first voltage-current characteristic is the same as the voltage-current characteristic shown in FIG. 4. Similar to the first voltage-current characteristic, the second voltage-current characteristic has a decreasing characteristic (second decreasing characteristic) in which the output voltage decreases as the output current increases, and a drooping characteristic (second drooping characteristic) in which the output voltage rapidly decreases when the output current is equal to or greater than the threshold value Itha (the fourth predetermined value). The second drooping characteristic is provided to protect the power supply device 10 (see FIG. 1) from overcurrent.

[0058] As shown in FIG. 6, the first decreasing characteristic (third decreasing characteristic) and the second decreasing characteristic (fourth decreasing characteristic) are set to be different from each other. Specifically, the second decreasing characteristic has a smaller degree of decrease in the output voltage with respect to the increase in the output current than the first decreasing characteristic. Therefore, for the output voltage of the value V0, the output current of the first decreasing characteristic becomes I0, and the output current of the second decreasing characteristic becomes Ia (I0 < Ia). That is, when the output current becomes Ia, the load of the power device increases. Therefore, when controlling the output voltage and the output current using the second decreasing characteristic, the load of the power device increases, and the SOC of the power storage unit rapidly decreases. Thus, when using the second decreasing characteristic, since the load of the power device increases, the threshold value Itha of the second drooping characteristic is set lower than the threshold value Ith0 of the first drooping characteristic (Itha < Ith0).

[0059] The change between the first voltage-current characteristic and the second voltage-current characteristic may be performed as follows. A plurality of voltage-current characteristics are stored in advance in the map 88 (see FIG. 2). The first CPU 46 changes the voltage-current characteristic used for controlling the first power conversion unit 60 by selecting an arbitrary voltage-current characteristic from among the plurality of voltage-current characteristics as the first voltage-current characteristic or the second voltage-current characteristic. Alternatively, only the first voltage-current characteristic is stored in the map 88. In this case, the first voltage-current characteristic is the base voltage-current characteristic. The first CPU 46 generates the second voltage-current characteristic by appropriately adjusting the base voltage-current characteristic. Thereby, the first CPU 46 changes the voltage-current characteristic used for controlling the first power conversion unit 60 from the first voltage-current characteristic to the second voltage-current characteristic.

[0060] The first CPU 46 sets target values ​​for the first output voltage and the first output current based on the changed second voltage-current characteristic. The first CPU 46 outputs a control signal according to the set target values ​​to the first power conversion unit 60. The first power conversion unit 60 outputs the first output voltage and the first output current based on the control signal. As a result, the first output current increases in response to a decrease in the first output voltage. As a result, as shown in FIG. 5, the SOC of the first power storage unit 40 (see FIG. 2) decreases rapidly with the passage of time after time point t1.

[0061] Furthermore, first CPU 46 determines that the voltage-current characteristics used for controlling second power conversion unit 82 should be maintained at the first voltage-current characteristics because the SOC of second power storage unit 62 is greater than the SOC of first power storage unit 40. First CPU 46 notifies second CPU 68 of the determination via first communication unit 54.

[0062] The second CPU 68 continues to control the second power conversion unit 82 based on the first voltage-current characteristic, based on the notification from the first CPU 46. As a result, the SOC of the second power storage unit 62 slowly decreases over time after time point t1.

[0063] In this manner, in the first embodiment, the first power conversion unit 60 and the second power conversion unit 82 are controlled by different voltage-current characteristics. The power shared by the first power device 12 and the second power device 14 with respect to the load 38 can be changed arbitrarily.

[0064] In step S5 of Fig. 3, the first CPU 46 (see Fig. 2) again obtains the current SOC from the first power storage unit 40. The second CPU 68 again obtains the current SOC from the second power storage unit 62. The second CPU 68 again notifies the first CPU 46 of the SOC of the second power storage unit 62 via the second communication unit 76. This enables the first CPU 46 to obtain the SOC of each of the first power storage unit 40 and the second power storage unit 62 again.

[0065] In step S6, the first CPU 46 determines whether the SOC of the first power storage unit 40 has decreased to a threshold value SOCth1 (first predetermined value, second predetermined value) shown in FIG.

[0066] When the SOC of the first power storage unit 40 has not decreased to the threshold SOCth1 (step S6: NO), the first CPU 46 repeats the process of step S5.

[0067] At time t2 in FIG. 5, when the SOC of first power storage unit 40 (see FIG. 2) falls to threshold SOCth1 (step S6 in FIG. 3: YES), first CPU 46 proceeds to step S7.

[0068] In step S7, the first CPU 46 determines that the SOC of the first power storage unit 40 has fallen to the threshold SOCth1 (see FIG. 5 ) and therefore that it is necessary to replace the first power storage unit 40. Next, the first CPU 46 transmits a message prompting the user to replace the first power storage unit 40 to the mobile terminal 26 via the first communication unit 54. The mobile terminal 26 notifies the outside of the received message. The user can recognize that it is time to replace the first power storage unit 40 by checking the contents of the notification from the mobile terminal 26.

[0069] In step S8, the first CPU 46 determines whether or not the user has replaced the first power storage unit 40. For example, when the SOC of the first power storage unit 40 becomes greater than the threshold SOCth1 due to the replacement of the first power storage unit 40, the first CPU 46 determines that the first power storage unit 40 has been replaced (step S8: YES).

[0070] In the next step S9, the first CPU 46 determines whether or not to stop the parallel operation. In this case, the first CPU 46 determines whether or not to stop the parallel operation by checking whether or not a command to stop the operation mode has been notified from the mobile terminal 26.

