Battery module and power supply system

Abstract

A battery module (13) is provided with a battery (132), a bidirectional DC-DC converter (131) that converts a direct-current voltage output from the battery (132) and outputs to a load (101), and a control unit (133) that performs constant voltage control of the bidirectional DC-DC converter (131) and receives a stop advance signal that advances output stop of the power supply unit (12). The control unit (133) controls so that the output voltage of the bidirectional DC-DC converter (131) is less than a first target voltage before the stop advance signal is received, and causes the output voltage of the bidirectional DC-DC converter (131) to increase to the first target voltage or more before the output of the power supply unit (12) stops after the stop advance signal is received.

Description

TECHNICAL FIELD

[0001] The present application relates to a battery module and a power supply system. BACKGROUND

[0002] A power supply system is proposed which has a converter section that converts alternating-current power supplied from a commercial power supply into direct-current power and outputs the direct-current power to a load, and a battery module that assists in supplying direct-current power to the load (see, for example, Patent Literature 1). Here, an output terminal of the battery module is connected between an output terminal of the converter section and the load, and the output voltage is controlled to be a predetermined output voltage target value and becomes fixed. In addition, the output voltage target value is set to rise in accordance with an increase in the current value of the current output from the converter section in a case where the current value of the current output from the converter section is equal to or higher than a first threshold value which is lower than a prescribed value. Furthermore, the output voltage target value is set to become higher than the output voltage of the converter section in a case where the current value of the current output from the converter section is lower than the prescribed value and is between a second threshold value which is higher than the first threshold value and the first threshold value. Thus, when the load is in a heavy load state, even if the output voltage of the converter section drops, direct-current power can be smoothly supplied from the battery module, and therefore, it is possible to stabilize the direct-current voltage supplied to the load.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: International Publication No. 2017 / 209238 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] However, in the case of the power supply system described in Patent Literature 1, for example, when a power outage of the commercial power supply occurs, the output voltage of the converter section sharply decreases. On the other hand, the battery module is controlled to maintain the direct-current voltage supplied to the load at the target value. In this case, the constant voltage control of the battery module does not follow the sharp increase in the output current of the battery module, and as a result, the direct-current voltage supplied to the load can temporarily decrease.

[0008] The present application was made in view of the above-described circumstances, and aims to provide a battery module and a power supply system that can suppress fluctuations in the voltage supplied to a load.

[0009] MEANS FOR SOLVING THE PROBLEMS

[0010] In order to achieve the above-described object, the battery module of the present application is a battery module connected to a power supply unit that outputs a predetermined target voltage to a load, in which

[0011] The battery module has:

[0012] a battery;

[0013] a DC-DC converter that converts a direct-current voltage output from the battery and outputs to the load; and

[0014] a control section that performs constant voltage control of the DC-DC converter and that receives a stop advance signal that advances output stop of the power supply unit,

[0015] the control section controls so that the output voltage of the DC-DC converter is less than the target voltage before receiving the stop advance signal, and after receiving the stop advance signal, increases the output voltage of the DC-DC converter to the target voltage or more before the output of the power supply unit is stopped.

[0016] Further, the battery module of the present application can also be,

[0017] the control section controls so that the voltage variation amount when the output voltage of the DC-DC converter reaches the target voltage is less than the maximum voltage variation amount in the period from when the stop advance signal is received to when the output voltage of the DC-DC converter is increased to a voltage in the vicinity of the target voltage.

[0018] Further, the battery module of the present application can also be,

[0019] the control section controls so that the output voltage of the DC-DC converter becomes fixed when the current value of the current flowing from the power supply unit to the load becomes less than a predetermined reference current value.

[0020] Further, the battery module of the present application can also be,

[0021] the control section controls so that the output voltage of the DC-DC converter becomes fixed when the output voltage of the DC-DC converter becomes the target voltage or more.

[0022] Further, the battery module of the present application can also be,

[0023] the control section gradually increases the output voltage of the DC-DC converter so that the variation amount per unit time of the current flowing from the DC-DC converter to the load is less than a predetermined variation upper limit value.

[0024] Further, the battery module of the present application can also be,

[0025] the control section controls so that the output voltage of the DC-DC converter becomes a voltage equal to the target voltage after controlling so that the output voltage of the DC-DC converter becomes fixed.

[0026] In addition, the battery module of the present application can also be,

[0027] An upper limit value of the output voltage of the DC-DC converter is set based on a rated voltage of the load.

[0028] The power supply system of the present application from another viewpoint is provided with:

[0029] a power supply unit having an AC-DC converter that converts AC power supplied from an AC power source into DC power and outputs to a load, and a first control section that performs constant voltage control of the AC-DC converter so that the voltage output from the AC-DC converter to the load becomes a target voltage set in advance, and outputs a stop advance signal that advances the stop of the output of the voltage to the load before the stop of the output of the voltage to the load;

[0030] a battery;

[0031] a DC-DC converter that converts the DC voltage output from the battery and outputs to a load; and

[0032] a second control section that performs constant voltage control of the DC-DC converter, and receives the stop advance signal that advances the stop of the output of the power supply unit,

[0033] the second control section controls so that the output voltage of the DC-DC converter is less than the target voltage before the reception of the stop advance signal, and increases the output voltage of the DC-DC converter to the target voltage or more before the stop of the output of the power supply unit after the reception of the stop advance signal.

[0034] The power supply system of the present application from another viewpoint is provided with:

[0035] a power supply unit having a first DC-DC converter that converts DC power supplied from a DC power source into DC power of a different voltage and outputs to a load, and a first control section that performs constant voltage control of the first DC-DC converter so that the voltage output from the first DC-DC converter to the load becomes a target voltage set in advance, and outputs a stop advance signal that advances the stop of the output of the voltage to the load before the stop of the output of the voltage to the load;

[0036] a battery;

[0037] a second DC-DC converter that converts the DC voltage output from the battery and outputs to a load; and

[0038] a second control section that performs constant voltage control of the second DC-DC converter and that receives a stop advance signal that advances output stop of the power supply unit,

[0039] The second control section controls the output voltage of the second DC-DC converter to be less than the target voltage before receiving the stop advance signal, and causes the output voltage of the second DC-DC converter to increase to be equal to or more than the target voltage before the output of the power supply unit is stopped after receiving the stop advance signal.

[0040] Effects of Invention

[0041] According to the present application, the control section controls the output voltage of the DC-DC converter to be less than the target voltage before receiving the stop advance signal of the power supply unit. In addition, the control section causes the output voltage of the DC-DC converter to increase to be equal to or more than the target voltage before the output of the power supply unit is stopped after receiving the stop advance signal of the power supply unit. Thereby, the increase speed of the current supplied from the battery module to the load at the time of switching the power supply source to the load from the power supply unit to the battery module can be reduced. Therefore, the variation of the voltage supplied to the load due to the constant voltage control of the battery module not following the variation of the output current of the battery module is suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 is a schematic configuration diagram of the power supply system of Embodiment 1.

