Uninterruptible power supply system

Abstract

To provide a small-sized and simply configured uninterruptible power supply system that supplies power to three or more systems of loads by synchronously controlling three or more systems of uninterruptible power supplies.SOLUTION: An uninterruptible power supply system 200 supplies power to three or more systems of loads 50a to 50c using three or more systems of uninterruptible power supplies 100a to 100c that include power conversion units 20a to 20c that convert power from an AC power supply S and output power to the loads 50a to 50c, and first bypass circuits 30a to 30c that directly output the power from the AC power supply S to the loads 50a to 50c, respectively. The uninterruptible power supplies 100a to 100c include information communication units 9a to 9c, respectively. The information communication units 9a to 9c are connected to other information communication units 9a to 9c so as to form a loop shape, and are configured to communicate with the other information communication units 9a to 9c connected in the loop shape.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an uninterruptible power supply system. [Background technology]

[0002] Conventionally, there is known an uninterruptible power supply system that supplies power to three or more loads using one of two uninterruptible power supplies connected to an AC power source (see, for example, Patent Document 1). The uninterruptible power supply system described in Patent Document 1 includes two uninterruptible power supply devices that supply power to three loads. Each uninterruptible power supply device includes an uninterruptible power supply that includes a bypass power supply circuit that supplies power from the AC power source directly to the load, a power conversion unit that adjusts the power supplied to the load, a voltage detector that detects the output of the power conversion unit of its own system and the output of the power conversion unit of the other system, and a synchronization selection circuit that acquires voltage via the voltage detector.

[0003] Furthermore, in Patent Document 1, each of the uninterruptible power supplies further includes a signal relay circuit for mutually communicating the voltages acquired by the synchronization selection circuits. In the uninterruptible power supply system described in Patent Document 1, the synchronization selection circuits in the uninterruptible power supplies mutually communicate information about the uninterruptible power supplies via the signal relay circuit, thereby synchronizing the outputs of the uninterruptible power supplies. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5347415 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned Patent Document 1, multiple voltage detectors are provided to detect the output of a power conversion unit of a home system and the output of a power conversion unit of another system. Patent Document 1 also discloses a configuration in which, among two uninterruptible power supply systems, the output of a power conversion unit of a home system and the output of a power conversion unit of another system are synchronized with the output voltage of one of the uninterruptible power supply systems. On the other hand, in an uninterruptible power supply system with three or more systems, if each uninterruptible power supply system is synchronized with the output voltage of one of the uninterruptible power supply systems, additional voltage detectors must be added to detect the output of the power conversion units of the third and subsequent systems, which results in a complex and large uninterruptible power supply system configuration. Therefore, there is a need for a compact and simply configured uninterruptible power supply system that supplies power to three or more loads by synchronously controlling three or more uninterruptible power supplies.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a small and simply configured uninterruptible power supply system that supplies power to three or more loads by synchronously controlling three or more uninterruptible power supplies. [Means for solving the problem]

[0007] In order to achieve the above object, an uninterruptible power supply system according to one aspect of the present invention is an uninterruptible power supply system that supplies power to three or more loads using three or more systems of uninterruptible power supplies, each system including a power conversion unit that converts power from an AC power supply and outputs it to a load, and a first bypass circuit that directly outputs the power from the AC power supply to the load, and each of the uninterruptible power supplies includes a detection unit that detects the voltage of the first bypass circuit of its own system in the uninterruptible power supply and the voltage of a bus bar to which power is output from the power conversion unit of its own system, a synchronization control unit that controls the voltage output by the power conversion unit of its own system to synchronize with a predetermined voltage, and an information communication unit that communicates detection information obtained based on the detection result of the detection unit, and the information communication unit is connected to other information communication units so as to form a loop and is configured to communicate with other information communication units connected in the loop, and the synchronization control unit is configured to control the voltage output by the power conversion unit of its own system to synchronize with the predetermined voltage based on the detection information obtained through communication by the information communication units connected in the loop.

[0008] In one aspect of the present invention, the uninterruptible power supply system includes an information communication unit connected to other information communication units to form a loop and configured to communicate with the other information communication units connected in the loop, and a synchronization control unit configured to control the voltage output by the power conversion unit of the home system to synchronize with a predetermined voltage based on detection information acquired through communication by the information communication units connected in the loop. This allows the information communication unit to acquire detection information from all of the other uninterruptible power supplies by communicating with the information communication units of the other systems connected in the loop, without the need for a new detection unit (voltage detector) for detecting the bus voltage of the other system. Therefore, the synchronization control unit can synchronize and control the power output from the power conversion unit of the home system to a predetermined voltage based on the detection information from the other uninterruptible power supplies. As a result, a compact and simple uninterruptible power supply system can be provided that supplies power to three or more loads by synchronously controlling three or more uninterruptible power supplies.

[0009] In the uninterruptible power supply system according to the above aspect, the predetermined voltage preferably includes the voltage of the first bypass circuit of the own system or the voltage of the bus bar of the other system, and the synchronization control unit is configured to perform control to switch and synchronize the voltage output by the power conversion unit of the own system with the voltage of the first bypass circuit of the own system or the voltage of the bus bar of the other system based on detection information acquired by communication from the information communication unit connected in the loop. With this configuration, control can be performed to synchronize the output voltage of the power conversion unit of the own system with a desired voltage, either the voltage of the first bypass circuit of the own system or the voltage of the bus bar of the other system, based on detection information acquired by communication from the information communication unit connected in the loop. As a result, the voltage output by the power conversion unit of the own system can be synchronized to an appropriate value, and power can be supplied to the load.

[0010] In this case, the detection information preferably includes at least one of the value, frequency, and phase of the voltage of the first bypass circuit of the own system and the voltage of the bus to which power is output from the power conversion unit of the own system, and the synchronization control unit included in each of the uninterruptible power supplies is configured to determine whether the detection information of the uninterruptible power supply of the own system, acquired through communication by the information communication unit connected in a loop, is within a normal range, and to perform control to switch and synchronize the voltage output from the power conversion unit of the own system with the voltage of the first bypass circuit of the own system or the voltage of the bus to which power is output from the power conversion unit of the other system based on the determination result. With this configuration, it is possible to determine whether the values ​​are appropriate for synchronization based on the voltage of the first bypass circuit of the own system and the voltage of the bus to which power is output from the power conversion unit of the own system. Therefore, the voltage output from the power conversion unit of the own system can be synchronized with the output voltage of the uninterruptible power supply determined to be outputting an appropriate value. As a result, the voltage output from the power conversion unit of the own system can be synchronized to a more appropriate value, allowing power to be supplied to the load.

