Uninterruptible power supply system and method for updating the uninterruptible power supply system
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- TMEIC CORP (100 00)
- Filing Date
- 2024-06-27
- Publication Date
- 2026-06-17
AI Technical Summary
Existing parallel redundant uninterruptible power supply systems require a bypass circuit during UPS unit replacement, leading to increased system size due to the need for a maintenance bypass panel.
The system eliminates the need for a bypass circuit by incorporating a parallel board with switches and a parallel test output terminal, allowing for parallel testing without increasing the system's physical size.
This configuration enables UPS updates without enlarging the system, reducing installation space requirements and maintaining uninterrupted power supply during testing.
Smart Images
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Abstract
Description
[Technical Field]
[0001] The present disclosure relates to an uninterruptible power supply system and a method for updating an uninterruptible power supply system. [Background technology]
[0002] Japanese Patent Laid-Open Publication No. 2017-50933 (Patent Document 1) discloses a parallel redundant uninterruptible power supply system, which includes a plurality of uninterruptible power supplies (UPS) connected in parallel to a load. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-50933 Summary of the Invention [Problem to be solved by the invention]
[0004] In the above-mentioned parallel redundant uninterruptible power supply system, when each of the multiple existing UPS units is replaced with a new UPS unit, a test (hereinafter also referred to as a "parallel test") must be conducted to check for any abnormalities in the parallel operation control of the multiple replaced UPS units. At the same time, it is necessary to continue supplying power to the load even during the parallel test. Therefore, it is necessary to provide a bypass circuit in the UPS system for the UPS replacement work. As a result, the size of the UPS system panel becomes larger.
[0005] Therefore, an object of the present disclosure is to provide an uninterruptible power supply system that does not require a bypass circuit for UPS update work, and an update method for the uninterruptible power supply system. [Means for solving the problem]
[0006] The uninterruptible power supply system of the present disclosure includes a plurality of uninterruptible power supplies and a parallel board arranged between output terminals of the plurality of uninterruptible power supplies and a load. The parallel board includes a plurality of parallel board switches, each arranged between the output terminal of a corresponding uninterruptible power supply and the load. Each of the plurality of uninterruptible power supplies includes a power converter that generates an AC voltage of a predetermined frequency from an AC power source, a bypass circuit that is arranged in parallel with the power converter and supplies power from the AC power source, a first switch arranged between the output of the power converter and the output terminal, a second switch arranged between the bypass circuit and the output terminal, a parallel test output terminal configured to be connectable to a parallel test cable for parallel testing of the plurality of uninterruptible power supplies, and a third switch connected between the output of the power converter and the parallel test output terminal.
[0007] In a method for updating an uninterruptible power supply system according to the present disclosure, the uninterruptible power supply system includes a plurality of uninterruptible power supplies and a parallel panel arranged between output terminals of the plurality of uninterruptible power supplies and a load. The parallel panel includes a plurality of parallel panel switches, each arranged between the output terminal of a corresponding uninterruptible power supply and the load. Each of the plurality of uninterruptible power supplies includes a power converter that generates an AC voltage of a predetermined frequency from an AC power source, a bypass circuit arranged in parallel with the power converter and supplying power from the AC power source, a first switch arranged between the output of the power converter and the output terminal, a second switch arranged between the bypass circuit and the output terminal, a parallel test output terminal configured to be connectable to a parallel test cable for parallel testing of the plurality of uninterruptible power supplies, and a third switch connected between the output of the power converter and the parallel test output terminal. The uninterruptible power supply system updating method includes, during parallel testing of at least two of the plurality of uninterruptible power supplies, turning on the third switch in at least two uninterruptible power supplies and turning on at least one of the plurality of parallel panel switches to supply power to the load. [Effects of the Invention]