[0043] Figure 2 is a graph showing the characteristics of the output voltage of the AC-DC converter of Embodiment 1.

[0044] Figure 3 is a block diagram of the control section of Embodiment 1.

[0045] Figure 4 is a graph showing the information stored in the voltage variation amount storage section of Embodiment 1.

[0046] Figure 5 is a graph showing the characteristics of the output voltage and the output current of the power supply unit and the battery module of the comparative example.

[0047] Figure 6 is a graph showing the characteristics of the output voltage and the output current of the power supply unit and the battery module of Embodiment 1.

[0048] Figure 7 is a flowchart showing an example of the battery module control processing flow performed by the control section of Embodiment 1.

[0049] Figure 8is a schematic configuration diagram of the power supply system of Embodiment 2 of the present application.

[0050] Figure 9 is a block diagram of the control section of Embodiment 2.

[0051] Figure 10 is a diagram showing information stored in the voltage variation amount storage section of Embodiment 2.

[0052] Figure 11 is a flowchart showing an example of the battery module control processing flow performed by the control section of Embodiment 2.

[0053] Figure 12 is a flowchart showing an example of the battery module control processing flow performed by the control section of the modified example.

[0054] Figure 13 is a flowchart showing an example of the battery module control processing flow performed by the control section of the modified example.

[0055] Figure 14 is a diagram showing characteristics of the output voltage of the power supply unit and the battery module of the modified example.

[0056] Figure 15 is a schematic configuration diagram of the power supply system of the modified example. DETAILED DESCRIPTION

[0057] (Embodiment 1)

[0058] Embodiment of the present application will be described in detail below with reference to the accompanying drawings. The battery module of the present embodiment is connected to a load together with a power supply unit having a function of controlling so that the voltage output to the load becomes a first target voltage set in advance, and outputting a stop notice signal that gives notice of stopping the voltage output to the load before stopping the voltage output to the load. The battery module has a battery, a DC-DC converter that converts the direct current voltage output from the battery and outputs to the load, and a control section that performs constant voltage control so that the output voltage of the DC-DC converter is maintained at a second target voltage set in advance. Moreover, the control section controls the output voltage of the DC-DC converter to be the second target voltage that is less than the first target voltage before the power supply unit outputs the stop notice signal. In addition, the control section controls the output voltage of the DC-DC converter to be the second target voltage that becomes the first voltage or more after the power supply unit outputs the stop notice signal.

[0059] Preferably, the control unit controls the output voltage of the DC-DC converter to be at least equal to the first target voltage before the power supply unit stops outputting. Furthermore, the stop warning signal is a signal sent from the power supply unit to the control unit of the battery module, sending either a high level or a low level. For example, if a drop in the AC voltage input to the power supply unit is detected, the power supply unit outputs a high-level signal to the control unit of the battery module. If no drop in the AC voltage input to the power supply unit is detected, the power supply unit outputs a low-level signal to the control unit of the battery module. This stop warning signal is output within the AC voltage drop detection time (e.g., 3 ms). Additionally, even in the case of a drop in the input AC voltage, the power supply unit can maintain the output voltage at the first target voltage only for a period of output holding time (e.g., 10 ms) reflecting the discharge time constant of the capacitor, by utilizing the charge stored in the capacitor (e.g., an electrolytic capacitor) within the power supply unit. Therefore, the control unit controls the output voltage of the DC-DC converter to be at least equal to the second target voltage during the period obtained by subtracting the AC voltage drop detection time from the aforementioned output holding time (e.g., 7 ms). By controlling it in this way, the voltage output to the load can be kept constant.

[0060] For example, Figure 1 As shown, the power supply system of this embodiment includes two power supply units 12 that convert AC power output from AC power source 100 into DC power and output it to load 101, two battery modules 13 with batteries 132, and a signal processing unit 14. The load 101 is, for example, a blade server. It should be noted that multiple loads 101 can also be connected in parallel with the power supply units 12 and battery modules 13. Furthermore, the two power supply units 12 are connected in parallel with the AC power source 100 for redundancy. Therefore, even if one of the two power supply units 12 fails, power can be continuously supplied from the AC power source 100 to the load 101 through the other power supply unit 12.

[0061] The power supply units 12 each have an AC-DC converter 121, a control section 123 that controls the AC-DC converter 121, and a current measurement section 124 that measures the current value of the current output from the AC-DC converter 121. The AC-DC converter 121 is connected between the AC power source 100 and the load 101. The AC-DC converter 121 converts the AC power (for example, AC of 200 V in voltage) supplied from the AC power source 100 into DC power (for example, DC of 12.3 V in voltage) and outputs to the load 101. The current measurement section 124 outputs a measurement signal corresponding to the current value obtained by measuring the output current of the AC-DC converter 121 to the control section 123.

[0062] The control section 123 is a first control section that performs constant voltage control of the AC-DC converter 121 so that the voltage output from the AC-DC converter 121 to the load 101 becomes a first target voltage set in advance. Here, the first target voltage is set based on the specifications of the input voltage of the load 101, for example, set to 12.3 V. In addition, the control section 123 has a so-called current sharing function, and based on the measurement signal input from the current measurement section 124, outputs a current sharing signal that reflects the magnitude of the output current of the AC-DC converter 121 that is a control target to the control sections 123 of the other power supply units 12. Then, the control section 123 controls the AC-DC converter 121 based on the measurement signal input from the current measurement section 124 and the current sharing signal input from the other control sections 123 so that the output current of the AC-DC converter 121 that is a control target and the output current of the other AC-DC converters 121 are equal to each other. Thereby, the state in which the output currents of the two AC-DC converters 121 are approximately equal is maintained. In addition, the control section 123 controls so that the output voltage of the AC-DC converter 121 decreases when the current value of the current output from the AC-DC converter 121 exceeds a current threshold set in advance. In addition, the control section 123 also outputs the current sharing signal to the signal processing unit 14.

[0063] For example, as Figure 2As shown, the control section 123 performs control so that the output voltage of the AC-DC converter 121 is the first target voltage VoutPT that is set in advance and becomes a fixed constant voltage control until the current value of the output current of the AC-DC converter 121 becomes the current threshold IoutPbl. Then, when the load 101 becomes a heavy load and the output current of the AC-DC converter 121 exceeds the current threshold IoutPbl, the control section 123 controls the AC-DC converter 121 so that the output voltage decreases in accordance with the increase of the output current of the AC-DC converter 121. Then, the control section 123 performs control so that the output current of the AC-DC converter 121 is maintained at the current threshold IoutPb2 and becomes a fixed constant current control when the output current of the AC-DC converter 121 reaches the current threshold IoutPb2 that is set in advance.