[0071] If the command to stop the operation mode has not been notified from the mobile terminal 26 (step S9: NO), the first CPU 46 decides to continue the parallel operation. Next, the first CPU 46 returns to step S3 and repeats the processes of steps S3 to S9.

[0072] When the SOC of the second power storage unit 62 (see FIG. 2) falls to the threshold value SOCth1 at time t3 in FIG. 5 (step S6: YES in FIG. 3), the first CPU 46 transmits a message prompting the replacement of the second power storage unit 62 to the mobile terminal 26 via the first communication unit 54 (step S7). The mobile terminal 26 notifies the outside of the received message, so that the user can recognize that it is time to replace the second power storage unit 62. Next, the user replaces the second power storage unit 62 in accordance with the message. When the SOC of the second power storage unit 62 becomes greater than the threshold value SOCth1, the first CPU 46 can determine that the second power storage unit 62 has been replaced (step S8: YES).

[0073] In step S9, when the user operates the mobile terminal 26 to issue a command (request) to stop the operation mode, the mobile terminal 26 transmits an instruction signal corresponding to the stop command to the first power device 12 and the second power device 14. The first communication unit 54 outputs the received instruction signal to the first CPU 46. The second communication unit 76 outputs the received instruction signal to the second CPU 68. When the first CPU 46 confirms that a stop command has been notified based on the instruction signal (step S9: YES), it proceeds to step S10.

[0074] In step S10, the first CPU 46 stops the control over the first power conversion unit 60. This stops the supply of the first output power from the first power device 12 to the load 38. The first CPU 46 also notifies the second CPU 68 via the first communication unit 54 that the supply of the first output power has stopped. In response to the notification from the first CPU 46, the second CPU 68 stops the control over the second power conversion unit 82. This stops the supply of the second output power from the second power device 14 to the load 38. As a result, the parallel operation of the power supply device 10 stops. The second CPU 68 may stop the supply of the second output power to the load 38 based on an instruction signal from the mobile terminal 26.

[0075] In the first embodiment, as shown in FIG. 5, the time point at which the SOC of first power storage unit 40 (see FIG. 2) falls to threshold SOCth1 can be adjusted to any time point within time period T1 from time t2 to time t3.

[0076] Furthermore, in the first embodiment, when the parallel operation is continued (step S9: NO) after the replacement of first power storage unit 40 (step S8 in FIG. 3 ), first CPU 46 may operate as follows. Due to the replacement of first power storage unit 40, the SOC of first power storage unit 40 may become higher than the SOC of second power storage unit 62. Therefore, in step S4, first CPU 46 changes the voltage-current characteristic for controlling first power conversion unit 60 back from the second voltage-current characteristic to the first voltage-current characteristic. This enables first CPU 46 to control first power conversion unit 60 based on the first voltage-current characteristic.

[0077] Furthermore, the first CPU 46 determines to change the voltage-current characteristics for controlling the second power conversion unit 82 from the first voltage-current characteristics to the second voltage-current characteristics. The first CPU 46 notifies the second CPU 68 of this determination via the first communication unit 54. The second CPU 68 changes the first voltage-current characteristics to the second voltage-current characteristics based on the notified determination. The second CPU 68 controls the second power conversion unit 82 based on the changed second voltage-current characteristics. This allows the SOC of the second power storage unit 62 to be reduced quickly.

[0078] In the first embodiment, the case where the SOC of the first power storage unit 40 is lower than the SOC of the second power storage unit 62 has been described. Even when the SOC of the second power storage unit 62 is lower than the SOC of the first power storage unit 40, the first CPU 46 can perform the same operation. That is, when the SOC of the second power storage unit 62 is lower than the SOC of the first power storage unit 40, the voltage-current characteristic for controlling the second power conversion unit 82 is changed from the first voltage-current characteristic to the second voltage-current characteristic. As a result, the second output current becomes larger than the first output current, and the supply of the second output power from the second power storage unit 62 to the load 38 is promoted.

[0079] Next, a second embodiment will be described with reference to Figures 7 and 8. In the second embodiment, a case in which the SOC of first power storage unit 40 (see Figure 2) is higher than the SOC of second power storage unit 62 will be described.

[0080] In step S11 of FIG. 7, the user of the power supply device 10 (see FIG. 1) operates the mobile terminal 26 to instruct execution of parallel operation, similar to step S1 of FIG. 3. The user operates the mobile terminal 26 to execute the operation mode (specification mode) of the second embodiment. The mobile terminal 26 transmits an instruction signal to the first power device 12 and the second power device 14 to instruct execution of the operation mode of the second embodiment, based on the user's operation content (request). The first communication unit 54 (see FIG. 2) of the first power device 12 receives the instruction signal and outputs it to the first CPU 46. The second communication unit 76 of the second power device 14 receives the instruction signal and outputs it to the second CPU 68.

[0081] In step S12, the first CPU 46 executes the operation mode based on the instruction signal, similarly to step S2 in FIG.

[0082] In this case, the first CPU 46 sets target values ​​for the first output voltage and the first output current based on the map 88 (see FIG. 4). The first CPU 46 outputs a control signal to the first power conversion unit 60 according to the target values.

[0083] The first power conversion unit 60 converts the DC voltage of the first power storage unit 40 into a first output voltage based on the control signal. This starts the supply of the first output power from the first power device 12 to the load 38. The first voltage sensor 50 detects the first output voltage and outputs the detection result to the first CPU 46. The first current sensor 52 detects the first output current and outputs the detection result to the first CPU 46. Therefore, the first CPU 46 can perform feedback control so that the first output voltage and the first output current become target values.