[0008] According to the present disclosure, the UPS system does not include a bypass circuit for UPS update work, so that it is possible to avoid increasing the size of the UPS system panel. [Brief explanation of the drawings]
[0009] [Figure 1] FIG. 2 is a diagram showing the configuration of a UPS 1 of a reference example. [Figure 2] FIG. 1 is a diagram showing the configuration of a parallel UPS system of a reference example. [Figure 3] FIG. 10 is a diagram for explaining a switching procedure when a third UPS 1C is newly installed or updated in the reference example. [Figure 4] FIG. 10 is a diagram showing the flow of power in step ST1 of a reference example. [Figure 5] FIG. 10 is a diagram showing the flow of power in step ST2 of a reference example. [Figure 6] FIG. 10 is a diagram showing the flow of power in step ST3 of a reference example. [Figure 7] FIG. 10 is a diagram showing the flow of power in step ST4 of a reference example. [Figure 8] FIG. 10 is a diagram showing the flow of power in step ST5 of a reference example. [Figure 9] FIG. 10 is a diagram showing the flow of power in step ST6 of a reference example. [Figure 10] FIG. 10 is a diagram showing the flow of power in step ST7 of a reference example. [Figure 11] FIG. 10 is a diagram showing the flow of power in step ST8 of a reference example. [Figure 12] FIG. 10 is a diagram showing the flow of power in step ST9 of a reference example. [Figure 13] FIG. 10 is a diagram showing the flow of power in step ST10 of a reference example. [Figure 14] 1 is a diagram showing the configuration of a UPS 1 according to an embodiment. [Figure 15] 1 is a diagram showing the configuration of a parallel UPS system according to an embodiment; [Figure 16]FIG. 10 is a diagram for explaining a switching procedure when a third UPS 1C is newly installed or updated in the embodiment. [Figure 17] FIG. 4 is a diagram showing the flow of power in step ST1 of the embodiment. [Figure 18] FIG. 4 is a diagram showing the flow of power in step ST2 of the embodiment. [Figure 19] FIG. 10 is a diagram showing the flow of power in step ST3 of the embodiment. [Figure 20] FIG. 10 is a diagram showing the flow of power in step ST4 of the embodiment. [Figure 21] FIG. 10 is a diagram showing the flow of power in step ST5 of the embodiment. [Figure 22] FIG. 10 is a diagram showing the flow of power in step ST6 of the embodiment. [Figure 23] FIG. 10 is a diagram showing the flow of power in step ST7 of the embodiment. DETAILED DESCRIPTION OF THE INVENTION
[0010] Hereinafter, embodiments will be described with reference to the drawings.
[0011] (Reference example) First, a reference example will be described.
[0012] FIG. 1 is a diagram showing the configuration of a UPS 1 of a reference example.
[0013] The UPS 1 includes an input terminal 18, a bypass input terminal 16, a battery terminal 20, an output terminal 7, a bypass circuit 2, an AC input contactor (switch) 11, a converter 10, an inverter 9, a bypass side contactor (switch) 5, a converter side contactor (switch) 6, a chopper circuit 8, and a control circuit 4. The converter 10 and the inverter 9 constitute a power converter PT.
[0014] An input terminal 18 receives AC power of commercial frequency from a commercial AC power source 17 .
[0015] The bypass input terminal 16 receives AC power of commercial frequency from a commercial AC power source 17 .
[0016] The battery terminal 20 is connected to a battery 14. The battery 14 stores DC power. A capacitor may be connected instead of the battery 14.
[0017] The output terminal 7 supplies power to a load 19 .
[0018] The switch 11 is disposed between the input terminal 18 and the converter 10 .
[0019] Converter 10 receives commercial frequency AC power from a commercial AC power supply 17 via an AC input contactor 11. Under normal conditions, converter 10 converts the AC power supplied from commercial AC power supply 17 via switch 11 into DC power and outputs it to DC line L1. The output voltage of converter 10 can be controlled to a desired value. In the event of a power outage at commercial AC power supply 17, operation of converter 10 is stopped.
[0020] The inverter 9 is connected to the DC line L1. The inverter 9 converts DC power supplied from the converter 10 via the DC line L1 into AC power of a commercial frequency and outputs the converted power. The AC power generated by the inverter 9 is supplied to a load 19 via a switch 6. The inverter 9 normally converts the DC power supplied from the converter 10 into AC power, and converts the DC power supplied from the battery 14 into AC power in the event of a power outage at the commercial AC power source 17. The output voltage of the inverter 9 can be controlled to a desired value.
