Power supply unit and power supply system

Abstract

To provide a power supply device and a power supply system capable of reliably maintaining an operation of the power supply device by a main battery at the time of charging / replacing of a spare battery and maintaining high safety even when a cable connected to the spare battery is removed.SOLUTION: A power supply device 1 comprises: a chargeable / dischargeable main battery 2; an inverter 4 that converts DC current into AC current to supply the same to a load; a CPU 7 that manages / controls the entire power supply device 1; a spare connection circuit 5 for electrically connecting an external spare battery 10 and the load; and a changeover switch 6 that switches between connection of the load to the main battery 2 and connection to the spare battery 10. The spare connection circuit 5 includes two wirings, that is, a first wiring 51a and a second wiring 52a parallel to each other for connection with one spare battery 10, and a first end connection 51c and a second end connection 52c corresponding to the respective wirings.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a power supply device or the like that is connected to an external backup battery and supplies power to a load.

Background Art

[0002] For example, Patent Document 1 discloses a power supply device using a lithium ion battery. Such a power supply device has begun to spread to ordinary households as a portable power supply and is a very important energy source especially in times of disaster.

[0003] On the other hand, in times of disaster, the commercial power supply for charging the above power supply device may stop for a long time. That is, after consuming the power charged in the power supply device, it is necessary to carry the power supply device to a place where the commercial power supply is operating for charging, and during that time, people in the disaster area have to live without power. This is a life-threatening problem especially for people who usually live wearing medical devices or the like.

[0004] In order to solve such a problem, instead of carrying the power supply device to a place where commercial power can be used, it is conceivable to externally connect a charged backup battery to the power supply device. In this case, for example, as shown in FIG. 6, by connecting the backup battery via a diode, the flow of current between the main battery and the backup battery can be prevented, and power can be supplied to the load from both the main battery and the backup battery.

[0005] Also, as an emergency battery, for example, a charger as shown in Patent Document 2 is known. Such a charger is widely popular as a mobile battery, and when the battery level of the main battery originally equipped in a mobile terminal such as a smartphone runs out, it is possible to continue using the mobile terminal by connecting such a mobile battery to the mobile terminal.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Patent No. 5352014 [Patent Document 2] Japanese Patent Publication No. 2011-41351 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, in the circuit configuration shown in Figure 6, power is drawn from the battery with the higher voltage, either the main battery or the auxiliary battery, until they reach the same potential. In this state, the voltage of both batteries gradually decreases. Ultimately, both the main battery and the auxiliary battery will reach a low potential requiring charging, and the power supply unit will be unable to operate while the auxiliary battery is being charged (or while it is being replaced with a fully charged auxiliary battery).

[0008] Furthermore, especially when used in evacuation shelters during disasters, the environment is more chaotic than usual, and many evacuees use the equipment. This increases the risk of accidentally disconnecting cables or accidentally detaching the cable between the power supply unit and the backup battery. In a configuration like that shown in Figure 6, if the cable suddenly disconnects while the backup battery is supplying power to the load, the backup battery will be completely disconnected, which is extremely dangerous as it can cause arcing. Therefore, technologies to ensure safety when connecting backup batteries are also desired.

[0009] The technology described in Patent Document 2 can be used as a mobile battery in emergencies, but since the current supplied is at the milliampere level, the risks mentioned above are very small. Furthermore, the devices that will be powered by the mobile battery are mainly mobile devices such as smartphones and laptops, and not medical equipment or household appliances that require immediate attention, so even if the main battery level drops, the possibility of life-threatening problems occurring is extremely low.

[0010] The present invention aims to provide a power supply device and power supply system that can reliably maintain the operation of the power supply device using the main battery when a spare battery is being charged or replaced, and that can maintain a high level of safety even if the cable connecting to the spare battery is disconnected. [Means for solving the problem]

[0011] The power supply device according to the present invention comprises a main battery that can be charged and discharged, an inverter that converts DC current to AC current and supplies it to a load, a control unit that manages and controls the entire power supply device, a connection circuit for electrically connecting an external spare battery to the load, and a changeover switch that switches whether the load is connected to the main battery or the spare battery, wherein the connection circuit has two parallel wires, a first wire and a second wire, and a first connection port and a second connection port corresponding to each wire for connection to one spare battery.

