Power supply system and inter-unit communication method

Abstract

To enhance failure resistance of a power supply system in which power supply units are made redundant.SOLUTION: A device according to an aspect of the present disclosure is a power supply system including first and second power supply units that supply DC power to a load through a diode OR circuit, the first power supply unit including a power conversion unit that converts power of a first power distribution system into DC power, the second power supply unit including a power conversion unit that converts power of a second power distribution system into DC power, the first and second power supply units are capable of controlling their own power converters with a reference voltage value acquired by inter-unit communication, one of the first and second power supply units serving as a master node repeatedly notifies a unit serving as a slave node of its own reference voltage value, and the unit serving as the slave node updates an output voltage of its own power converter to the reference voltage value when notified of the reference voltage value.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a power supply system and a method of communication between units. [Background technology]

[0002] Patent Document 1 describes a power supply device in which the outputs of two power supply modules are configured in a diode-OR configuration to perform parallel operation. This power supply device has the following circuit configuration. 1) A first resistor is connected in parallel to the output of the first power supply module, and the midpoint of the first resistor is set as the first input of the error amplifier. 2) A second resistor is connected in parallel to the output of the second power supply module, and the midpoint of the second resistor is used as the second input of the error amplifier.

[0003] 3) The output of the error amplifier is used as the input to the driver circuit that controls the output voltage, and the output of the driver circuit is connected to one of the power supply modules. According to the power supply device of Patent Document 1, the output voltage of the power supply module on the high voltage side can be reduced, thereby reducing the imbalance in load current. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 62-73315 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, active elements such as an error amplifier and a driver circuit section are used, so if these circuits fail, the imbalance in the load current cannot be resolved, resulting in the problem that redundancy of the power supply module (hereinafter also referred to as the "power supply unit") cannot be achieved. In view of the above-described conventional problems, the present disclosure aims to improve the fault tolerance of a power supply system in which power supply units are made redundant. [Means for solving the problem]

[0006] An apparatus according to one embodiment of the present disclosure is a power supply system including first and second power supply units that supply DC power to a load through a diode OR circuit, wherein the first power supply unit has a power conversion unit that converts power from a first power distribution system into DC power, and the second power supply unit has a power conversion unit that converts power from a second power distribution system into DC power, and the first and second power supply units are capable of controlling their own power conversion units using a reference voltage value obtained through inter-unit communication, and among the first and second power supply units, a unit that is a master node repeatedly notifies a unit that is a slave node of its own reference voltage value, and when the reference voltage value is notified, the slave node unit updates the output voltage of its own power conversion unit to the reference voltage value. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to improve the fault tolerance of a power supply system having redundant power supply units. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing an example of the internal structure of a communication device. [Figure 2] FIG. 2 is a block diagram showing an example of a circuit configuration of a communication device. [Figure 3] FIG. 3 is an explanatory diagram showing an example of a connection form for communication between units. [Figure 4] FIG. 4 is an explanatory diagram showing another example of a connection form for communication between units. [Figure 5] FIG. 5 is an explanatory diagram showing an embodiment of the communication control 1. In FIG. [Figure 6] FIG. 6 is an explanatory diagram showing an embodiment of the communication control 1. In FIG. [Figure 7] FIG. 7 is an explanatory diagram showing an embodiment of communication control 2. [Figure 8] FIG. 8 is an explanatory diagram showing an embodiment of the communication control 3. [Figure 9] FIG. 9 is an explanatory diagram showing an embodiment of the communication control 4. [Figure 10] FIG. 10 is a sequence diagram illustrating an example of repeated notification of the reference voltage value. [Figure 11] FIG. 11 is a flowchart illustrating an example of a node type determination process. [Figure 12] FIG. 12 is a sequence diagram illustrating an example of a process for specifying a node type. [Figure 13] FIG. 13 is a sequence diagram illustrating an example of a process for stopping periodic notifications. [Figure 14] FIG. 14 is a sequence diagram illustrating an example of a process for collecting output voltages. DETAILED DESCRIPTION OF THE INVENTION

[0009] <Summary of Embodiments of the Present Disclosure> The following provides an outline of embodiments of the present disclosure. (1) The device of this embodiment is a power supply system including first and second power supply units that supply DC power to a load through a diode OR circuit, wherein the first power supply unit has a power conversion unit that converts power from a first power distribution system into DC power, and the second power supply unit has a power conversion unit that converts power from a second power distribution system into DC power.

[0010] In addition, the first and second power supply units are capable of controlling their own power conversion units using a reference voltage value obtained through inter-unit communication, and of the first and second power supply units, the unit that is a master node repeatedly notifies the unit that is a slave node of its own reference voltage value, and when the unit that is a slave node is notified of the reference voltage value, it updates the output voltage of its own power conversion unit to that reference voltage value.

[0011] According to the power supply system of this embodiment, the master node unit repeatedly notifies the slave node unit of its reference voltage value, and the slave node unit updates the output voltage of its power conversion unit to the reference voltage value upon receiving the notification. This makes it possible to equalize the current values ​​of the first and second distribution lines and suppress imbalances in received power without using active elements such as error amplifiers or driver circuits. This makes it possible to improve the fault tolerance of a power supply system with redundant power supply units.

[0012] (2) In the power supply system of (1) above, the first and second power supply units may be connectable to different connectors on the backplane, and may determine whether their node type is a master node or a slave node based on information indicating their own connection position and information indicating the connection position of the other party received through unit-to-unit communication. In this way, the first and second power supply units can autonomously determine their own node types.

[0013] (3) In the power supply system of (2) above, the first and second power supply units may determine whether their node type is a master node or a slave node in response to instructions received from a control unit via inter-unit communication. In this way, the node types of the first and second power supply units can be switched in response to an instruction from the control unit, which is an external device.