[0064] In addition, the control section 123 outputs a stop notice signal that notifies of the stop of the output of the voltage to the load 101 to the signal processing unit 14 before the AC-DC converter 121 stops the output of the voltage to the load 101. The control section 123 outputs the stop notice signal, for example, when the input voltage input to the AC-DC converter 121 connected to the alternating current power source 100 is lower than a reference value (for example, an alternating current voltage of 180 V). Figure 1 The stop notice signal is output when the input voltage input to the AC-DC converter 121 connected to the alternating current power source 100 is lower than a reference value (for example, an alternating current voltage of 180 V).

[0065] The signal processing unit 14 outputs the current sharing signal to the control section 133 of each of the two battery modules 13 when the current sharing signal is input from either of the control sections 123. In addition, the signal processing unit 14 outputs the stop notice signal to the control section 133 of each of the two battery modules 13 when the stop notice signal is input from either of the control sections 123.

[0066] The battery module 13 has a bidirectional DC-DC converter 131, a battery 132, a control section 133 that controls the bidirectional DC-DC converter 131, and a current measurement section 134 that measures the current value of the output current of the bidirectional DC-DC converter 131. The battery 132 is, for example, a lithium ion battery. The bidirectional DC-DC converter 131 is connected between the battery 132 and the load 101. The bidirectional DC-DC converter 131 is, for example, a circuit having a step-up function and a step-down function to operate in a discharging mode in which the battery 132 is discharged or a charging mode in which the battery 132 is charged. The bidirectional DC-DC converter 131 converts the direct current voltage output from the battery 132 and outputs to the load 101 when operating in the discharging mode. On the other hand, the bidirectional DC-DC converter 131 converts the output voltage of the power supply unit 12 and outputs to the battery 132 when operating in the charging mode.

[0067] The control section 133, which is, for example, an integrated circuit having an MPU and a memory, controls the output voltage of the bidirectional DC-DC converter 131 by varying the second target voltage. Specifically, the control section 133 performs constant voltage control of the bidirectional DC-DC converter 131 so that the output voltage of the bidirectional DC-DC converter 131 is maintained at a second target voltage set in advance. Also, the control section 133 varies the second target voltage based on the current sharing signal input from the signal processing unit 14. Further, the control section 133 controls the output voltage of the bidirectional DC-DC converter 131 so that the output voltage of the bidirectional DC-DC converter 131, i.e., the second target voltage, is less than the above-mentioned first target voltage before receiving a stop advance signal that advances the output stop of the power supply unit 12. For example, in the case where the first target voltage of the power supply unit 12 is set to 12.3 V, the second target voltage is set to 12.2 V. In addition, the control section 133 increases the output voltage of the bidirectional DC-DC converter 131, i.e., the second target voltage, to be equal to or more than the first target voltage after receiving the above-mentioned stop advance signal. Here, the control section 133 gradually increases the second target voltage set to be less than the first target voltage immediately after the power supply unit 12 outputs the above-mentioned stop advance signal, so that the second target voltage reaches a voltage equal to or more than the first target voltage. Here, "gradually increase" means, for example, gradually increasing the output voltage of the bidirectional DC-DC converter 131 so that the amount of change per unit time of the output current of the bidirectional DC-DC converter 131 is not more than a size set in advance. In addition, the control section 133 gradually increases the output voltage of the DC-DC converter so that the second target voltage becomes equal to or more than the first voltage within a period of time obtained by subtracting an AC voltage drop detection time (for example, 3 msec) from the above-mentioned output retention time (for example, 10 msec) (for example, 7 msec). Thus, it is possible to reduce the increase speed of the current supplied from the battery module 13 to the load 101 when the power supply source that supplies electric power to the load 101 is switched from the power supply unit 12 to the battery module 13.

[0068] In addition, the control section 133 maintains the second target voltage to be constant when the current value of the current flowing from the power supply unit 12 to the load 101, i.e., the output current of the AC-DC converter 121, becomes equal to or less than a reference current value set in advance. Here, the reference current value can be set to a current value of 50% or less of the rated current value of the load 101, for example. For example, if the rated current value of the load 101 is 20 A, it can be set to 10 A or 0 A.

[0069] In the control section 133, for example, a program stored in the memory is executed by the MPU, so that the control section 133 performs the above-mentioned control. Figure 3As shown, the current output acquisition unit 331, the BM output current acquisition unit 332, the determination unit 333, the target voltage setting unit 334, the voltage variation amount determination unit 337, the difference amount calculation unit 336, the current variation amount calculation unit 335, and the stop warning signal acquisition unit 339 function as a PSU (Power Supply Unit) output current acquisition unit 331, a BM (Battery Module) output current acquisition unit 332, a determination unit 333, a target voltage setting unit 334, a voltage variation amount determination unit 337, a difference amount calculation unit 336, a current variation amount calculation unit 335, and a stop warning signal acquisition unit 339, respectively. In addition, the memory has a target voltage storage unit 341, a reference value storage unit 342, a current value storage unit 343, and a voltage variation amount storage unit 344. Furthermore, the control unit 133 is implemented by a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), or the like, and has a converter drive unit 338 that drives the bidirectional DC-DC converter 131 by outputting a PWM (Pulse Width Modulation) signal to the bidirectional DC-DC converter 131. The target voltage storage unit 341 stores information indicating a voltage value of the second target voltage set by the target voltage setting unit 334. The converter drive unit 338 acquires the information indicating the voltage value of the second target voltage stored by the target voltage storage unit 341. Then, the converter drive unit 338 generates a PWM signal and outputs it to the bidirectional DC-DC converter 131 so that the output voltage of the bidirectional DC-DC converter 131 is maintained at the second target voltage when the bidirectional DC-DC converter 131 is caused to operate in the discharge mode.

[0070] The reference value storage unit 342 stores information indicating a current threshold value for the output current of the AC-DC converter 121 set in advance. The current value storage unit 343 stores information indicating a current value of the output current of the bidirectional DC-DC converter 131 acquired by the BM output current acquisition unit 332 in chronological order.

[0071] For example, as shown in Figure 4 The voltage variation amount storage unit 344 stores information indicating a variation amount of the second target voltage, i.e., a target voltage variation amount, in correspondence with a range of the difference amount (dIoutBL - dIoutB). Here, dIoutB is a variation amount per unit time of the output current of the bidirectional DC-DC converter 131, and dIoutBL is an upper limit value of dIoutB set in advance. Here, dIoutBL is set to 10 A / sec, for example.

[0072] Returning to Figure 3The PSU output current acquisition section 331 acquires a current value of the output current of the AC-DC converter 121 corresponding to the current sharing signal input from the signal processing unit 14. The BM output current acquisition section 332 acquires a current value of the output current of the bidirectional DC-DC converter 131 corresponding to the measurement signal input from the current measurement section 134. Then, the BM output current acquisition section 332 stores, in the current value storage section 343, information indicating the current value of the output current of the bidirectional DC-DC converter 131 in time series.