[0012] As described above, the power supply device according to the present invention comprises a rechargeable main battery, an inverter that converts DC current to AC current and supplies it to a load, a control unit that manages and controls the entire power supply device, a connection circuit for electrically connecting an external spare battery to the load, and a changeover switch that switches whether the load is connected to the main battery or the spare battery. The connection circuit has two parallel wires, a first wire and a second wire, and a first connection port and a second connection port corresponding to each wire, so that when a spare battery is connected, the power supply device can be operated using only the battery charge of the spare battery without consuming the battery charge of the main battery, thereby suppressing the power consumption of the main battery and making it possible to maintain the battery charge at a predetermined level. In other words, even if the spare battery needs to be charged or replaced, the power supply device can be operated using the main battery during that time, thus providing the effect of always supplying power without stopping the power supply device.

[0013] Furthermore, because the wiring connecting the backup battery and the load consists of two parallel wires, even if one wire is accidentally cut, current will continue to flow through the other wire, suppressing the generation of an arc and ensuring safety. This is especially important when used in places like evacuation shelters during disasters, where the situation is different from everyday life and accidents are more likely to occur. Ensuring safety is crucial, but the configuration of this invention makes it possible to secure a power source safely even in such situations. [Brief explanation of the drawing]

[0014] [Figure 1] This is a system configuration diagram of a power supply system using a power supply device according to the first embodiment. [Figure 2] This is a circuit block diagram showing the configuration of a power supply device and a power supply system using the first embodiment. [Figure 3] This is another circuit block diagram showing the configuration of a power supply device and a power supply system using the first embodiment. [Figure 4] This is a circuit block diagram showing the configuration of a power supply device and a power supply system using the power supply device according to the second embodiment. [Figure 5] This is an external view of the control panel of the power supply unit according to the third embodiment. [Figure 6] This figure shows an example of a circuit configuration when a spare battery is connected. [Modes for carrying out the invention]

[0015] (First embodiment of the present invention) The power supply device according to this embodiment will be described with reference to Figures 1 to 3. The power supply device according to this embodiment has a capacity of approximately 100Wh to 100kWh and can supply power of approximately 100W to 100kW. It is equipped with a lithium-ion battery as the main battery and can be connected to an external spare lithium-ion battery pack.

[0016] Figure 1 is a system configuration diagram of a power supply system using the power supply device according to this embodiment. The power supply system 100 includes a power supply device 1 that supplies power to a load from a lithium-ion battery and stores power in the lithium-ion battery from an external source, a portable spare battery 10 consisting of a lithium-ion battery that can be connected to the power supply device 1 from an external source, and two cables, a first cable 11 and a second cable 12, that connect the power supply device 1 and the spare battery 10 in parallel.

[0017] As will be described later, the power supply unit 1 can be operated independently using its internal main battery. However, in emergencies, the power supply system 100 can be constructed by connecting the spare battery 10, enabling a longer and more stable power supply. In other words, under normal operation when charging from commercial power is possible, the power supply unit 1 can be operated while charging and discharging while placed near the load. However, in situations where commercial power is unavailable due to a disaster or other reason, it is necessary to move to a location where commercial power is available to charge, and during that time, power cannot be supplied to the load. In particular, for people who wear medical devices in their daily lives or who need medical devices for the treatment of injuries or illnesses, the lack of power supply can be a life-threatening issue. Therefore, in the power supply unit 1 according to this embodiment, this problem is solved by connecting the highly portable spare battery 10, enabling a longer and more stable power supply.

[0018] FIG. 2 is a circuit block diagram showing the configuration of a power supply device and a power supply system using the power supply device according to the present embodiment. The power supply device 1 includes a main battery 2 composed of a rechargeable lithium ion battery, a charger 3 for charging the main battery 2, an inverter 4 for converting the current supplied to the connected load from a direct current to an alternating current, a standby connection circuit 5 for electrically connecting an externally connected standby battery 10 and the load, a changeover switch 6 for switching whether the load is connected to the main battery 2 or the standby battery 10, a CPU 7 for monitoring and controlling the entire power supply device 1 and the power supply system 100, and a main switch 8 for switching ON / OFF the connection between the load and each battery (main battery 2 or standby battery 10) under the control of the CPU 7.