[0014] (4) In the power supply system of (3) above, the control unit may be capable of transmitting an instruction to the master node unit to stop the repeated notification of the reference voltage value. In this way, repeated notification of the reference voltage value by the master node can be stopped in response to an instruction from the control unit, which is an external device.

[0015] (5) In the power supply systems (2) to (4) above, when the slave node detects that the master node has been removed from the backplane, the slave node may switch its node type to a master node. The reason is that if the power supply unit of the communication partner is removed, the output voltage of the voltage conversion unit becomes unstable unless the node itself becomes the master node and determines the output voltage independently.

[0016] (6) In the power supply systems (1) to (5) described above, when the notification of the reference voltage value from the master node is interrupted, the slave node may determine whether to use the reference voltage value depending on the amount of time that has elapsed since the notification was interrupted. The reason for this is that if the communication with the master node is interrupted for such a long time that the elapsed time exceeds a predetermined value, the output voltage of the voltage conversion unit will become unstable unless the unit itself determines the output voltage independently.

[0017] (7) The method according to this embodiment is an inter-unit communication method executed in the power supply systems (1) to (6) described above. Therefore, the inter-unit communication method according to this embodiment has the same effects as the power supply systems (1) to (6) described above.

[0018] <Details of the embodiment of the present disclosure> Hereinafter, details of embodiments of the present disclosure will be described with reference to the drawings. Note that at least some of the embodiments described below may be combined in any manner.

[0019] [Example of communication device structure] FIG. 1 is a perspective view showing an example of the internal structure of a communication device 1. As shown in FIG. FIG. 2 is a block diagram showing an example of a circuit configuration of the communication device 1. As shown in FIG. 1 and 2, the communication device 1 includes a housing 2, a backplane 3, a control unit 4, a line unit 5, a power supply unit 6, and a fan unit 7.

[0020] The housing 2 is, for example, a 1U-sized metal casing. The housing 2 has a front opening 21 and a rear opening 22 through which the units 4, 5, 6, and 7 can be inserted and removed. A backplane 3 is installed inside the housing 2. The backplane 3 is a circuit board that is long in the left-right direction and has roughly the same shape as the cross section of the interior of the housing 2. The backplane 3 is located roughly in the center of the housing 2 in the front-to-rear direction, and serves as a wall that divides the storage space of the housing 2 into roughly two halves in the front-to-rear direction.

[0021] The backplane 3 has a plurality of connectors 31 for inter-unit communication. The connectors 31 are, for example, female. The backplane 3 has a plurality of ventilation holes 32 for circulating cooling air from the fans in the front-rear direction. In the illustrated example, five connectors 31 are arranged in a row in the left-right direction on the front side of the backplane 3. Although they are hidden in Fig. 1, five connectors 31 are also arranged in a row in the left-right direction on the rear side of the backplane 3. Note that the number of connectors 31 to be installed on the backplane 3 is not limited to 10 and can be designed as desired.

[0022] The communication device 1 includes, as units connectable to a connector 31 of a backplane 3, a control unit 4 that is a monitoring entity that monitors the status through inter-unit communication, and a plurality of controlled units 5, 6, and 7 that are to be monitored. That is, the control unit 4 is a unit that monitors the states of the other units 5, 6, and 7 attached to the backplane 3, and the line unit 5, power supply unit 6, and fan unit 7 are the objects that the control unit 4 monitors.

[0023] The communication standard for communication between units is not particularly limited as long as it enables digital communication, but may be, for example, HDLC (High-Level Data Link Control), I2C, Ethernet, etc. In this embodiment, HDLC is adopted.

[0024] The structural example in Figure 1 illustrates a case in which one control unit 4 and three line units 5 are mounted on the front side of the backplane 3, and two power supply units 6 and three fan units 7 are mounted on the rear side of the backplane 3. However, there is no particular limit to the number of each of the units 4, 5, 6, and 7 that can be installed. However, since the power supply unit 6 is a unit that supplies power to the communication device 1, at least one power supply unit 6 must always be installed in the backplane 3 to keep the device in operation.

[0025] [Internal structure of the control unit] 2, the control unit 4 includes a circuit board 40 and a connector 41 provided on an edge of the circuit board 40. The connector 41 is, for example, a male connector that is detachable from the connector 31 of the backplane 3. The control unit 4 may include a housing that covers the circuit board 40.

[0026] The control unit 4 includes, as electronic components mounted on a circuit board 40, a signal processing unit 42, a CPU (Central Processing Unit) 43, a memory 44, a communication processing unit 45, a management port 46, a power supply unit 47, and a diode OR circuit 48. These electronic components are electrically connected by the wiring pattern of the circuit board 40 shown by solid lines in FIG.

[0027] The signal processing unit 42 is an electronic circuit including, for example, an FPGA (Field-Programmable Gate Array). A signal processing circuit for inter-unit communication conforming to a predetermined communication standard such as HDLC is set in the FPGA. The CPU 43 is an arithmetic processing device that comprehensively controls the operation of the control unit 4. The CPU 43 changes the settings of the signal processing unit 42, the communication processing unit 45, etc., based on predetermined setting information recorded in the memory 44, for example.

[0028] The communication processing unit 45 is, for example, a MAC (Media Access Control) chip. The management port 46 is, for example, an RJ-45 connector. The management port 46 is connected to a management computer owned by a communications administrator or a router connected to the Internet. The communication processing unit 45 is connected not only to the CPU 43 of its own unit but also to the CPU 53 of the line unit 5 via the management signal line 33. The communication processing unit 45 receives an Ethernet frame ("Ethernet" is a registered trademark) containing management information from the management computer.

