Power supply system

Abstract

In a non-contact power supply system (110), each of a master power supply device and a slave power supply device is provided with a time counter (25) that counts at a predetermined cycle, and generates an alternating current on the basis of the count value of the time counter (25). And the main control power supply device sends the rectangular wave to the slave power supply device. The slave power supply device generates an interrupt process at a timing at which the value of the rectangular wave transmitted from the master power supply device changes, compares the count value of the time counter (25) at the timing with a determination value, and when the comparison result is that the count value is less than the determination value, shortens the carrier cycle of the time counter (25) than a predetermined cycle, and transmits the interrupt process to the master power supply device. When the comparison result is that the count value is greater than the determination value, the period of the time counter is made longer than the predetermined period.

Description

Technical Field

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

[0002] As a conventional power supply system, for example, the technology described in Patent Document 1 is known. The power supply system described in Patent Document 1 includes: a master power conversion device and one or more slave power conversion devices. Each power conversion device includes: a time counter and a carrier generating unit that generates a carrier in synchronization with the time counter. The master power conversion device includes a synchronization data generating unit and a communication unit. When the time counter reaches a predetermined value, the synchronization data generating unit generates synchronization data for synchronizing the value of the time counter of the slave power conversion device with the value of the time counter of the master power conversion device; and the communication unit sends the synchronization data to the slave power conversion device. The slave power conversion device includes: a communication unit that receives the synchronization data, a time counter correction processing unit that corrects the value of the time counter according to the synchronization data, a current sensor that detects the output current of the slave power conversion device, and a gating timing adjustment unit that advances or delays the phase of the gating signal of the slave power conversion device according to the circulating current component.

[0003] Prior Art Literature

[0004] [Patent Document 1] Japanese Patent No. 5901861 Summary of the invention

[0005] Problem that the invention aims to solve

[0006] In the conventional power supply system, the synchronization data generated by the synchronization data generation unit of the master power conversion device includes the communication time. When the synchronization data includes the communication time, it takes time to generate the synchronization data, and it also takes time to receive the synchronization data. Therefore, when it is required to perform synchronization control in a shorter time, such as when it is used in a high-frequency power supply, there is a concern that appropriate synchronization control cannot be achieved.

[0007] An aspect of the present invention is to provide a power supply system capable of realizing high-speed synchronous control among a plurality of power supply devices.

[0008] A power supply system according to one aspect of the present invention comprises a first power supply device and one or more second power supply devices, the first power supply device generates an alternating current, the second power supply device generates an alternating current whose phase is synchronized with the alternating current of the first power supply device, the first power supply device and the second power supply device respectively comprise a time counter for counting at a prescribed period, and generate the alternating current according to the count value of the time counter, the first power supply device sends a rectangular wave having a first value when the count value of the time counter is less than a threshold value and having a second value when the count value is greater than or equal to the threshold value to the second power supply device, the second power supply device generates an interrupt processing at a timing when the value of the rectangular wave sent from the first power supply device changes, compares the count value of the time counter at the timing with a determination value, and when the comparison result is that the count value is less than the determination value, makes the period of the time counter shorter than the prescribed period, and when the comparison result is that the count value is greater than the determination value, makes the period of the time counter longer than the prescribed period.

[0009] In a power supply system according to one aspect of the present invention, the second power supply device generates an interruption process at the timing when the value of the rectangular wave sent from the first power supply device changes, and compares the count value of the time counter at the timing with the judgment value. The second power supply device makes the period of the time counter shorter than the prescribed period when the comparison result is that the count value is less than the judgment value, and makes the period of the time counter longer than the prescribed period when the comparison result is that the count value is greater than the judgment value. In this way, in the power supply system, since the information (data, signal) sent from the first power supply device to the second power supply device is a rectangular wave, the time used to create information related to synchronous control in the first power supply device can be shortened, and the time to receive information in the second power supply device can be shortened. In addition, in the power supply system, the time from when the time counter becomes above the threshold to when the interruption process is generated can be shortened, so that the first power supply device and the second power supply device can be synchronized in a short time (high speed). Therefore, in the power supply system, high-speed synchronous control between multiple power supply devices can be achieved.

[0010] In one embodiment, the judgment value may be a value set based on the communication time and threshold required for communication between the first power supply device and the second power supply device. In this configuration, the judgment value is set in consideration of the delay generated by the communication between the first power supply device and the second power supply device. Therefore, in the power supply system, the first power supply device and the second power supply device can be properly synchronized.