[0084] Moreover, the first CPU 46 notifies the second power device 14 that the first power device 12 has started executing the operation mode via the first communication unit 54. The second CPU 68 executes the operation mode based on the contents of the notification from the first CPU 46.

[0085] Specifically, the second CPU 68 sets target values ​​of the second output voltage and the second output current based on the map 88. In this case, the second CPU 68 sets the target values ​​so that the first output voltage and the second output voltage are equal. The second CPU 68 outputs a control signal according to the target values ​​to the second power conversion unit 82. The second power conversion unit 82 converts the DC voltage of the second power storage unit 62 to the second output voltage based on the control signal. This starts the supply of the second output power from the second power device 14 to the load 38. The second voltage sensor 72 detects the second output voltage and outputs the detection result to the second CPU 68. The second current sensor 74 detects the second output current and outputs the detection result to the second CPU 68. Therefore, the second CPU 68 can perform feedback control so that the second output voltage and the second output current become the target values.

[0086] In this manner, a parallel operation is started in which the first output power is supplied from the first power device 12 to the load 38, and the second output power is supplied from the second power device 14 to the load 38. Note that in the second embodiment as well, a synchronization process may be performed in the parallel operation to match the first output voltage and the second output voltage.

[0087] In step S13, similar to step S3 in FIG. 3, first CPU 46 obtains the current SOC of first power storage unit 40 and the current SOC of second power storage unit 62.

[0088] In step S14, the first CPU 46 identifies the power storage unit having the higher SOC from the first power storage unit 40 or the second power storage unit 62. Specifically, the first CPU 46 identifies that the SOC of the first power storage unit 40 is higher than the SOC of the second power storage unit 62. Next, the first CPU 46 decides to promote the supply of the first output power from the first power storage unit 40 to the load 38.

[0089] Fig. 8 is a timing chart showing the change over time in the SOC of first power storage unit 40 (see Fig. 2) and second power storage unit 62. In Fig. 8, the change over time in the SOC of first power storage unit 40 is indicated by a solid line, and the change over time in the SOC of second power storage unit 62 is indicated by a dashed dotted line. Time point t11 ​​is the time point immediately after the start of parallel operation.

[0090] Since the SOC of the first power storage unit 40 is higher than the SOC of the second power storage unit 62, the first CPU 46 changes the voltage-current characteristic used for controlling the first power conversion unit 60 from the first voltage-current characteristic of FIG. 4 to the second voltage-current characteristic of FIG. 6. The first CPU 46 sets target values ​​of the first output voltage and the first output current based on the changed second voltage-current characteristic. The first CPU 46 outputs a control signal according to the set target values ​​to the first power conversion unit 60. The first power conversion unit 60 outputs the first output voltage and the first output current based on the control signal. As a result, the first output current increases in response to the decrease in the first output voltage. As a result, the SOC of the first power storage unit 40 decreases rapidly with the passage of time after time t11 in FIG. 8.

[0091] Furthermore, first CPU 46 determines that the voltage-current characteristics used for controlling second power conversion unit 82 should be maintained at the first voltage-current characteristics because the SOC of second power storage unit 62 is lower than the SOC of first power storage unit 40. First CPU 46 notifies second CPU 68 of the determination via first communication unit 54.

[0092] The second CPU 68 continues to control the second power conversion unit 82 based on the first voltage-current characteristic, based on the notification from the first CPU 46. As a result, the SOC of the second power storage unit 62 slowly decreases over time after time point t11.

[0093] In this way, also in the second embodiment, the first power conversion unit 60 and the second power conversion unit 82 are controlled by different voltage-current characteristics. The power shared by the first power device 12 and the second power device 14 with respect to the load 38 can be changed arbitrarily.

[0094] In step S15, first CPU 46 acquires the current SOC of first power storage unit 40 and the current SOC of second power storage unit 62 again, similar to step S5 in FIG.

[0095] In step S16, first CPU 46 determines whether the SOC of first power storage unit 40 has fallen below the SOC of second power storage unit 62 (SOClow).

[0096] When the SOC of first power storage unit 40 is not lower than the SOC of second power storage unit 62 (step S16: NO), first CPU 46 repeats the process of step S15.

[0097] At time t12 in FIG. 8, if the SOC of first power storage unit 40 falls below the SOC (SOClow) of second power storage unit 62 (step S16: YES), first CPU 46 proceeds to step S17.

[0098] In step S17, the first CPU 46 determines whether the SOC of the first power storage unit 40 is equal to or lower than a threshold SOCth2.

[0099] When the SOC of first power storage unit 40 is not equal to or lower than threshold SOCth2 (step S17: NO), first CPU 46 returns to step S14 and repeats the processes of steps S14 to S17.

[0100] In this case, in step S14, the first CPU 46 determines to promote the supply of the second output power from the second power storage unit 62, which has a higher SOC, to the load 38, because the SOC of the first power storage unit 40 is lower than the SOC of the second power storage unit 62.

[0101] The first CPU 46 changes the voltage-current characteristics used for controlling the first power conversion unit 60 back from the second voltage-current characteristics to the first voltage-current characteristics, and controls the first power conversion unit 60 based on the changed first voltage-current characteristics. As a result, the first output current becomes smaller, and the SOC of the first power storage unit 40 gradually decreases over time.

[0102] Furthermore, the first CPU 46 determines to change the voltage-current characteristics used for controlling the second power conversion unit 82 from the first voltage-current characteristics to the second voltage-current characteristics. The first CPU 46 notifies the second CPU 68 of the determination via the first communication unit 54. The second CPU 68 controls the second power conversion unit 82 based on the second voltage-current characteristics, based on the notification from the first CPU 46. As a result, the second output current becomes large, and the SOC of the second power storage unit 62 decreases quickly over time.