[0029] If the management information included in the received frame is setting information of its own unit, the communication processing unit 45 transmits the setting information to the CPU 43 of its own unit. The CPU 43 records the received setting information in the memory 44. If the management information included in the received frame is setting information for the line unit 5, the communication processing unit 45 transmits the setting information to the CPU 53 of the line unit 5. The CPU 53 records the received setting information in the memory 54.

[0030] The power supply unit 47 is an electronic circuit including, for example, a DC / DC converter. The DC / DC converter converts the DC voltage of the DC distribution line 34 into a predetermined voltage and supplies the converted DC voltage to an electronic circuit including an active element mounted on the circuit board 40. The diode OR circuit 48 is a passive component having two diodes connected in parallel. The diode OR circuit 48 supplies the DC voltage of the higher-voltage power supply line of the two power supply lines 34A, 34B included in the DC distribution line 34 to the power supply unit 47.

[0031] [Internal structure of the line unit] 2, the line unit 5 includes a circuit board 50 and a connector 51 provided on an edge of the circuit board 50. The connector 51 is, for example, a male connector that is detachable from the connector 31 of the backplane 3. The line unit 5 may include a housing that covers the circuit board 50.

[0032] The line unit 5 includes, as electronic components mounted on a circuit board 50, a signal processing unit 52, a CPU 53, a memory 54, a switch unit 55, an external port 56, a power supply unit 57, and a diode OR circuit 58. These electronic components are electrically connected by the wiring pattern of the circuit board 50 shown by solid lines in FIG.

[0033] The signal processing unit 52 is an electronic circuit including, for example, an FPGA, in which a signal processing circuit for inter-unit communication conforming to a predetermined communication standard such as HDLC is set. The CPU 53 is an arithmetic processing unit that comprehensively controls the operation of the line unit 5. The CPU 53 changes the settings of the signal processing unit 52, the switch unit 55, etc., based on predetermined setting information recorded in the memory 54, for example.

[0034] The switch unit 55 is, for example, a high-speed Ethernet switch LSI (Large Scale Integration) of 10 gigabits, etc. The external port 56 is, for example, a connector into which a pluggable optical transceiver (not shown) can be inserted or removed. The power supply unit 57 is an electronic circuit including, for example, a DC / DC converter. The DC / DC converter converts the DC voltage of the DC distribution line 34 into a predetermined voltage and supplies the converted DC voltage to an electronic circuit including an active element mounted on the circuit board 50.

[0035] The diode OR circuit 58 is a passive component having two diodes connected in parallel. The diode OR circuit 58 supplies the DC voltage of the higher-voltage power supply line of the two power supply lines 34A, 34B included in the DC distribution line 34 to the power supply unit 57.

[0036] [Internal structure of the power supply unit] 2, the power supply unit 6 includes a circuit board 60 and a connector 61 provided on the edge of the circuit board 60. The connector 61 is, for example, a male connector that is detachable from the connector 31 of the backplane 3. The power supply unit 6 may include a housing that covers the circuit board 60.

[0037] The power supply unit 6 includes electronic components mounted on a circuit board 60, such as a signal processing unit 62, a first voltage conversion unit 63, a second voltage conversion unit 64, and a voltage sensor 65. These electronic components are electrically connected by the wiring pattern of the circuit board 60 shown by solid lines in FIG. The signal processing unit 62 is an electronic circuit including, for example, an FPGA, in which a signal processing circuit for inter-unit communication conforming to a predetermined communication standard such as HDLC is set.

[0038] The first voltage conversion unit 63 is an electronic circuit including, for example, an AC / DC converter. The first voltage conversion unit 63 converts an AC voltage supplied from a commercial power source or the like into a DC voltage of a predetermined voltage, and outputs the converted DC voltage to the DC distribution line 34 and the second voltage conversion unit 64. The second voltage conversion unit 64 is an electronic circuit including, for example, a DC / DC converter. The second voltage conversion unit 64 converts the DC voltage supplied from the first voltage conversion unit 63 into a DC voltage of a predetermined voltage, and supplies the converted DC voltage to an electronic circuit including an active element mounted on the circuit board 60.

[0039] The voltage sensor 65 is a sensor module that outputs the measurement result of the output voltage (DC voltage) of the first voltage conversion unit 63 to the signal processing unit 62. The circuit system of the voltage sensor 65 may be any of a photocoupler output type, a DC three-wire type, a DC two-wire type, or the like. The signal processing unit 62 is capable of performing feedback control to control the output voltage of the first voltage conversion unit 63. Specifically, the signal processing unit 62 calculates parameters such as a duty ratio from the measurement result of the voltage sensor 65, and outputs the calculation result to the first voltage conversion unit 63.

[0040] First voltage conversion unit 63 performs conversion processing using the latest parameters input from signal processing unit 62. As a result, the output voltage of first voltage conversion unit 63 is controlled to a predetermined reference voltage value (for example, 48 V). The power supply system (e.g., commercial power supply) of the communication device 1 can be configured as a redundant system with multiple systems. For example, Fig. 2 illustrates a case where power is supplied to the communication device 1 from two commercial power supplies, a first power supply system 8A and a second power supply system 8B.

[0041] When the power supply system for the communication device 1 is made redundant with two systems, a first power supply unit 6A connected to the first power supply system 8A and a second power supply unit 6B connected to the second power supply system 8B are connected to the backplane 3. In this case, the first power supply unit 6A is a power supply unit 6 that applies a DC voltage to the first power supply line 34A of the DC distribution line 34, and the second power supply unit 6B is a power supply unit 6 that applies a DC voltage to the second power supply line 34B of the DC distribution line 34.