[0011] In the uninterruptible power supply system, the synchronization control unit included in each of the uninterruptible power supplies determines whether detection information of the uninterruptible power supply of its own system, acquired through communication by the information communication unit connected in a loop, is within a normal range. Preferably, the synchronization control unit included in each of the uninterruptible power supplies is configured to perform control to exclude from synchronization uninterruptible power supplies of other systems that are determined to have detection information with a value outside the normal range, based on the detection information acquired through communication by the information communication unit connected in a loop. This configuration can prevent the voltage output by the power conversion unit of the own system from being synchronized with an uninterruptible power supply that is operating abnormally. As a result, the voltage output by the power conversion unit of the own system can be synchronized with that of an uninterruptible power supply that is operating normally, and power can be supplied to a load.

[0012] In the uninterruptible power supply system according to the above aspect, preferably, each of the uninterruptible power supplies is connected in parallel in its own system and includes a parallel communication unit that communicates detection information with a synchronization control unit included in each of the uninterruptible power supplies in its own system, and the parallel communication unit is configured to communicate detection information with the parallel communication units of other uninterruptible power supplies in its own system. With this configuration, even when multiple uninterruptible power supplies are arranged in one system, the output voltages from the power conversion units included in the multiple uninterruptible power supplies in each system can be synchronized and output to the load. As a result, even when multiple uninterruptible power supplies are in one system, the voltage output by the power conversion unit of the own system can be synchronized with that of one of the systems to supply power to the load.

[0013] In the uninterruptible power supply system according to the above aspect, preferably, the busbar further includes a switch that disconnects the uninterruptible power supply from the load, and the detection unit is configured to detect the voltage of the busbar of the system that is closer to the uninterruptible power supply than the switch. With this configuration, since the detection unit is configured to detect the voltage of the busbar of the system that is closer to the uninterruptible power supply than the switch, the uninterruptible power supply can be easily removed when performing maintenance or replacement of the uninterruptible power supply by opening the switch (off state). As a result, the workability of maintaining or replacing the uninterruptible power supply can be improved.

[0014] In this case, the system preferably further includes a bypass unit that is provided separately from the uninterruptible power supply, connected to a bus on the load side of the switch, and including a second bypass circuit that directly outputs power from the AC power supply to the load, a bypass voltage detection unit that detects the voltage of the second bypass circuit, and a bypass information communication unit that communicates detection information obtained by the bypass voltage detection unit. The bypass information communication unit is connected to other information communication units to form a loop and communicates with the other information communication units connected in the loop. With this configuration, even in a system from which the uninterruptible power supply has been removed for maintenance or replacement, power can be supplied to the load via the second bypass circuit. Furthermore, based on the detection information obtained via the information communication unit of the bypass unit, the voltage output by the power conversion unit of the system from which the uninterruptible power supply has not been removed can be synchronized with the voltage of the second bypass circuit. As a result, even if the uninterruptible power supply is removed from one system, power can be supplied to the load by synchronizing the voltage output by the power conversion unit of the system from which the uninterruptible power supply has not been removed with the voltage of one of the systems. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a small-sized uninterruptible power supply system with a simple configuration that supplies power to three or more loads by synchronously controlling three or more uninterruptible power supplies. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram showing the configuration of an uninterruptible power supply system according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing a configuration relating to connections of an information communication unit according to the first embodiment of the present invention. [Figure 3] FIG. 10 is a diagram for explaining a case where four information communication units are connected in a loop. [Figure 4] FIG. 1 is a diagram showing the configuration of an uninterruptible power supply system according to a comparative example. [Figure 5] FIG. 10 is a diagram showing the configuration of an uninterruptible power supply system according to a second embodiment of the present invention. [Figure 6] FIG. 10 is a diagram showing the configuration of an uninterruptible power supply system according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0018] [First embodiment] The configuration of an uninterruptible power supply system 200 according to a first embodiment will be described with reference to FIG.

[0019] (Configuration of uninterruptible power supply system 200) As shown in FIG. 1, the uninterruptible power supply system 200 supplies power output from an AC power supply S to three loads 50a, 50b, and 50c via a bus 10a, which is the output of a first system A, a bus 10b, which is the output of a second system B, and a bus 10c, which is the output of a third system C. The uninterruptible power supply system 200 includes transformers 1a, 1b, and 1c for converting the power supplied from the AC power supply S, and switchers 40a, 40b, and 40c for switching the system supplying power to the loads 50a, 50b, and 50c. The uninterruptible power supply system 200 also includes a first bypass circuit 30a, a second bypass circuit 2a, and an uninterruptible power supply 100a in system A. The uninterruptible power supply system 200 also includes a first bypass circuit 30b, a second bypass circuit 2b, and an uninterruptible power supply 100b in system B. The uninterruptible power supply system 200 also includes a first bypass circuit 30c, a second bypass circuit 2c, and an uninterruptible power supply 100c in system C. In the following explanation, the configuration of the first system A will be described, but the same explanation can be applied to the second system B and the third system C.

[0020] The first bypass circuit 30a is configured so that a part of it is included in the uninterruptible power supply 100a of the first system A, and is a circuit for transmitting power output from the transformer 1a to a connection point Aout on the bus 10a of the first system A. The first bypass circuit 30a is configured to include a switch 31a, a power line 32a, a thyristor switch 33a, and a first bypass switch 34a. In the uninterruptible power supply 100a of the first system A, if the power conversion unit 20a becomes unable to operate normally due to an abnormality, the switch 31a is turned on, and power is supplied to the connection point Aout on the bus 10a of the first system A through the thyristor switch 33a. Then, when a current flows through the thyristor switch 33a and the first bypass switch 34a is turned on, power is supplied via the first bypass switch 34a. The power line 32a used in the first bypass circuit 30a is a cable line made of a single wire or a twisted wire covered with a coating, or a metal bus bar.

[0021] The second bypass circuit 2a is a circuit for transmitting power supplied from the AC power supply S to the loads 50a to 50c via the second bypass circuit 2a when the uninterruptible power supply 100a of the first system A is removed for maintenance, replacement, or the like. The second bypass circuit 2a is a power line for transmitting power output from the transformer 1a to a connection point Aout on the bus 10a of the first system A. The second bypass circuit 2a also includes a second bypass switch 3a that opens and closes as necessary. The power line used in the second bypass circuit 2a may be a cable wire with a coated solid wire or a coated stranded wire, or a metal bus bar.

