Power-feeding system

Abstract

[Problem] To provide a power-feeding system that can confirm the presence or absence of an abnormal connection between power-feeding devices. [Solution] A power-feeding system PSS for supplying power comprises: a plurality of power-feeding devices 10 that are electrically connected to each other; and a detection unit 20 that detects the presence or absence of an electrical connection between the power-feeding devices 10. Each of the power-feeding devices 10 has a first switch 34 connected between a power-feeding unit 32 and a first connection unit 30, and a second switch 35 connected between the power-feeding unit 32 and a second connection unit 31. The power-feeding system PSS controls, to an ON state, the first switch 34 of a first power-feeding device among the plurality of power-feeding devices 10 and the second switch 35 of a second power-feeding device having the second connection unit 31, which should be connected to the first connection unit 30 of the first power-feeding device, and controls the other first switches 34 and second switches 35 to an OFF state, and in these states, the power-feeding system PSS detects the presence or absence of an electrical connection between the first power-feeding device and the second power-feeding device using the detection result from the detection unit 20.

Description

Power Supply System

[0001] The present invention relates to a power supply system.

[0002] Patent Literature 1 discloses a power supply system including a plurality of power supply devices that supply power to a track. The plurality of power supply devices are electrically connected to each other via power supply lines. Therefore, if one power supply device abnormally stops, the other power supply devices can make up for the power shortage via the power supply lines.

[0003] International Publication No. 2022 / 074974

[0004] In the above-described power supply system, there is a possibility of the power supply line being incorrectly wired or broken, etc. Therefore, it is necessary to check whether there is an abnormality in the connection between the power supply devices.

[0005] An object of the present invention is to provide a power supply system that can check whether or not there is an abnormality in the connection between power supply devices.

[0006] A power supply system according to an aspect of the present invention is a power supply system that supplies power to a plurality of power supply targets, and includes a plurality of power supply devices that are electrically connected to each other, and a detection unit that detects whether or not there is an electrical connection between the power supply devices, and each power supply device includes a first connection portion and a second connection portion to which another power supply device is respectively connected, a power supply portion that can exchange power with the power supply devices connected to each of the first connection portion and the second connection portion, a first switch connected between the power supply portion and the first connection portion, and a second switch connected between the power supply portion and the second connection portion, and the power supply system controls the first switch of a first power supply device among the plurality of power supply devices and the second switch of a second power supply device having the second connection portion that should be connected to the first connection portion of the first power supply device to an on state, and controls the other first switches and second switches to an off state, and detects whether or not there is an electrical connection between the first power supply device and the second power supply device using the detection result of the detection unit.

[0007] In the power supply system according to an embodiment of the present invention, a detection unit is provided for detecting whether or not there is an electrical connection between power supply devices, and therefore it is possible to check whether or not there is an abnormality in the connection between the power supply devices (such as incorrect wiring of the power supply line or a broken power supply line).

[0008] In the power supply system according to the above aspect, the detection unit may include a sensor provided in each of the power supply devices, and the sensor may measure the voltage or current applied to the first connection part or the second connection part. With this configuration, it is possible to standardize the power supply devices.

[0009] According to the power supply system of the above aspect, each power supply device includes a communication unit for communicating with other power supply devices, and the multiple power supply devices are composed of one master device and multiple slave devices. The master device may execute the following steps: a first step of transmitting an OFF command to all other power supply devices to turn off all first switches and second switches; a second step of transmitting, after the first step, an ON command to the first power supply device and the second power supply device to turn on only the first switch of the first power supply device and the second switch of the second power supply device; and a third step of receiving, after the second step, information indicating whether or not there is an electrical connection between the first power supply device and the second power supply device from either the first power supply device or the second power supply device.

[0010] In the power supply system according to the above aspect, the master device may repeatedly perform a series of operations including the first step, the second step, and the third step while sequentially switching between the first power supply device and the second power supply device among the plurality of power supply devices until the presence or absence of electrical connections between all of the power supply devices is detected. With this configuration, it is possible to confirm whether the plurality of power supply devices are properly connected in a correct combination.

[0011] In the power supply system according to the above aspect, communication between the master device and each slave device may be polling communication. Furthermore, each power supply device may be connected to the master device by a power supply line for transmitting and receiving power, and the power supply devices may be connected in a ring shape as a whole.