[0042] In this embodiment, the units 4, 5, and 7, which are loads, are connected to the DC distribution line 34 via diode OR circuits 48, 58, and 75, respectively. Therefore, the first power supply unit 6A and the second power supply unit 6B constitute a redundant power supply system that supplies DC power to the loads (respective units 4, 5, 7) through the diode OR circuits 48, 58, 75.

[0043] The diode OR circuits 48, 58, and 75 have the function of supplying a larger amount of current from the higher voltage side. Therefore, by controlling the voltage values ​​of the first distribution line 34A and the second distribution line 34B to be equal, the current values ​​of the two distribution lines 34A, 34B become almost constant, and load balancing can be achieved to suppress the imbalance in the received power from the two power supply systems 8A, 8B.

[0044] Therefore, the signal processing units 62 of the power supply units 6A and 6B use inter-unit communication between the two to execute communication control for adjusting the output voltages of the first voltage conversion units 63 of the two power supply units 6A and 6B to the same set value. Details of this communication control (see FIG. 10, etc.) will be described later.

[0045] [Internal structure of the fan unit] 2, the fan unit 7 includes a circuit board 70 and a connector 71 provided on the edge of the circuit board 70. The connector 71 is, for example, a male connector that is detachable from the connector 31 of the backplane 3. The fan unit 7 may include a housing that covers the circuit board 70.

[0046] The fan unit 7 includes electronic components mounted on a circuit board 70, such as a signal processing unit 72, a cooling fan 73, a power supply unit 74, and a diode OR circuit 75. These electronic components are electrically connected by the wiring pattern of the circuit board 70, which is shown by the solid lines in FIG. The signal processing unit 72 is an electronic circuit including, for example, an FPGA, in which a signal processing circuit for inter-unit communication conforming to a predetermined communication standard such as HDLC is set.

[0047] The cooling fan 73 is a fan whose air volume can be adjusted by controlling the rotation speed of an electric motor. The rotation speed of the cooling fan 73 is controlled by a control signal from the signal processing unit 72. The power supply unit 74 is an electronic circuit including, for example, a DC / DC converter. The DC / DC converter converts the DC voltage of the DC distribution line 34 into a predetermined voltage and supplies the converted DC voltage to the signal processing unit 72 and the electric motor of the cooling fan 73.

[0048] The diode OR circuit 75 is a passive component having two diodes connected in parallel. The diode OR circuit 75 supplies the DC voltage of the higher-voltage power supply line of the two power supply lines 34A, 34B included in the DC distribution line 34 to the power supply unit 74.

[0049] [Power supply unit relay function] As shown in FIG. 2, the power supply unit 6 of this embodiment functions as a relay unit capable of relaying the second control signal out of the following first control signal and second control signal. First control signal: A control signal for monitoring itself (power supply unit 6) Second control signal: A control signal for monitoring a controlled unit (here, the fan unit 7 as an example) other than itself (the power supply unit 6).

[0050] That is, the signal processing unit 62 of the power supply unit 6 is configured to perform signal processing that does not relay the first control signal but relays the second control signal to another unit. Therefore, when the control unit 4, power supply unit 6, and fan unit 7 are mounted on the backplane 3, the communication between the units includes the following "first communication" and "second communication."

[0051] First communication: The control unit 4 and the power supply unit 6 transmit and receive a first control signal without a relay. Second communication: The control unit 4 and the fan unit 7 transmit and receive a second control signal using the power supply unit 6 as a relay node.

[0052] [Backplane wiring structure] The printed wiring of the backplane 3 includes a control signal line 33, a DC distribution line 34, and a monitoring signal line 35. The control signal line 33 is a signal line used for control communication between the control unit 4 and the line unit 7. The DC distribution line 34 includes a first power feed line 34A, a second power feed line 34B, and a ground line 34G. The first power feed line 34A is a power feed line that uses the first power feed system 8A as its power supply source. The second power feed line 34B is a power feed line that uses the second power feed system 8B as its power supply source.

[0053] The management signal line 35 has a wiring structure that is premised on the three units 4, 6, and 7 executing the above-mentioned first and second communications, and includes at least the following three types of signal lines. 1st signal line 35A: At least two signal lines electrically connecting the control unit 4 and the power supply unit 6 Second signal line 35B: At least two signal lines electrically connecting the power supply unit 6 and the fan unit 7 Third signal line 35C: At least two signal lines electrically connecting the control unit 4 and the line unit 5

[0054] Specifically, when the control unit 4, line unit 5, and power supply unit 6 are attached to the connectors 31 of the specified numbers on the backplane 3, the signal processing unit 42 of the control unit 4 and the signal processing unit 62 of the power supply unit 6 are connected by the first signal line 35A. Similarly, the signal processing unit 62 of the power supply unit 6 and the signal processing unit 72 of the fan unit 7 are connected by a second signal line 35B, and the signal processing unit 42 of the control unit 4 and the signal processing unit 52 of the line unit 5 are connected by a third signal line 35C.

[0055] In this way, if the control unit 4, power supply unit 6, and fan unit 7 perform the above-mentioned first and second communications, the connection topology of these units 4, 6, and 7 can be such that the control unit 4 and power supply unit 6 are connected one-to-one, and the power supply unit 6 and fan unit 7 are connected one-to-one.

[0056] 2, for the sake of simplicity, a circuit configuration in which there is one control unit 4, one line unit 5, one power supply unit 6, and one fan unit 7 is illustrated. Therefore, the number of first, second and third signal lines 35A, 35B, 35C to be wired to the backplane 3 increases according to the number of units that can be mounted on the backplane 3 (the number of connectors 31 that can be installed).