[0022] The uninterruptible power supply 100a is a power supply for supplying power to loads 50a to 50c during a power outage, etc. The uninterruptible power supply 100a includes a first bypass circuit 30a, a power conversion unit 20a including a converter unit 21a and an inverter unit 22a, a detection unit 7a that detects the voltage of the first bypass circuit 30a and the voltage of a connection point Aout on a bus 10a, a synchronization control unit 8a that controls the operation of the power conversion unit 20a, and an information communication unit 9a that communicates information obtained based on the results of detection by the detection unit 7a.

[0023] The detector 7a is configured with a voltage dividing resistor and the like, and detects the voltage of the first bypass circuit 30a applied via the transformer 12a and the voltage of the connection point Aout on the bus 10a applied via the transformer 11a. The detector 7a is also connected to the synchronization controller 8a, and transmits detection information including information such as the voltage value, frequency, and phase of the detected voltage to the synchronization controller 8a.

[0024] The synchronization control unit 8a is connected to the detection unit 7a, the information communication unit 9a, and the power conversion unit 20a, and controls the operation of the power conversion unit 20a based on detection information based on the voltage detected by the detection unit 7a and detection information from other systems acquired from the information communication unit 9a. More specifically, the synchronization control unit 8a controls the operation of the inverter unit 22a so that the voltage at the connection point Aout on the bus 10a output from the inverter unit 22a of the power conversion unit 20a is synchronized with either the voltage of the first bypass circuit 30a, the voltage at the connection point Bout on the bus 10b of the B system, or the voltage at the connection point Cout on the bus 10a of the C system. The synchronization control unit 8a also determines whether the detection information transmitted from the detection unit 7a is within a normal range and, based on the determination result, performs control such as switching the synchronization target of the voltage output by the inverter unit 22a. The synchronization control unit 8a uses a microcomputer or the like and is mounted on, for example, a PCB board. The synchronization control unit 8a includes a CPU (Central Processing Unit) as a processor, a ROM (Read Only Memory), and a RAM (Random Access Memory).

[0025] The information communication unit 9a is connected to the synchronization control unit 8a, the information communication unit 9b included in the uninterruptible power supply 100b of the B system, and the information communication unit 9c included in the uninterruptible power supply 100c of the C system, and communicates information obtained based on the results of detection by the detection unit 7a. The information communication units 9a, 9b, and 9c are connected to each other, thereby forming a loop. The information communication unit 9a communicates with the information communication units 9b and 9c connected in the loop, thereby acquiring detection information obtained based on the results of detection by the detection units 7b and 7c, and transmitting it to the synchronization control unit 8a. The information communication units 9a to 9c are configured with electronic circuits including logic circuits.

[0026] Here, the configuration of the information communication units 9a to 9c connected in a loop will be described using FIG. 2, which is a simplified diagram of the uninterruptible power supplies 100a to 100c. As shown in FIG. 2, the information communication units 9a to 9c included in the uninterruptible power supplies 100a to 100c are configured to form a loop (annular) when viewed as a whole, and each of the information communication units 9a to 9c can acquire information output by all of the information communication units 9a to 9c by mutually communicating information with the other information communication units 9a to 9c connected thereto. Here, for example, as shown in FIG. 3, a description will be given assuming that an uninterruptible power supply 100d is added and the information communication units 9a to 9d included in each of the uninterruptible power supplies 100a to 100d are connected in a loop. In this case, the information communication units 9a and 9d are not directly connected, but communicate information with each other via the information communication units 9b and 9c connected in a loop. Furthermore, information communication units 9b and 9c are not directly connected, but communicate information with each other via information communication units 9a and 9d, which are connected in a loop. In this way, even if the number of uninterruptible power supplies increases to four or more, information can be communicated without interconnecting all of the information communication units by connecting the information communication units included in each uninterruptible power supply in a loop.

[0027] Next, a case will be described in which a communication failure occurs due to a breakdown or the like in the communication line connecting the information communication unit 9a of the uninterruptible power supply 100a and the information communication unit 9d of the uninterruptible power supply 100d. In this case, the information communication unit 9a of the uninterruptible power supply 100a and the information communication unit 9d of the uninterruptible power supply 100d cannot communicate information using the communication line connecting them to each other, but they communicate information with each other using the communication line connecting the information communication unit 9a of the uninterruptible power supply 100a with the information communication unit 9b of the uninterruptible power supply 100b, the communication line connecting the information communication unit 9b of the uninterruptible power supply 100b with the information communication unit 9c of the uninterruptible power supply 100c, and the communication line connecting the information communication unit 9c of the uninterruptible power supply 100c with the information communication unit 9d of the uninterruptible power supply 100d. In this way, even if a communication failure occurs at one point among the information communication units 9a to 9d connected in a loop, the information communication units 9a to 9d can still communicate information with each other.

[0028] The power conversion unit 20a outputs power from the AC power source S via the transformer 1a as a voltage to the connection point Aout on the bus 10a. The power conversion unit 20a can be electrically disconnected from the AC power source S and the load 50a by opening (turning off) the switches 4a, 5a, and 6a. When outputting power using the power conversion unit 20a, the switches 4a, 5a, and 6a are closed (turned on) to supply power to the converter unit 21a. The converter unit 21a is a so-called AC-DC converter that can convert supplied AC power into DC power. The DC power output from the converter unit 21a is stored in a storage unit (not shown) and output to the inverter unit 22a. When DC power is supplied from the converter unit 21a or the storage unit (not shown), the inverter unit 22a is controlled by the synchronization control unit 8a to output the desired AC power to the connection point Aout on the bus 10a. The converter section 21a and the inverter section 22a are configured by electronic circuits that combine diode bridges, switches, and the like.

[0029] The switch 40a receives two of the powers input from the connection point Aout on the bus 10a, the power from the connection point Bout on the bus 10b, and the power from the connection point Cout on the bus 10c, and switches between supplying one of the powers to the load 50a. In this first embodiment, the switch 40a is connected to the connection point Aout on the bus 10a, the connection point Bout on the bus 10a, and the load 50a. The switch 40a is a switch using, for example, a relay, and switches the power supplied to the load 50a under desired conditions according to settings. The load 50a is an electrical device that operates on AC power, such as a motor or a pump.

[0030] (Operation of the uninterruptible power supply system 200 in the first embodiment) Here, an example of the operation of the uninterruptible power supply system 200 in the first embodiment will be described. In this description, a case will be described in which each of the first system A, the second system B, and the third system C supplies power to the load side using the power conversion units 20a, 20b, and 20c of the uninterruptible power supplies 100a to 100c, without using the first bypass circuits 30a to 30c and the second bypass circuits 2a to 2c. At this time, the synchronization control unit 8b of the uninterruptible power supply 100b controls the operation of the inverter unit 22b so as to synchronize with the voltage at the connection point Aout on the bus 10a of the first system A. Similarly, the synchronization control unit 8c of the uninterruptible power supply 100c controls the operation of the inverter unit 22c so as to synchronize with the voltage at the connection point Aout on the bus 10a of the first system A.