[0012] FIG. 1 is a diagram showing a schematic configuration of a power supply system according to the present embodiment; FIG. 2 is a diagram showing a schematic configuration of a power supply device according to the present embodiment; FIG. 3 is a diagram explaining a connection relationship of the power supply device according to the present embodiment; FIG. 4 is a diagram explaining normal operation of the power supply system according to the present embodiment; FIG. 5 is a diagram explaining operation of the power supply system according to the present embodiment in the event of an abnormality; FIG. 6 is a flow diagram of connection confirmation processing according to the present embodiment; and FIG. 7 is a sequence diagram of connection confirmation processing according to the present embodiment.

[0013] The present invention will be described below through embodiments, but the following embodiments do not limit the scope of the invention. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention. In the drawings, identical or similar parts may be designated by the same reference numerals, and redundant explanations may be omitted. Furthermore, the shapes and sizes of elements in the drawings may be exaggerated for clarity.

[0014] 1 is a schematic diagram of a power supply system PSS according to this embodiment. The power supply system PSS supplies power to a plurality of power supply targets. The power supply targets are, for example, a track R.

[0015] The track R is a member that allows the overhead transport vehicle to travel and is suspended from the ceiling. For example, the track R is provided at a position higher than the floor surface, such as the ceiling of a clean room. The overhead transport vehicle is, for example, a transport vehicle that transports articles, and transports the articles along the track R. The articles house, for example, wafers or reticles used in the manufacture of semiconductor devices. For example, the articles are purgable front opening unified pods (FOUPs), SMIF pods, or reticle pods.

[0016] The track R is provided with a running rail on which the overhead transport vehicle travels and a power supply rail for supplying power to the overhead transport vehicle traveling on the running rail. The power supply rail is arranged, for example, below the running rail. A power supply cable fc is arranged on the power supply rail and supplies power to the overhead transport vehicle. Power is supplied from the power supply rail to the overhead transport vehicle, for example, by contactless power supply. The power supply method for contactless power supply can be any of the following: electromagnetic induction method, magnetic field (electric field) resonance method, electric field coupling method, and electromagnetic wave method. The track R is, for example, a circular orbit. The track R is arranged in each area.

[0017] The power supply system PSS includes multiple power supply devices 10 and a detection unit 20. The multiple power supply devices 10 are electrically connected in a ring configuration as a whole. The multiple power supply devices 10 are classified, for example, into power supply devices that continuously supply power (hereinafter referred to as "normal power supply devices") and backup power supply devices (hereinafter referred to as "backup power supply devices"). In the example shown in FIG. 1, the power supply system PSS includes four power supply devices 10-A to 10-D. The power supply devices 10-A to 10-C are normal power supply devices, and the power supply device 10-D is a backup power supply device. However, this is not limited to this, and all of the power supply devices included in the power supply system PSS may be normal power supply devices. Note that the reference numerals following the hyphen distinguish multiple components of the same type from one another. When multiple components of the same type are not to be distinguished from one another, the reference numerals following the hyphen may be omitted.

[0018] Each regular power supply device is assigned to a respective track R. The regular power supply device is connected to a power feed cable fc of the track R and supplies power to the power feed cable fc. If an abnormality occurs in the regular power supply device and the power supply is stopped, the shortage of power supply by the regular power supply device can be compensated for by power from the backup power supply device.

[0019] In the example shown in Fig. 1, a power feed cable fc1 of a track R1 is connected to the power feeding device 10-A. A power feed cable fc2 of a track R2 is connected to the power feeding device 10-B. A power feed cable fc3 of a track R3 is connected to the power feeding device 10-C. Note that the power feed cables fc1, fc2, and fc3 are power feed cables of different tracks R (tracks R1, R2, and R3). In other words, the tracks R to which the power feeding devices 10-A, 10-B, and 10-C feed power are different from each other.

[0020] Fig. 2 is a schematic diagram of the power supply device 10 according to this embodiment. Fig. 3 is a diagram showing the connection relationship of the power supply devices 10-A to 10-D. As shown in Fig. 2, the power supply device 10 includes a first connection unit 30, a second connection unit 31, a power supply unit 32, a communication unit 33, a first switch 34, a second switch 35, and a control unit 36.

[0021] The first connection portion 30 and the second connection portion 31 are each connected to another power supply device 10. The first connection portion 30 is connected to the second connection portion 31 of the other power supply device 10 via a power supply line L. In addition, the second connection portion 31 is connected to the first connection portion 30 of the other power supply device 10 via the power supply line L.

[0022] 3, the second connection portion 31-A of the power supply device 10-A is connected to the first connection portion 30-D of the power supply device 10-D via a power supply line L1. The connection between the second connection portion 31-A and the first connection portion 30-D may be referred to as the "first connection." The first connection portion 30-A of the power supply device 10-A is connected to the second connection portion 31-B of the power supply device 10-B via a power supply line L2. The connection between the first connection portion 30-A and the second connection portion 31-B may be referred to as the "second connection."