[0021] The chopper circuit 8 is connected to the converter 10 and the switch 13. The chopper circuit 8 is connected to the converter 10 in parallel with the inverter 9, and adjusts the voltage level of the DC voltage supplied to the battery 14.
[0022] When supplying AC power generated by inverter 9 to load 19, control circuit 4 sets switch 5 off and switch 6 on. Under normal circumstances, control circuit 4 sets switch 11 on and switch 13 off, and controls converter 10 and inverter 9 to generate AC power of the commercial frequency. During a power outage, control circuit 4 sets switch 11 off and switch 13 on, stops operation of converter 10, and controls inverter 9 to generate AC power of the commercial frequency.
[0023] Control circuit 4 sets switch 5 on and switch 6 off when AC power is to be supplied from commercial AC power supply 17 to load 19 without going through inverter 9. Even if a failure occurs in converter 10 or inverter 9, power can be continuously supplied to load 19.
[0024] Next, a parallel UPS system will be described. A parallel UPS system is a system configured by connecting multiple UPS units in parallel when a large capacity is required.
[0025] FIG. 2 is a diagram showing the configuration of a parallel UPS system according to a reference example.
[0026] The UPS system of the reference example includes a first UPS 1A, a second UPS 1B, a third UPS 1C, a parallel panel 27, a maintenance bypass panel 26, and a UPS input panel 35.
[0027] The maintenance bypass panel 26 includes circuit breakers (switches) 21, 22, and 23. The UPS input panel 35 includes circuit breakers (switches) 36A, 36B, and 36C. The parallel panel 27 includes reactors 28A, 28B, and 28C, and parallel circuit breakers (switches) 29A, 29B, and 29C.
[0028] Switch 21 is disposed between commercial AC power supply 17 and first terminals of switches 36A, 36B, and 36C. A second terminal of switch 36A is connected to input terminal 18A and bypass input terminal 16A. A second terminal of switch 36B is connected to input terminal 18B and bypass input terminal 16B. A second terminal of switch 36C is connected to input terminal 18C and bypass input terminal 16C.
[0029] An output terminal 7A of the UPS 1A is connected to a first terminal of a switch 29A via a reactor 28A. An output terminal 7B of the UPS 1B is connected to a first terminal of a switch 29B via a reactor 28B. An output terminal 7C of the UPS 1C is connected to a first terminal of a switch 29C via a reactor 28C.
[0030] The second terminals of the switches 29A, 29B, and 29C are connected to the parallel bus 31 and the first terminal of the switch 23. The second terminal of the switch 23 is connected to the load 19.
[0031] A first terminal of the switch 22 is connected to a first terminal of the switch 21 and the commercial AC power supply 17 , and a second terminal of the switch 22 is connected to a second terminal of the switch 23 and the load 19 .
[0032] In a parallel UPS system such as the one shown in Figure 2, a parallel test must be performed when installing or updating a UPS. If the parallel test is performed while continuing to supply power to the load, it is necessary to provide a circuit that bypasses UPS 1A, 1B, and 1C and isolates UPS 1A, 1B, and 1C from the load equipment so as not to affect the power supply to load 19. For this purpose, a maintenance bypass panel 26 is required to house maintenance bypass circuit 24, which is not used under normal conditions.
[0033] (Procedure for installing or updating a UPS) Next, a description will be given of the procedure for installing or updating one UPS 1. Fig. 3 is a diagram for explaining the switching procedure for installing or updating a third UPS 1C in the reference example.
[0034] In step ST1, switches 21, 36A, 36B, 11A, 11B, 6A, 6B, 29A, 29B, and 23 are set to ON. The other switches are turned OFF. At this time, as shown in FIG. 4, power is supplied from commercial AC power supply 17 to first UPS 1A and second UPS 1B. Converter 10A and inverter 9A of first UPS 1A are supplied with power from commercial AC power supply 17 and operate, and converter 10B and inverter 9B of second UPS 1B are supplied with power from commercial AC power supply 17 and operate, and power from first UPS 1A and second UPS 1B is supplied to load 19.
[0035] In step ST2, the switches 36C and 5C are set to ON. At this time, as shown in Fig. 5, the third UPS 1C is supplied with power from the commercial AC power supply 17. In the third UPS 1C, the bypass circuit 2C is turned ON.