[0031] Here, in the first embodiment, a case will be described in which the power conversion unit 20a in the uninterruptible power supply 100a of the first system A is unable to output a normal voltage to the connection point Aout on the bus 10a due to some influence, such as a failure. At this time, the synchronization control unit 8a determines that the voltage of Aout detected by the detection unit 7a is abnormal. For example, a threshold value is set in advance for the voltage value, and the synchronization control unit 8a determines that the voltage of Aout is abnormal when the voltage value of Aout detected by the detection unit 7a is smaller than the threshold value. Alternatively, the synchronization control unit 8a may detect the frequency or phase of the voltage to determine that it is abnormal. Then, the synchronization control unit 8a communicates detection information including the voltage of Aout detected by the detection unit 7a and the determination result that the voltage of Aout is abnormal to the information communication unit 9b.

[0032] At this time, the information communication unit 9b of the uninterruptible power supply 100b of the second system B acquires detection information including the voltage of Aout and a determination result that the voltage of Aout is abnormal from the information communication unit 9a of the uninterruptible power supply 100a of the first system A. As a result, the synchronization control unit 8b controls to switch the operation of the inverter unit 22b so that it is not synchronized with the voltage of the connection point Aout on the bus 10a of the first system A. Furthermore, the information communication unit 9b of the uninterruptible power supply 100b of the second system B communicates with the information communication unit 9c of the uninterruptible power supply 100c of the third system C, and transmits detection information including the voltage of Aout and a determination result that the voltage of Aout is abnormal, and detection information including the voltage of Bout and a determination result that the voltage of Bout is normal. Then, the synchronization control unit 8c controls to switch the operation of the inverter unit 22c so that it is not synchronized with the voltage of the connection point Aout on the bus 10a of the first system A. The multiple uninterruptible power supplies 100a to 100c are assigned a priority order for synchronization, and in this first embodiment, the synchronization control unit 8c controls the operation of the inverter unit 22c so that the output of the inverter unit 22c is synchronized with the voltage at the connection point Bout on the bus 10b of the second system B.

[0033] Thereafter, in the first system A, the switches 4a, 5a, and 6a are opened (off), and the switch 31a and the first bypass switch 34a are closed (on) so that power is supplied via the first bypass circuit 30a. At this time, the detection unit 7a detects the voltage at the connection point Aout on the bus 10a via the transformer 11a. Then, the synchronization control unit 8a determines that the connection point Aout on the bus 10a is normal based on the detection result obtained from the detection unit 7a, and transmits this determination to the information communication unit 9a. Furthermore, the detection unit 7a detects the voltage on the power line 32a of the first bypass circuit 30a via the transformer 12a. Here, the first bypass circuit 30a does not include a device that converts the output voltage, such as the power conversion unit 20a. Therefore, when power is supplied using the first bypass circuit 30a, the power supplied to the connection point Aout on the bus 10a is the same as the power output from the AC power source S. In other words, when power is supplied using the first bypass circuit 30a, the voltage at the connection point Aout on the bus 10a cannot be synchronized with the voltage at the connection point Bout on the bus 10b of the other system or the voltage at the connection point Cout on the bus 10c of the other system. In this case, the synchronization control unit 8a generates operating state information indicating that the voltage cannot be synchronously controlled in the first system A, based on the voltage of the first bypass circuit 30a obtained from the detection unit 7a, and transmits this information to the information communication unit 9a.

[0034] The information communication unit 9b of the uninterruptible power supply 100b of the second system B acquires, from the information communication unit 9a of the uninterruptible power supply 100a of the first system A, the Aout voltage detected by the detection unit 7a, detection information that the Aout voltage is normal, and operating state information that synchronous control of the voltage in the first system A is not possible. Then, the synchronization control unit 8b performs control to synchronize the voltage output from the inverter unit 22b with the voltage at the connection point Aout on the bus 10a of the first system A. Furthermore, the information communication unit 9b of the uninterruptible power supply 100b of the second system B communicates with the information communication unit 9c of the uninterruptible power supply 100c of the third system C, and transmits the Aout voltage and detection information including information that the Aout voltage is normal, operating state information that synchronous control of the voltage in the first system A is not possible, and the Bout voltage and detection information including information that the Bout voltage is normal. As a result, the synchronization control unit 8c performs control to switch the operation so as to synchronize the output of the inverter unit 22c with the voltage at the connection point Aout on the bus 10a of the first system A.

[0035] As described above, each of systems B and C acquires the detection information and operating state information of the other system via the information communication units 9a to 9c connected in a loop. Then, the synchronization control units 8a to 8c control the voltage at the connection point Bout or Cout on the bus 10a output by the power conversion units 20b and 20c of the system itself so as to synchronize with the voltage at the connection point Aout on the bus 10a of the other system.

[0036] (Comparative Example) Here, FIG. 4 illustrates an uninterruptible power supply system 201 of a comparative example in which, in each of the uninterruptible power supplies 100a to 100c, the voltages of connection points Aout, Bout and Cout on the bus 10a of the uninterruptible power supplies 100a to 100c of the other systems are synchronized to supply power to three systems of loads 50a to 50c.

[0037] The uninterruptible power supply system 201 of the comparative example includes a central monitoring panel 60. The central monitoring panel 60 includes a synchronization selection circuit 61 that outputs information for controlling the operation of the power conversion units 20a-20c included in each of the uninterruptible power supplies 100a-100c, a central information communication unit 62 that communicates information with the information communication units 9a-9c included in each of the uninterruptible power supplies 100a-100c, and a central detection unit 63 that detects the voltages at the connection points Aout, Bout, and Cout on the bus 10a. The synchronization selection circuit 61 included in the central monitoring panel 60 acquires detection information based on the voltages at the connection points Aout, Bout, and Cout on the bus 10a detected by the central detection unit 63. The synchronization selection circuit 61 also acquires detection information obtained by communicating with the information communication units 9a-9c of the uninterruptible power supplies 100a-100c. The synchronization selection circuit 61 then outputs information to select one of the systems to be synchronized based on the acquired detection information and operating state information. Each of the synchronization control units 8a to 8c controls the operation of the power conversion units 20a to 20c so as to synchronize the output of its own system with the voltages of the connection points Aout, Bout and Cout on the bus 10a of the system to be synchronized, which are obtained via the information communication units 9a to 9c.