[0023] The first connection portion 30-B of the power supply device 10-B is connected to the second connection portion 31-C of the power supply device 10-C via a power supply line L3. The connection between the first connection portion 30-B and the second connection portion 31-C may be referred to as the "third connection." The first connection portion 30-C of the power supply device 10-C is connected to the second connection portion 31-D of the power supply device 10-D via a power supply line L4. The connection between the first connection portion 30-C and the second connection portion 31-D may be referred to as the "fourth connection."

[0024] 2 , power supply unit 32 can exchange power with the power supply devices connected to first connection unit 30 and second connection unit 31. Power supply unit 32 is connected to first connection unit 30 via a first switch 34. Power supply unit 32 is also connected to second connection unit 31 via a second switch 35. Power supply unit 32 includes, for example, an inverter 40 and a selector switch 41.

[0025] The inverter 40 converts AC power from a commercial power source or the like into predetermined power. The changeover switch 41 is connected between the output of the inverter 40 and the power supply cable fc. One end of the changeover switch 41 is connected to the output terminal of the inverter 40. The other end of the changeover switch 41 is connected to the power supply cable fc. In the example shown in FIG. 2 , the power supply device 10 is provided with a connection terminal CT to which the power supply cable fc is connected. A current path 50 is formed between the connection terminal CT and the output terminal of the inverter 40.

[0026] When the changeover switch 41 is in the on state, the output terminal of the inverter 40 and the power supply cable fc are electrically connected. When the changeover switch 41 is in the off state, the output terminal of the inverter 40 and the power supply cable fc are electrically disconnected. The changeover switch 41 is, for example, an electromagnetic switch.

[0027] The communication unit 33 communicates with the communication units 33 of the other power supply devices 10. The communication units 33 of each power supply device 10 are daisy-chain connected via a communication line T. The communication line T is, for example, a serial communication line. For example, power supply device 10-A and power supply device 10-B are connected via a communication line T1, power supply device 10-B and power supply device 10-C are connected via a communication line T2, and power supply device 10-C and power supply device 10-D are connected via a communication line T3. This allows the multiple power supply devices 10 to send and receive information to and from each other.

[0028] The first switch 34 is connected between the power supply unit 32 and the first connection unit 30. In other words, as shown in FIG. 2 , the first switch 34 is inserted in the current path K1 between the power supply unit 32 and the first connection unit 30. Specifically, the first switch 34 is inserted in the current path K1 between the current path 50 and the first connection unit 30.

[0029] When the first switch 34 is in the on state, the current path 50 is electrically connected to the first connection part 30. When the first switch 34 is in the off state, the electrical connection between the current path 50 and the first connection part 30 is released.

[0030] The second switch 35 is connected between the power supply unit 32 and the second connection unit 31. In other words, the second switch 35 is inserted in the current path K2 between the power supply unit 32 and the second connection unit 31. Specifically, the second switch 35 is inserted in the current path K2 between the current path 50 and the second connection unit 31.

[0031] When the second switch 35 is in the on state, the current path 50 is electrically connected to the second connection part 31. When the second switch 35 is in the off state, the electrical connection between the current path 50 and the second connection part 31 is released. Each of the first switch 34 and the second switch 35 is, for example, an electromagnetic switch.

[0032] The control unit 36 ​​controls the on / off of each of the changeover switch 41, the first switch 34, and the second switch 35. The control unit 36 ​​is connected to the communication unit 33 and can send and receive information to and from other power supply devices 10 via the communication unit 33. The control unit 36 ​​also monitors whether or not there is an abnormality in the power supply unit 32, and if an abnormality occurs in the power supply unit 32, controls the changeover switch 41 to change from the on state to the off state.

[0033] The control unit 36 ​​may include a processor such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit) and a non-volatile or volatile semiconductor memory (e.g., RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), or EEPROM (Electrically Erasable Programmable Read Only Memory)). For example, the control unit 36 ​​may be a microcontroller such as an MCU.

[0034] The detector 20 detects whether or not there is an electrical connection between the power supply devices 10. In the example shown in Fig. 1 , the detector 20 can detect whether or not there is an electrical connection for each of the first connection, the second connection, the third connection, and the fourth connection. The detector 20 may be configured separately from the power supply device 10, or may be provided within the power supply device 10.