[0073] The determination section 333 determines whether the output current of the AC-DC converter 121 is greater than a current threshold value for the output current of the AC-DC converter 121 set in advance. The current change amount calculation section 335 calculates a change amount per unit time of the output current based on the information indicating the current value of the output current of the bidirectional DC-DC converter 131 stored in the current value storage section 343. The difference amount calculation section 336 calculates a difference amount obtained by subtracting the change amount per unit time of the output current of the bidirectional DC-DC converter 131 calculated by the current change amount calculation section 335 from an upper limit value of the change amount per unit time of the output current of the bidirectional DC-DC converter 131.

[0074] The voltage change amount decision section 337 decides, from the information indicating a plurality of kinds of target voltage change amounts stored in the voltage change amount storage section 344, information indicating a target voltage change amount corresponding to a range to which the difference amount calculated by the difference amount calculation section 336 belongs. The target voltage setting section 334 decides a new second target voltage based on the information indicating the second target voltage stored in the target voltage storage section 341 and the voltage change amount decided by the voltage change amount decision section 337.

[0075] The stop warning signal acquisition section 339, when acquiring the stop warning signal from the signal processing unit 14, notifies the PSU output current acquisition section 331 and the BM output current acquisition section 332 of stop warning signal acquisition notification information notifying that the stop warning signal is acquired.

[0076] Next, the operation of the power supply system of the present embodiment will be described in comparison with the operation of the power supply system of the comparative example. The power supply system of the comparative example is configured so that the battery module 13 and the power supply unit 12 operate independently of each other, and the signal processing unit 14 is not provided in the power supply system of the present embodiment as shown in FIG. 1. In the power supply system of the comparative example, for example, as shown in FIG. 2, the battery module 13 and the power supply unit 12 are connected to each other via the current sharing signal line 15, and the signal processing unit 14 is not provided. Figure 1 The signal processing unit 14 is not provided in the power supply system of the present embodiment as shown in FIG. 1, and the battery module 13 and the power supply unit 12 operate independently of each other. In the power supply system of the comparative example, for example, as shown in FIG. 2, the battery module 13 and the power supply unit 12 are connected to each other via the current sharing signal line 15, and the signal processing unit 14 is not provided. Figure 5As shown, before time T91, the control unit 123 of the power supply unit 12 performs constant voltage control on the AC-DC converter 121, and the AC-DC converter 121 outputs a first target voltage VT. At this time, the control unit 133 of the battery module 13 also performs constant voltage control in discharge mode on the bidirectional DC-DC converter 131, and the bidirectional DC-DC converter 131 outputs a second target voltage Vs. Here, the second target voltage Vs is set to be lower than the first target voltage VT. In this case, a current of value IT is supplied from the power supply unit 12 to the load 101, and the current value supplied from the battery module 13 to the load 101 shifts to 0.

[0077] Then, when the power supply from AC power source 100 is cut off, at time T91, the output voltage of AC-DC converter 121 drops sharply, and at this time, the output current of battery module 13 changes sharply from 0 to 1T. At this time, the constant voltage control of battery module 13 cannot keep up with this sharp change in output current. Thus, in the power supply system of the comparative example, when the power supply source for supplying power to load 101 is switched from power supply unit 12 to battery module 13 due to the cessation of AC power supply from AC power source 100, a momentary drop in the voltage supplied to load 101 occurs.

[0078] In contrast, in the power supply system of this embodiment, for example, Figure 6 As shown, when a stop warning signal is input from the signal processing unit 14, the control unit 133 gradually increases the second target voltage of the bidirectional DC-DC converter 131 from voltage Vs to voltage VT during the period from time T1 to time T2 after time T1. Then, after time T2, the control unit 133 further gradually increases the second target voltage of the bidirectional DC-DC converter 131. Figure 6 As shown, the voltage change at time T2 (the change in voltage per unit time) is less than the voltage change during the period from time T1 to time T2. At this time, the output current of the AC-DC converter 121 of the power supply unit 12 gradually decreases as the output voltage of the bidirectional DC-DC converter 131 increases. Then, at time T3 after time T2, the output current of the AC-DC converter 121 decreases to a preset reference current value IoutP1 that is smaller than the current value IoutB1. At this time, the control unit 133 maintains the second target voltage of the bidirectional DC-DC converter 131 at a fixed value. At this time, the output current of the bidirectional DC-DC converter 131 reaches a current value IoutB1 that is smaller than the current value IT.

[0079] After that, at time T4, the output current and the output voltage of the power supply unit 12 become 0, at this time, the output current of the battery module 13 reaches IT. That is, in the power supply system of the present embodiment, before the supply of the alternating current power from the alternating current power supply 100 is stopped, the current value of the current supplied from the bidirectional DC-DC converter 131 of the battery module 13 to the load 101 is raised to a current value close to the current value IT of the current that should be supplied to the load 101. At this time, the current value of the current supplied from the power supply unit 12 to the load 101 is reduced to the preset reference current value IoutP1 close to 0. Thus, when the supply of the alternating current power from the alternating current power supply 100 is stopped and the output of the AC-DC converter 121 of the power supply unit 12 is stopped, the sharp increase of the current supplied from the bidirectional DC-DC converter 131 of the battery module 13 to the load 101 is less. Therefore, when the power supply source that supplies the power to the load 101 is switched from the power supply unit 12 to the battery module 13, it is possible to maintain the voltage supplied to the load 101 to be fixed.

[0080] Next, the output voltage control processing performed by the control section 133 of the present embodiment at the time of backup transfer of the battery module will be described with reference to Figure 7 . Note that the battery module control processing is started with the power supply to the battery module 13 being turned on. Further, the initial value of the second target voltage is set to 12.2 V, for example. Further, the initial value of the voltage variation amount of the second target voltage is set to 0.01 V, for example. First, the stop warning signal acquisition section 339 determines whether or not a stop warning signal is input from the signal processing section 14 (step S101). The stop warning signal acquisition section 339 repeats the processing of step S101 as long as a stop warning signal is not input from the signal processing section 14 (step S101: No). On the other hand, when the stop warning signal acquisition section 339 determines that a stop warning signal is input from the signal processing section 14 (step S101: Yes), the BM output current acquisition section 332 acquires output current value information indicating the magnitude of the output current of the bidirectional DC-DC converter 131 (step S102). Next, the PSU output current acquisition section 331 acquires output current value information indicating the magnitude of the output current of the AC-DC converter 121 of the power supply unit 12 corresponding to the current sharing signal received from the signal processing section 14 (step S103).

[0081] Next, the determination section 333 acquires information indicating the current threshold value for the output current of the AC-DC converter 121 from the reference value storage section 342. Then, the determination section 333 determines whether the output current IoutP indicated by the output current value information of the AC-DC converter 121 is greater than the current threshold value IoutPth (step S104). Here, when the determination section 333 determines that the output current IoutP of the AC-DC converter 121 is equal to or less than the current threshold value IoutPth (step S104: "No"), the battery module backup transfer time output voltage control processing ends.