[0019] The standby connection circuit 5 includes a first wiring 51a for electrically connecting the standby battery 10 to the load via the inverter 4, a first communication line 5lb for transmitting a signal from the standby battery 10 to the CPU 7, and a first connection port 51c which is a connector of a first cable ll connected to the standby battery 10. The first cable 11 is a composite cable in which an electric wire and a communication line are combined into one line, and by connecting to the first connection port 51c, it is possible to connect to the first wiring 51a and the first communication line 51b simultaneously.

[0020] Further, the standby connection circuit 5 includes a second wiring 52a arranged in parallel with the first wiring 51a for electrically connecting the standby battery 10 to the load via the inverter 4, a second communication line 52b for transmitting a signal from the standby battery 10 to the CPU 7, and a second connection port 52c which is a connector of a second cable 12 connected to the standby battery 10. The second cable 12 is a composite cable in which an electric wire and a communication line are combined into one line, and by connecting to the second connection port 52c, it is possible to connect to the second wiring 52a and the second communication line 52b simultaneously.

[0021] Main battery 2 is the main battery built into power supply unit 1. It is a rechargeable lithium-ion battery that discharges to supply power to a load and stores power by charging from an external power source when the battery level is low.

[0022] Charger 3 is a charger for charging the main battery 2 with power from the commercial power supply or from the backup battery. When charging from the commercial power supply, it converts AC to DC for charging, and when charging from the backup battery, it charges using DC as is.

[0023] The inverter 4 converts the DC current supplied from the main battery 2, or the DC current supplied from the auxiliary battery 10, into AC current and supplies it to the load.

[0024] The auxiliary connection circuit 5 is a circuit for connecting an external auxiliary battery 10 to the power supply unit 1, and as described above, two parallel cables, the first cable 11 and the second cable 12, are connected to the first connection port 51c and the second connection port 52c, respectively.

[0025] The changeover switch 6 is a switch that switches the destination of the load to either the main battery 2 or the auxiliary battery 10, and in the second embodiment, the switching is performed by a circuit breaker on the control panel, which will be described later.

[0026] The CPU 7 monitors and controls the power supply unit 1 and the power supply system 100. For example, it detects when the start button 13 is pressed and turns on the main switch 8, and monitors the main battery 2 by receiving information such as its charge / discharge status, battery level, cell balance, usage status (current, voltage), and temperature. When the spare battery 10 is connected to the spare connection circuit 5, the CPU 7 also monitors the status of the spare battery 10 by receiving and transmitting information from the spare battery 10's BMS (Battery Management System) in parallel via the first communication line 51b and the second communication line 52b. At this time, the information transmitted from the spare battery 10's BMS is sent to the CPU 7 via the communication line of the first cable 11 and the first connection port 51c, and is also sent and received from the CPU 7 to the spare battery 10's BMS via the second connection port 52c and the communication line of the second cable 12. In other words, information from the spare battery 10 is constantly flowing through the communication network formed in a loop.

[0027] In normal operation (for example, when there is no disaster and commercial power is available), the power supply unit 1, configured as described above, operates by charging the main battery 2 with power from an external commercial power source using the charger 3, and then supplying the power stored in the main battery 2 to the load. Nothing is connected to the first connection port 51c or the second connection port 52c, and the unit operates using only the main battery 2. In other words, in normal operation, the changeover switch 6 is connected to the main battery 2 side.

[0028] On the other hand, in backup operation (for example, when commercial power is unavailable due to a disaster and an external backup battery is used), the first cable 11 of the backup battery 10 is connected to the first connection port 51c, and the second cable 12 of the backup battery 10 is connected to the second connection port 52c. At this time, the changeover switch 6 is connected to the backup connection circuit 5, and only the power from the backup battery 10 is supplied to the load, while the battery level of the main battery 2 remains unchanged.

[0029] As mentioned above, in the event of a disaster or other situation where commercial power is unavailable, the main battery 2 cannot be charged, but it is possible to receive a supply of a charged backup battery 10 from an area outside the disaster zone or from an area where commercial power is available. In this case, if the main battery 2 has no remaining charge, the power supply unit 1 cannot be operated while the backup battery 10 is being replaced or charged (for example, while the backup battery 10 is being transported to an area where commercial power is available, charged there, and then transported back to the disaster zone once fully charged). In other words, in a backup operation state, it is ideal to minimize the power consumption of the main battery 2 and prioritize the use of power from the backup battery 10, supplementing the power from the main battery 2 while the backup battery 10 is being replaced or charged.