[0011] In one embodiment, the first value and the second value may each be 1-bit information. In this configuration, a change in the value of the rectangular wave can be determined with 1 bit, so interrupt processing can be generated at high speed.

[0012] In one embodiment, the second power supply device may make the period of the time counter shorter than the prescribed period by a prescribed amount when the comparison result is that the count value is less than the judgment value, and make the period of the time counter longer than the prescribed period by a prescribed amount when the comparison result is that the count value is greater than the judgment value, and after changing the period of the time counter, when the comparison result is that the count value is the same as the judgment value, the period of the time counter is returned to the prescribed period. In this configuration, the change of the period of the time counter is limited to the prescribed amount, so that a large change of the period can be suppressed.

[0013] In one embodiment, the first power supply device and the second power supply device may each supply power in a contactless manner.

[0014] In one embodiment, each of the first power supply device and the second power supply device may be set by performing switching control in each of the plurality of power supply devices, a number is set for each of the plurality of power supply devices, and switching to the first power supply device or the second power supply device is performed based on the presence or absence of power supply and the number. In this configuration, the first power supply device and the second power supply device may be appropriately set in the plurality of power supply devices.

[0015] Effect of the Invention: According to one aspect of the present invention, it is possible to realize high-speed synchronous control among a plurality of power supply devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a diagram schematically showing a track of a transportation system including a power supply system according to an embodiment.

[0017] Figure 2 It is a diagram showing the structure of a contactless power supply device.

[0018] Figure 3 This is a diagram showing communication between contactless power supply devices in the power supply system.

[0019] Figure 4 This is a diagram showing the configuration of a control device.

[0020] Figure 5 This is a diagram showing the relationship between the operation of the power supply device and the state of the non-contact power supply device.

[0021] Figure 6 is a diagram showing the carrier period and synchronization signal.

[0022] Figure 7 (a) and Figure 7 (b) is a diagram showing an example of a determination value of a carrier period.

[0023] Figure 8 This is a diagram for explaining synchronization processing.

[0024] Description of Reference Numerals

[0025] 1A, 1B, 1C, 1D: contactless power supply device (first power supply device, second power supply device);

[0026] 25: time counter;

[0027] 110: Contactless power supply system (power supply system). DETAILED DESCRIPTION

[0028] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or corresponding elements are given the same reference numerals, and repeated description is omitted.

[0029] like Figure 1 As shown, the transport system 100 is a system for transporting articles using an overhead transport vehicle 120 that is movable along a track rail T. The track rail T is a member for the overhead transport vehicle 120 to travel, and is suspended from the ceiling.

[0030] The transport system 100 includes: a contactless power supply system (power supply system) 110 and an overhead transport vehicle 120. In the transport system 100, power is supplied to the overhead transport vehicle 120 in a contactless manner from power supply lines 12A and 12B provided on the track rails T. The overhead transport vehicle 120 is driven by the power supplied from the power supply lines 12A and 12B. Various devices provided on the overhead transport vehicle 120 are driven by the power supplied from the power supply lines 12A and 12B.

[0031] The overhead transport vehicle 120 includes, for example, a ceiling-suspended crane, an OHT (Overhead Hoist Transfer), etc. The articles include, for example, a container storing a plurality of semiconductor wafers, a container storing a glass substrate, a grating storage box, general parts, and the like.

[0032] The track rail T is, for example, a circular track. The overhead transport vehicle 120 travels in a clockwise direction on the track rail T. Power is supplied to the power supply lines 12A and 12B from the contactless power supply devices 1A, 1B, 1C, and 1D. The power supply lines 12A and 12B are arranged below the track rail T in the travel direction of the overhead transport vehicle 120, and are arranged on at least one of the right and left sides with respect to the center of the track. In addition, the power supply line 12B is arranged below the power supply line 12A, so that Figure 1 In this case, the power supply line 12A is overlapped with the power supply line 12A.

[0033] The switch 30 is used to change the arrangement of the power supply lines 12A, 12B relative to the track rail T. The power supply lines 12A, 12B are arranged on the left side of the track rail T in the initial area connected to the contactless power supply devices 1A, 1B, 1C, 1D. If the track rail T moves in the direction of travel of the overhead transport vehicle 120, the switch 30 is used to switch the arrangement of the power supply lines 12A, 12B from the left side of the track rail T to the right side.

[0034] The contactless power supply system 110 includes contactless power supply devices 1A, 1B, 1C, and 1D. The contactless power supply devices 1A, 1B, 1C, and 1D supply power to the overhead traveling vehicle 120 in a contactless manner. The contactless power supply devices 1A, 1B, 1C, and 1D supply high-frequency current. The high frequency is, for example, 9 kHz.

