Power supply system and power supply method

Abstract

To provide a power supply system and power supply method that uses multiple battery packs as a power source to supply power to a monitoring system that collects ambient information, and that can maintain a stable power supply while preventing performance degradation associated with the use of battery packs. [Solution] The power supply system 1, which uses multiple battery packs BT as a power source to supply power to electrical equipment, comprises a parallel control unit 3 that outputs power from multiple battery packs BT when the multiple battery packs BT are connected in parallel, a voltage measuring means for measuring the voltage output from the multiple battery packs BT, and a control unit 4 that controls the parallel control unit 3 to stop the power supply from the battery packs BT that have reached a preset supply stop voltage V2 when the voltage measured by the voltage measuring means reaches a preset supply stop voltage V2.

Description

Technical Field

[0001] The present invention relates to a power supply system and a power supply method for supplying power to a device using a plurality of battery packs.

Background Art

[0002] Conventionally, a power supply system that supplies power to various devices using a plurality of battery packs has been used. In such a power supply system, compared with the case of supplying power from only one battery pack, it becomes possible to supply power for a long time or increase the supply voltage.

[0003] For example, Patent Document 1 describes a power supply system that uses a plurality of battery packs and supplies power by switching the battery packs one by one.

[0004] In this power supply system, by using a DC-DC converter, the voltage supplied from the battery pack in use to the device is made constant. Further, when the voltage of the battery pack in use drops to a termination voltage, which is a predetermined voltage higher than the cut-off voltage, the power supply from the battery pack is stopped and sequentially switched to the power supply from another battery pack.

[0005] In such a power supply system, compared with the case of using a single battery pack, it becomes possible to supply power for a long time with a stable voltage. Further, by switching the battery pack to be used before the voltage drops to the cut-off voltage, it becomes possible to prevent a decrease in the performance of the battery pack due to over-discharge.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] Incidentally, in conventional power supply systems that use multiple battery packs, when the supply voltage of the battery pack currently in use drops and the system switches to power supply from another battery pack, there is a risk that the power supply may be temporarily or permanently interrupted due to malfunctions in the control device, switch, or other switching mechanism.

[0008] Such power outages pose a significant problem, for example, when supplying power to monitoring systems installed inside rail containers to collect various types of surrounding information in order to monitor cargo within those containers.

[0009] Therefore, the present invention has been made in view of the above, and aims to provide a power supply system and a power supply method that use multiple battery packs and can continue to supply power stably while preventing a decrease in the performance of the battery packs due to use. [Means for solving the problem]

[0010] The present invention is a power supply system that uses multiple battery packs as a power source to supply power to a monitoring system that collects ambient information, and is characterized by comprising: a parallel control unit that outputs power from the multiple battery packs when the multiple battery packs are connected in parallel; a voltage measuring means for measuring the voltage output from the multiple battery packs; and a control unit that controls the parallel control unit to stop the power supply from the battery pack that has reached the supply stop voltage when the voltage measured by the voltage measuring means reaches a preset supply stop voltage.

[0011] In the above power supply system, it is preferable that the control unit issues a first alarm signal to the alarm target when the voltage of the battery pack that last supplies power reaches an alarm voltage higher than the preset supply stop voltage, and also issues a second alarm signal to the alarm target when the supply stop voltage is reached.

[0012] Furthermore, the power supply system may further include a storage means for storing the surrounding information collected by the monitoring system, and the control unit may cause the storage means to save the surrounding information when issuing the first alarm signal and / or the second alarm signal.

[0013] Furthermore, the present invention is a power supply method for supplying power to electrical equipment using a plurality of battery packs as a power source, characterized in that it includes the steps of: connecting the plurality of battery packs in parallel; measuring the voltage of each of the plurality of battery packs; and stopping the power supply from the battery pack that has reached a predetermined supply stop voltage when the measured voltage reaches the supply stop voltage.

[0014] In the above invention, it is preferable to further include the steps of issuing a first alarm signal to the target of alarm when the voltage of the battery pack that last supplies power reaches an alarm voltage higher than a preset supply stop voltage, and issuing a second alarm signal to the target of alarm when the supply stop voltage is reached.