[0030] In power supply unit 1, the changeover switch 6 determines whether the load is connected to the main battery 2 or the auxiliary battery 10. Therefore, while the auxiliary battery 10 has remaining charge, the load is connected to the auxiliary battery 10. When the auxiliary battery 10 runs out of charge and needs to be replaced or charged, the connection is switched to the main battery 2. This minimizes the power consumption of the main battery 2 and allows power supply unit 1 to be kept running at all times.

[0031] The connection to the spare battery 10 uses two cables: the first cable 11 and the second cable 12. The first connection, in which the first wiring 51a and the first cable 11 are connected at the first connection port 51c, and the second connection, in which the second wiring 52a and the second cable 12 are connected at the second connection port 52c, have the same specifications, and power from the spare battery 10 is supplied almost equally to both the first and second connections. Even if one cable becomes disconnected or malfunctions, the other cable remains electrically connected, so it can be used safely without the generation of arcs or other problems. In particular, when an unspecified number of people use the power supply 1 in a cluttered environment such as an evacuation center, accidents and incidents such as cables becoming disconnected or snagged are to be anticipated, so distributing the connection path into two connections, the first and second connections, is particularly effective in suppressing the generation of arcs and other problems from a safety perspective.

[0032] Furthermore, in the event of an accident or incident where any cable becomes disconnected, it is desirable to prioritize safety and instantly shut down the operation of the power supply unit 1. To achieve this, the CPU 7 needs to detect an abnormality, such as the first cable 11 becoming disconnected from the first connection port 51c, or the second cable 12 becoming disconnected from the second connection port 52c, and then turn off the main switch 8. In this embodiment, information from the BMS of the spare battery 10 is constantly transmitted and received between the CPU 7 and the BMS via a loop communication network through the first communication line 51b and the second communication line 52b. Therefore, if the first cable 11 or the second cable 12 becomes disconnected, or if any abnormality occurs, the communication will be interrupted, allowing the CPU 7 to instantly detect the abnormality. If the spare battery 10 were connected with a single cable, it would be dangerous as an arc or other problem could occur the moment the cable becomes disconnected. By connecting with two separate cables as in this embodiment, even if an abnormality occurs in one cable, the other cable remains connected, which helps to suppress the occurrence of arcs and other malfunctions. Furthermore, the CPU 7 can instantly detect the abnormality and control the other connected system to safely shut down its operation.

[0033] In addition, in the power supply device 1 according to this embodiment, it is also possible to charge the main battery 2 while supplying power to the load from the auxiliary battery 10. As described above, although the power consumption of the main battery 2 is minimized in this embodiment, if the restoration of commercial power is delayed or the period of unusability is prolonged, the remaining charge of the main battery 2 may gradually decrease. In such cases, by using the system configuration shown in Figure 3, it is possible to supply power to the load with the auxiliary battery 10 while charging the main battery 2 with the other auxiliary battery 10a.

[0034] In Figure 3, the changeover switch 6 is connected to the auxiliary connection circuit 5. The charger 3 that charges the main battery 2 is connected to the other auxiliary battery 10a via the DC / AC converter 14. In other words, by using the DC / AC converter 14, the main battery 2 can be charged from the other auxiliary battery 10a in the same way as when the main battery 2 is charged from the commercial power supply during normal operation. This makes it possible to charge the main battery 2 while continuing to supply power to the load, even if the battery level of the main battery 2 decreases when the commercial power supply is unavailable, enabling stable operation.

[0035] As described above, the power supply unit 1 according to this embodiment includes a rechargeable main battery 2, an inverter 4 that converts DC current to AC current and supplies it to the load, a CPU 7 that manages and controls the entire power supply unit 1, a spare connection circuit 5 for electrically connecting an external spare battery 10 to the load, and a changeover switch 6 that switches whether the load is connected to the main battery 2 or the spare battery 10. The spare connection circuit 5 has two parallel wires, a first wire 51a and a second wire 52a, and a first connection port 51c and a second connection port 52c corresponding to each wire, so that when a spare battery 10 is connected, the power supply unit 1 can be operated using only the battery charge of the spare battery 10 without consuming the battery charge of the main battery 2, thereby suppressing the power consumption of the main battery 2 and making it possible to maintain the battery charge at a predetermined level. In other words, even if the spare battery 10 needs to be charged or replaced, the power supply unit 1 can be operated using the main battery 2 during that time, so power can be supplied at all times without stopping the power supply unit 1.