[0103] In this manner, by repeatedly performing the processes of steps S14 to S17, the voltage-current characteristics used by first CPU 46 and second CPU 68 are alternately switched between the first voltage-current characteristic and the second voltage-current characteristic after time t12 in Fig. 8. As a result, after time t12, the SOCs of first power storage unit 40 and second power storage unit 62 decrease by approximately the same value over time.

[0104] If the SOC of each of first power storage unit 40 and second power storage unit 62 has decreased to threshold SOCth2 at time point t13 (step S17: YES), first CPU 46 proceeds to step S18.

[0105] In step S18, the first CPU 46 determines whether the SOC of the first power storage unit 40 has decreased to a threshold value SOCth3 (first predetermined value, second predetermined value).

[0106] After time point t13, first CPU 46 controls first power conversion unit 60 based on the second voltage-current characteristic. Second CPU 68 controls second power conversion unit 82 based on the first voltage-current characteristic. Therefore, the SOC of first power storage unit 40 decreases quickly with time, and the SOC of second power storage unit 62 decreases gently with time.

[0107] If the SOC of first power storage unit 40 has decreased to threshold SOCth3 at time point t14 (step S18: YES), first CPU 46 proceeds to step S19.

[0108] In step S19, the first CPU 46 determines that the SOC of the first power storage unit 40 has decreased to the threshold SOCth3 and therefore that it is necessary to replace the first power storage unit 40. Next, the first CPU 46 transmits a message prompting the user to replace the first power storage unit 40 to the mobile terminal 26 via the first communication unit 54. The mobile terminal 26 notifies the outside of the received message. By checking the contents of the notification from the mobile terminal 26, the user can recognize that it is time to replace the first power storage unit 40.

[0109] In step S20, the first CPU 46 determines whether or not the user has replaced the first power storage unit 40. For example, when the SOC of the first power storage unit 40 becomes greater than the threshold SOCth3 due to the replacement of the first power storage unit 40, the first CPU 46 determines that the first power storage unit 40 has been replaced (step S20: YES).

[0110] In the next step S21, the first CPU 46 determines whether or not to stop the parallel operation, similarly to step S9 in FIG.

[0111] If a command to stop the operation mode has not been notified from the mobile terminal 26 (step S21: NO), the first CPU 46 returns to step S13 and repeats the processes of steps S13 to S21.

[0112] When the SOC of the second power storage unit 62 falls to the threshold value SOCth3 at time point t15 (step S18: YES), the first CPU 46 transmits a message prompting the replacement of the second power storage unit 62 to the mobile terminal 26 via the first communication unit 54 (step S19). The mobile terminal 26 notifies the outside of the received message, so that the user can recognize that it is time to replace the second power storage unit 62. Therefore, the user replaces the second power storage unit 62 in accordance with the message. When the SOC of the second power storage unit 62 becomes greater than the threshold value SOCth3, the first CPU 46 can determine that the second power storage unit 62 has been replaced (step S20: YES).

[0113] In step S21, when the user operates the mobile terminal 26 to issue a command (request) to stop the operation mode, the mobile terminal 26 transmits an instruction signal corresponding to the stop command to the first power device 12 and the second power device 14. The first communication unit 54 outputs the received instruction signal to the first CPU 46. The second communication unit 76 outputs the received instruction signal to the second CPU 68. When the first CPU 46 confirms that the stop command has been notified based on the instruction signal (step S21: YES), it proceeds to step S22.

[0114] In step S22, the first CPU 46 stops the control over the first power conversion unit 60, similarly to step S10 in FIG. 3. This stops the supply of the first output power from the first power device 12 to the load 38. The first CPU 46 also notifies the second CPU 68 via the first communication unit 54 that the supply of the first output power has stopped. In response to the notification from the first CPU 46, the second CPU 68 stops the control over the second power conversion unit 82. This stops the supply of the second output power from the second power device 14 to the load 38. As a result, the parallel operation of the power supply device 10 stops. The second CPU 68 may stop the supply of the second output power to the load 38 based on an instruction signal from the mobile terminal 26.

[0115] In the second embodiment, as shown in Fig. 8, the time when the SOC of first power storage unit 40 (see Fig. 2) falls to threshold SOCth3 can be adjusted to any time within time T2 from time t14 to time t15. Also, the time when the SOC of second power storage unit 62 falls to threshold SOCth3 can be adjusted to any time within time T3 from time t15 to time t16.

[0116] In the second embodiment, the case where the SOC of the first power storage unit 40 is higher than the SOC of the second power storage unit 62 has been described. Even when the SOC of the second power storage unit 62 is higher than the SOC of the first power storage unit 40, the first CPU 46 can perform the same operation. That is, when the SOC of the second power storage unit 62 is higher than the SOC of the first power storage unit 40, the voltage-current characteristic for controlling the second power conversion unit 82 is changed from the first voltage-current characteristic to the second voltage-current characteristic. As a result, the second output current becomes larger than the first output current, and the supply of the second output power from the second power storage unit 62 to the load 38 is promoted.

[0117] In the first and second embodiments, as described above, signals or information can be transmitted and received by wireless communication between the mobile terminal 26 and the first and second power devices 12 and 14. Therefore, the mobile terminal 26 may monitor the SOCs of the first and second power storage units 40 and 62 by application software (app).