[0035] The detection unit 20 includes, for example, a plurality of sensors 60 that detect the presence or absence of an electrical connection between the power supply devices 10. The sensor 60 is provided in each of the power supply devices 10. The sensor 60 measures, for example, the voltage or current applied to the first connection portion 30 or the second connection portion 31 of the connected power supply device 10. As an example, the sensor 60 measures, for example, the voltage or current applied to the current path K1 or the current path K2. That is, the sensor 60 may be a voltmeter or an ammeter. In the example shown in FIG. 2 , the sensor 60 is connected to the current path K2 and measures the voltage or current applied to the current path K2 as a sensor value.

[0036] Normal operation of the power supply system PSS according to this embodiment will be described below with reference to FIG. 4. The diagonal lines in FIG. 4 indicate paths through which power is supplied. During normal operation, the selector switches 41 of all power supply devices 10 are controlled to the on state, and the first switches 34 and second switches 35 of all power supply devices 10 are controlled to the on state. The power supply device 10-A supplies power from the power supply unit 32-A via the selector switch 41-A to the power supply cable fc1 of the track R1. The power supply device 10-B supplies power from the power supply unit 32-B via the selector switch 41-B to the power supply cable fc2 of the track R2. The power supply device 10-C supplies power from the power supply unit 32-C via the selector switch 41-C to the power supply cable fc3 of the track R3. That is, during normal operation, the power supply devices 10 other than the backup power supply device, i.e., the normal power supply devices, supply power to their respective tracks R.

[0037] During normal operation, although the first switch 34 and the second switch 35 are in the on state, almost no current flows through the power feed lines L between the power supply devices 10. In other words, almost no current flows through the power feed lines L1, L2, L3, and L4, and almost no power is exchanged between the power supply devices 10.

[0038] Next, the operation of the power supply system PSS according to this embodiment in the event of an abnormality will be described with reference to FIG. 5. The diagonal lines in FIG. 5 indicate the paths through which power is supplied. For example, assume that an abnormality occurs in the power supply device 10-C. In this case, the power supply device 10-C controls the changeover switch 41-C to the off state. When the changeover switch 41-C is turned off, the power supply from the inverter 40-C to the power supply cable fc3 of the track R3 is stopped. When the power supply is stopped, the power supply device 10-C receives power from the two power supply devices 10-B and 10-D adjacent to the power supply device 10-C, and continues to supply power to the track R3.

[0039] Specifically, when the changeover switch 41-C is turned off, power is supplied from the power feeding unit 32-B of the power feeding device 10-B to the power feeding device 10-C via the power feed line L3. Then, the power is supplied to the power feed cable fc3 via the current path K2 and the current path 50. Also, power is supplied from the power feeding unit 32-D of the power feeding device 10-D to the power feeding device 10-C via the power feed line L4. Then, the power is supplied to the power feed cable fc3 via the current path K1 and the current path 50. As a result, even if an abnormality occurs in the power feeding device 10-C, the power feeding to the track R3 corresponding to the power feeding device 10-C can be continued without stopping the power feeding.

[0040] Here, an abnormality may occur in the connection between the power supply devices 10. For example, this abnormality may occur when the wiring (power supply line L) is broken or when the wiring is incorrect. When an abnormality occurs between the power supply devices 10, power cannot be exchanged between the power supply devices 10. For example, in FIG. 5, if an abnormality occurs in the connection (third connection) between the power supply devices 10-C and 10-D or the connection (second connection) between the power supply devices 10-C and 10-B, the power supply device 10-C may not receive power from the power supply devices 10-B and 10-D. In such a case, sufficient power cannot be supplied to the track R3. Therefore, in order to detect such an abnormality early, the power supply system PSS performs a connection confirmation process to confirm that the appropriate connection relationship is maintained.

[0041] The connection confirmation process of the power supply system PSS according to this embodiment will be described below. Fig. 6 is a flow diagram of the connection confirmation process. For example, among the power supply devices 10-A to 10-D, the power supply device 10-A is set as the master device, and the other power supply devices 10-B to 10-D are set as slave devices. For example, polling communication is performed between the power supply device 10-A and each of the other power supply devices 10-B to 10-D.

[0042] The power supply system PSS turns off all of the first switches 34 and the second switches 35 (step S101). For example, the power supply device 10-A transmits an all-off command to all of the power supply devices 10-A to 10-D to turn off all of the first switches 34 and the second switches 35 (step S101). The destination of the all-off command includes, for example, information about each of the power supply devices 10-A to 10-D. Upon receiving the all-off command, each power supply device 10 turns off the first switches 34 and the second switches 35.