[0036] In step ST3, the switch 5C is set to OFF, and the switches 11C and 6C are set to ON. At this time, as shown in Fig. 6, in the third UPS 1C, the bypass circuit 2C is turned OFF, and the converter 10C and the inverter 9C operate by receiving power from the commercial AC power supply 17. Since the output of the third UPS 11C is not connected to the load 19, an independent test of the third UPS 1C is performed.
[0037] In step ST4, switches 5A, 5B, and 5C are set to ON, and switches 11A, 11B, 11C, 6A, 6B, and 6C are set to OFF. At this time, as shown in FIG. 7, power is supplied from commercial AC power supply 17 to load 19 via bypass circuits 2A and 2B.
[0038] In step ST5, the switches 29C and 22 are set to ON. At this time, as shown in FIG. 8, power is supplied from the commercial AC power supply 17 to the load 19 via the bypass circuits 2A, 2B, and 2C and the maintenance bypass path 41.
[0039] In step ST6, the switch 23 is set to OFF. At this time, power is supplied from the commercial AC power supply 17 to the load 19 via only the maintenance bypass path 41, as shown in FIG.
[0040] In step ST7, switches 5A, 5B, and 5C are set to OFF, and switches 11A, 11B, 11C, 6A, 6B, and 6C are set to ON. At this time, a parallel test is performed as shown in Fig. 10. During this time, power is supplied to load 19 from commercial AC power supply 17 only via maintenance bypass path 41.
[0041] In step ST8, switches 5A, 5B, and 5C are set to ON, and switches 11A, 11B, 11C, 6A, 6B, and 6C are set to OFF. At this time, as shown in FIG. 11 , power is supplied from commercial AC power supply 17 to load 19 via only maintenance bypass path 41.
[0042] In step ST9, the switch 23 is set to ON and the switch 22 is set to OFF. At this time, as shown in Fig. 12, power is supplied from the commercial AC power supply 17 to the load 19 only via the bypass circuits 2A, 2B, and 2C.
[0043] In step ST10, switches 5A, 5B, and 5C are set to OFF, and switches 11A, 11B, 11C, 6A, 6B, and 6C are set to ON. At this time, as shown in Fig. 13, power is supplied from commercial AC power supply 17 to load 19 via inverter 9A, converter 10A, inverter 9B, converter 10B, inverter 9C, and converter 10C, and normal operation is performed.
[0044] The UPS system in the reference example needs to be equipped with a maintenance bypass circuit. In the reference example, a panel is required to house the maintenance bypass circuit, which is not normally used, which poses the problem of having to prepare extra installation space.
[0045] Embodiment FIG. 14 is a diagram showing the configuration of a UPS 1 according to an embodiment.
[0046] UPS 1 includes an input terminal 18, a bypass input terminal 16, a battery terminal 20, an output terminal 7, a parallel test output terminal 38, a bypass circuit 2, an AC input contactor (switch) 11, a converter 10, an inverter 9, a bypass side contactor (switch) 5, a converter side contactor (switch) 6, a parallel test contactor (switch) 37, a chopper circuit 8, and a control circuit 4. Converter 10 and inverter 9 constitute a power converter PT.
[0047] An input terminal 18 receives AC power of commercial frequency from a commercial AC power source 17 .
[0048] The bypass input terminal 16 receives AC power of commercial frequency from a commercial AC power source 17 .
[0049] The battery terminal 20 is connected to a battery 14. The battery 14 stores DC power. A capacitor may be connected instead of the battery 14.
[0050] The output terminal 7 supplies power to a load 19 .
[0051] The switch 11 is disposed between the input terminal 18 and the converter 10 .
[0052] Converter 10 receives commercial frequency AC power from a commercial AC power supply 17 via an AC input contactor 11. Under normal conditions, converter 10 converts the AC power supplied from commercial AC power supply 17 via switch 11 into DC power and outputs it to DC line L1. The output voltage of converter 10 can be controlled to a desired value. In the event of a power outage at commercial AC power supply 17, operation of converter 10 is stopped.