[0015] Furthermore, in the above invention, it is preferable to include a step of saving the surrounding information when the first alarm signal and / or the second alarm signal is issued. [Effects of the Invention]

[0016] According to the power supply system and power supply method of the present invention described above, in a power supply system using multiple battery packs, it is possible to continue to supply power stably while preventing performance degradation associated with the use of battery packs.

Brief Description of the Drawings

[0017] [Figure 1] It is a schematic diagram showing a power supply system according to an embodiment of the present invention. [Figure 2] It is a circuit diagram showing a part of a power supply system according to an embodiment of the present invention. [Figure 3] It is a graph showing the change over time of the voltage of a power supply system according to an embodiment of the present invention.

Modes for Carrying Out the Invention

[0018] Hereinafter, an embodiment of a power supply system according to this invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited by the following embodiments.

[0019] FIG. 1 is a schematic diagram showing a power supply system 1 according to an embodiment of the present invention. As shown in FIG. 1, the power supply system 1 according to the present embodiment includes a plurality (eight in this embodiment) of battery packs BT (BT1, BT2,..., BT8), a parallel housing portion 2 that houses the plurality of battery packs BT so as to be connected in parallel, a parallel control portion 3 that outputs power from the plurality of battery packs BT to an external device E, a control portion 4, and a storage means 5.

[0020] The battery pack BT is a commercially available storage battery that is widely used generally, and can be repeatedly used by charging it using an arbitrary charging device even after discharging.

[0021] The parallel housing portion 2 is a battery holder that can house the battery packs BT connected in parallel. In the present embodiment, eight battery packs BT1, BT2,..., BT8 can be housed. Then, the parallel housing portion 2 enables power supply from the plurality of battery packs BT to the parallel control portion 3 by connecting the plurality of battery packs BT housed in parallel to the parallel control portion each.

[0022] The parallel control unit 3 is a unit that outputs power from a plurality of battery packs BT while the plurality of battery packs BT are connected in parallel. The parallel control unit 3 also has a function as voltage measurement means for measuring the voltage output from the plurality of battery packs BT.

[0023] The parallel control unit 3 includes a display unit 31, a display switching switch 32, and voltage switching buttons 33 and 34.

[0024] The display unit 31 is a display provided in the parallel control unit 3, and displays the voltage of the battery pack BT measured by the parallel control unit 3 (39.2V in FIG. 1), the charge rate of the battery pack BT (100% at full charge, the state in FIG. 1), and a display graphic that shows the charge rate as an increase or decrease of a black-filled gauge in a graphic simulating a battery.

[0025] The display switching switch 32 is a dial, and by turning this, the battery pack BT for which the voltage and the charge rate are displayed on the display unit 31 can be switched.

[0026] The voltage switching buttons 33 and 34 are buttons for switching the voltage supplied to an external device E (in the example of FIG. 1, sensing devices such as a camera C, a microphone M, a vibration / temperature / humidity sensor S, a GPS G, etc., which do not have storage means), which is a measuring device that constitutes a monitoring system for collecting surrounding information from the parallel control unit 3 via the control unit 4. For example, by pressing the voltage switching button 33, the output voltage can be set to 12V, and by pressing the voltage switching button 34, the output voltage can be set to 5V.

[0027] The control unit 4 is a microcomputer or a processor including a central processing unit (CPU), a graphics processing unit (GPU), etc., and controls the operation of the parallel control unit 3 based on the voltage of the battery pack BT measured by the parallel control unit 3.

[0028] Specifically, when the power supply system 1 is in use, the control unit 4 controls the parallel control unit 3 to start supplying power simultaneously from all battery packs BT connected in parallel and housed in the parallel housing unit 2.

[0029] Then, when the voltage of a certain battery pack BT reaches a preset power supply stop voltage V2 (see Figure 3), the parallel control unit 3 is controlled to stop the power supply from that battery pack BT.