[0057] For example, if four connectors 31 for the line units 5 are provided, that is, if a maximum of four line units 5 can be connected to one control unit 4, the number of third signal lines 35C wired to the backplane 3 will be four times the number shown in the figure (e.g., five). This also applies to the first and second signal lines 35A and 35B. Hereinafter, with reference to FIGS. 3 and 4, advantages of using the power supply unit 6 as a relay unit in this embodiment will be described.

[0058] [Connection form for communication between units] Fig. 3 is an explanatory diagram showing an example of a connection mode for inter-unit communication (hereinafter referred to as "connection mode 1"), and Fig. 4 is an explanatory diagram showing another example of a connection mode for inter-unit communication (hereinafter referred to as "connection mode 2").

[0059] 3 and 4, "CT" denotes a control unit 4, "LN" denotes a line unit 5, "PW" denotes a power supply unit 6, and "FN" denotes a fan unit 7. The numbers after CT, LN, PW, and FN are identification numbers of units of the same type when units of the same type can be mounted on the backplane 3.

[0060] Here, the control signals used for inter-unit communication include the following five types, and each control signal is transmitted over one signal line. Therefore, each arrow in Figure 3 includes at least five signal lines. 1) EXT: Insertion of own unit completed (attachment to connector 31 completed) 2) RDY: Startup status of your unit 3) RST: Requests restart of the other unit 4) TX: Data transmission 5) RX: Data reception

[0061] In a hot-swap communication device, it is common to use connection topology 1 (star connection) in FIG. 3, in which the CT and the LN, PW, and FN to be monitored are connected one-to-one. Therefore, in the case of connection type 1, a backplane 3 with a wiring pattern that allows CT 1 to be connected to seven units is required. In this case, the number of signal lines required for the CT connector 31 is 5 lines x 7 units = 35 lines. However, there are naturally restrictions on the size of the backplane 3 that can be accommodated in, for example, a 1U chassis 2.

[0062] Therefore, if the connector 31 for the CT becomes large, a structural problem occurs in that it becomes impossible to arrange the multiple connectors 31 in desired positions on the backplane 3 (for example, positions where the cooling air from the cooling fan 73 can easily circulate). In contrast, in connection configuration 2 of Figure 4, by utilizing the fact that PW has the function of relaying the second control signal, CT and PW are connected by a first signal line 35A on the upper side, and PW and FN are connected by a second signal line 35B on the lower side, and a connection configuration is adopted in which PW acts as a relay node.

[0063] In this case, it is only necessary to adopt a backplane 3 with a wiring pattern that allows CT1 to be connected to PW1, PW2, LN1, and LN2, respectively. Therefore, the number of signal lines required for the connector 31 for CT1 is 5 lines x 4 units = 20 lines, which is a significant reduction in the number of signal lines required for the connector 31 for CT1 compared to the case of connection configuration 1 in Figure 3.

[0064] In this way, by connecting CT and PW with the first signal line 35A on the upper side and connecting PW and FN with the second signal line 35B on the lower side, the number of signal lines in the connector 31 for CT can be reduced. Therefore, the connector 31 for the CT can be made more compact than in connection mode 1 in which LN, PW, and FN are all connected to the CT, which has the advantage of making it easier to arrange the connector 31 at a desired position on the backplane 3 and improving the design freedom of the communication device 1.

[0065] For example, as the connector 31 for the CT becomes more compact, the size of the ventilation opening 32 in the backplane 3 can be increased or its shape changed, thereby improving the circulation of cooling air within the communication device 1. Furthermore, when considering a new communication device, it is highly likely that only the PW can be newly designed and the CT and FN can be reused as the same units as those in the communication device 1.

[0066] In order to accommodate redundancy of PW and FN, it is only necessary to adopt a wiring backplane 3 that allows PW1 and PW2 to be connected to CT1, FN1, FN2, and FN3, respectively, and also allows PW1 and PW2 to be connected to each other. In this case, the number of signal lines required for the PW connector 31 is 5 lines x 5 units = 25. However, this number is also less than the number of signal lines (= 35 lines) required for the CT1 connector 31 in the connection configuration 1 of FIG.

[0067] [Communication control in connection type 2] As described above, if connection mode 2 in which PW is used as a relay unit is adopted, there is a structural advantage that the connector 31 for the CT can be made compact. However, in the case of connection mode 2 in which a relay unit is provided, it is necessary to employ the following multiple communication controls in order to properly perform communication between units.

[0068] (Communication Control 1) Communication control 1 is a control for transmitting the first control signal and the second control signal to the first signal line 35A without causing collisions. Communication control 1 includes time division multiplexing in the downstream direction (FIG. 5) and time division multiplexing in the upstream direction (FIG. 6). (Communication Control 2) Communication control 2 is a control in which the PW, which is a relay unit, adds EXT (insertion complete) of the subordinate FN to the RDY (startup status) that is periodically notified to the CT.

[0069] (Communication Control 3) Communication control 3 is a control in which the CT, which is the monitoring entity, adds FN identification information (for example, the connector number of the FN) to the RST (restart request) sent to the PW. (Communication Control 4) The communication control 4 is a control in which, when the PW is configured redundantly, the redundant PW1 and PW2 autonomously switch the operating state (=relay function).

[0070] Hereinafter, examples of the above-mentioned communication controls will be described with reference to FIGS. 5 to 9, "HDLC_TX" refers to the function of transmitting a communication frame conforming to HDLC that includes a predetermined control signal (hereinafter abbreviated as "communication frame"). "HDLC_RX" refers to the function of receiving a communication frame.