[0053] The inverter 9 is connected to the DC line L1. The inverter 9 converts DC power supplied from the converter 10 via the DC line L1 into AC power of a commercial frequency and outputs the converted power. The AC power generated by the inverter 9 is supplied to a load 19 via a switch 6. The inverter 9 normally converts the DC power supplied from the converter 10 into AC power, and converts the DC power supplied from the battery 14 into AC power in the event of a power outage at the commercial AC power source 17. The output voltage of the inverter 9 can be controlled to a desired value.
[0054] The chopper circuit 8 is connected to the converter 10 and the switch 13. The chopper circuit 8 is connected to the converter 10 in parallel with the inverter 9, and adjusts the voltage level of the DC voltage supplied to the battery 14.
[0055] The parallel test output terminal 38 is configured to be connectable to a parallel test cable for parallel testing of a plurality of UPSs.
[0056] The switch 37 is provided between the output of the inverter 9 and a parallel test output terminal 38 .
[0057] When supplying AC power generated by inverter 9 to load 19, control circuit 4 sets switch 5 off and switch 6 on. Under normal circumstances, control circuit 4 sets switch 11 on and switch 13 off, and controls converter 10 and inverter 9 to generate AC power of the commercial frequency. During a power outage, control circuit 4 sets switch 11 off and switch 13 on, stops operation of converter 10, and controls inverter 9 to generate AC power of the commercial frequency.
[0058] Control circuit 4 sets switch 5 on and switch 6 off when AC power is to be supplied from commercial AC power supply 17 to load 19 without going through inverter 9. Even if a failure occurs in converter 10 or inverter 9, power can be continuously supplied to load 19.
[0059] When a parallel test of a plurality of UPSs 1 is to be performed, the control circuit 4 sets the switch 37 to ON.
[0060] Next, a parallel UPS system will be described. A parallel UPS system is a system configured by connecting multiple UPS units in parallel when a large capacity is required.
[0061] FIG. 15 is a diagram showing the configuration of a parallel UPS system according to an embodiment.
[0062] The UPS system includes a first UPS 1A, a second UPS 1B, a third UPS 1C, a parallel panel 27, and a UPS input panel 35.
[0063] The UPS input panel 35 includes circuit breakers (switches) 36A, 36B, and 36C. The parallel panel 27 includes reactors 28A, 28B, and 28C, and parallel circuit breakers (switches) 29A, 29B, and 29C.
[0064] First terminals of switches 36A, 36B, and 36C are connected to commercial AC power supply 17. A second terminal of switch 36A is connected to input terminal 18A and bypass input terminal 16A. A second terminal of switch 36B is connected to input terminal 18B and bypass input terminal 16B. A second terminal of switch 36C is connected to input terminal 18C and bypass input terminal 16C.
[0065] An output terminal 7A of the UPS 1A is connected to a first terminal of a switch 29A via a reactor 28A. An output terminal 7B of the UPS 1B is connected to a first terminal of a switch 29B via a reactor 28B. An output terminal 7C of the UPS 1C is connected to a first terminal of a switch 29C via a reactor 28C.
[0066] The second terminals of the switches 29A, 29B, 29C are connected to the parallel bus 31 and the load 19.
[0067] First terminals of switches 37A, 37B, and 37C are connected to the outputs of inverters 9A, 9B, and 9C. Second terminals of switches 37A, 37B, and 37C are connected to parallel test output terminals 38A, 38B, and 38C. Parallel test output terminals 38A, 38B, and 38C are connected to parallel test cable 39.
[0068] (Procedure for installing or updating a UPS) Next, a description will be given of the procedure for newly installing or updating one UPS 1. Fig. 16 is a diagram for explaining the switching procedure for newly installing or updating a third UPS 1C in the embodiment.
[0069] In step ST1, switches 36A, 36B, 11A, 11B, 6A, 6B, 29A, and 29B are set to ON. The other switches are turned OFF. At this time, as shown in FIG. 17, power is supplied from commercial AC power supply 17 to first UPS 1A and second UPS 1B. Converter 10A and inverter 9A of first UPS 1A are supplied with power from commercial AC power supply 17 and operate, and converter 10B and inverter 9B of second UPS 1B are supplied with power from commercial AC power supply 17 and operate, and power from first UPS 1A and second UPS 1B is supplied to load 19.