[0043] Next, the power supply device 10-A controls the first switch 34 of the first power supply device and the second switch 35 of the second power supply device that is the power supply device that should be connected to the first power supply device to be in the on state (step S102). For example, the power supply device 10-A transmits a confirmation command (hereinafter referred to as "connection confirmation polling") to the first power supply device and the second power supply device among the multiple power supply devices 10-A to check whether or not there is a connection abnormality between the first power supply device and the second power supply device (step S102).

[0044] Here, the first power supply device is any one of the power supply devices 10-A to 10-D. Information about the first power supply device and the second power supply device is set in advance. The connection between the first power supply device and the second power supply device is the connection to be confirmed in the connection confirmation process. The connection confirmation polling includes the destination of the first power supply device, the destination of the second power supply device, and a command to turn on only the first switch 34 of the first power supply device and the second switch 35 of the second power supply device.

[0045] When the first power supply device receives a connection confirmation polling message addressed to the first power supply device, the first switch 34 is controlled to be in the on state only. When the second power supply device receives a connection confirmation polling message addressed to the second power supply device, the second switch 35 is controlled to be in the on state only.

[0046] Next, the first power supply device acquires a sensor value (detection result) of the sensor 60 provided in the first power supply device (step S103). The sensor value of the sensor 60 is information indicating whether or not there is an electrical connection between the first power supply device and the second power supply device. The first power supply device transmits a connection confirmation response including the acquired sensor value to the power supply device 10-A, which is the master device (step S104). The power supply device 10-A receives the sensor value of the sensor 60 from the first power supply device.

[0047] Here, the connection between the first power supply device and the second power supply device refers to the connection between each power supply device 10. In the power supply system PSS shown in Fig. 1 , there are four connections, namely, a first connection, a second connection, a third connection, and a fourth connection, between each power supply device 10. Therefore, the power supply system PSS detects the presence or absence of each of the first connection, the second connection, the third connection, and the fourth connection by repeatedly executing the series of operations from step S101 to step S104 while sequentially switching between the first power supply device and the second power supply device.

[0048] The flow of the connection confirmation process for confirming the presence or absence of each of the first, second, third, and fourth connections will be described below with reference to Fig. 7. Fig. 7 is a sequence diagram of the connection confirmation process according to this embodiment.

[0049] First, the power supply device 10-A saves on / off information indicating the current states of all the first switches 34 and second switches 35 (step S201). The states of the first switches 34 and second switches 35 are information indicating whether the first switches 34 and second switches 35 are in the on state or the off state, respectively. For example, the power supply device 10-A communicates with each of the power supply devices 10-B to 10-D to acquire the states of the first switches 34 and second switches 35 of each of the power supply devices 10-B to 10-D.

[0050] The power supply device 10-A transmits an all-off command to the power supply devices 10-A to 10-D to turn off all of the first switches 34 and the second switches 35 (step S202). As a result, the power supply devices 10-A to 10-D turn off the first switches 34 and the second switches 35 based on the all-off command (step S203).

[0051] In order to check the connection status of the first connection, the power supply device 10-A transmits a connection confirmation polling including an ON command to turn on the first switch 34-A and the second switch 35-D (step S204). The power supply devices 10-A and 10-D are set as destinations of this connection confirmation polling. Upon receiving the connection confirmation polling, the power supply device 10-A (corresponding to the second power supply device) controls the second switch 35-A to the ON state (step S205). Furthermore, upon receiving the connection confirmation polling, the power supply device 10-D (corresponding to the first power supply device) controls the first switch 34-D to the ON state (step S206). Note that the power supply device 10-A may not include itself as a destination of the connection confirmation polling, and may instead control its own second switch 35-A to the ON state upon transmission of the connection confirmation polling.

[0052] The power supply device 10-A acquires the sensor value of the sensor 60-A while both the second switch 35-A and the first switch 34-D are on (step S207). If the sensor value of the sensor 60-A indicates the application of a voltage or a current, this indicates that the connection state of the first connection is normal.

[0053] For example, if the connection state of the first connection is normal, the sensor value of the sensor 60-A is a voltage or current value of a first level (e.g., Hi level). On the other hand, if the power supply line L1 is disconnected, the sensor value of the sensor 60-A is a voltage or current value of a second level (e.g., Lo level) lower than the first level. Even if the power supply line L1 is not disconnected, if the second connection part 31-A and the first connection part 30-D are not connected via the power supply line L1, i.e., if a wiring error has occurred, the sensor value of the sensor 60-A is a voltage or current value of the second level. The sensor value of the first level is, for example, a voltage or current value equal to or greater than a first threshold value. The sensor value of the second level is, for example, a voltage or current value less than a second threshold value that is lower than the first threshold value. The first threshold value and the second threshold value may be the same value.