[0082] On the other hand, assume that the determination section 333 determines that the output current IoutP of the AC-DC converter 121 is greater than the current threshold value IoutPth (step S104: "Yes"). In this case, the target voltage setting section 334 acquires information indicating the second target voltage VoutBT stored by the target voltage storage section 341, and sets a voltage (VoutBT + dVoutBT) obtained by adding the voltage variation amount dVoutBT to the second target voltage VoutBT indicated by the acquired information as a new second target voltage (step S105). Here, the voltage variation amount dVoutBT is an initial value of the voltage variation amount or a voltage variation amount determined by the voltage variation amount determination section 337.

[0083] After that, the BM output current acquisition section 332 acquires output current value information indicating the magnitude of the output current of the bidirectional DC-DC converter 131 (step S106). Next, the current variation amount calculation section 335 acquires information indicating the current value of the past output current of the bidirectional DC-DC converter 131 from the current value storage section 343. Then, the current variation amount calculation section 335 calculates the variation amount dloutB of the output current of the bidirectional DC-DC converter 131 (step S107).

[0084] Next, the difference amount calculating section 336 calculates a difference amount (dIoutBL - dIoutB) obtained by subtracting the calculated change amount dIoutB of the output current of the bidirectional DC-DC converter 131 per unit time from the upper limit value dIoutBL of the change amount of the output current of the bidirectional DC-DC converter 131 per unit time (step S108). Thereafter, the voltage change amount determining section 337 determines information indicating the target voltage change amount corresponding to the range to which the difference amount calculated by the difference amount calculating section 336 belongs, from among the information indicating a plurality of kinds of target voltage change amounts stored in the voltage change amount storage section 344 (step S109). Next, the processing of step S103 is executed again. In this way, the control section 133 causes the second target voltage to gradually increase by executing the series of processing of steps S103 to S109, so that the current change amount per unit time of the output current of the bidirectional DC-DC converter 131, that is, the current flowing from the bidirectional DC-DC converter 131 to the load 101, is smaller than the change amount upper limit value set in advance.

[0085] As explained above, according to the battery module 13 of the present embodiment, the control section 133 controls the output voltage of the bidirectional DC-DC converter 131 to be the second target voltage smaller than the first target voltage before the output stop warning signal is output from the power supply unit 12. In addition, the control section 133 controls the output voltage of the bidirectional DC-DC converter 131 to be the second target voltage to be the first target voltage or more after the output stop warning signal is output from the power supply unit 12. Thereby, when the power supply source that supplies electric power to the load 101 is switched from the power supply unit 12 to the battery module 13, the abrupt increase of the current supplied from the battery module 13 to the load 101 can be reduced. Therefore, the variation of the voltage supplied to the load 101 due to the constant voltage control failing to follow the variation of the load current of the battery module 13 is suppressed.

[0086] In addition, the control section 133 of the battery module 13 of the present embodiment gradually increases the second target voltage set to be smaller than the first target voltage immediately after the output stop warning signal is output from the power supply unit 12. Thereby, the output voltage of the bidirectional DC-DC converter 131 of the battery module 13 can be smoothly increased.

[0087] Further, the control section 133 of the battery module 13 of the present embodiment maintains the second target voltage to be fixed when the current value of the current flowing from the power supply unit 12 to the load 101, that is, the output current of the AC-DC converter 121, becomes the reference current value set in advance or less. Thereby, the voltage supplied from the battery module 13 to the load 101 is suppressed from excessively increasing, and therefore, the occurrence of the malfunction of the load 101 due to the excessive increase of the voltage supplied to the load 101 is suppressed.

[0088] Furthermore, in this embodiment, the control unit 133 of the battery module 13 maintains the second target voltage at a fixed value when the second target voltage of the bidirectional DC-DC converter 131 is higher than or equal to the first target voltage. This suppresses fluctuations in the voltage supplied from the battery module 13 to the load 101, thereby stabilizing the operation of the load 101.

[0089] Furthermore, in this embodiment, the control unit 133 of the battery module 13 gradually increases the second target voltage, causing the current change per unit time of the output current of the bidirectional DC-DC converter 131 to be less than a preset upper limit value for the change. This suppresses the instantaneous drop in the output voltage of the bidirectional DC-DC converter 131, thus stabilizing the voltage supplied to the load 101.

[0090] (Implementation Method 2)

[0091] The battery module of this embodiment, like the battery module 13 of Embodiment 1, includes a bidirectional DC-DC converter, a battery, and a control unit. However, it differs from the battery module 13 of Embodiment 1 in that it lacks a current measuring unit for measuring the output current of the bidirectional DC-DC converter.

[0092] For example, Figure 8 As shown, the power supply system of this embodiment includes two power supply units 12, two battery modules 2013 with batteries 132, and a signal processing unit 14. It should be noted that... Figure 8 In the text, the structural designations are the same as those for the power supply system in Implementation Method 1. Figure 1 Same markings. Battery module 2013 has a bidirectional DC-DC converter 131, a battery 132, and a control unit 2133 that controls the bidirectional DC-DC converter 131.

[0093] Similar to the control unit 133 in Embodiment 1, the control unit 2133, for example, has an integrated circuit including an MPU and a memory, and performs constant voltage control to maintain the output voltage of the bidirectional DC-DC converter 131 at a preset second target voltage. Furthermore, the control unit 2133 changes the second target voltage based on a current sharing signal input from the signal processing unit 14. Moreover, before the control unit 123 of the power supply unit 12 outputs the aforementioned stop warning signal, the control unit 2133 controls the output voltage of the bidirectional DC-DC converter 131 to be less than the aforementioned first target voltage. After the control unit 123 outputs the stop warning signal, the control unit 2133 controls the output voltage of the DC-DC converter to be greater than or equal to the first target voltage.

[0094] In the control unit 2133, for example, a program stored in memory is executed by the MPU, such as... Figure 9 As shown, it functions as the PSU output current acquisition unit 2331, the determination unit 333, the target voltage setting unit 334, the voltage change determination unit 2337, the differential calculation unit 2336, the current change calculation unit 2335, and the stop warning signal acquisition unit 339. It should be noted that in... Figure 9 In the middle, for the same structural annotations as in implementation method 1 and Figure 3 The same markings are used. Additionally, the memory includes a target voltage storage unit 341, a reference value storage unit 342, a current value storage unit 2343, and a voltage change amount storage unit 2344. Furthermore, the control unit 2133 includes a converter drive unit 338 that drives the bidirectional DC-DC converter 131 by outputting a PWM signal to it. The current value storage unit 2343 stores information representing the output current of the AC-DC converter 121 of the power supply unit 12, obtained by the PSU output current acquisition unit 2331, in a time sequence.

[0095] For example, Figure 10 As shown, the voltage change storage unit 2344 stores information representing the change in the second target voltage, i.e., the target voltage change, in correspondence with the range of the differential component (dIoutPL-dIoutP). Here, dIoutP is the change in the output current of the AC-DC converter 121 of the power supply unit 12 per unit time, and dIoutPL is a preset lower limit value of dIoutP. Here, dIoutPL is set to, for example, -10A / sec.