[0038] In the case of the uninterruptible power supply system 200 of the first embodiment shown in Fig. 1, if any of the detection units 7a-7c, synchronization control units 8a-8c, or information communication units 9a-9c included in the uninterruptible power supplies 100a-100c fails, synchronous control with the system including the failed equipment becomes impossible, but synchronous control can be performed using the remaining systems to supply power to the loads 50a-50c. On the other hand, the uninterruptible power supply system 201 of the comparative example shown in Fig. 4 is configured so that the functions of each of the uninterruptible power supplies 100a-100c in the uninterruptible power supply system 200 are integrated into the central monitoring panel 60. Therefore, if any of the synchronization selection circuit 61, central information communication unit 62, or central detection unit 63 fails, all of the uninterruptible power supplies 100a-100c will be unable to perform synchronous control.

[0039] (Effects of the first embodiment) Next, the effects of the first embodiment will be described.

[0040] The uninterruptible power supply system 200 of the first embodiment supplies power to three loads 50a-50c using three systems of uninterruptible power supplies 100a-100c, each system including power conversion units 20a-20c that convert the power of an AC power supply S and output it to the loads 50a-50c, and first bypass circuits 30a-30c that directly output the power of the AC power supply S to the loads 50a-50c. Each of the uninterruptible power supplies 100a-100c includes detection units 7a-7c that detect the voltage of first bypass circuits 30a-30c of its own system in the uninterruptible power supplies 100a-100c and the voltage of connection points Aout, Bout, or Cout on a bus 10a to which power is output from power conversion units 20a-20c of its own system, synchronization control units 8a-8c that perform control to synchronize the voltages output from the power conversion units 20a-20c of its own system with a predetermined voltage, and information communication units 9a-9c that communicate detection information obtained based on the detection results of the detection units 7a-7c. The information communication units 9a-9c are connected to each other to form a loop, and are configured to communicate with any of the other information communication units 9a-9c connected in the loop. The synchronization control units 8a-8c are configured to control the voltages output by the power conversion units 20a-20c of their own system to synchronize with a predetermined voltage based on detection information acquired through communication by the information communication units 9a-9c connected in a loop. This allows the information communication units 9a-9c to acquire detection information from all of the uninterruptible power supplies 100a-100c of the other system by communicating with the information communication units 9a-9c of the other system connected in a loop, without providing a new detection unit for detecting the voltage at the connection points Aout, Bout, or Cout on the bus 10a of the other system. This allows the synchronization control units 8a-8c to synchronize and control the power output from the power conversion units 20a-20c of their own system to a predetermined voltage based on the detection information from the uninterruptible power supplies 100a-100c of the other system. As a result, it is possible to provide a small-sized and simply configured uninterruptible power supply system 200 that supplies power to three loads 50a to 50c by synchronously controlling three uninterruptible power supplies 100a to 100c.Furthermore, the information communication units 9a-9c can acquire detection information from the uninterruptible power supplies 100a-100c of the other systems by communicating with the information communication units 9a-9c of the other systems connected in a loop, without providing a mechanism for collectively detecting the voltages of the connection points Aout, Bout, or Cout on the bus bars 10a of all systems, such as the central monitoring panel 60. Therefore, the synchronization control units 8a-8c synchronously control the power output from the power conversion units 20a-20c of their own system based on the detection information from each of the uninterruptible power supplies 100a-100c of the other systems, so that compared to when information is aggregated in a single mechanism for synchronous control, there is a smaller possibility that all of the uninterruptible power supplies 100a-100c will become unable to synchronize due to a failure, and highly reliable synchronous control can be performed.

[0041] In the uninterruptible power supply system 200 of the first embodiment, the predetermined voltage includes the voltage of the first bypass circuit 30a of the own system or the voltage of the connection point Aout, Bout, or Cout on the bus 10a of the other system, and the synchronization control units 8a-8c are configured to perform control to switch and synchronize the voltage output by the power conversion units 20a-20c of the own system with the voltage of the first bypass circuit 30a-30c of the own system or the voltage of the connection point Aout, Bout, or Cout on the bus 10a of the other system based on detection information obtained by communication with the information communication units 9a-9c connected in a loop. With this configuration, it is possible to perform control to synchronize the output voltage of the power conversion units 20a-20c of the own system with a desired voltage from the voltage of the first bypass circuit 30a-30c of the own system or the voltage of Aout, Bout, or Cout on the bus 10a of the other system based on detection information obtained by communication with the information communication units 9a-9c connected in a loop. As a result, the voltages output by the power conversion units 20a to 20c of the own system can be synchronized with an appropriate value, and power can be supplied to the loads 50a to 50c.

[0042] In addition, in the first embodiment, the detection information includes at least one of the value, frequency, and phase of the voltage of the first bypass circuit 30a to 30c of the own system and the voltage Aout, Bout, or Cout on the bus 10a to which power is output from the power conversion units 20a to 20c of the own system, and the synchronization control units 8a to 8c included in each of the uninterruptible power supplies 100a to 100c are configured to determine whether the detection information of the uninterruptible power supplies 100a to 100c of the own system obtained through communication by the information communication units 9a to 9c connected in a loop is within a normal range, and based on the determination result, to switch and synchronize the voltage output by the power conversion units 20a to 20c of the own system with the voltage of the first bypass circuit 30a to 30c of the own system or the voltage Aout, Bout, or Cout on the bus 10a of the other system. With this configuration, it is possible to determine whether the voltages of the first bypass circuits 30a-30c of the own system and the voltages Aout, Bout, and Cout of the bus 10a to which power is output from the power conversion units 20a-20c of the own system are appropriate values ​​to be synchronized. Therefore, the voltages output by the power conversion units 20a-20c of the own system can be synchronized with the output voltages of the uninterruptible power supplies 100a-100c that have been determined to be outputting appropriate values. As a result, the voltages output by the power conversion units 20a-20c of the own system can be synchronized with more appropriate values, and power can be supplied to the loads 50a-50c.

[0043] In the first embodiment, in the uninterruptible power supply system 200, the synchronization control units 8a-8c included in each of the uninterruptible power supplies 100a-100c determine whether the detection information of the uninterruptible power supplies 100a-100c of its own system, acquired through communication by the information communication units 9a-9c connected in a loop, is within a normal range. Preferably, the synchronization control units 8a-8c included in each of the uninterruptible power supplies 100a-100c are configured to perform control to exclude from synchronization the uninterruptible power supplies 100a-100c of the other system that are determined to have detection information that is outside the normal range, based on the detection information acquired through communication by the information communication units 9a-9c connected in a loop. This configuration makes it possible to prevent the voltage output by the power conversion units 20a-20c of its own system from being synchronized with an uninterruptible power supply 100a-100c that is operating abnormally. As a result, the voltages output by the power conversion units 20a to 20c of the own system can be synchronized with the voltages of the uninterruptible power supplies 100a to 100c that are operating normally, and power can be supplied to the loads 50a to 50c.