[0035] like Figure 2 As shown, the contactless power supply device 1A, 1B, 1C, 1D includes: a power supply 2, a wiring circuit breaker 3, a noise filter 4, a power factor improvement device 5, a rectifier 6, a smoother 7, an inverter 8, a filter circuit 9, a first current sensor 10, a second current sensor 11, power supply lines 12A, 12B, and a control device 13. The noise filter 4, the power factor improvement device 5, the rectifier 6, and the smoother 7 constitute a power converter 16.

[0036] The power supply 2 is a device that supplies an AC power source such as a commercial power source, and supplies AC power (three-phase 200V). The frequency of the AC power is, for example, 50Hz or 60Hz. The wiring circuit breaker 3 disconnects the circuit when an overcurrent flows. The noise filter 4 removes noise from the AC power. The noise filter 4 is composed of, for example, a capacitor. The power factor improvement device 5 improves the power factor by making the input current close to a sine wave. The power factor improvement device 5 is composed of, for example, a reactor.

[0037] The rectifier 6 converts the AC power supplied from the power source 2 (power factor improvement device 5) into DC power. The rectifier 6 is composed of a rectifying element such as a diode, for example. The rectifier 6 can also be composed of a switching element such as a transistor. The smoother 7 smoothes the DC power converted by the rectifier 6. The smoother 7 is composed of an electrolytic capacitor, for example. The power converter can also further have a step-up and step-down function.

[0038] The inverter 8 converts the DC power output from the smoother 7 into AC power and outputs it to the filter circuit 9. The inverter 8 changes the switching frequency according to the control signal output from the control device 13, thereby changing the size of the AC power output to the filter circuit 9. The inverter 8 has a plurality of switching elements 14. The switching element 14 is an element that can switch an electrical switch. As the switching element 14, for example, MOSFET (Metal Oxide Semiconductor Field Effect Transistor), IGBT (Insulated Gate Bipolar Transistor), and bipolar transistors can be used.

[0039] The filter circuit 9 is provided between the inverter 8 and the power supply lines 12A and 12B. The filter circuit 9 suppresses harmonic noise. The filter circuit 9 includes a reactor RT1, a capacitor C0, a capacitor C1, a reactor RT2, and a capacitor C2.

[0040] The capacitor C0 and the reactor RT1 are connected in series to form a first resonant circuit RC1. The reactor RT1 includes a coil L11 and a coil L12. The reactor RT2 and the capacitor C2 are connected in series to form a second resonant circuit RC2. The first resonant circuit RC1 and the second resonant circuit RC2 are connected in series.

[0041] The first current sensor 10 detects the current I1 (inverter current) output from the inverter 8, that is, flowing through the inverter 8. The first current sensor 10 outputs a first current signal indicating the detected current I1 to the control device 13. The second current sensor 11 detects the current I2 (power supply current) of the AC power passing through the second resonant circuit RC2. The second current sensor 11 outputs a second current signal indicating the detected current I2 to the control device 13.

[0042] The control device 13 controls the operation of the inverter 8. The control device 13 is a computer system or a processor installed in an integrated circuit. The control device 13 is composed of a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc., and an input and output interface, etc. Various programs or data are stored in the ROM.

[0043] The control device 13 is connected to the first current sensor 10 and the second current sensor 11 of the filter circuit 9. The control device 13 receives the first current signal and the second current signal outputted from the first current sensor 10 and the second current sensor 11, respectively.

[0044] The control device 13 controls the size of the AC power (AC current) supplied to the power supply lines 12A, 12B by controlling the inverter 8, thereby controlling the size of the power supplied to the overhead transport vehicle 120. In the present embodiment, for example, phase shift control is used to perform power control. In the phase shift control, the power control parameter used to control the size of the AC power is changed. The control unit 15 implements phase shift control to change the size (frequency) of the AC power by changing the conduction (ON) period of the inverter 8. The control device 13 uses a drive signal for a plurality of switching elements 14 of the inverter 8 to adjust the switching frequency of each switching element 14, thereby changing the conduction period of each switching element 14. The power control parameter of the phase shift control is the conduction period of each switching element 14 of the inverter 8.

[0045] The control device 13 performs power control so that the power value supplied to the overhead travelling vehicle 120 becomes a target value based on the first current signal and the second current signal outputted from the first current sensor 10 and the second current sensor 11 , respectively.