[0071] In Figures 5 to 9, "QiRj_HDLC" written below the arrow indicates the name of the physical wiring between the units, where the unit connected to the transmitting side is Qi and the unit connected to the receiving side is Rj. Moreover, the rectangle above the arrow and "SiTj" inside it mean a communication frame whose source is Si and whose destination is Tj.

[0072] "XXk_EXT" means a communication frame notifying the insertion of unit XXk (connection to connector 31). "YYl_RDY" means a communication frame notifying the startup status of unit YYl. "ZZm_RST" means a communication frame notifying a restart request for unit ZZm.

[0073] where Q to T are variables that represent the initials of any of the units CT, PW, and FN, and XX, YY, and ZZ are variables that represent any of the units CT, PW, and FN. Also, i to m are variables that represent the identification numbers of units of the same type.

[0074] [Example of communication control 1] 5 and 6 are explanatory diagrams showing an embodiment of the communication control 1. FIG. Specifically, Fig. 5 is an explanatory diagram showing an example of time division multiplexing in the downlink direction, and Fig. 6 is an explanatory diagram showing an example of time division multiplexing in the uplink direction.

[0075] 5, when CT1 transmits communication frames to four units, for example, PW1, FN1, FN2, and FN3, it sends out C1P1, C1F1, C1F2, and C1F3, which it has generated, one by one to C1P1_HDLC (first signal line 35A) in a time-division manner. In this case, C1P1 is a first control signal in the downstream direction, and C1F1, C1F2, and C1F3 are second control signals in the downstream direction.

[0076] Next, PW1 performs the following process on the received downstream communication frame. Process 1: Capture a communication frame (first control signal) addressed to itself. Process 2: On the condition that the unit itself is in an operating state (Act), a communication frame (second control signal) for monitoring the non-relay unit is transferred in the downstream direction.

[0077] Therefore, in the example of FIG. 5, PW1 captures C1P1 and performs the processing requested by this communication frame. Furthermore, when PW1 itself is in an operating state (Act), it sends C1F1, C1F2, and C1F3 to P1F1_HDLC, P1F2_HDLC, and P1F3_HDLC, which are the second signal line 35B, respectively, and broadcasts them to FN1, FN2, and FN3.

[0078] In this case, FN1, FN2, and FN3 can accept the communication frame received from PW1 if it is addressed to them, and discard it if it is not addressed to them. In this way, the CT performs downstream transmission to the PW in a time-division manner, so that the first and second control signals in the downstream direction can be transmitted to the first signal line 35A without collision.

[0079] 6, PW1 has a switching circuit SW with multiple inputs (four in the example) and one output. The input side of the switching circuit SW is connected to multiple upstream transmission buffers BF1 to BF4.

[0080] The transmission buffer BF1 stores the communication frame received from FN1, which is a second control signal in the upstream direction generated by FN1. The transmission buffer BF2 stores the communication frame received from FN2, which is a second control signal in the upstream direction generated by FN2.

[0081] The transmission buffer BF3 stores the communication frame received from FN3, which is a second control signal in the upstream direction generated by FN3. The transmission buffer BF4 stores communication frames generated by the frame processing unit of the device itself (PW1). The frame processing unit generates a P1C1 addressed to CT1 in response to a C1P1 addressed to itself, and stores this communication frame in the transmission buffer BF4. This communication frame is a first control signal in the upstream direction.

[0082] PW1 has an output control unit that inputs switching information to the switching circuit SW. The output control unit determines which of the transmission buffers BF1, BF2, BF3, and BF4 will transmit communication frames in the upstream direction based on the accumulation status of communication frames in the transmission buffers BF1, BF2, BF3, and BF4.

[0083] For example, if a communication frame is not currently being sent to P1C1_HDLC but is stored in the transmission buffer BF4, the switching information of the transmission buffer BF4 is input to the gate of the switching circuit SW, and P1C1 selects it as the upstream communication frame to send to P1C1_HDLC.

[0084] Similarly, if a communication frame is not currently being sent to P1C1_HDLC but a communication frame is stored in the transmit buffer BF1, the switching information of the transmit buffer BF1 is input to the gate of the switching circuit SW, and F1C1 is selected as the upstream communication frame to send to P1C1_HDLC. When communication frames are stored in the transmission buffers BF2 and BF3, the same selection as above is made.

[0085] Since CT1 transmits downstream communication frames one by one in a time-division manner, gate input to the switching circuit SW due to the accumulation of communication frames in the transmission buffers BF1, BF2, BF3, and BF4 occurs at approximately the same cycle as the downstream frame transmission interval. In this way, by the PW performing upstream transmission to the CT in a time-division manner, the first and second control signals in the upstream direction can be transmitted to the first signal line 35A without collision.

[0086] [Example of communication control 2] FIG. 7 is an explanatory diagram showing an embodiment of communication control 2. As shown in Figure 7, assume that only FN1 is inserted under PW1, and that the insertion information (e.g., the connector number corresponding to FN1) is recorded in the memory of PW1 through inter-unit communication between PW1 and FN1. In this case, PW1 adds FN1_EXT to the data field of PW1_RDY for notifying its own startup status, and sends the PW1_RDY after the addition to P1C1_HDLC to transmit it to CT1.

[0087] Upon receiving the PW1_RDY, the CT1 decodes the communication frame, extracts FN1_EXT, and records the extracted information in memory. This allows CT1 to check the insertion information of FN1 that is not directly connected to itself, and to store the insertion information of FN1.

[0088] [Example of communication control 3] FIG. 8 is an explanatory diagram showing an embodiment of the communication control 3. 8, CT1 sends FN1_RST to C1P1_HDLC to notify FN1 of a restart request. As described above, FN1_RST includes identification information (such as a slot number) of FN1, which is the target of restart.