[0118] The mobile terminal 26 may be any device capable of wireless communication with the first power device 12 or the second power device 14. A smartphone, a tablet, or a server may be the mobile terminal 26. Furthermore, commands may be transmitted from the mobile terminal 26 to the first power device 12 and the second power device 14 by wireless communication. The wireless communication method may be Bluetooth (registered trademark), WiFi (registered trademark), or an Internet line.

[0119] In the first and second embodiments, the first CPU 46 is the main operator. Since the first and second power devices 12 and 14 have the same configuration, the second CPU 68 may be the main operator. That is, in the first and second embodiments, the first CPU 46 controls the operations of the first and second power devices 12 and 14 in an integrated manner as described above. In the first and second embodiments, the second CPU 68 may control the operations of the first and second power devices 12 and 14 in an integrated manner. Alternatively, the functions of the CPU may be integrated in one of the power devices, and the operations of the first and second power devices 12 and 14 may be controlled by the CPU with the integrated functions.

[0120] In addition, since signals or information can be sent and received between the first power device 12 and the second power device 14, it is also possible for the first CPU 46 to control only the operation of the first power device 12 and the second CPU 68 to control only the operation of the second power device 14.

[0121] As described above, in the first and second embodiments, an operation command or a stop command is transmitted from the mobile terminal 26 to both the first power device 12 and the second power device 14. Each of the first power device 12 and the second power device 14 starts operating based on the operation command. Each of the first power device 12 and the second power device 14 stops operating based on the stop command. In other words, each of the first power device 12 and the second power device 14 operates in response to a request from the mobile terminal 26.

[0122] Therefore, when the voltage-current characteristics are switched, as described above, signals or information are transmitted and received between the first power device 12 and the second power device 14. When the voltage-current characteristics are not switched, communication between the first power device 12 and the second power device 14 is not necessary.

[0123] In the first and second embodiments, a case has been described in which the voltage-current characteristics are switched based on the SOC of each of the first and second power storage units 40 and 62 after parallel operation is started. When the SOC of each of the first and second power storage units 40 and 62 is known in advance, the voltage-current characteristics of the first and second power devices 12 and 14 may be initially set to be different from each other. This makes communication between the first and second power devices 12 and 14 unnecessary.

[0124] In the first and second embodiments, the user of the power supply device 10 operates the mobile terminal 26 to instruct the power supply device 10, and various notifications are sent from the power supply device 10 to the mobile terminal 26 (user). In the first and second embodiments, the owner or manager of the power supply device 10 may operate the mobile terminal 26 to instruct the power supply device 10, and various notifications may be sent from the power supply device 10 to the mobile terminal 26 (owner or manager). Alternatively, the user, owner or manager of the first power storage unit 40 or the second power storage unit 62 may operate the mobile terminal 26 to instruct the power supply device 10, and various notifications may be sent from the power supply device 10 to the mobile terminal 26 (user, owner or manager). The owner of the power supply device 10, the first power storage unit 40 or the second power storage unit 62 may be the rightful owner of the power supply device 10, the first power storage unit 40 or the second power storage unit 62.

[0125] In the first and second embodiments, it is only necessary to notify the mobile terminal 26 (user) that a power storage unit needs to be replaced in steps S7 and S19. Therefore, in the first and second embodiments, it is only necessary for the first CPU 46 to obtain the SOC of at least one power storage unit (power storage unit to be replaced) of the first power storage unit 40 and the second power storage unit 62.

[0126] In the first and second embodiments, the first CPU 46 may acquire the power consumption of the load 38. For example, a power monitoring device (not shown) sequentially monitors the power consumption of the load 38. The power monitoring device transmits the monitoring result of the power consumption to the mobile terminal 26. The first CPU 46 acquires the power consumption of the load 38 from the mobile terminal 26 by wireless communication. The first CPU 46 calculates the time when each SOC becomes SOCth1 or SOCth3 or less based on the acquired power consumption and each SOC of the first power storage unit 40 and the second power storage unit 62. Alternatively, the first CPU 46 calculates the period from the current time to the time when each SOC becomes SOCth1 or SOCth3 or less based on the acquired power consumption and each SOC of the first power storage unit 40 and the second power storage unit 62. This makes it possible to notify the mobile terminal 26 (user) in advance of the remaining power supply time of the first power storage unit 40 and the second power storage unit 62, the timing of replacement, etc.

[0127] 1, the connection point between the first power transmission path 16 and the second power transmission path 18 is provided outside the first housing 22 of the first power device 12 and the second housing 24 of the second power device 14. In the present embodiment, the connection point between the first power transmission path 16 and the second power transmission path 18 may be provided inside the first housing 22 of the first power device 12 or inside the second housing 24 of the second power device 14. That is, it is sufficient that the connection point between the first power transmission path 16 and the second power transmission path 18 is provided at any position between the first power conversion unit 60 and the second power conversion unit 82 and the load connection unit 28.

[0128] The load 38 may be any AC device that operates using the output power (AC power) supplied from the power supply device 10. Examples of such AC devices include AC consumer appliances, AC motors, and AC / DC inverters.

[0129] The mobile terminal 26 may notify the user of the power supply device 10 of various types of information visually and audibly.

[0130] The mobile terminal 26 may transmit the power share, the power share ratio, or the supply power value of the first power storage unit 40 and the second power storage unit 62 relative to the power consumption amount of the load 38 to the first power device 12 and the second power device 14 together with the operation command. Alternatively, the mobile terminal 26 may transmit the power share, the power share ratio, or the supply power value of one of the first power storage unit 40 and the second power storage unit 62 to the first power device 12 and the second power device 14.