[0046] like Figure 3 As shown, in the contactless power supply system 110, the control devices 13 of the contactless power supply devices 1A, 1B, 1C, and 1D are connected in a manner that allows mutual communication. In this embodiment, the control device 13 communicates by, for example, half-duplex communication. Specifically, the control device 13 communicates by, for example, RS485 communication. The control device 13 communicates synchronization signals and data.

[0047] In the contactless power supply system 110, the current phase of the AC current generated by one of the contactless power supply devices 1A, 1B, 1C, and 1D is synchronized with the current phase of the AC current generated by the other three contactless power supply devices 1A, 1B, 1C, and 1D. In the contactless power supply system 110, by synchronizing the current phases of the AC currents of the contactless power supply devices 1A, 1B, 1C, and 1D, the cancellation of the AC currents in the contactless power supply devices 1A, 1B, 1C, and 1D is suppressed.

[0048] In the contactless power supply system 110, the AC current phases in the contactless power supply devices 1A, 1B, 1C, and 1D are synchronized based on a synchronization signal sent from one of the contactless power supply devices 1A, 1B, 1C, and 1D to the other three contactless power supply devices. In the contactless power supply system 110, one of the contactless power supply devices 1A, 1B, 1C, and 1D becomes a master contactless power supply device, and the other three contactless power supply devices become slave contactless power supply devices, and a synchronization signal is sent from the master contactless power supply device to the slave contactless power supply devices. Hereinafter, the master contactless power supply device that sends the synchronization signal is referred to as a "master power supply device (an example of a first power supply device)", and the slave contactless power supply device that receives the synchronization signal is referred to as a "slave power supply device (an example of a second power supply device)".

[0049] like Figure 4 As shown, the control device 13 of each of the contactless power supply devices 1A, 1B, 1C, and 1D includes a first communication unit 20 , a second communication unit 21 , a control unit 22 , a synchronization processing unit 23 , a current control unit 24 , and a time counter 25 .

[0050] The first communication unit 20 performs data communication with the control device 13 of the other contactless power supply devices 1A, 1B, 1C, and 1D. The first communication unit 20 transmits and receives data. In this embodiment, the first communication unit 20 communicates in a half-duplex communication mode. The first communication unit 20 is designed to switch between a transmission mode and a reception mode.

[0051] The first communication unit 20 of the master power supply device waits in the receiving mode, switches to the sending mode at a predetermined timing, and sends the inquiry data to the slave power supply device. When the first communication unit 20 receives the response data sent by the slave power supply device in the receiving mode, it outputs the response data to the control unit 22.

[0052] The first communication unit 20 of the slave power supply device is on standby in the receiving mode, and switches to the sending mode when receiving the inquiry data sent from the master power supply device. The first communication unit 20 sends the response data prepared according to the received inquiry data to the master power supply device. The response data may include data indicating the status of the device (whether power is supplied or not, power on / off), etc.

[0053] The second communication unit 21 communicates the synchronization signal with the control device 13 of the other contactless power supply devices 1A, 1B, 1C, and 1D. The second communication unit 21 sends and receives the synchronization signal. In this embodiment, the second communication unit 21 uses a half-duplex communication method (see Figure 4) to communicate. The second communication unit 21 is designed to be switchable between a transmission mode and a reception mode. The switching between the transmission mode and the reception mode of the second communication unit 21 is performed by the control unit 22.

[0054] When the second communication unit 21 is a master power supply device, it enters a transmission mode for transmitting a synchronization signal and transmits the synchronization signal output from the current control unit 24 to the slave power supply device. The second communication unit 21 transmits a synchronization signal whose value changes between two values, Hi and Low, at a certain interval (e.g., 100 μs).

[0055] When the second communication unit 21 is a slave power supply device, it enters a reception mode for receiving a synchronization signal and receives the synchronization signal. The second communication unit 21 of the slave power supply device receives the synchronization signal at intervals of, for example, 100 μs. The second communication unit 21 outputs the received synchronization signal to the synchronization processing unit 23.

[0056] The control unit 22 switches between the master power supply device and the slave power supply device. When the control unit 22 switches to the master power supply device, the second communication unit 21 is set to the transmission mode, and the synchronization processing in the synchronization processing unit 23 is set to invalid. When the control unit 22 switches to the slave power supply device, the second communication unit 21 is set to the reception mode, and the synchronization processing in the synchronization processing unit 23 is set to valid.

[0057] The control unit 22 switches between the master power supply device and the slave power supply device according to the presence or absence of power supply and the number set for the contactless power supply device 1A, 1B, 1C, 1D. In this embodiment, for example, the contactless power supply device 1A is set to number "1", the contactless power supply device 1B is set to number "2", the contactless power supply device 1C is set to number "3", and the contactless power supply device 1D is set to number "4".