[0044] [Second embodiment] Next, an uninterruptible power supply system 202 according to the second embodiment will be described with reference to Fig. 5. The uninterruptible power supply system 202 is configured such that bypass units 110a, 110b, and 110c are provided in each of systems A to C of the uninterruptible power supply system 200 shown in Fig. 1. Note that a description of the points common to the first embodiment in the second embodiment will be omitted.

[0045] In the second embodiment, bypass units 110a to 110c are provided for each of systems A to C. Here, the first system A will be described, but a similar description can be applied to the second system B and the third system C. The bypass unit 110a is a panel configured to include a part of the power line of the second bypass circuit 2a, a second bypass switch 3a, a bypass information communication unit 15a, and a bypass voltage detection unit 13a.

[0046] The bypass voltage detection unit 13a is, for example, a voltage dividing resistor, and is configured to detect the voltage of the second bypass circuit 2a via a transformer 14a. The bypass voltage detection unit 13a is also connected to a bypass information communication unit 15a, and detection information including information such as the voltage value, frequency, and phase of the detected voltage is transmitted to the bypass information communication unit 15a.

[0047] The bypass information communication unit 15a is connected to the bypass voltage detection unit 13a, the information communication unit 9a in the uninterruptible power supply 100a of the first system A, and the information communication unit 9c in the uninterruptible power supply 100c of the third system C. Here, the information communication units 9a to 9c and the bypass information communication units 15a to 15c are connected in a loop in the following order: bypass information communication unit 15a, information communication unit 9a, bypass information communication unit 15b, information communication unit 9b, bypass information communication unit 15c, and information communication unit 9c. As a result, the bypass information communication unit 15a is configured to communicate with the information communication units 9a and 9c connected in the loop to acquire all of the detection information acquired by the information communication units 9a to 9c and the bypass information communication units 15a to 15c.

[0048] (Operation of the uninterruptible power supply system 202 in the second embodiment) Here, an example of the operation of the uninterruptible power supply system 202 in the second embodiment will be described. In this description, first, a case will be described in which the first system A, the second system B, and the third system C each supply power to the load side using the power conversion units 20a, 20b, and 20c of the uninterruptible power supplies 100a to 100c without using the first bypass circuits 30a to 30c and the second bypass circuits 2a to 2c.

[0049] At this time, the information communication units 9a to 9c and the bypass information communication units 15a to 15c each acquire, through communication, detection information that the output voltages Aout, Bout, and Cout are within the normal range. Furthermore, the information communication units 9a to 9c and the bypass information communication units 15a to 15c acquire, through communication, detection information that the voltages of the first bypass circuits 30a to 30c and the second bypass circuits 2a to 2c are zero in each of the systems A to C. In the second embodiment, the synchronization control unit 8b of the uninterruptible power supply 100b controls the operation of the inverter unit 22b so as to synchronize with the voltage at the connection point Aout on the bus 10a of the first system A. Similarly, the synchronization control unit 8c of the uninterruptible power supply 100c controls the operation of the inverter unit 22c so as to synchronize with the voltage at the connection point Aout on the bus 10a of the first system A.

[0050] In the second embodiment, a case will be described in which the uninterruptible power supply 100a of the first system A is unable to output a normal voltage to the connection point Aout on the bus 10a using the first bypass circuit 30a and the power conversion unit 20a due to some influence, such as a failure of the thyristor switch 33a. In this case, the synchronization control unit 8a determines that the voltage of Aout detected by the detection unit 7a is abnormal. The synchronization control unit 8a then transmits the voltage of Aout detected by the detection unit 7a and detection information that the voltage of Aout is abnormal to the bypass information communication unit 15b. Because the information communication units 9a to 9c and the bypass information communication units 15a to 15c are connected in a loop, each of the information communication units 9a to 9c and the bypass information communication units 15a to 15c acquires the voltage of Aout detected by the detection unit 7a and detection information that the voltage of Aout is abnormal. Thereafter, the operations of the power conversion units 20b and 20c of the second system B and the third system C are controlled in the same manner as in the first embodiment.

[0051] At this time, since power supply via the uninterruptible power supply 100a is no longer possible in the first system A, power is supplied via the second bypass circuit 2a. When the second bypass switch 3a closes and power supply via the second bypass circuit 2a begins, the bypass voltage detection unit 13a detects the voltage of the second bypass circuit 2a via the transformer 14a. The bypass information communication unit 15a transmits the detection information acquired from the bypass voltage detection unit 13a by communicating with the information communication unit 9a connected in a loop. The information communication unit 9a also acquires the voltage at the connection point Aout on the bus 10a detected by the detection unit 7a and detection information that a normal voltage is being output from the connection point Aout on the bus 10a determined by the synchronization control unit 8a, and transmits the information by communicating with the bypass information communication unit 15b connected in a loop. Since the information communication units 9a to 9c and the bypass information communication units 15a to 15c are connected in a loop, each of the information communication units 9a to 9c and the bypass information communication units 15a to 15c acquires the voltage of Aout detected by the detection unit 7a and detection information that the voltage of Aout is normal.

[0052] As a result of the above operation, even if the uninterruptible power supply 100a of the first system A is no longer able to output normal voltage to the connection point Aout on the bus 10a using the first bypass circuit 30a and the power conversion unit 20a, the synchronization control units 8b and 8c control the operation of the inverter units 22b and 22c based on information obtained from the information communication units 9b and 9c connected in a loop, and supply power to the loads 50a to 50c.

[0053] (Effects of the second embodiment) Next, the effects of the second embodiment will be described.

[0054] In the second embodiment, the bus 10a further includes power output switches 16a, 16b, and 16c that disconnect the uninterruptible power supplies 100a-100c from the loads 50a-50c, and the detection units 7a-7c are configured to detect the voltage of the bus 10a of the own system that is closer to the uninterruptible power supplies 100a-100c than the power output switches 16a-16c. As a result, the detection units 7a-7c are configured to detect the voltage of the bus 10a of the own system that is closer to the uninterruptible power supplies 100a-100c than the power output switches 16a-16c. Therefore, by opening the power output switches 16a-16c (turning off), the uninterruptible power supplies 100a-100c can be easily removed when performing maintenance or replacing the uninterruptible power supplies 100a-100c. As a result, the workability can be improved when maintaining or replacing the uninterruptible power supplies 100a to 100c.