[0054] In this way, when the second connection part 31-A and the first connection part 30-D that should be connected to the second connection part 31-A are connected via the power supply line L1 and the power supply line L1 is not broken, the sensor value of the sensor 60-A becomes a first level voltage value or current value that indicates a normal value. After the sensor value of the sensor 60-A is acquired, the second switch 35-A is controlled to be in the OFF state (step S208), and the first switch 34-D is controlled to be in the OFF state (step S209).

[0055] After confirming the connection status of the first connection, the power supply device 10-A turns on the first switch 34-A of the power supply device 10-A and transmits a connection confirmation polling including an instruction to turn on only the second switch 35-B of the power supply device 10-B in order to confirm the connection status of the second connection (step S210).

[0056] When the power supply device 10-A (corresponding to the first power supply device) receives the connection confirmation polling, it controls the first switch 34-A to the ON state (step S211). When the power supply device 10-B (corresponding to the second power supply device) receives the connection confirmation polling, it controls the second switch 35-B to the ON state (step S212). Note that the power supply device 10-A may not include itself as a destination of the connection confirmation polling, and may instead control its own first switch 34-A to the ON state in response to the transmission of the connection confirmation polling.

[0057] With both the first switch 34-A and the second switch 35-B on, the power supply device 10-B acquires the sensor value of the sensor 60-B (step S213). After acquiring the sensor value of the sensor 60-B, the power supply device 10-B transmits a connection confirmation response including the sensor value to the power supply device 10-A (step S214). If the sensor value of the sensor 60-B indicates the application of a voltage or a current, this indicates that the connection state of the second connection is normal.

[0058] For example, if the connection state of the second connection is normal, the sensor value of sensor 60-B is a voltage value or current value of the first level. On the other hand, if the power supply line L2 is disconnected, the sensor value of sensor 60-B is a voltage value or current value of the second level. Also, even if the power supply line L2 is not disconnected, if the first connection part 30-A and the second connection part 31-B are not connected via the power supply line L2, that is, if a wiring error has occurred, the sensor value of sensor 60-B is a voltage value of the voltage value or current value.

[0059] In this way, when the second connection part 31-B and the first connection part 30-A that should be connected to the second connection part 31-B are connected via the power supply line L2 and the power supply line L2 is not broken, the sensor value of the sensor 60-B becomes a first level voltage value or current value that indicates a normal value. After the sensor value of the sensor 60-B is acquired, the first switch 34-A is controlled to be in the OFF state (step S215), and the second switch 35-B is controlled to be in the OFF state (step S216).

[0060] After confirming the connection status of the second connection, the power supply device 10-A turns on the first switch 34-B of the power supply device 10-B and transmits a connection confirmation polling including an instruction to turn on only the second switch 35-C of the power supply device 10-C in order to confirm the connection status of the third connection (step S217).

[0061] When the power supply device 10-B (corresponding to the first power supply device) receives the connection confirmation polling, it controls the first switch 34-B to the ON state (step S218). When the power supply device 10-C (corresponding to the second power supply device) receives the connection confirmation polling, it controls the second switch 35-C to the ON state (step S219).

[0062] With both the first switch 34-B and the second switch 35-C on, the power supply device 10-C acquires the sensor value of the sensor 60-C (step S220). After acquiring the sensor value of the sensor 60-C, the power supply device 10-C transmits a connection confirmation response including the sensor value to the power supply device 10-A (step S221). If the sensor value of the sensor 60-C indicates the application of a voltage or a current, this indicates that the connection state of the third connection is normal.

[0063] For example, if the connection state of the third connection is normal, the sensor value of sensor 60-C is a voltage value of the first level. On the other hand, if the power supply line L3 is disconnected, the sensor value of sensor 60-C is a voltage value or current value of the second level. Furthermore, even if the power supply line L3 is not disconnected, if the first connection part 30-B and the second connection part 31-C are not connected via the power supply line L3, that is, if a wiring error has occurred, the sensor value of sensor 60-C is a voltage value or current value of the second level.

[0064] In this way, when the second connection part 31-C and the first connection part 30-B that should be connected to the second connection part 31-C are connected via the power supply line L3 and the power supply line L3 is not broken, the sensor value of the sensor 60-C becomes a first level voltage value or current value that indicates a normal value. After the sensor value of the sensor 60-C is acquired, the first switch 34-B is controlled to be in the OFF state (step S222), and the second switch 35-C is controlled to be in the OFF state (step S223).

[0065] After confirming the connection status of the third connection, the power supply device 10-A turns on the first switch 34-C of the power supply device 10-C and transmits a connection confirmation polling including an instruction to turn on only the second switch 35-D of the power supply device 10-D in order to confirm the connection status of the fourth connection (step S224).