[0089] Upon receiving the FN1_RST, PW1 decodes the communication frame and, upon determining that the communication frame is not addressed to itself, broadcasts FN1_RST by sending FN1_RST to P1F1_HDLC, P1F2_HDLC, and P1F3_HDLC.

[0090] In this case, as a result of decoding the communication frame, only FN1 executes a restart in response to the RST addressed to itself, while FN2 and FN3 discard the RST not addressed to themselves. In this way, PW1 broadcasts a RST (a RST containing the identification information of FN1) addressed to its subordinate FN1 in the downstream direction, so that CT1 can have PW1 act on its behalf to issue a restart request (RST) to FN1 that is not directly connected to CT1.

[0091] [Example of communication control 4] FIG. 9 is an explanatory diagram showing an embodiment of the communication control 4. In Figure 9, "unit insertion position information" is information that indicates the insertion position of the unit relative to the backplane 3, and PW1 and PW2 hold position information values ​​according to, for example, the connector number of the backplane 3 into which the unit is inserted. Hereinafter, the unit insertion position information may be abbreviated as "position information." Here, the position information of PW1 is assumed to be [1] and the position information of PW2 is assumed to be [0], and the unit with the larger number will be in operation and the unit with the smaller number will be inactive.

[0092] 9, PW2 transmits P2P1 including location information = 0 to PW1. Upon receiving P2P1, PW1 compares its own location information = 1 with PW2's location information = 0 to determine its own operating state. In this case, since the location information of PW1 is greater than the location information of PW2, PW1 sets its own operation state to the active state (Act).

[0093] Conversely, PW1 transmits P1P2 containing location information = 1 to PW2. Upon receiving P1P2, PW2 compares its own location information = 0 with PW1's location information = 1 to determine its own operating state. In this case, since the position information of PW2 is smaller than the position information of PW1, PW2 sets its own operating state to the dormant state (Stby).

[0094] The PW1 in the active state broadcasts a downstream communication frame (second control signal) to the subordinate FNs. Inactive PW2 does not transmit downstream and upstream communication frames, which prevents downstream and upstream communication frames from reaching the FN or CT twice.

[0095] Even if the inactive PW2 is removed, the active PW1 continues to relay communication frames, so communication between the CT and FN is maintained. When PW1 in the active state is removed, PW2 in the inactive state becomes active in response to the loss of communication with PW1 and starts relaying downstream communication frames. Therefore, even if PW1 is removed, communication between the CT and FN is maintained.

[0096] 9 shows an example in which there are two PWs, but the PWs may be made redundant with N (N≧3). In this case, among the N PWs, the unit that determines that its own unit insertion position information is the largest through the above-mentioned inter-unit communication becomes in an operating state (Act) and functions as a relay unit. As described above, the redundant PW1 and PW2 execute communication processing to adjust the output voltages of the respective first voltage conversion units 63 to the same set value.

[0097] The processing related to the above communication control will be explained below with reference to Figures 10 to 14. In Figures 10 to 14, "QiRj_HDLC" written below the arrows indicates the name of the physical wiring between units, where the unit connected to the transmitting side is Qi and the unit connected to the receiving side is Rj. Moreover, the rectangle above the arrow and "SiTj" inside it mean a communication frame whose source is Si and whose destination is Tj.

[0098] [Repeated notification of reference voltage value] 10 is a sequence diagram showing an example of repeated notification of the reference voltage value Vr. In this embodiment, the node types of the power supply units 6 to be made redundant include the following types. "Master node": A node that independently determines the set value of the output voltage of the first voltage conversion unit 63 "Slave node": A node that updates the set value of the output voltage of the first voltage conversion unit 63 to a value notified by the master node.

[0099] Hereinafter, the master node will be abbreviated as “master,” and the slave node will be abbreviated as “slave.” Also, as shown in Fig. 10, it is assumed here that PW1 is the master and PW2 is the slave. In this case, PW1 (master) repeatedly notifies PW2 of a reference voltage value Vr (for example, 48 V). The reference voltage value Vr is, for example, the set value of the output voltage of the first voltage conversion unit 63 currently being used in PW1.

[0100] Specifically, PW1 (master) notifies PW2 (slave) of the reference voltage value Vr every predetermined communication period T (for example, 1 second) (step S11). Upon receiving the notification, PW2 (slave) returns a response to PW1 (master) (step S12) and then records the reference voltage value Vr in its own register (step S13). As a result, the set value of the output voltage of the first voltage conversion unit 63 in PW2 is updated to the reference voltage value Vr notified by PW1.

[0101] In this way, the master PW1 repeatedly notifies PW2 of its current reference voltage value Vr via inter-unit communication, and the slave PW2 adjusts the output voltage of the first voltage conversion unit 63 based on the notified reference voltage value Vr. As a result, the voltage values ​​of the first distribution line 34A and the second distribution line 34B are maintained at the same reference voltage value Vr, and the current values ​​of the first distribution line 34A and the second distribution line 34B become approximately equal. This allows for load balancing that suppresses imbalances in the received power from the two power supply systems 8A and 8B.

[0102] In the example of FIG. 10, the reference voltage value Vr is periodically notified at every predetermined communication cycle T, but the timing of notification is not limited to this. Specifically, for example, the transmission cycle T may be changed between daytime and nighttime, or the timing of notification may be varied, such as changing the transmission cycle T according to the number and type of connected loads (units 4, 5, 7).