[0058] In the switching process of the control unit 22, the priority is set for the presence or absence of power supply and the number of the contactless power supply device 1A, 1B, 1C, 1D. In the present embodiment, the presence or absence of power supply is set as the first priority, and the number of the contactless power supply device 1A, 1B, 1C, 1D is set as the second priority. That is, the priority of the presence or absence of power supply is higher than the number of the contactless power supply device 1A, 1B, 1C, 1D. The control unit 22 switches between the master and the slave according to the presence or absence of power supply in the contactless power supply device 1A, 1B, 1C, 1D and the number of the contactless power supply device 1A, 1B, 1C, 1D.

[0059] The control unit 22 switches between the master and the slave by polling the other contactless power supply devices 1A, 1B, 1C, and 1D. The control unit 22 obtains the status of other devices by polling and switches between the master and the slave. Specifically, the control unit 22 switches between the master and the slave based on the polling record and the response record to the polling record. When the control unit 22 is to switch from the master power supply device to the slave power supply device, it sends a record of the master request to the other device. When the control unit 22 receives a record of the master consent from the other device, it switches to the slave power supply device. The control unit 22 of the other device switches to the master power supply device in accordance with the record of sending the master consent.

[0060] For an example of switching between the master and the slave of the control unit 22, refer to Figure 5 For explanation. Figure 5 As shown, the control unit 22 switches the contactless power supply devices 1A, 1B, 1C, and 1D between four states: master power supply device (power supply), slave power supply device (power supply), master power supply device (standby), and slave power supply device (standby).

[0061] For example, when the contactless power supply devices 1A and 1C are in standby mode (standby state without power supply) and the contactless power supply devices 1B and 1D are in power supply mode, the control units 22 of the contactless power supply devices 1A, 1B, 1C, and 1D are switched so that the contactless power supply device 1B becomes the master power supply device (power supply) and the contactless power supply devices 1A, 1C, and 1D become the slave power supply devices (standby and power supply). For example, when the contactless power supply device 1C is in standby mode and the contactless power supply devices 1A, 1B, and 1D are in power supply mode, the control units 22 of the contactless power supply devices 1A, 1B, 1C, and 1D are switched so that the contactless power supply device 1A becomes the master power supply device (power supply) and the contactless power supply devices 1B, 1C, and 1D become the slave power supply devices (standby and power supply).

[0062] For example, regarding the relationship between the contactless power supply device 1A and the contactless power supply device 1B, when the contactless power supply device 1A is in standby mode and the contactless power supply device 1B is in power supply mode, the control unit 22 of each device is switched so that the contactless power supply device 1A becomes the slave power supply device (standby mode) and the contactless power supply device 1B becomes the master power supply device (power supply). Then, when the contactless power supply device 1B becomes in standby mode, the control unit 22 of each device is switched so that the contactless power supply device 1A becomes the master power supply device (standby mode) and the contactless power supply device 1B becomes the slave power supply device. Then, when the contactless power supply device 1B becomes in power supply mode after the contactless power supply device 1A becomes in power supply mode, the control unit 22 of each device is switched so that the contactless power supply device 1A becomes the master power supply device (power supply) and the contactless power supply device 1B becomes the slave power supply device (power supply).

[0063] For example, regarding the relationship between the contactless power supply device 1A and the contactless power supply device 1B, when the contactless power supply device 1A is in power supply and the contactless power supply device 1B is in standby mode, the control unit 22 of each device is switched so that the contactless power supply device 1A becomes the master power supply device (power supply) and the contactless power supply device 1B becomes the slave power supply device (standby). Then, when the contactless power supply device 1A is in standby mode, the control unit 22 of the contactless power supply device 1A is switched so that the contactless power supply device 1A becomes the master power supply device (standby). Then, when the contactless power supply device 1B becomes in power supply after the contactless power supply device 1A becomes in power supply mode, the control unit 22 of each device is switched so that the contactless power supply device 1A becomes the master power supply device (power supply) and the contactless power supply device 1B becomes the slave power supply device (power supply).