[0036] Furthermore, since the wiring connecting the spare battery 10 and the load consists of two parallel wires, even if one wire is accidentally cut, current will flow through the other wire, suppressing the generation of an arc and ensuring safety. In particular, when used in places like evacuation shelters during disasters, the situation is different from everyday life, making accidents and incidents more likely, and ensuring safety is especially important. With the configuration of the present invention, it is possible to secure a power source safely even in such situations.

[0037] Furthermore, the system includes a first communication line 51b corresponding to the first wiring 51a, which communicates between the CPU 7 and the BMS of the spare battery, and a second communication line 52b corresponding to the second wiring 52a, which communicates between the CPU 7 and the BMS of the spare battery. Since a communication network is formed in a loop shape by the CPU 7, the first communication line 51b, the second communication line 52b, and the BMS of the spare battery, if an abnormality occurs at any point in this loop-shaped communication network and communication is interrupted, the CPU 7 can instantly detect the abnormality and turn off the main switch 8, thereby ensuring a high level of safety.

[0038] Furthermore, since the system is equipped with a charger 3 that charges the main battery 2 from another spare battery 10a when the load is connected to the spare battery 10 via the changeover switch 6, even if the battery level of the main battery 2 decreases, it is possible to increase the battery level of the main battery 2 while maintaining power supply to the load with the spare battery 10.

[0039] In this embodiment, the first cable 11 and the second cable 12 have been described as composite cables combining electric wires and communication lines, but the cables are not limited to this, and may be separate cables with corresponding electric wires and communication lines. That is, the first connection port 51c may have an electric wire connector for connecting to the first wiring 51a and a signal connector for connecting to the first communication line 51b, and the second connection port 52c may have an electric wire connector for connecting to the second wiring 52a and a signal connector for connecting to the second communication line 52b.

[0040] (Second embodiment of the present invention) The power supply device according to this embodiment will be described with reference to Figure 4. The power supply device according to this embodiment can supply power to the load from an external spare battery 10 and simultaneously charge the main battery 2. In this embodiment, explanations that overlap with those of the first embodiment will be omitted.

[0041] Figure 4 is a circuit block diagram showing the configuration of a power supply device and a power supply system using the second embodiment. The difference between the configuration in Figure 4 and that in Figure 2 is that Figure 4 includes a CT 60 for measuring the output current of the inverter 4 and an auxiliary charging switch 61 for switching the connection between the auxiliary battery 10 and the main battery 2 ON / OFF, and the output cable of the inverter 4 is connected to the main battery 2 via the auxiliary charging switch 61.

[0042] The CPU 7 controls the ON / OFF status of the auxiliary charging switch 61 based on the measurements taken by the CT 60, the battery information obtained from the BMU of the main battery 2, and the battery information obtained from the BMU of the auxiliary battery 10. Specifically, when the auxiliary battery 10 is supplying power to the load, and it is determined that the power supply to the load is sufficient relative to the remaining battery capacity of the auxiliary battery 10, the auxiliary charging switch 61 is turned ON to also charge the main battery 2 from the auxiliary battery 10. This allows for efficient use of the power from the auxiliary battery 10 and increases the remaining battery capacity of the main battery 2.

[0043] In particular, during disasters, as explained above, it is important to maintain the battery level of the main battery 2 as much as possible while prioritizing power supply to the load. However, there are cases where it is desirable to prioritize maintaining the battery level of the main battery 2. For example, if the battery level of the main battery 2 is extremely low and it would take time to replace the spare battery 10, it is necessary to prioritize increasing the battery level of the main battery 2. To address such cases, the start button 13 may be configured to include a load switching switch.