[0055] In the second embodiment, bypass units 110a-110c are provided separately from the uninterruptible power supplies 100a-100c, connected to the bus 10a closer to the loads 50a-50c than the power supply output switches 16a-16c, and including a second bypass circuit 2a that directly outputs power from the AC power supply S to the loads 50a-50c, bypass voltage detection units 13a-13c that detect voltages of the second bypass circuits 2a-2c, and bypass information communication units 15a-15c that communicate detection information obtained by the bypass voltage detection units 13a-13c. The bypass information communication units 15a-15c are connected to other information communication units 9a-9c to form a loop, and are configured to communicate with the other information communication units 9a-9c connected in the loop. As a result, even in a system from which uninterruptible power supply 100a has been removed for maintenance or replacement of uninterruptible power supply 100a, power can be supplied to loads 50a and 50c via second bypass circuit 2a. Furthermore, based on detection information obtained via information and communications units 9a to 9c of bypass units 110a to 110c, the voltage output by power conversion unit 20b of uninterruptible power supply 100b or the power conversion unit 20c of uninterruptible power supply 100c can be synchronized with the voltage of second bypass circuit 2a. As a result, even when uninterruptible power supply 100a is removed, the voltage output by power conversion unit 20b or 20c of uninterruptible power supply 100b or 100c can be synchronized with the voltage of either system to supply power to loads 50a to 50c.

[0056] The other effects of the second embodiment are the same as those of the first embodiment.

[0057] [Third embodiment] Next, an uninterruptible power supply system 203 according to a third embodiment will be described with reference to Fig. 6. The first system A will be described below, but a similar description can be applied to the second system B and the third system C. Note that in the third embodiment, a description of points common to the first and second embodiments will be omitted.

[0058] The uninterruptible power supply system 203 is configured such that uninterruptible power supplies are connected in parallel in each of systems A to C. Specifically, the uninterruptible power supply system 203 includes uninterruptible power supplies 101a and 102a, second bypass circuits 2a corresponding to the uninterruptible power supplies 101a and 102a, and a bypass unit 110a provided on one side of the two second bypass circuits 2a. The uninterruptible power supply system 203 is configured to supply power such that the power output from the two second bypass circuits 2a, the uninterruptible power supply 101a, and the uninterruptible power supply 102a is common to a connection point Aout on the bus 10a. The uninterruptible power supply system 203 also includes a power output switch 16a that separates the uninterruptible power supplies 101a and 102a, and is configured to switch the power source to which power is supplied to the connection point Aout on the bus 10a by the second bypass switch 3a and the power output switch 16a.

[0059] 1, 4, and 5, the uninterruptible power supply 101a is configured such that the detection unit 7a in the uninterruptible power supply 101a shown in Fig. 3 detects the voltage at the contacts of the power conversion unit 20a and the first bypass circuit 30a, which are closer to the uninterruptible power supply 101a than the power output switch 16a, rather than at the connection point Aout on the bus 10a. The uninterruptible power supply 101a also includes a parallel communication unit 17a, which obtains, from the synchronization control unit 8a, detection information based on the voltage detection results and operating state information relating to the operating state of the uninterruptible power supply 101a.

[0060] 1, 4, and 5, the uninterruptible power supply 102a differs from the uninterruptible power supply 100a shown in FIGS. 1, 4, and 5 in that the detection unit 7a is configured to detect only the input voltage of the first bypass circuit 30a. Similarly to the uninterruptible power supply 101a, the uninterruptible power supply 102a also includes a parallel communication unit 17a. The parallel communication units 17a of the uninterruptible power supplies 101a and 102a are connected to each other and exchange operating status information with each other. Based on the information acquired from the parallel communication units 17a, the uninterruptible power supplies 101a and 102a control the operation of their respective power conversion units 20a so that the output powers are synchronized.

[0061] 6, the detailed configurations of the second system B and the third system C are omitted, but they include the same configuration as the first system A. At this time, the information communication unit 9a included in the uninterruptible power supply 102a in the first system A is connected to the bypass information communication unit 15b of the bypass unit 110b in the second system B. In this way, the information communication units 9a to 9c and the bypass information communication units 15a to 15c are connected to each other, and are connected to form a loop when viewed as a whole.

[0062] (Effects of the third embodiment) Next, the effects of the third embodiment will be described.

[0063] In the third embodiment, a plurality of uninterruptible power supplies 101a and 102a, 101b and 102b, or 101c and 102c are connected in parallel in the same system. Each of the uninterruptible power supplies 101a and 102a includes a parallel communication unit 17a that communicates detection information with the synchronization control unit 8a. Each of the uninterruptible power supplies 101b and 102b includes a parallel communication unit 17b that communicates detection information with the synchronization control unit 8a. Each of the uninterruptible power supplies 101c and 102c includes a parallel communication unit 17c that communicates detection information with the synchronization control unit 8c. The parallel communication unit 17a communicates detection information between the other uninterruptible power supplies 101a and 102a in the same system. The parallel communication unit 17b communicates detection information between 101b and 102b. The parallel communication unit 17b communicates detection information between 101c and 102c. Thus, even when a plurality of uninterruptible power supplies 101a and 102a, 101b and 102b, or 101c and 102c are arranged in one system, the output voltages from the power conversion units 20a to 20c included in the plurality of uninterruptible power supplies 101a and 102a, 101b and 102b, or 101c and 102c in each system can be synchronized and output to the loads 50a to 50c. As a result, even when a plurality of uninterruptible power supplies 100a to 100c are in one system, the voltage output from the power conversion units 20a to 20c of the system can be synchronized with that of one of the systems to supply power to the loads 50a to 50c.

[0064] The other effects of the third embodiment are the same as those of the first or second embodiment.

[0065] [Variations] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the above description of the embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0066] For example, in the first to third embodiments, an example of an uninterruptible power supply system 200 is shown in which three uninterruptible power supplies 100a to 100c are used to supply power to three loads 50a to 50c, but the present invention is not limited to this. The present invention may be configured to use four or more uninterruptible power supplies to supply power to four or more loads, and the number of systems in the uninterruptible power supply system may be increased depending on the number of loads and the target availability rate (load factor). Note that increasing the number of systems allows more systems to be switched, thereby improving the load factor of the uninterruptible power supply system. However, since increasing the number of systems increases the size of the uninterruptible power supply system, the number of systems is preferably three to five.