[0131] In the above description, a case has been described in which signals or information are transmitted and received by wireless communication between the mobile terminal 26 and the first power device 12 and the second power device 14. In this embodiment, signals or information may be transmitted and received by wired communication between the mobile terminal 26 and the first power device 12 and the second power device 14. Also, in this embodiment, signals or information may be transmitted and received by wired communication between the first power device 12 and the second power device 14.

[0132] In the above description, the first power device 12 and the second power device 14 are both controlled so that the first output voltage and the second output voltage are equal. In this embodiment, either of the power devices may operate so that one of the first output voltage and the second output voltage is matched to the other output voltage. Alternatively, the first power device 12 and the second power device 14 may cooperate to control so that the first output voltage and the second output voltage are equal.

[0133] Furthermore, in the above description, the components of the first power device 12 including the first power storage unit 40 are arranged inside the first housing 22, and the components of the second power device 14 including the second power storage unit 62 are arranged in the second housing 24. In the present embodiment, the components of the first power device 12 and the second power device 14 may be arranged inside the same (single) housing. In this case, even the load connection unit 28 may be arranged (contained) inside the same housing.

[0134] The invention that can be understood from the above-described embodiments will be described below.

[0135] A first aspect of the present invention is a power supply device (10) that outputs electric power to an outside, the power supply device including a first power storage unit (40), a second power storage unit (62), a first power transmission path (16) that connects the first power storage unit and a load connection unit (28) to which a load (38) is connected, a second power transmission path (18) that connects the second power storage unit and the load connection unit, a first power conversion unit (60) that is arranged on the first power transmission path and converts electric power supplied from the first power storage unit, a second power conversion unit (82) that is arranged on the second power transmission path and converts electric power supplied from the second power storage unit, a first control unit (46) that controls the first power conversion unit, and and a second control unit (68) that controls the first power conversion unit based on a first step-down characteristic such that a first output voltage output from the first power conversion unit steps down as a first output current output from the first power conversion unit increases, and the second control unit controls the second power conversion unit based on a second step-down characteristic such that a second output voltage output from the second power conversion unit steps down as a second output current output from the second power conversion unit increases, and the first step-down characteristic and the second step-down characteristic are set to be different from each other.

[0136] According to the present invention, the timing of replacement of the two power storage units does not overlap, so it is possible to continue supplying power to the load.

[0137] The present invention will be described in more detail. Since the timing of replacement of the two storage units is shifted, by replacing the storage unit with a charged one, the power supply device can theoretically supply output power to the load indefinitely. Also, unlike an uninterruptible power supply (UPS) with a so-called pass-through function, it is not necessary to connect to the power system. Furthermore, even when two storage units with arbitrary remaining capacity (storage capacity) are installed, the timing of replacement of each storage unit can be easily controlled.

[0138] In the first aspect of the present invention, the first control unit may control the first power conversion unit so that the first output voltage and the second output voltage are equal to each other.

[0139] This makes it possible to suppress the occurrence of cross currents of output currents between the first and second power storage units due to an imbalance in the output voltages, thereby ensuring that the output current flows to the load.

[0140] In a first aspect of the present invention, the first control unit may control the first power conversion unit so that the first output current is greater than the second output current when the amount of power stored in the first power storage unit is less than the amount of power stored in the second power storage unit.

[0141] This makes it possible to replace the first power storage unit early.

[0142] In a first aspect of the present invention, the first control unit may control the first power conversion unit so that the first output current is greater than the second output current when the amount of power stored in the first power storage unit is greater than the amount of power stored in the second power storage unit.

[0143] Even in this case, it is possible to replace the first power storage unit early, or to synchronize the replacement timing of both the first power storage unit and the second power storage unit.

[0144] In a first aspect of the present invention, the power supply device may further include a stored power amount acquisition unit (46, 68) that acquires at least one of the stored power amount of the first storage unit and the stored power amount of the second storage unit, and a notification unit that notifies a user, owner or manager of the power supply device, the first storage unit or the second storage unit when the stored power amount acquired by the stored power amount acquisition unit becomes equal to or less than a first predetermined value (SOCth1, SOCth3).

[0145] This makes it possible to reliably notify the user, owner, or manager of the timing for replacing the power storage unit.

[0146] In a first aspect of the present invention, the power supply device may further include a power consumption acquisition unit (46, 68) that acquires the power consumption of the load, and a calculation unit (46, 68) that calculates, based on the amount of stored power acquired by the stored power acquisition unit and the amount of power consumption acquired by the power consumption acquisition unit, the point in time when the stored power amount will be equal to or less than a second predetermined value (SOCth1, SOCth3), or a period from a current point in time until the stored power amount will be equal to or less than the second predetermined value.

[0147] This makes it possible to notify the user in advance of the remaining power supply time of the power storage unit and the timing for replacement.

[0148] In a first aspect of the present invention, the first control unit may control the first power conversion unit based on a first drooping characteristic such that the first output voltage suddenly decreases when the first output current is equal to or greater than a third predetermined value (Ith0), and the second control unit may control the second power conversion unit based on a second drooping characteristic such that the second output voltage suddenly decreases when the second output current is equal to or greater than a fourth predetermined value (Itha).

[0149] This makes it possible to protect the power supply device from overcurrent.

[0150] In the first aspect of the present invention, the power supply device may further include a receiving unit (54, 76) that receives a user's request regarding the usage mode of the electricity stored in at least one of the first storage unit and the second storage unit.

[0151] This makes it possible to supply output power from the power supply device to the load in a specification mode that meets the needs of the user.