[0066] When the power supply device 10-C (corresponding to the first power supply device) receives the connection confirmation polling, it controls the first switch 34-C to the ON state (step S225).Furthermore, when the power supply device 10-D (corresponding to the second power supply device) receives the connection confirmation polling, it controls the second switch 35-D to the ON state (step S226).

[0067] With both the first switch 34-C and the second switch 35-D on, the power supply device 10-D acquires the sensor value of the sensor 60-D (step S227). After acquiring the sensor value of the sensor 60-D, the power supply device 10-D transmits a connection confirmation response including the sensor value to the power supply device 10-A (step S228). If the sensor value of the sensor 60-D indicates the application of a voltage or a current, this indicates that the connection state of the fourth connection is normal.

[0068] For example, if the connection state of the fourth connection is normal, the sensor value of sensor 60-D is a voltage value or current value of the first level. On the other hand, if the power supply line L4 is disconnected, the sensor value of sensor 60-D is a voltage value or current value of the second level. Furthermore, even if the power supply line L4 is not disconnected, if the first connection part 30-C and the second connection part 31-D are not connected via the power supply line L4, that is, if a wiring error has occurred, the sensor value of sensor 60-D is a voltage value or current value of the second level.

[0069] In this way, when the second connection part 31-D and the first connection part 30-C that should be connected to the second connection part 31-D are connected via the power supply line L4 and the power supply line L4 is not broken, the sensor value of the sensor 60-D becomes a first level voltage value or current value that indicates a normal value.

[0070] When the power supply device 10-A acquires the presence or absence of an abnormality in each of the first, second, third, and fourth connections, it restores the on / off information of all the first switches 34 and the second switches 35 to the previously saved state before the connection confirmation process. For example, the power supply device 10-A transmits a restoration command to all the power supply devices 10-A to 10-D to restore the states of the first switches 34 and the second switches 35 of all the power supply devices 10-A to 10-D according to the previously saved on / off information (step S229). When each power supply device 10 receives the restoration command, it controls the on / off of the first switches 34 and the second switches 35 in accordance with the restoration command, thereby restoring the on / off states of all the first switches 34 and the second switches 35 (step S230).

[0071] Even when the connection check process is being executed, the changeover switch 41 remains in the on state. That is, even when the connection check process is being executed, the power supply from the track R1 to the track R3 continues. Furthermore, the connection check process may be executed periodically or at a preset timing.

[0072] In step 202, the power supply device 10-A, which is the master device, transmits the all-off command to the power supply devices 10-A to 10-D, but this is not limiting. The power supply device 10-A may transmit the all-off command to the power supply devices 10-B to 10-D and control the first switch 34-A and the second switch 35-A of its own device to the off state.

[0073] The power supply device 10-A may output information on the presence or absence of each of the first, second, third, and fourth connections to an external device. The external device may be a computer, a mobile information terminal, or the like. The external device may have a display device, and may display information on the presence or absence of each of the first, second, third, and fourth connections on the display device. Furthermore, the power supply device 10-A may output information on an abnormal connection among the first, second, third, and fourth connections to the external device.

[0074] The above embodiment discloses the following configurations: (Configuration 1) A power supply system PSS for supplying power to a plurality of power supply targets (R), comprising: a plurality of power supply devices 10 electrically connected to each other; and a detection unit 20 for detecting the presence or absence of an electrical connection between the power supply devices 10, wherein each power supply device 10 comprises: a first connection unit 30 and a second connection unit 31 to which another power supply device 10 is respectively connected; a power supply unit 32 capable of supplying and receiving power with the power supply devices 10 connected to the first connection unit 30 and the second connection unit 31, a first switch 34 connected between the power supply unit 32 and the first connection unit 30; and a second switch 35 connected between the power supply unit 32 and the second connection unit 31. The power supply system PSS controls a first switch 34 of a first power supply device among the plurality of power supply devices 10 and a second switch 35 of a second power supply device having a second connection portion 31 to be connected to the first connection portion 30 of the first power supply device to an on state, and controls the other first switches 34 and second switches 35 to an off state, and detects whether or not the first power supply device and the second power supply device are electrically connected using the detection result of the detection unit 20. (Configuration 2) The power supply system PSS according to configuration 1, wherein the detection unit 20 includes a sensor 60 provided in each of the power supply devices 10, and the sensor 60 measures a voltage or a current applied to the first connection portion 30 or the second connection portion 31. (Configuration 3) The power supply system PSS according to Configuration 1 or 2, wherein each power supply device 10 includes a communication unit 33 for communicating with other power supply devices 10, and the plurality of power supply devices 10 are composed of one master device (10-A) and a plurality of slave devices (10-B to 10-D), and the master device executes the following steps: a first step of transmitting an OFF command to all of the other power supply devices 10 to turn off all of the first switches 34 and the second switches 35; a second step of transmitting, after the first step, an ON command to the first power supply device and the second power supply device to turn on only the first switch 34 of the first power supply device and the second switch 35 of the second power supply device; and a third step of receiving, after the second step, from either the first power supply device or the second power supply device, information indicating whether or not there is an electrical connection between the first power supply device and the second power supply device.(Configuration 4) The power supply system PSS according to any one of Configurations 1 to 3, wherein the master device repeatedly executes a series of operations of the first step, the second step, and the third step while sequentially switching between the first power supply device and the second power supply device among the plurality of power supply devices 10 until it detects whether an electrical connection exists between all of the power supply devices 10. (Configuration 5) The power supply system PSS according to any one of Configurations 1 to 4, wherein communication between the master device and each slave device is polling communication. (Configuration 6) The power supply system PSS according to any one of Configurations 1 to 5, wherein each power supply device 10 is connected by a power supply line for transmitting and receiving power, and the power supply devices 10 are connected in a ring shape as a whole.