[0064] For example, regarding the relationship between the contactless power supply device 1A and the contactless power supply device 1B, when the contactless power supply device 1A is in power supply and the contactless power supply device 1B is in standby mode, the control unit 22 of each device is switched so that the contactless power supply device 1A becomes the master power supply device (power supply) and the contactless power supply device 1B becomes the slave power supply device (standby). Then, when the contactless power supply device 1B is in power supply, the control unit 22 of the contactless power supply device 1B is switched so that the contactless power supply device 1B becomes the slave power supply device (power supply). Then, when the contactless power supply device 1A is in standby mode, the control unit 22 of each device is switched so that the contactless power supply device 1A becomes the slave power supply device (standby) and the contactless power supply device 1B becomes the master power supply device (power supply). Then, when the contactless power supply device 1A is in power supply, the control unit 22 of each device is switched so that the contactless power supply device 1A becomes the master power supply device (power supply) and the contactless power supply device 1B becomes the slave power supply device (power supply).

[0065] like Figure 3 As shown, the synchronization processing unit 23 synchronizes the carrier cycle of the slave power supply device according to the synchronization signal sent from the master power supply device. The synchronization processing unit 23 corrects the carrier cycle of the slave power supply device according to the count value of the time counter 25 and the synchronization signal. The time counter 25 counts within a certain (specified) carrier cycle. In this embodiment, the certain carrier cycle is 9KHz. That is, in the time counter 25, the specified period of the carrier cycle is set to 9KHz. However, the specified period is not limited to 9KHz, and can also be other frequencies.

[0066] Figure 6 2 is a diagram showing the carrier cycle and synchronization signal of the time counter 25. Figure 6 As shown in FIG. 1 , the carrier period is a sawtooth wave, and the synchronization signal is a rectangular wave. In this embodiment, the synchronization signal is a U-phase positive signal. The synchronization signal is Hi (an example of a first value) when the count value of the time counter 25 is less than the threshold value, and is Low (an example of a second value) when the count value is greater than or equal to the threshold value. Hi and Low are 1-bit information. Figure 6 As shown, the time counter 25 counts up within one cycle of the synchronization signal.

[0067] The synchronization processing unit 23 generates an interrupt processing at the timing when the value of the synchronization signal sent from the master power supply device changes, and compares the count value of the time counter 25 at the timing with the judgment value. The synchronization processing unit 23 stores the judgment value. The judgment value is set arbitrarily by the user. The judgment value is a value set based on the communication time required for communication between the master power supply device and the slave power supply device and the control delay time and threshold of the synchronization processing in the slave power supply device. The communication time may include the delay time. The judgment value is set to the middle value (threshold value) of the carrier cycle as an initial value. The user performs a specified input (operation) to change (correct) the judgment value from the initial value.

[0068] Figure 7 (a) and Figure 7 (b) is a diagram showing an example of a determination value. Figure 7 (a) An example in which the determination value is displayed as an initial value. Figure 7 (b) An example of displaying the judgment value as a correction value. Figure 7 In the example shown in (b), the determination value is set to a count value higher than the initial value (the middle value of the carrier cycle).

[0069] In the synchronization processing unit 23, when the synchronization signal output from the second communication unit 21 is input, an interrupt process is generated. Specifically, the synchronization processing unit 23 generates an interrupt process at the falling edge (from Hi to Low) of the synchronization signal. The synchronization processing unit 23 compares the falling edge of the synchronization signal with the count value of the carrier cycle, and performs synchronization processing according to the comparison result.

[0070] The synchronization processing unit 23 does not change the carrier period when the comparison result is that the count value is the same as the judgment value (count value = judgment value). The synchronization processing unit 23 makes the carrier period shorter than the prescribed period by a prescribed amount when the comparison result is that the count value is less than the judgment value (count value < judgment value). The prescribed amount is, for example, 0.5μs. The synchronization processing unit 23 makes the carrier period longer than the prescribed period by a prescribed amount when the comparison result is that the count value is greater than the judgment value (count value > judgment value). The prescribed amount is, for example, 0.5μs. After changing the carrier period of the time counter 25, the synchronization processing unit 23 returns the carrier period to the prescribed period when the comparison result is that the count value is the same as the judgment value (count value = judgment value). In addition, in the present embodiment, "same" may include values ​​other than equal, such as values ​​containing slight differences within a preset range.

[0071] The synchronization processing unit 23, for example Figure 8 As shown in P1 in FIG. 1 , when the count value is less than the judgment value, the carrier cycle is shortened by a predetermined amount. The synchronization processing unit 23, as shown in FIG. Figure 8As shown in P2 in FIG. 1 , when the count value is still less than the judgment value, the carrier cycle is kept shortened by a predetermined amount. Figure 8 As shown in P3 in FIG. 1 , when the count value becomes the same as the judgment value, the carrier cycle is set to the predetermined cycle. That is, the synchronization processing unit 23 returns the carrier cycle to the predetermined cycle when the count value and the judgment value are consistent as a result of the change of the carrier cycle.