[0030] In this manner, the control unit 4 sequentially stops supplying power from battery packs BT whose voltage reaches the supply stop voltage V2, and issues an alarm when the voltage of the last battery pack BT to supply power drops to a predetermined voltage. Details of the alarm will be described later.

[0031] Furthermore, the control unit 4 stores various data received from external devices in the storage means 5.

[0032] The storage means 5 is an internal storage device such as a hard disk, a removable external storage device such as a removable disk, or a cloud server, which stores various data, which are ambient information received by the control unit 4 from external devices, and performs data storage operations based on the control of the control unit 4.

[0033] Figure 2 is a circuit diagram showing a part of the power supply system 1 according to an embodiment of the present invention.

[0034] As shown in Figure 2 (and also in Figure 1), in the power supply system 1 according to this embodiment, multiple battery packs BT are connected in parallel to each other. Each of the multiple battery packs BT is connected to a reverse current prevention diode D (D1, D2, ..., D8) to prevent current from flowing backward.

[0035] Furthermore, the power supply system 1 shown in Figure 2 is equipped with two switches SW1 and SW2 and two DC-DC converters DC1 and DC2, and the voltage output from the power supply system 1 can be changed by turning one on and the other off.

[0036] Specifically, by turning on switch SW1 and turning off switch SW2, the output circuit P1 on the switch SW1 side is turned on. A DC-DC converter DC1 is provided in the middle of this output circuit P1, which can adjust the voltage output from the power supply system 1 to 12V.

[0037] Furthermore, by turning switch SW1 off and switch SW2 on, the output circuit P2 on the switch SW2 side is turned on. A DC-DC converter DC2 is provided in the middle of this output circuit P2, which can adjust the voltage output from the power supply system 1 to 5V.

[0038] These switches SW1, SW2 and DC-DC converters DC1, DC2 are located within the parallel control unit 3, and the user can switch between switches SW1 and SW2 by operating the voltage switching buttons 33 and 34.

[0039] Furthermore, by rotating the display selector switch 32 to align the scale on the display selector switch 32 with the scale indicating the desired battery pack BT located around the display selector switch 32, the battery pack BT whose voltage and charge level are displayed on the display unit 31 can be switched.

[0040] Next, the alarm and power supply control by the control unit 4 will be described in detail. Figure 3 is a graph showing the change in voltage over time in the power supply system 1 according to an embodiment of the present invention.

[0041] As shown in Figure 3, power is supplied from the power supply system 1, and the voltage is adjusted to either 12V or 5V by DC-DC converter DC1 or DC-DC converter DC2.

[0042] This 12V or 5V power supply is initially provided simultaneously from all eight battery packs BT1, BT2, ..., BT8 connected in parallel within the power supply system 1. Therefore, compared to the case where power is supplied from a single battery pack BT, the power consumption of each battery pack BT is suppressed, making it possible to supply power for a long period of time.

[0043] Then, while continuing to supply power, if the voltage of any of the eight battery packs BT1, BT2, ..., BT8 drops to a supply stop voltage V2 which is lower than 12V and 5V and higher than the over-discharge voltage V3, the control unit 4 instructs the parallel control unit 3 to stop supplying power from that battery pack BT.

[0044] This power supply cutoff voltage V2 is higher than the cutoff voltage V3, which is the voltage when the battery pack BT is empty and corresponds to over-discharge that can lead to a deterioration in the quality of the battery pack BT. By stopping the power supply from the battery pack BT at a power supply cutoff voltage V2 that is higher than the cutoff voltage V3, it is possible to prevent the deterioration of the battery pack's performance due to over-discharge.

[0045] Even though one battery pack BT is removed and power is supplied by seven battery packs BT, the power supply from these seven battery packs BT connected in parallel continues without interruption, and the supplied voltage is maintained at the original 12V or 5V.

[0046] Similarly, when the voltages of the second battery pack BT and the third battery pack BT sequentially drop to the power supply shutdown voltage V2, the power supply from each battery pack BT is shut off.

[0047] Even at this time, power supply from the remaining five parallel-connected battery packs BT continues, and the supplied voltage is maintained at the original 12V or 5V.