[0067] In the above first to third embodiments, the synchronization control units 8a to 8c included in each of the uninterruptible power supplies 100a to 100c determine whether or not the detection information of the uninterruptible power supplies 100a to 100c of its own system, acquired through communication by the information communication units 9a to 9c connected in a loop, is within a normal range, but the present invention is not limited to this. In the present invention, the synchronization control units 8a to 8c included in each of the uninterruptible power supplies 100a to 100c may be configured to determine whether or not the detection information of the uninterruptible power supplies 100a to 100c of its own system and the uninterruptible power supplies 100a to 100c of the other system, acquired through communication by the information communication units 9a to 9c connected in a loop, is within a normal range.

[0068] In the above first to third embodiments, the synchronization control units 8a to 8c included in each of the uninterruptible power supplies 100a to 100c perform control to exclude from synchronization targets the uninterruptible power supplies 100a to 100c of other systems that are determined to have detection information that is out of the normal range based on the detection information acquired through communication by the information communication units 9a to 9c connected in a loop, but the present invention is not limited to this. In the present invention, the synchronization control units 8a to 8c included in each of the uninterruptible power supplies 100a to 100c may perform control to exclude from synchronization targets the uninterruptible power supplies 100a to 100c of other systems that are determined to have detection information that is out of the normal range for a predetermined time based on the detection information acquired through communication by the information communication units 9a to 9c connected in a loop.

[0069] In the first to third embodiments, an example was shown in which each of the systems A to C includes the second bypass circuit 2a separate from the uninterruptible power supplies 100a to 100c, but the present invention is not limited to this. In the present invention, each of the systems A to C may be configured to include only the uninterruptible power supplies 100a to 100c.

[0070] Furthermore, in the third embodiment, an example was shown in which two uninterruptible power supplies 101a and 102a are connected in parallel in the first system A, two uninterruptible power supplies 101b and 102b are connected in parallel in the second system B, and two uninterruptible power supplies 101c and 102c are connected in parallel in the third system C, but the present invention is not limited to this. In the present invention, each of systems A to C may be configured to have three or more uninterruptible power supplies connected in parallel. [Explanation of symbols]

[0071] 2a, 2b, 2c Second bypass circuit 3a, 3b, 3c Second bypass switch 7a, 7b, 7c detection section 8a, 8b, 8c Synchronization control section 9a, 9b, 9c Information and Communication Department 10a, 10b, 10c busbar 13a, 13b, 13c Bypass voltage detection unit 15a, 15b, 15c Bypass Information and Communication Department 16a, 16b, 16c power output switch 17a, 17b, 17c parallel communication circuit 20a, 20b, 20c Power conversion unit 21a, 21b, 21c Converter section 22a, 22b, 22c Inverter section 30a, 30b, 30c First bypass circuit 40a, 40b, 40c switch 50a, 50b, 50c load 100a~102a, 100b~102b, 100c~102c uninterruptible power supply 110a, 110b, 110c bypass section 200a~203a, 200b~203b, 200c~203c Uninterruptible Power Supply System A. First line B. Second line C. The third lineage S AC power supply

Claims

1. An uninterruptible power supply system supplies power to three or more loads using three or more uninterruptible power supplies, the three or more loads including a power conversion unit that converts power of an AC power supply and outputs the power to a load, and a first bypass circuit that directly outputs the power of the AC power supply to the load, Each of the uninterruptible power supplies comprises: a detection unit that detects a voltage of the first bypass circuit of the own system in the uninterruptible power supply and a voltage of a bus to which power is output from the power conversion unit of the own system; A synchronization control unit that performs control to synchronize a voltage output by the power conversion unit of the own system with a predetermined voltage; an information communication unit that communicates detection information acquired based on a detection result of the detection unit, the information communication unit is connected to other information communication units to form a loop, and is configured to communicate with the other information communication units connected in the loop; an information communication unit connected in a loop configuration to communicate with the power conversion unit of the system in question, and

2. the predetermined voltage includes a voltage of the first bypass circuit of the own system or a voltage of the bus bar of another system, 2. The uninterruptible power supply system according to claim 1, wherein the synchronization control unit is configured to perform control to switch and synchronize the voltage output by the power conversion unit of the own system with the voltage of the first bypass circuit of the own system or the voltage of the bus bar of the other system, based on the detection information acquired by the information communication unit connected in a loop.

3. The detection information includes at least one of a voltage of the first bypass circuit of the own system and a voltage value, a frequency, and a phase of the bus bar to which power is output from the power conversion unit of the own system, 3. The uninterruptible power supply system according to claim 2, wherein the synchronization control unit included in each of the uninterruptible power supplies is configured to determine whether the detection information of the uninterruptible power supply of its own system, acquired through communication by the information communication unit connected in a loop, is within a normal range, and based on the result of the determination, to perform control to switch and synchronize the voltage output by the power conversion unit of its own system with the voltage of the first bypass circuit of its own system or the voltage of the bus bar of another system.

4. The uninterruptible power supply system of claim 3, wherein the synchronization control unit included in each of the uninterruptible power supplies is configured to perform control to exclude from synchronization an uninterruptible power supply of another system that is determined to have detection information that is not within a normal range based on the detection information obtained by communication by the information communication unit connected in a loop.

5. The information communication unit is configured to further communicate operating state information indicating an operating state of each of the uninterruptible power supplies, 2. The uninterruptible power supply system according to claim 1, wherein the synchronization control unit is configured to control the voltage output by the power conversion unit of its own system to be synchronized with the bus voltage of the uninterruptible power supply in a state in which the bus voltage cannot be synchronously controlled, based on the operating status information obtained by the information and communication unit connected in a loop through communication, the uninterruptible power supply being in a state in which the bus voltage cannot be synchronously controlled.

6. Each of the uninterruptible power supplies includes a parallel communication unit that is connected in parallel in a plurality of units in its own system and communicates the detection information with the synchronization control unit included in each of the uninterruptible power supplies in its own system, The uninterruptible power supply system according to claim 1 , wherein the parallel communication unit is configured to communicate the detection information with the parallel communication unit of another uninterruptible power supply of the same system.

7. The bus bar further includes a switch that disconnects the uninterruptible power supply from the load, 7. The uninterruptible power supply system according to claim 1, wherein the detection unit is configured to detect a voltage of the busbar of the own system that is closer to the uninterruptible power supply than the switch.

8. a second bypass circuit that is provided separately from the uninterruptible power supply, that is connected to the bus bar on the load side relative to the switch, and that directly outputs power of the AC power supply to the load; a bypass voltage detection unit that detects a voltage of the second bypass circuit; a bypass information communication unit that communicates the detection information obtained by the bypass voltage detection unit, 8. The uninterruptible power supply system according to claim 7, wherein the bypass information communication unit is connected to other information communication units in a loop shape by being mutually connected to the other information communication units, and is configured to communicate with the other information communication units connected in the loop shape.

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