[0070] In step ST2, the switches 36C and 5C are set to ON. At this time, as shown in Fig. 18, the third UPS 1C is supplied with power from the commercial AC power supply 17. In the third UPS 1C, the bypass circuit 2C is turned ON.
[0071] In step ST3, the switch 5C is set to OFF, and the switches 11C and 6C are set to ON. At this time, as shown in Fig. 19, in the third UPS 1C, the bypass circuit 2C is turned OFF, and the converter 10C and the inverter 9C operate by receiving power from the commercial AC power supply 17. Since the output of the third UPS 11C is not connected to the load 19, an independent test of the third UPS 1C is performed.
[0072] In step ST4, switches 5A and 5B are set to ON, and switches 11A, 11B, 6A, and 6B are set to OFF. At this time, as shown in Fig. 20, power is supplied from commercial AC power supply 17 to load 19 via bypass circuits 2A and 2B.
[0073] In step ST5, the switches 11B, 37B, 11C, and 37C are set to ON. At this time, a parallel test of the second UPS 1B and the third UPS 1C is performed as shown in Fig. 21. Power supply from the bypass circuits 2A and 2B continues.
[0074] In step ST6, switches 5C and 29C are turned on and switches 37B and 37C are turned off. At this time, power is supplied from commercial AC power supply 17 to load 19 via bypass circuits 2A, 2B, and 2C, as shown in FIG.
[0075] In step ST7, switches 5A, 5B, and 5C are set to OFF, and switches 6A, 6B, and 6C are set to ON. At this time, as shown in Fig. 23, power is supplied from commercial AC power supply 17 to load 19 via inverter 9A, converter 10A, inverter 9B, converter 10B, inverter 9C, and converter 10C, and normal operation is performed.
[0076] As described above, according to this embodiment, since there is no need to provide a maintenance bypass panel as in the reference example, the size of the UPS system can be reduced, and as a result, the UPS system can be installed in a relatively small space.
[0077] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The present invention is defined by the claims rather than the above description, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]
[0078] 2, 2A, 2B, 2C: Bypass circuit, 4, 4A, 4B, 4C: Control circuit, 5, 5A, 5B, 5C, 6, 6A, 6B, 6C, 11, 11A, 11B, 11C, 13, 13A, 13B, 13C, 21, 22, 23, 29A, 29B, 29C, 36A, 36B, 36C, 37, 37A, 37B, 37C: Switch, 7, 7A, 7B, 7C: Output terminal, 8, 8A, 8B, 8C: Chopper circuit, 9, 9A, 9B, 9C: Inverter, 10, 10A, 10B, 10C: Converter, 14, 14A, 14B, 14C: Battery, 16, 16A, 16B, 16C: Bypass input terminal, 17: Commercial AC power supply, 18, 18A, 18B, 18C Input terminal, 19 load, 20, 20A, 20B, 20C battery terminals, 24 maintenance bypass circuit, 26 maintenance bypass panel, 27 parallel panel, 28A, 28B, 28C reactor, 31 parallel busbar, 35 input panel, 38, 38A, 38B, 38C parallel test output terminal, 39 parallel test cable, 41 maintenance bypass path, L1 DC line.
Claims
1. Multiple uninterruptible power supplies, The system comprises a parallel panel positioned between the output terminals of the multiple uninterruptible power supplies and the load, Each parallel panel comprises a plurality of parallel panel switches, each positioned between the output terminal of the corresponding uninterruptible power supply and the load. Each of the aforementioned plurality of uninterruptible power supplies is: A power converter that generates an AC voltage of a predetermined frequency from an AC power source, A bypass circuit is provided in parallel with the power converter and supplies power from an AC power source, A first switch is positioned between the output of the power converter and the output terminal, A second switch is positioned between the bypass circuit and the output terminal, For parallel testing of the aforementioned multiple uninterruptible power supplies, a parallel test output terminal configured to be connectable to a parallel test cable is provided, An uninterruptible power supply system comprising a third switch connected between the output of the power converter and the parallel test output terminal.