[0044] This load switching switch can, for example, switch between emergency mode and normal mode. In normal mode, power is supplied from the spare battery 10 to any load, but in emergency mode, power from the spare battery 10 is supplied only to pre-registered critical equipment (for example, critical equipment such as medical equipment that would be life-threatening if it stopped working), and power is not supplied to other loads (for example, smartphones that are not in an emergency). More specifically, there is an emergency outlet and a normal outlet. When the load switching switch is set to normal mode, power is supplied to loads regardless of which outlet they are connected to, but when the load switching switch is set to emergency mode, power is supplied only to loads connected to the emergency outlet. In emergency mode, any surplus power is used to charge the main battery 2. The switching of these switches is controlled by the CPU 7.

[0045] Thus, in the power supply device according to this embodiment, it becomes possible to charge the main battery 2 with the power from the spare battery 10, and to efficiently and appropriately utilize the power from the spare battery 10 according to the priority of the load.

[0046] (Third embodiment of the present invention) The power supply device according to this embodiment will be described with reference to Figure 5. In the following embodiment, the operation panel and operation method for safer operation of the power supply system 100 will be specifically described. Note that in this embodiment, explanations that overlap with the previous embodiments will be omitted.

[0047] Figure 5 is an external view of the control panel of the power supply unit according to this embodiment. The control panel 20 is located on the outer side of the power supply unit 1 and has a first connection port 51c (connection connector for two electric wires (positive and negative), two communication lines, and a ground wire) for connecting the first cable 11, a second connection port 52c (connection connector for two electric wires (positive and negative), two communication lines, and a ground wire) for connecting the second cable 12, and a breaker 21 for switching the connection of the changeover switch 6. It also has a notch 22 for pulling out the connected first cable 11 and second cable 12, and a cover 23 is installed to cover the entire control panel 20. This cover 23 is openable and closable and has a structure that prevents it from being easily opened by a locking mechanism 24.

[0048] Furthermore, the control panel 20 and cover 23 are equipped with open / close sensors 25, and information on whether the cover 23 is closed is transmitted from the open / close sensors 25 to the CPU 7. When the start button 13 is pressed, the CPU 7 turns on the main switch 8 to electrically connect the spare battery 10 to the load, provided that the first communication line 51b and the second communication line 52b are connected (information from the spare battery 10 is being transmitted and received in a loop), the changeover switch 6 is connected to the spare connection circuit 5 by the breaker 21, and the open / close sensor 25 is closed. If even one of these conditions is not met, the main switch 8 will not turn on and the system will not operate, no matter how many times the start button 13 is pressed. In other words, the system cannot operate if safety is not sufficiently ensured.

[0049] Note that the above operating conditions apply to backup operation. In normal operation, the CPU 7 turns on the main switch 8 and starts operating based on information such as the status of the main battery 2, which is a common practice. The simplest way to determine whether it is starting up in normal operation or backup operation is by the status of the circuit breaker 21 (for example, if the circuit breaker 21 is ON (the changeover switch 6 is connected to the backup connection circuit 5), it is backup operation; if it is OFF (the changeover switch 6 is connected to the main battery 2), it is normal operation). However, it is also desirable to consider whether information from the backup battery 10 is being successfully transmitted to the CPU 7 as a factor in the determination.

[0050] As described above, the power supply unit 1 according to this embodiment includes an operation panel 20 disposed on the surface of the housing of the power supply unit 1, a cover 23 installed on the operation panel 20 in a manner that allows it to be opened and closed, and an open / close sensor 25 that detects whether the cover 23 is closed. The CPU 7 controls the power supply unit to supply power from the auxiliary battery 10 to the load when the first cable 11 and the second cable 12 are connected to the first connection port 51c and the second connection port 52c respectively, and the cover 23 is closed while the breaker 21 is ON, thus ensuring an extremely high level of safety.

[0051] (Other embodiments of the present invention) Other embodiments are described below. In each of the above embodiments, if the first cable 11 and / or the second cable 12 are disconnected or unplugged, the CPU 7 instantly detects this and opens the main switch 8, prioritizing safety. In addition, even if the cables themselves remain physically connected to the connectors, a malfunction in the wires or communication lines within the cables may interrupt communication, causing the CPU 7 to open the main switch 8.

[0052] In the former case, reconnecting the disconnected cable and restarting the system will allow for operation as before. In the latter case, even after restarting, it will be difficult to operate the system as before unless the cable is replaced. However, even if operation in a loop-shaped communication network is difficult, it is possible to maintain operation using serial communication with only one cable.