[0072] The current control unit 24 controls the current in the contactless power supply devices 1A, 1B, 1C, and 1D. The current control unit 24 generates an alternating current according to the count value of the time counter 25. When the current control unit 24 is a master power supply device, it sends a synchronization signal to the slave power supply device via the second communication unit 21. When the current control unit 24 is a slave power supply device, it synchronizes the time counter 25 according to the synchronization signal output from the synchronization processing unit 23, and generates an alternating current according to the count value of the time counter 25.

[0073] As described above, in the contactless power supply system 110 of the present embodiment, the slave power supply device generates an interruption process at the timing when the value of the rectangular wave, which is the output signal sent from the master power supply device, changes, and compares the count value of the time counter at the timing with the judgment value. The slave power supply device makes the carrier cycle of the time counter 25 shorter than the prescribed cycle when the comparison result shows that the count value is less than the judgment value, and makes the carrier cycle of the time counter 25 longer than the prescribed cycle when the comparison result shows that the count value is greater than the judgment value. In this way, in the contactless power supply system 110, since the information (data, signal) sent from the master power supply device to the slave power supply device is a rectangular wave, it is possible to reduce the time for the master power supply device to create information related to synchronization and reduce the time for the slave power supply device to receive information. In addition, in the contactless power supply system 110, the time from when the time counter 25 becomes above the threshold to when the interruption process is generated can be shortened, so that the master power supply device and the slave power supply device can be synchronized in a short time (high speed). Therefore, in the contactless power supply system 110, it is possible to achieve high-speed synchronization control between multiple power supply devices.

[0074] In the contactless power supply system 110 of the present embodiment, the judgment value is a value set according to the communication time and threshold required for communication between the master power supply device and the slave power supply device. In this configuration, the judgment value is set in consideration of the delay generated by the communication between the master power supply device and the slave power supply device. Therefore, in the contactless power supply system 110, the master power supply device and the slave power supply device can be properly synchronized.

[0075] In the contactless power supply system 110 of this embodiment, the Hi and Low values ​​of the synchronization signal are each 1-bit information. In this configuration, the change in the value of the synchronization signal can be determined using 1 bit, so interrupt processing can be generated at high speed.

[0076] In the contactless power supply system 110 of the present embodiment, the slave power supply device may be configured such that, when the comparison result is that the count value is less than the judgment value, the carrier cycle of the time counter 25 is shorter than the prescribed cycle by a prescribed amount, and when the comparison result is that the count value is greater than the judgment value, the carrier cycle of the time counter is longer than the prescribed cycle by a prescribed amount, and after the carrier cycle of the time counter 25 is changed, when the comparison result is that the count value is the same as the judgment value, the cycle of the time counter 25 is returned to the prescribed cycle. In this configuration, the change in the cycle of the time counter 25 is limited to a prescribed amount, so that a large change in the carrier cycle can be suppressed.

[0077] In the contactless power supply system 110 of the present embodiment, the control unit 22 of the control device 13 switches between the master power supply device and the slave power supply device according to the presence or absence of power supply and the number set to the contactless power supply device 1A, 1B, 1C, 1D. In this configuration, the switching between the master power supply device and the slave power supply device can be appropriately performed.

[0078] Although the embodiments of the present invention have been described above, the present invention is not necessarily limited to the above embodiments, and various modifications can be made without departing from the gist of the present invention.

[0079] In the above embodiment, the non-contact power supply system 110 is applied to the transport system 100 as an example for description. However, the non-contact power supply system 110 may also be applied to other systems.

[0080] In the above embodiment, the power supply system is described as a contactless power supply system 110 that supplies power in a contactless manner. However, the power supply mode in the power supply system is not limited to the contactless mode.

[0081] In the above embodiment, the non-contact power supply system 110 is described as an example in which the non-contact power supply system 110 includes four non-contact power supply devices 1A, 1B, 1C, and 1D. However, the non-contact power supply system 110 only needs to include at least two non-contact power supply devices.

[0082] In the above embodiment, the synchronization processing unit 23 generates an interrupt processing at the falling edge (from Hi to Low) of the synchronization signal. However, the synchronization processing unit 23 may also generate an interrupt processing at the rising edge (from Low to Hi) of the synchronization signal.

[0083] In the above embodiment, the traveling vehicle is an overhead transport vehicle 120 as an example for explanation. However, the traveling vehicle is not limited to an overhead transport vehicle, and any traveling vehicle that can travel on the track rails T can be used. For example, the traveling vehicle can also be a ground transport vehicle (ground traveling vehicle). When the traveling vehicle is a ground transport vehicle, the track rails are laid on the ground.