[0096] return Figure 9 The PSU output current acquisition unit 2331 acquires the current value of the AC-DC converter 121 corresponding to the current sharing signal input from the signal processing unit 14. Then, the PSU output current acquisition unit 2331 stores the acquired information representing the current value of the AC-DC converter 121's output current in the current value storage unit 2343 according to a time sequence. The current change calculation unit 2335 calculates the change in the output current of the AC-DC converter 121 per unit time based on the information representing the current value of the AC-DC converter 121's output current stored in the current value storage unit 2343. The differential calculation unit 2336 calculates the differential component obtained by subtracting the change in the output current of the AC-DC converter 121 per unit time calculated by the current change calculation unit 2335 from the lower limit value of the change in the output current of the AC-DC converter 121 per unit time.

[0097] The voltage variation amount decision section 2337 decides information indicating a target voltage variation amount corresponding to a range to which the difference amount calculated by the difference amount calculation section 2336 belongs, from among information indicating a plurality of kinds of target voltage variation amounts stored in the voltage variation amount storage section 2344.

[0098] Next, the battery module backup transfer time output voltage control processing performed by the control section 2133 of the present embodiment will be described with reference to Figure 11 to Embodiment 1, and the initial value of the voltage variation amount of the second target voltage is set to 0.01 V, for example. First, the stop warning signal acquisition section 339 determines whether or not a stop warning signal is received from the signal processing unit 14 (step S2101). The stop warning signal acquisition section 339 repeats the processing of step S2101 as long as a stop warning signal is not received from the signal processing unit 14 (step S2101: "No"). On the other hand, assume that the stop warning signal acquisition section 339 determines that a stop warning signal is received from the signal processing unit 14 (step S2101: "Yes"). In this case, the PSU output current acquisition section 2331 acquires output current value information indicating the magnitude of the output current of the AC-DC converter 121 of the power supply unit 12 corresponding to the current sharing signal received from the signal processing unit 14 (step S2102).

[0099] Next, the determination section 333 acquires information indicating the current threshold value for the output current of the AC-DC converter 121 from the reference value storage section 342. Then, the determination section 333 determines whether or not the output current IoutP indicated by the output current value information of the AC-DC converter 121 is greater than the current threshold value IoutPth (step S2103). Here, when the determination section 333 determines that the output current IoutP of the AC-DC converter 121 is equal to or less than the current threshold value IoutPth (step S2103: "No"), the battery module backup transfer time output voltage control processing ends.

[0100] On the other hand, assume that the determination section 333 determines that the output current IoutP of the AC-DC converter 121 is greater than the current threshold value IoutPth (step S2103: "Yes"). In this case, the target voltage setting section 334 acquires information indicating the second target voltage VoutBT stored by the target voltage storage section 341, and sets a voltage (VoutBT + dVoutBT) obtained by adding the voltage variation amount dVoutBT to the second target voltage VoutBT indicated by the acquired information as a new second target voltage (step S2104). Here, the voltage variation amount dVoutBT is the initial value of the voltage variation amount or the voltage variation amount decided by the voltage variation amount decision section 2337.

[0101] Next, the PSU output current acquisition section 2331 acquires output current value information indicating the magnitude of the output current of the AC-DC converter 121 (step S2105). Thereafter, the current variation amount calculation section 2335 acquires information indicating the current value of the past output current of the AC-DC converter 121 from the current value storage section 2343. Then, the current variation amount calculation section 2335 calculates the variation amount dIoutP of the output current of the AC-DC converter 121 (step S2106).

[0102] Next, the difference amount calculation section 2336 calculates a difference amount (dIoutPL- dIoutP) obtained by subtracting the calculated variation amount dIoutP of the output current of the AC-DC converter 121 from the lower limit value dIoutPL of the variation amount per unit time of the output current of the AC-DC converter 121 (step S2107). Next, the voltage variation amount determination section 2337 determines information indicating the target voltage variation amount corresponding to the range to which the difference amount calculated by the difference amount calculation section 2336 belongs, from among the information indicating a plurality of kinds of target voltage variation amounts stored in the voltage variation amount storage section 2344 (step S2108). Thereafter, the processing of step S2103 is performed again.

[0103] As explained above, according to the battery module 2013 of the present embodiment, the output voltage of the bidirectional DC-DC converter 131 is controlled without using information indicating the current value of the output current of the bidirectional DC-DC converter 131. Thereby, the current measurement section that measures the output current of the bidirectional DC-DC converter 131 can be omitted, and accordingly the structure of the battery module 2013 can be simplified.

[0104] The above describes the embodiments of the present application, but the present application is not limited to the structure of the above-described embodiments. For example, it can also be that, when the battery module 13 gradually increases the output voltage of the bidirectional DC-DC converter 131 after acquiring the stop warning signal from the power supply unit 12, the second target voltage is maintained to be fixed when the second target voltage exceeds a pre-set upper limit value of the target voltage. In this case, the reference value storage section 342 stores information indicating the current threshold value for the output current of the AC-DC converter 121 that is pre-set, and also stores information indicating the voltage upper limit value for the output voltage of the bidirectional DC-DC converter 131. This voltage upper limit value is the upper limit value of the output voltage in the case where the bidirectional DC-DC converter 131 operates in the discharging mode, and is set based on the rated voltage of the load 101.

[0105] Here, reference is made to Figure 12The battery module backup transfer time output voltage control processing performed by the control section 133 of this modification example will be described. Note that, in Figure 12 the same marks as Figure 7 the same marks as in Embodiment 1 are affixed to the same processes. First, after the processes of steps S101 to S103 are performed, the determination section 333 acquires from the reference value storage section 342 information indicating a current threshold value for the output current of the AC-DC converter 121. Then, the determination section 333 determines whether the output current IoutP indicated by the output current value information of the AC-DC converter 121 is greater than the current threshold value IoutPth (step S104). Here, assume that the determination section 333 determines that the output current IoutP of the AC-DC converter 121 is greater than the current threshold value IoutPth (step S104: "Yes"). In this case, the determination section 333 acquires from the reference value storage section 342 information indicating an upper limit value of the output voltage of the bidirectional DC-DC converter 131. In addition, the determination section 333 acquires information indicating the second target voltage VoutBT stored in the target voltage storage section 341, and calculates a voltage (VoutBT + dVoutBT) obtained by adding the voltage variation amount dVoutBT to the second target voltage VoutBT indicated by the acquired information. Then, the determination section 333 determines whether the calculated voltage (VoutBT + dVoutBT) is less than the above-mentioned upper limit value VoutBTUL (step S3001). When the determination section 333 determines that the calculated voltage (VoutBT + dVoutBT) is the above-mentioned upper limit value or more (step S3001: "No"), the battery module backup transfer time output voltage control processing ends. On the other hand, when the determination section 333 determines that the calculated voltage (VoutBT + dVoutBT) is less than the above-mentioned upper limit value VoutBTUL (step S3001: "Yes"), the processes after step S105 are performed.