[0075] Although the embodiments have been described above, the technical scope of the present invention is not limited to the above-described embodiments. Furthermore, it will be apparent to those skilled in the art that various modifications and improvements can be made to the above-described embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention. Furthermore, one or more of the requirements described in the above-described embodiments may be omitted. Furthermore, the requirements described in the above-described embodiments may be combined as appropriate. Furthermore, the execution order of each step shown in the embodiments can be implemented in any order as long as the results of a previous step are not used in a subsequent step. Furthermore, even if the operations in the above-described embodiments are described using terms such as "first," "next," and "continuously" for convenience, this order is not required. Furthermore, to the extent permitted by law, the disclosures of Japanese Patent Application No. 2023-182266 and all documents cited in the above-described embodiments are incorporated herein by reference.

[0076] REFERENCE SIGNS LIST 1... power supply system, 10... power supply device, 20... detection unit, 30... first connection unit, 31... second connection unit, 32... power supply unit, 33... communication unit, 34... first switch, 35... second switch, 36... control unit, 50... sensor

Claims

1. A power supply system that supplies power to a plurality of power supply targets, comprising: a plurality of power supply devices electrically connected to each other; and a detection unit that detects whether or not there is an electrical connection between the power supply devices, wherein each of the power supply devices comprises: a first connection portion and a second connection portion to which another of the power supply devices is respectively connected; a power supply portion capable of supplying and receiving power with the power supply devices that are connected to each of the first connection portion and the second connection portion; a first switch connected between the power supply portion and the first connection portion; and a second switch connected between the power supply portion and the second connection portion, wherein the power supply system controls the first switch of a first power supply device among the plurality of power supply devices and the second switch of a second power supply device having the second connection portion that should be connected to the first connection portion of the first power supply device to an on state, and controls the other first switches and second switches to an off state, and detects whether or not there is an electrical connection between the first power supply device and the second power supply device using the detection result of the detection unit.

2. The power supply system according to claim 1, wherein the detection unit includes a sensor provided in each of the power supply devices, and the sensor measures the voltage or current applied to the first connection portion or the second connection portion.

3. The power supply system according to claim 1, wherein each of the power supply devices includes a communication unit for communicating with the other power supply devices, and the multiple power supply devices are composed of one master device and multiple slave devices, and the master device executes the following steps: a first step of transmitting an OFF command to all of the other power supply devices to turn off all of the first switches and the second switches; after the first step, a second step of transmitting an ON command to the first power supply device and the second power supply device to turn on only the first switch of the first power supply device and the second switch of the second power supply device; and a third step of receiving, after the second step, information indicating the presence or absence of an electrical connection between the first power supply device and the second power supply device from either the first power supply device or the second power supply device.

4. The power supply system according to claim 3, wherein the master device repeatedly executes a series of operations including the first step, the second step and the third step while sequentially switching between the first power supply device and the second power supply device among the plurality of power supply devices until the presence or absence of an electrical connection between all of the power supply devices is detected.

5. The power supply system according to claim 4, wherein communication between the master device and each of the slave devices is polling communication.

6. The power supply system according to claim 1, wherein the power supply devices are connected to each other by power supply lines for transmitting and receiving electric power, and the power supply devices are connected in a ring shape as a whole.