[0048] Then, when power supply from the seven battery packs BT stops and power is supplied only from the last battery pack BT, the decrease in charge will eventually make it impossible to maintain a voltage of 12V or 5V, and the voltage will begin to drop (point P1 in Figure 3).

[0049] Then, when the voltage drops to a preset alarm voltage V1 (point P2 in Figure 3), the control unit 4 issues an alarm signal (first alarm signal) to the alarm target. In this embodiment, the alarm target is a management terminal such as a personal computer or tablet, owned by the administrator who remotely monitors the power supply system 1 via an external device E. Upon receiving the alarm signal, the management terminal notifies the administrator that an alarm has been issued via a display device such as a display or a speaker.

[0050] Furthermore, when the control unit 4 issues the first alarm signal, it causes the storage means 5 to save the surrounding information collected by the external device E.

[0051] Then, when the voltage drops further below the alarm voltage V1 to the preset power supply stop voltage V2 (point P3 in Figure 3), the control unit 4 issues another alarm signal (second alarm signal) to the alarm target and commands the parallel control unit 3 to stop the power supply from the last battery pack BT, thereby stopping the power supply from the last battery pack BT to the external device.

[0052] Furthermore, when the control unit 4 issues a second alarm signal, it causes the storage means 5 to save the surrounding information collected by the external device E, just as it does when the second alarm signal is issued.

[0053] Once the power supply from all battery packs BT is terminated, the external device E, which was operating on power supplied from power supply system 1, will cease operation.

[0054] According to the power supply system 1 of the above embodiment, by connecting multiple battery packs BT in parallel, power supply from other battery packs BT can be continued even if power supply from one battery pack BT stops. In continuing this power supply, there is no need for a switching operation of the battery pack BT supplying power, as in the conventional technology. Therefore, there is no risk of the power supply being temporarily stopped or completely unavailable due to errors in the control unit 4 or malfunctions in the switches, etc., which may prevent the switching from being performed properly.

[0055] Furthermore, by stopping the power supply from the battery pack BT at a supply termination voltage V2 that is higher than the cutoff voltage V3, it becomes possible to maintain a stable power supply while preventing performance degradation associated with the use of the battery pack BT.

[0056] Furthermore, by emitting a first alarm signal when the supply voltage drops to the alarm voltage V1, it is possible to notify the user that a power supply shutdown is imminent and that the battery pack BT will soon need to be replaced, enabling appropriate preparations, such as preparing to replace the battery pack BT, to be made early.

[0057] Furthermore, by emitting a second alarm signal when the alarm voltage drops to V2, the administrator performing remote monitoring can be notified that the power supply from the battery pack BT has stopped and that it is necessary to replace the battery pack BT, giving them another opportunity to prepare for the replacement of the battery pack BT.

[0058] Furthermore, when the first and second alarm signals are issued, the storage means 5 saves the surrounding information collected from the external device E, thereby reliably preventing the collected surrounding information from being lost due to a power outage.

[0059] The power supply system 1 according to the above embodiment is particularly suitable for use in locations where there is no power source and where damage caused by a temporary or permanent interruption of power supply would be significant, such as when supplying power to a monitoring system (surveillance camera, etc.) for monitoring cargo loaded in a container transported by rail or truck.

[0060] Furthermore, the present invention is not limited to the embodiments described above, and various modifications can be adopted.

[0061] For example, in the power supply system 1 according to the above embodiment, eight battery packs BT were used as the power supply source. However, the present invention is not limited to this, and seven or fewer or nine or more battery packs BT may be connected in parallel and used as the power supply source.

[0062] Furthermore, in this embodiment, the parallel housing unit 2 housed the eight battery packs BT1, BT2, ..., BT8 all connected in parallel to each other. However, the present invention is not limited to this, and other housing configurations can also be adopted.

[0063] For example, two battery packs BT1 and BT2 (battery pair BP1) may be housed in series, two other battery packs BT3 and BT4 (battery pair BP2) may be housed in series, two more battery packs BT5 and BT6 (battery pair BP3) may be housed in series, and two more battery packs BT7 and BT8 (battery pair BP4) may be housed in series.