[0152] In a first aspect of the present invention, at least one of the first control unit and the second control unit may control at least one of the first power conversion unit and the second power conversion unit based on the request received by the receiving unit.

[0153] This makes it possible to appropriately control the power conversion unit in response to the user's request.

[0154] In the first aspect of the present invention, the receiving unit may be capable of communicating with a mobile terminal (26) of the user and may receive the request input by the user to the mobile terminal.

[0155] This makes it possible to more appropriately control the power conversion unit in response to the user's request.

[0156] In a first aspect of the present invention, the receiving unit may receive the request for a share of power to be shared by at least one of the first power storage unit and the second power storage unit with respect to power consumption of the load.

[0157] This makes it possible to externally control the proportion of the power consumption of the load shared by the first power storage unit and the second power storage unit.

[0158] In the first aspect of the present invention, the first power storage unit and the second power storage unit may be detachable from the power supply device.

[0159] This makes it possible to easily replace the first power storage unit and the second power storage unit.

[0160] In a first aspect of the present invention, the power supply device may further include a first housing (22) that houses the first power storage unit, the first power conversion unit, and the first control unit, and a second housing (24) that houses the second power storage unit, the second power conversion unit, and the second control unit.

[0161] This makes it possible for the first and second housings to function as independent power devices.

[0162] In the first aspect of the present invention, the first control unit and the second control unit may be provided so as to be able to communicate with each other.

[0163] This makes it possible to easily transmit and receive signals or information between the first housing portion and the second housing portion.

[0164] A second aspect of the present invention is a power supply device (14) including a second power storage unit connected in parallel to the first power storage unit with respect to a load when a first power storage unit and a load are connected via a first power transmission path, the power supply device including: a second power transmission path connecting the second power storage unit and the load; a power conversion unit (82) disposed on the second power transmission path and converting power supplied from the second power storage unit; and a control unit (68) controlling the power conversion unit, wherein when the first power storage unit outputs power based on a third step-down characteristic such that a first output current output from the first power transmission path steps down as a first output voltage output from the first power transmission path increases, the control unit controls the power conversion unit based on a fourth step-down characteristic such that a second output current output from the power conversion unit steps down as a second output voltage output from the power conversion unit increases, and the fourth step-down characteristic is set to be different from the third step-down characteristic.

[0165] The present invention also provides the same effects as the first aspect.

[0166] In a second aspect of the present invention, the power supply device further includes a voltage acquisition unit (68) that acquires the first output voltage, and the control unit may control the power conversion unit to control a first state quantity that correlates with the frequency of the second output voltage and a second state quantity that correlates with the phase of the second output voltage to match the first output voltage acquired by the voltage acquisition unit.

[0167] This makes it possible to suppress the occurrence of cross currents of output currents between the first and second power storage units due to an imbalance in the output voltages, thereby ensuring that the output current flows to the load.

[0168] In a second aspect of the present invention, the control unit may control the power conversion unit to control a third state quantity correlated to an amplitude of the second output voltage so as to match the first output voltage acquired by the voltage acquisition unit.

[0169] This further reduces the occurrence of cross currents between the first and second power storage units due to an imbalance in the output voltages, thereby ensuring that the output current flows to the load more reliably.

[0170] A third aspect of the present invention is a method for controlling a power supply device that outputs power to an outside, the power supply device comprising: a first power storage unit; a second power storage unit; a first power transmission path connecting the first power storage unit and a load connection unit to which a load is connected; a second power transmission path connecting the second power storage unit and the load connection unit; a first power conversion unit that is arranged on the first power transmission path and converts power supplied from the first power storage unit; a second power conversion unit that is arranged on the second power transmission path and converts power supplied from the second power storage unit; and a control unit that controls the first power conversion unit and the second power conversion unit, The first power storage unit and the second power storage unit are connected in parallel to the load connection unit, and the control method includes a step of gradually decreasing a first output voltage output from the first power conversion unit as a first output current output from the first power conversion unit increases by controlling the first power conversion unit based on a first step-down characteristic, and a step of gradually decreasing a second output voltage output from the second power conversion unit as a second output current output from the second power conversion unit increases by controlling the second power conversion unit based on a second step-down characteristic different from the first step-down characteristic.

[0171] The present invention also provides the same effects as the first and second aspects.

[0172] A fourth aspect of the present invention is a program for causing a computer (46, 68) to execute the power supply device control method according to the third aspect.

[0173] The present invention also provides the same effects as the first and second aspects.

[0174] A fifth aspect of the present invention is a storage medium (86) that stores the program of the fourth aspect.

[0175] The present invention also provides the same effects as the first and second aspects.

[0176] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention.

Claims

1. A power supply device (10) that outputs power to an outside, A first power storage unit (40); A second storage unit (62); a first power transmission path (16) connecting the first storage unit and a load connection unit (28) to which a load (38) is connected; a second power transmission path (18) connecting the second power storage unit and the load connection unit; a first power conversion unit (60) disposed in the first power transmission path and configured to convert power supplied from the first power storage unit; a second power conversion unit (82) disposed in the second power transmission path and configured to convert power supplied from the second power storage unit; A first control unit (46) that controls the first power conversion unit; A second control unit (68) that controls the second power conversion unit; Equipped with the first power storage unit and the second power storage unit are connected in parallel to the load connection unit, The first control unit controls the first power conversion unit based on a first decrement characteristic such that a first output voltage output from the first power conversion unit is decremented as a first output current output from the first power conversion unit increases, The second control unit controls the second power conversion unit based on a second step-down characteristic such that a second output voltage output from the second power conversion unit gradually decreases as a second output current output from the second power conversion unit increases; The first and second step-down characteristics are set to be different from each other.