[0053] In this embodiment, in addition to normal operation and backup operation modes, there is also an emergency operation mode. If an abnormality occurs in the first cable 11 or the second cable 12 (when electrical or communication connections become impossible), the system can be activated by pressing an emergency operation mode button (not shown). When supplying power to medical equipment as described above, maintaining operation is just as important as safety. That is, if it is possible to connect to the backup battery 10 using only one cable, and it is determined to be an extremely urgent situation, operation will be resumed in emergency operation mode.

[0054] In emergency operation mode, the spare battery 10 and the power supply unit 1 are connected by a single wire, making it difficult to maintain the extremely high level of safety as in the first and second embodiments described above, where the CPU 7 instantly detects the moment the connection is lost and turns off the main switch 8. However, power supply to the load can be continued. Activation by the emergency operation mode button is performed when the CPU 7 turns on the main switch 8, provided that communication with the spare battery 10 is possible and the breaker 21 is ON (the changeover switch 6 is connected to the spare connection circuit 5).

[0055] Thus, in the power supply device according to this embodiment, even if a malfunction occurs in either the first cable 11 or the second cable 12 and it becomes unusable, it is possible to continue supplying power to the load by connecting the power supply device 1 and the spare battery 10 with a single wire. However, it is desirable to establish a rule that this operation is only for emergencies and should be used only temporarily until a replacement cable is supplied. [Explanation of Symbols]

[0056] 1 Power supply 2 Main Battery 3 charger 4 Inverters 5. Auxiliary connection circuit 6. Changeover switch 7 CPU 8 Main Switch 10 spare batteries 10a Other spare batteries 11 Cable 1 12. Second cable 13. Start button 14 DC / AC Converters 20 Control Panel 21 Circuit breaker 22 Notch 23 Cover 24 Locking mechanism 25 Open / Close Sensor 51a First wiring 51b First communication line 51c First connection port 52a Second wiring 52b Second communication line 52c Second connection port 60 CT 61 Auxiliary charging switch 100 Power Systems

Claims

1. A rechargeable main battery, An inverter converts direct current to alternating current and supplies it to the load, A control unit that manages and controls the entire power supply unit, A connection circuit for electrically connecting an external backup battery and the load, The system includes a changeover switch that switches whether the load is connected to the main battery or the auxiliary battery, The power supply device is characterized in that the connection circuit has two parallel wires, a first wire and a second wire, and a first connection port and a second connection port corresponding to each wire, for connection to one spare battery.

2. In the power supply device according to claim 1, A first communication line corresponding to the first wiring, which communicates between the control unit and the BMS of the spare battery, The system includes a second communication line corresponding to the second wiring, which communicates between the control unit and the BMS of the spare battery, A power supply device characterized in that a communication network is formed in a loop shape by the control unit, the first communication line, the second communication line, and the BMS of the spare battery.

3. In the power supply device according to claim 2, The power supply device is characterized in that the control unit performs a process to stop the operation of the power supply device when a communication disconnection and an open state are detected at any point in the loop-shaped communication network.

4. In the power supply device according to any one of claims 1 to 3, A power supply device characterized by comprising a charger that charges the main battery from another spare battery when the load is connected to the spare battery by the aforementioned changeover switch.

5. In the power supply device according to any one of claims 1 to 3, A power supply device characterized in that, when the load is connected to the auxiliary battery by the changeover switch, the control unit determines whether to charge the main battery from the auxiliary battery based on the remaining charge of the auxiliary battery and the power consumption of the load.

6. In the power supply device according to any one of claims 1 to 3, An operating unit is provided on the surface of the housing of the power supply unit and has a first connection port, a second connection port, and a circuit breaker for switching the changeover switch, A cover is installed in a manner that allows it to be opened and closed relative to the aforementioned operating section, The system includes a detection sensor that detects whether the cover is closed, A power supply device characterized in that the control unit controls the supply of power from the backup battery to the load when cables are connected to the first connection port and the second connection port, and the cover is closed with the circuit breaker ON.

7. A power supply system comprising the power supply device according to claim 2 or 3 and the auxiliary battery connected, A power supply system characterized in that the first connection port and the spare battery are connected by a first composite cable having electric wires and communication lines, and the second connection port and the spare battery are connected by a second composite cable having electric wires and communication lines.

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