[0064] Furthermore, these four battery pairs BP1, BP2, BP3, and BP4 may be connected in parallel to each other and housed in the parallel housing unit 2. This type of housing configuration also makes it possible to maintain a stable power supply while preventing performance degradation associated with the use of the battery pack BT.

[0065] Furthermore, in the power supply system 1 according to the embodiment described above, there were two selectable output voltages: 12V and 5V. However, the present invention is not limited to these voltages, and other voltages may be used. There may also be three or more selectable voltage types, or it may be possible to output only one type of voltage.

[0066] Furthermore, in the power supply system 1 according to the above embodiment, the control unit 4 caused the storage means 5 to save ambient information collected from the external device E when the first alarm signal and the second alarm signal were issued. However, the present invention is not limited to this, and the storage means 5 may be caused to save ambient information when the first alarm signal or the second alarm signal is issued. This also reliably prevents the collected ambient information from being lost due to the interruption of power supply.

[0067] Furthermore, if data saving is to be performed when either the first or second alarm signal is issued, it is preferable to perform data saving when the second alarm signal is issued, because this allows for a longer period of time to collect ambient information stored in the storage means 5.

[0068] Furthermore, while the power supply system 1 according to the above embodiment had a storage means 5 on the power supply system 1 side, the present invention is not limited to this, and the storage means 5 may not be provided on the power supply system 1 side, but on the external device E side. In this case, the control unit 4 may issue a command to the external device E to save the collected data when the first alarm signal and the second alarm signal are issued. This also reliably prevents the collected ambient information from being lost due to the interruption of power supply. [Explanation of Symbols]

[0069] 1. Power supply system 2 Parallel storage section 3. Parallel Control Unit 4. Control Unit 5 Memory means 31 Display section 32 Display Switching Switch 33, 34 Voltage selector buttons BT, BT1, BT2, BT3, BT4, BT5, BT6, BT7, BT8 Battery Packs C Camera D, D1, D2, D3, D4, D5, D6, D7, D8 Reverse current protection diodes DC1, DC2 DC-DC converter E External equipment G GPS M Mike P1, P2 output circuit S Vibration, temperature, and humidity sensor SW1, SW2 switches

Claims

1. A power supply system that uses multiple battery packs as a power source to supply power to a monitoring system that collects information about the surroundings, A parallel control unit that outputs power from the plurality of battery packs when the plurality of battery packs are connected in parallel, A voltage measuring means for measuring the voltage output from the plurality of battery packs, When the voltage measured by the voltage measuring means reaches a preset supply stop voltage, the control unit controls the parallel control unit to stop the power supply from the battery pack that has reached the supply stop voltage, A power supply system equipped with the following features.

2. The power supply system according to claim 1, wherein the control unit emits a first alarm signal to the alarm target when the voltage of the battery pack that last supplies power reaches an alarm voltage higher than a preset supply stop voltage, and emits a second alarm signal to the alarm target when the supply stop voltage is reached.

3. The system further comprises a storage means for storing the surrounding information collected by the aforementioned monitoring system, The power supply system according to claim 2, wherein the control unit causes the storage means to save the surrounding information when it issues the first alarm signal and / or the second alarm signal.

4. A power supply method for supplying power to a monitoring system that collects ambient information using multiple battery packs as a power source, The process of connecting the aforementioned multiple battery packs in parallel, A step of measuring the voltage of each of the aforementioned multiple battery packs, The process includes stopping the power supply from the battery pack that has reached a predetermined supply stop voltage when the measured voltage reaches the said supply stop voltage, A method of supplying power, including the following.

5. The power supply method according to claim 4, further comprising the steps of: issuing a first alarm signal to the alarm target when the voltage of the battery pack that last supplies power reaches an alarm voltage higher than a preset supply stop voltage; and issuing a second alarm signal to the alarm target when the supply stop voltage is reached.

6. The power supply method according to claim 5, further comprising the step of saving the surrounding information when issuing the first alarm signal and / or the second alarm signal.

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