2. 2. The power supply device according to claim 1, The first control unit controls the first power conversion unit so that the first output voltage and the second output voltage are equal to each other.

3. 3. The power supply device according to claim 1, A power supply device, wherein the first control unit controls the first power conversion unit so that the first output current is greater than the second output current when the amount of stored power in the first storage unit is less than the amount of stored power in the second storage unit.

4. 3. The power supply device according to claim 1, A power supply device, wherein the first control unit controls the first power conversion unit so that the first output current is greater than the second output current when the amount of stored power in the first storage unit is greater than the amount of stored power in the second storage unit.

5. 3. The power supply device according to claim 1, a storage amount acquisition unit (46, 68) that acquires at least one of a storage amount of the first power storage unit and a storage amount of the second power storage unit; a notification unit that notifies a user, an owner, or a manager of the power supply device, the first power storage unit, or the second power storage unit when the stored power amount acquired by the stored power amount acquisition unit becomes equal to or less than a first predetermined value (SOCth1, SOCth3); The power supply device further comprising:

6. 6. The power supply device according to claim 5, A power consumption acquisition unit (46, 68) that acquires the power consumption of the load; a calculation unit (46, 68) that calculates a time point when the stored power amount becomes equal to or less than a second predetermined value (SOCth1, SOCth3) based on the stored power amount acquired by the stored power amount acquisition unit and the power consumption amount acquired by the power consumption amount acquisition unit, or a period from a current time point to a time point when the stored power amount becomes equal to or less than the second predetermined value; The power supply device further comprising:

7. 3. The power supply device according to claim 1, The first control unit controls the first power conversion unit based on a first drooping characteristic such that the first output voltage is rapidly reduced when the first output current is equal to or greater than a third predetermined value (Ith0); The second control unit controls the second power conversion unit based on a second drooping characteristic such that the second output voltage suddenly decreases when the second output current is equal to or greater than a fourth predetermined value (Itha).

8. 3. The power supply device according to claim 1, The power supply device further comprises a receiving unit (54, 76) that receives a user's request regarding a usage mode of the electric power stored in at least one of the first storage unit and the second storage unit.

9. 9. The power supply device according to claim 8, A power supply device, wherein at least one of the first control unit and the second control unit controls at least one of the first power conversion unit and the second power conversion unit based on the request received by the receiving unit.

10. 9. The power supply device according to claim 8, The receiving unit is capable of communicating with a mobile terminal (26) of the user and receives the request input by the user to the mobile terminal.

11. 9. The power supply device according to claim 8, The receiving unit receives the request regarding a share of power to be shared by at least one of the first power storage unit and the second power storage unit with respect to power consumption of the load.

12. 3. The power supply device according to claim 1, The first power storage unit and the second power storage unit are detachable from the power supply unit.

13. 3. The power supply device according to claim 1, A first housing (22) that houses the first power storage unit, the first power conversion unit, and the first control unit; a second housing (24) that houses the second power storage unit, the second power conversion unit, and the second control unit; The power supply device further comprising:

14. 14. The power supply device according to claim 13, The power supply device, wherein the first control unit and the second control unit are provided so as to be able to communicate with each other.

15. A power supply device (14) including a second power storage unit connected in parallel with the first power storage unit to a load when the first power storage unit and the load are connected via a first power transmission path, a second power transmission path connecting the second power storage unit and the load; a power conversion unit (82) disposed on the second power transmission path and configured to convert power supplied from the second power storage unit; A control unit (68) for controlling the power conversion unit; Equipped with When the first power storage unit outputs power based on a third decreasing characteristic such that a first output current output from the first power transmission path decreases as a first output voltage output from the first power transmission path increases, the control unit controls the power conversion unit based on a fourth decrement characteristic such that a second output current output from the power conversion unit decrements as a second output voltage output from the power conversion unit increases; A power supply device, wherein the fourth step-down characteristic is set to be different from the third step-down characteristic.

16. 16. The power supply device of claim 15, A voltage acquisition unit (68) that acquires the first output voltage, The control unit controls the power conversion unit to control a first state quantity correlated with a frequency of the second output voltage and a second state quantity correlated with a phase of the second output voltage so as to match the first output voltage acquired by the voltage acquisition unit.

17. 17. The power supply device of claim 16, The control unit controls the power conversion unit to control a third state quantity correlated to the amplitude of the second output voltage so as to match the first output voltage acquired by the voltage acquisition unit.

18. A method for controlling a power supply device that outputs power to an external device, comprising: the power supply device includes a first power storage unit, a second power storage unit, a first power transmission path connecting the first power storage unit and a load connection unit to which a load is connected, a second power transmission path connecting the second power storage unit and the load connection unit, a first power conversion unit arranged on the first power transmission path and converting power supplied from the first power storage unit, a second power conversion unit arranged on the second power transmission path and converting power supplied from the second power storage unit, and a control unit that controls the first power conversion unit and the second power conversion unit, the first power storage unit and the second power storage unit are connected in parallel to the load connection unit, The control method includes: controlling the first power conversion unit based on a first step-down characteristic to step-down a first output voltage output from the first power conversion unit as a first output current output from the first power conversion unit increases; controlling the second power conversion unit based on a second step-down characteristic different from the first step-down characteristic, thereby stepping down a second output voltage output from the second power conversion unit as a second output current output from the second power conversion unit increases; A method for controlling a power supply device comprising the steps of:

19. A program for causing a computer (46, 68) to execute the power supply device control method according to claim 18.

20. A storage medium (86) storing the program according to claim 19.

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