2. The uninterruptible power supply system according to claim 1, wherein during parallel testing of at least two of the plurality of uninterruptible power supplies, the third switch is turned on in at least two of the uninterruptible power supplies, at least one of the plurality of parallel panel switches is turned on, and power is supplied to the load.
3. The uninterruptible power supply system according to claim 2, wherein during parallel testing of at least two of the plurality of uninterruptible power supplies, the first switch is turned off and the second switch is turned on in at least two of the uninterruptible power supplies.
4. The uninterruptible power supply system according to claim 3, in which the uninterruptible power supply is connected to at least one parallel panel switch that turns on, the first switch is turned off and the second switch is turned on.
5. The aforementioned power converter is An inverter connected to the aforementioned AC power supply and converting the voltage of the AC power supply to a DC voltage, The uninterruptible power supply system according to claim 1, further comprising a converter connected to the inverter and converting the DC voltage to an AC voltage.
6. Each of the aforementioned plurality of uninterruptible power supplies is: Energy storage device, The uninterruptible power supply system according to claim 5, further comprising a chopper circuit connected in parallel with the inverter and the converter, and which adjusts the voltage level of the DC voltage supplied to the energy storage device.
7. The aforementioned parallel panel is, The uninterruptible power supply system according to claim 1, comprising a plurality of reactors, each having a first end connected to the output terminal of the corresponding uninterruptible power supply and a second end connected to the corresponding parallel panel switch.
8. Each of the aforementioned plurality of uninterruptible power supplies is: An input terminal connected to the input of the power converter, Includes a bypass input terminal connected to the bypass circuit, The system comprises an AC power supply and an input panel positioned between the input terminals and bypass input terminals of the plurality of uninterruptible power supplies, The uninterruptible power supply system according to claim 1, wherein the input panel includes a plurality of input panel switches, each positioned between the AC power source and the input terminal and the bypass input terminal of the uninterruptible power supply corresponding to the AC power source.
9. Each of the aforementioned plurality of uninterruptible power supplies is: The uninterruptible power supply system according to claim 8, further comprising a fourth switch disposed between the input terminal and the input of the power converter.
10. A method for updating an uninterruptible power supply system, The aforementioned uninterruptible power supply system is Multiple uninterruptible power supplies, The system comprises a parallel panel positioned between the output terminals of the multiple uninterruptible power supplies and the load, Each parallel panel comprises a plurality of parallel panel switches, each positioned between the output terminal of the corresponding uninterruptible power supply and the load. Each of the aforementioned plurality of uninterruptible power supplies is: A power converter that generates an AC voltage of a predetermined frequency from an AC power source, A bypass circuit is provided in parallel with the power converter and supplies power from an AC power source, A first switch is positioned between the output of the power converter and the output terminal, A second switch is positioned between the bypass circuit and the output terminal, For parallel testing of the aforementioned multiple uninterruptible power supplies, a parallel test output terminal configured to be connectable to a parallel test cable is provided, The system includes a third switch connected between the output of the power converter and the parallel test output terminal, The method for updating the aforementioned uninterruptible power supply system is: A method for updating an uninterruptible power supply system, comprising the step of, during a parallel test of at least two of the plurality of uninterruptible power supplies, setting the third switch on and setting at least one of the plurality of parallel panel switches on to supply power to the load.
11. A method for updating an uninterruptible power supply system according to claim 10, comprising the step of setting the first switch to the off position and the second switch to the on position in at least two of the plurality of uninterruptible power supplies during a parallel test of at least two of the plurality of uninterruptible power supplies.
12. A method for updating an uninterruptible power supply system according to claim 11, comprising the step of setting the first switch to off and the second switch to on, in an uninterruptible power supply connected to the at least one parallel panel switch that is turned on.
13. During a standalone test of the first uninterruptible power supply (UPS) that is the subject of the parallel test among the plurality of UPS units, Of the plurality of parallel panel switches, the parallel panel switch connected to the first uninterruptible power supply is set to OFF, and in the first uninterruptible power supply, the first switch is set to ON, the second switch is set to OFF, and the third switch is set to OFF. A method for updating an uninterruptible power supply system according to any one of claims 10 to 12, further comprising the step of turning on a parallel panel switch connected to at least one of the plurality of parallel panel switches other than the first uninterruptible power supply to supply power to the load.