[0106] According to the present configuration, the output voltage of the bidirectional DC-DC converter 131 can be prevented from becoming excessively high by exceeding the above-mentioned upper limit value, and thus the occurrence of malfunctions of the load 101 due to the application of an excessively high voltage to the load 101 can be suppressed.

[0107] In Embodiment 1, the battery module 13 can also determine whether the power supply from the power supply unit 12 to the load 101 is stopped after the power supply source that supplies electric power to the load 101 is switched from the power supply unit 12 to the battery module 13. Then, the battery module 13 can also reset the voltage value of the second target voltage supplied to the load 101 after determining that the power supply from the power supply unit 12 to the load 101 is stopped.

[0108] Here, reference is made toFigure 13 The battery module backup transfer time output voltage control processing performed by the control section 133 of this modification example will be described. Note that, in Figure 13 , the same reference signs as Figure 7 are affixed to the same processing as in Embodiment 1. First, after the processing of steps S101 to S103 is performed, the determination section 333 acquires information indicating a current threshold value for the output current of the AC-DC converter 121 from the reference value storage section 342. Then, the determination section 333 determines whether the output current IoutP indicated by the output current value information of the AC-DC converter 121 is greater than the current threshold value IoutPth (step S104). Here, assume that the determination section 333 determines that the output current IoutP of the AC-DC converter 121 is equal to or less than the current threshold value IoutPth (step S104: "No"). In this case, the determination section 333 determines whether a stop completion signal notifying that the AC-DC converter 121 has stopped operating is input from the signal processing unit 14 (step S4001). Here, in the case where the output of the AC-DC converter 121 is stopped, the control section 123 outputs the stop completion signal to the signal processing unit 14. Then, the signal processing unit 14 outputs the stop completion signal to the control section 133 when the stop completion signal is input. Here, the determination section 333 repeats the processing of step S4001 as long as it determines that the stop completion signal is not input from the signal processing unit 14 (step S4001: "No"). On the other hand, assume that the determination section 333 determines that the stop completion signal is input from the signal processing unit 14 (step S4001: "Yes"), in which case the target voltage setting section 334 re-sets the voltage value of the second target voltage to a voltage equal to the first target voltage (step S4002). Next, the battery module backup transfer time output voltage control processing ends.

[0109] Note that, in this modification example, the example in which the control section 133 in the battery module 13 of Embodiment 1 performs the processing of steps S4001 and S4002 described above is described, but the present technology is not limited thereto. For example, it can be that, in the battery module 2013 of Embodiment 2, the control section 2133 determines that the output current IoutP indicated by the output current value information of the AC-DC converter 121 is equal to or less than the current threshold value IoutPth when the processing of steps S2101 to S2103 is performed (step S2103: "No"), and performs the processing of steps S4001 and S4002. Figure 11

[0110] ​According to this structure, after the power supply unit 12 stops, the battery module 13 resets the second target voltage to a voltage equal to the first target voltage. Therefore, before and after switching the power supply source to the load 101 from the power supply unit 12 to the battery module 13, the voltage supplied to the load 101 can be kept constant.

[0111] In Embodiment 1, the control unit 133 of the battery module 13 can also be controlled such that the voltage change when the output voltage of the bidirectional DC-DC converter 131 reaches the first target voltage is less than the maximum voltage change during the period when the output voltage of the bidirectional DC-DC converter 131 increases to a voltage near the first target voltage after receiving the stop warning signal. Here, the voltage near the first target voltage is equivalent to a voltage of 95% or more and less than 100% of the first target voltage.

[0112] For example, Figure 14 As shown, in this modified example, after receiving a stop warning signal, the control unit 133 causes the voltage change (voltage change per unit time) of the output voltage of the bidirectional DC-DC converter 131 to change over time. Here, immediately after the stop warning signal is input to the control unit 133 at time T61 (refer to...) Figure 14 The control unit 133 maintains the output voltage of the bidirectional DC-DC converter 131 at a voltage change A (= 0). Then, starting from time T62 after time T61, the control unit 133 increases the output voltage of the bidirectional DC-DC converter 131 by a voltage change B (refer to LiA). Figure 14 (LiB). Next, starting from time T63 after time T62, the control unit 133 maintains the output voltage of the bidirectional DC-DC converter 131 at a voltage change C (=0) (refer to...). Figure 14 (LiC). Next, starting from time T64 after time T63, the control unit 133 increases the output voltage of the bidirectional DC-DC converter 131 by a voltage change amount D (refer to...). Figure 14 (LiD), starting from time T65 after time T64, the output voltage of the bidirectional DC-DC converter 131 is increased by a voltage change E (refer to...) Figure 14 (LiE). Then, when the output voltage of the bidirectional DC-DC converter 131 exceeds the voltage VT at time T65 after time T64, the control unit 133 increases the output voltage of the bidirectional DC-DC converter 131 by a voltage change F (refer to LiE). Figure 14B > D > E > F > A = C holds. Note that the voltage change amounts A, C are both 0. In this way, the control section 133 sets the voltage change amount (voltage change amount F) at which the output voltage of the bidirectional DC-DC converter 131 reaches the voltage VT to be smaller than the maximum voltage change amount B in the period from when the stop advance signal is received to when the output voltage of the bidirectional DC-DC converter 131 is increased to the vicinity of the voltage VT.

[0113] According to the present configuration, the output voltage of the bidirectional DC-DC converter 131 can be brought to the target voltage in a relatively short time, and the rise in the current value of the current supplied from the battery module 13 to the load 101 can be moderated. Therefore, the fluctuation in the voltage supplied to the load 101 when the power supply source that supplies electric power to the load 101 is switched from the power supply unit 12 to the battery module 13 can be suppressed.

[0114] In each embodiment, a configuration in which two power supply units 12 are provided is described, but the present application is not limited thereto, and for example, a configuration in which only one power supply unit 12 is provided, or a configuration in which three or more power supply units 12 are provided can be employed. Also, in each embodiment, a configuration in which two battery modules 13 are provided is described, but the present application is not limited thereto, and for example, a configuration in which only one battery module 13 is provided, or a configuration in which three or more battery modules 13 are provided can be employed.

[0115] In each embodiment, a configuration in which the signal processing unit 14 is provided is described, but the present application is not limited thereto, and for example, a configuration in which the current sharing signal or the stop advance signal output from the control section 123 of the power supply unit 12 is input directly to the control section 133 of the battery module 13, or both can be employed.

[0116] In each embodiment, an example in which the power supply unit 12 has an AC-DC converter 121 that converts the alternating current power supplied from the alternating current power source 100 into direct current power is described. However, the present application is not limited thereto, and for example, as shown in Figure 15 , the power supply unit 5012 can have a DC-DC converter 5121 that converts the direct current power supplied from the direct current power source 5100 into direct current power of a different voltage. Note that in Figure 15 , the same reference numerals as in Embodiment 1 are attached to the same configurations as in Embodiment 1. Figure 1The same reference signs are used. In this case, the power supply unit 5012 has a control section 5123 that controls the DC-DC converter 5121 and a current measurement section 124 that measures the current value of the current output from the DC-DC converter 5121. As the direct-current power supply 5100, for example, a direct-current voltage bus connected to a power generation facility via a PV converter is cited.