[0084] The technical subject matter of one aspect of the present invention can be described as follows.

[0085] [1] A power supply system comprising a first power supply device and one or more second power supply devices, wherein the first power supply device generates an alternating current, and the second power supply device generates an alternating current whose phase is synchronized with the alternating current of the first power supply device,

[0086] The first power supply device and the second power supply device each include a time counter that counts at a predetermined cycle, and generates the alternating current according to the count value of the time counter.

[0087] The first power supply device sends a rectangular wave to the second power supply device, which has a first value when the count value of the time counter is less than a threshold value and has a second value when the count value is greater than or equal to the threshold value.

[0088] The second power supply device generates an interrupt process at a timing when the value of the rectangular wave transmitted from the first power supply device changes, and compares the count value of the time counter at the timing with a determination value.

[0089] When the comparison result shows that the count value is smaller than the determination value, the cycle of the time counter is made shorter than the prescribed cycle.

[0090] When the comparison result shows that the count value is greater than the determination value, the cycle of the time counter is made longer than the predetermined cycle.

[0091] [2] A power supply system as described in [1], wherein

[0092] The determination value is a value set based on the communication time required for communication between the first power supply device and the second power supply device and the threshold value.

[0093] [3] The power supply system as described in [1] or [2], wherein:

[0094] The first value and the second value are each 1-bit information.

[0095] [4] A power supply system as described in any one of [1] to [3], wherein:

[0096] The second power supply device is:

[0097] When the comparison result shows that the count value is smaller than the determination value, the cycle of the time counter is made shorter by a predetermined amount than the predetermined cycle.

[0098] When the comparison result shows that the count value is greater than the determination value, the cycle of the time counter is made longer by a predetermined amount than the predetermined cycle,

[0099] After the cycle of the time counter is changed, when the comparison result shows that the count value is identical to the determination value, the cycle of the time counter is returned to the predetermined cycle.

[0100] [5] A power supply system as described in any one of [1] to [4], wherein:

[0101] The first power supply device and the second power supply device each supply power in a contactless manner.

[0102] [6] A power supply system as described in any one of [1] to [5], wherein:

[0103] Each of the first power supply device and the second power supply device is set by performing switching control in each of the plurality of power supply devices.

[0104] Setting a number for each of the plurality of power supply devices,

[0105] Switching to the first power supply device or the second power supply device is performed according to the presence or absence of power supply and the number.

Claims

1. A power supply system comprising a first power supply device and one or more second power supply devices, wherein the first power supply device generates an alternating current, and the second power supply device generates an alternating current whose phase is synchronized with the alternating current of the first power supply device, The first power supply device and the second power supply device each include a time counter that counts at a predetermined cycle, and generates the alternating current according to the count value of the time counter. The first power supply device sends a rectangular wave to the second power supply device, which has a first value when the count value of the time counter is less than a threshold value and has a second value when the count value is greater than or equal to the threshold value. The second power supply device generates an interrupt process at a timing when the value of the rectangular wave transmitted from the first power supply device changes, and compares the count value of the time counter at the timing with a determination value. When the comparison result shows that the count value is smaller than the determination value, the cycle of the time counter is made shorter than the prescribed cycle. When the comparison result shows that the count value is greater than the determination value, the cycle of the time counter is made longer than the predetermined cycle.

2. The power supply system according to claim 1, wherein: The determination value is a value set based on the communication time required for communication between the first power supply device and the second power supply device and the threshold value.

3. The power supply system according to claim 1 or 2, wherein: The first value and the second value are each 1-bit information.

4. The power supply system according to claim 1 or 2, wherein: The second power supply device is: When the comparison result shows that the count value is smaller than the determination value, the cycle of the time counter is made shorter by a predetermined amount than the predetermined cycle. When the comparison result shows that the count value is greater than the determination value, the cycle of the time counter is made longer by a predetermined amount than the predetermined cycle, After the cycle of the time counter is changed, when the comparison result shows that the count value is identical to the determination value, the cycle of the time counter is returned to the predetermined cycle.

5. The power supply system according to claim 1 or 2, wherein: The first power supply device and the second power supply device each supply power in a contactless manner.

6. The power supply system according to claim 1 or 2, wherein: Each of the first power supply device and the second power supply device is set by performing switching control in each of the plurality of power supply devices. Setting a number for each of the plurality of power supply devices, Switching to the first power supply device or the second power supply device is performed according to the presence or absence of power supply and the number.

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