[0117] Here, the DC-DC converter 5121 is a first DC-DC converter that includes a step-up circuit, a step-down circuit, or a step-up and step-down circuit. The control section 5123 is a first control section that performs constant voltage control of the DC-DC converter 5121 so that the voltage output from the DC-DC converter 5121 to the load 101 becomes a target voltage set in advance. In addition, the control section 5123 outputs a stop notice signal that gives notice of stopping the output of the voltage to the load 101 to the signal processing unit 14 before stopping the output of the voltage to the load 101. Note that the power supply system of the present modified example has, like the embodiment 1, the battery module 13 that includes the battery 132, the bidirectional DC-DC converter 131, and the control section 133. Here, the bidirectional DC-DC converter 131 is a second DC-DC converter that converts the direct-current voltage output from the battery 132 and outputs it to the load 101. In addition, the control section 133 is a second control section that, before receiving the stop notice signal, controls so that the output voltage of the bidirectional DC-DC converter 131 is less than the target voltage, and after receiving the stop notice signal, increases the output voltage of the bidirectional DC-DC converter 131 to be equal to or more than the target voltage before the output of the power supply unit 5012 is stopped.

[0118] The above describes the embodiment and the modified example of the present application, but the present application is not limited to this. The present application includes a mode obtained by appropriately combining the embodiment and the modified example, a mode obtained by appropriately changing the embodiment and the modified example.

[0119] This application is based on Japanese Patent Application No. 2019-188509 filed on October 15, 2019. In this specification, the description, claims, and drawings of Japanese Patent Application No. 2019-188509 are incorporated by reference in their entirety.

[0120] Industrial Applicability

[0121] The present application is suitable for a power supply system for a blade server.

[0122] Explanation of Reference Signs

[0123] 12, 5012: power supply unit; 13, 2013: battery module; 14: signal processing unit; 100: AC power source; 101: load; 121: AC-DC converter; 123, 133, 2133, 5123: control section; 124, 134: current measuring section; 131: bidirectional DC-DC converter; 132: battery; 331, 2331: PSU output current acquisition section; 332: BM output current acquisition section; 333: determination section; 334: target voltage setting section; 335, 2335: current variation amount calculation section; 336, 2336: difference amount calculation section; 337, 2337: voltage variation amount determination section; 338: converter drive section; 339: stop warning signal acquisition section; 341: target voltage storage section; 342: reference value storage section; 343; 2343: current value storage section; 344, 2344: voltage variation amount storage section; 5100: DC power source; 5121: DC-DC converter.

Claims

1. A battery module that is connected to a power supply unit that outputs a predetermined target voltage to a load, wherein the battery module includes: a battery; a DC-DC converter that converts a direct-current voltage output from the battery and outputs to the load; and a control section that performs constant voltage control of the DC-DC converter, and that receives a stop advance signal that advances output stop of the power supply unit, the control section controls so that the output voltage of the DC-DC converter is less than the target voltage before receiving the stop advance signal, and so that the output voltage of the DC-DC converter is increased to be equal to or greater than the target voltage before the output stop of the power supply unit after receiving the stop advance signal, the control section controls so that the voltage variation amount when the output voltage of the DC-DC converter reaches the target voltage is less than the maximum voltage variation amount in a period from when the stop advance signal is received to when the output voltage of the DC-DC converter is increased to be equal to a voltage in the vicinity of the target voltage.

2. The battery module according to claim 1, wherein the control section controls so that the output voltage of the DC-DC converter becomes fixed when the current value of the current flowing from the power supply unit to the load becomes equal to or less than a predetermined reference current value.

3. The battery module according to claim 1 or 2, wherein the control section controls so that the output voltage of the DC-DC converter becomes fixed when the output voltage of the DC-DC converter becomes equal to or greater than the target voltage.

4. The battery module according to claim 1 or 2, wherein the control section gradually increases the output voltage of the DC-DC converter so that the variation amount per unit time of the current flowing from the DC-DC converter to the load is less than a predetermined upper limit variation value.

5. The battery module according to claim 1 or 2, wherein the control section controls so that the output voltage of the DC-DC converter becomes a voltage equal to the target voltage after controlling so that the output voltage of the DC-DC converter becomes fixed.

6. The battery module according to claim 1 or 2, wherein the upper limit value of the output voltage of the DC-DC converter is set based on the rated voltage of the load.

7. A power supply system, wherein the power supply system includes: a power supply unit that has an AC-DC converter that converts alternating-current power supplied from an alternating-current power supply into direct-current power and outputs to a load, and a first control section that performs constant voltage control of the AC-DC converter so that the voltage output from the AC-DC converter to the load becomes a predetermined target voltage, and that outputs a stop advance signal that advances stop of the voltage output to the load before the stop of the voltage output to the load; a battery; a DC-DC converter that converts a direct-current voltage output from the battery and outputs to the load; and a second control section that performs constant voltage control of the DC-DC converter so that the voltage output from the DC-DC converter to the load becomes the target voltage. a second control section that performs constant voltage control of the DC-DC converter and that receives a stop advance signal that advances output stop of the power supply unit, the second control section controls so that the output voltage of the DC-DC converter is less than the target voltage before receiving the stop advance signal, and increases the output voltage of the DC-DC converter to be equal to or more than the target voltage before the output of the power supply unit is stopped after receiving the stop advance signal, the second control section controls so that the voltage variation amount when the output voltage of the DC-DC converter reaches the target voltage is less than the maximum voltage variation amount in a period from when the stop advance signal is received to when the output voltage of the DC-DC converter is increased to a voltage in the vicinity of the target voltage.

8. A power supply system, wherein the power supply system includes: a power supply unit that has a first DC-DC converter that converts direct current power supplied from a direct current power supply into direct current power of a different voltage and that outputs to a load, and a first control section that performs constant voltage control of the first DC-DC converter so that the voltage output from the first DC-DC converter to the load is a target voltage set in advance, and that outputs a stop advance signal that advances stop of output of the voltage to the load before the output of the voltage to the load is stopped; a battery; a second DC-DC converter that converts a direct current voltage output from the battery and that outputs to the load; and a second control section that performs constant voltage control of the second DC-DC converter and that receives a stop advance signal that advances stop of output of the power supply unit, the second control section controls so that the output voltage of the second DC-DC converter is less than the target voltage before receiving the stop advance signal, and increases the output voltage of the second DC-DC converter to be equal to or more than the target voltage before the output of the power supply unit is stopped after receiving the stop advance signal, the second control section controls so that the voltage variation amount when the output voltage of the second DC-DC converter reaches the target voltage is less than the maximum voltage variation amount in a period from when the stop advance signal is received to when the output voltage of the second DC-DC converter is increased to a voltage in the vicinity of the target voltage.

Images