[0103] 〔Determination Process of Node Type〕 FIG. 11 is a flowchart showing an example of a determination process of node type that is autonomously executed by the signal processing units 62 of the power supply units 6A and 6B. Here, the position information of the power supply units 6A and 6B as the determination subjects is PS1, and the position information of the other party's power supply units 6B and 6A received by the determination subjects is PS2. Also, it is assumed that the unit with the larger numerical value becomes the master and the unit with the smaller numerical value becomes the slave.

[0104] As shown in FIG. 11, after the signal processing unit 62 of the power supply unit 6 acquires its own position information PS1 from the memory (step ST11), it transmits the acquired position information PS1 to the other party's power supply unit 6 (step ST12). Next, after the signal processing unit 62 waits for a predetermined time (for example, 2m seconds to 10m seconds) which is a set value (step ST13), it determines whether it has received the other party's position information PS2 (step ST14).

[0105] If the determination result in step S14 is affirmative, the signal processing unit 62 compares the magnitude of its own position information PS1 and the other party's position information PS2 (step ST15), and determines whether to make itself a slave or a master according to the comparison result. Specifically, when PS1 < PS2, the signal processing unit 62 determines its own node type as "slave" (step ST16), and when PS1 > PS2, it determines its own node type as "master" (step ST17).

[0106] If the determination result in step S14 is negative, the signal processing unit 62 determines whether the number of times of the determination process is a predetermined upper limit number M (for example, 20 times) (step ST17). If the determination result in step S17 is negative, the signal processing unit 62 returns the process to before step ST 13. If the determination result in step S17 is positive, the signal processing unit 62 determines its own node type to be "master" (step ST17).

[0107] [Node type specification process] FIG. 12 is a sequence diagram showing an example of a node type designation process executed by the signal processing unit 42 of the control unit 4. In FIG. Here, a case where PW1 is designated as the master by CT1 and PW2 is designated as the slave by CT1 is illustrated.

[0108] 12, CT1 transmits a communication frame to PW1 instructing it to operate as a master (step S21). After receiving the communication frame, PW1 returns a response to CT1 (step S22), and then determines its own node type as master. Similarly, CT1 transmits a communication frame to PW2 instructing it to operate as a slave (step S23). After receiving the communication frame, PW2 returns a response to CT1 (step S24), and then determines its own node type as a slave.

[0109] Thereafter, repeated notifications similar to those in FIG. 10 are executed between PW1, which has become the master, and PW2, which has become the slave. In this way, PW1 and PW2 may not only autonomously determine their node types through inter-unit communication between the two, but may also determine their own node types according to instructions in a communication frame received from CT1.

[0110] [Processing to stop repeated notifications] FIG. 13 is a sequence diagram showing an example of a process for stopping repeated notifications, which is executed by the signal processing unit 42 of the control unit 4. In FIG. Here, it is assumed that PW1 operates as a master and PW2 operates as a slave, and that the repeated notification of FIG. 10 is being executed between PW1 and PW2.

[0111] As shown in FIG. 13, the CT1 transmits a communication frame to the PW1 operating as the master, instructing it to stop notifying the reference voltage value Vr (step S31). After receiving the above communication frame, PW1 returns a response to CT1 (step S32), and then stops repeating notifications to PW2. In this case, PW2, whose communication with PW1 has been cut off, switches to the master node and independently determines the output voltage of the first voltage conversion unit 63 through feedback control based on the measurement result of its own voltage sensor 65.

[0112] [Output voltage collection process] FIG. 14 is a sequence diagram showing an example of the output voltage collection process executed by the signal processing unit 42 of the control unit 4. In FIG. Here, it is assumed that PW1 operates as a master and PW2 operates as a slave, and CT1 inquires about voltage values ​​from both PW1 and PW2.

[0113] As shown in FIG. 14, CT1 transmits a communication frame to PW1, which is operating as the master, requesting the current output voltage of the first voltage conversion unit 63 (step S41). Upon receiving the communication frame, PW1 reads the requested voltage value from the register (slave S42) and transmits a response frame including the read voltage value to CT1 (step S43).

[0114] Similarly, CT1 transmits a communication frame to PW2, which is operating as a slave, requesting the current output voltage of the first voltage conversion unit 63 (step S44). Upon receiving the above communication frame, PW2 reads the requested voltage value from the register (slave S45) and transmits a response frame including the read voltage value to CT1 (step S46).

[0115] [First variant]: When repeated notifications cease In the repeated notification of the reference voltage value Vr in FIG. 10, if the notification of the reference voltage value Vr from the master PW1 is interrupted midway due to a malfunction of the inter-unit communication between PW1 and PW2, the slave PW2 may decide whether or not to use the reference voltage value Vr that has already been notified, depending on the length of time Te that has elapsed since the notification was interrupted.

[0116] Specifically, the slave PW1 may determine whether or not to use the reference voltage value Vr as follows: Note that "N" in the following formula is a natural number (for example, 60 times). 1) When Te≦T×N PW2 continues to use the reference voltage value Vr at the time when the notification was discontinued.

[0117] 2) When Te>T×N PW2 stops using the reference voltage value Vr and switches to the master. In this case, PW2 determines the output voltage of the first voltage conversion unit 63 independently by feedback control based on the measurement result of its own voltage sensor 65. The reason why PW2 does not invoke when Te>T×N is that if communication with PW1 is interrupted for a long period of time, the output voltage of the first voltage conversion unit 63 becomes unstable unless PW2 determines the output voltage independently.

[0118] [Second Variation]: When PW1 is removed In the repeated notification of the reference voltage value Vr in FIG. 10, if PW2 detects the removal of PW1, PW2, which is the slave, may switch to the master and independently determine the output voltage of the first voltage conversion unit 63 by feedback control based on the measurement result of its own voltage sensor 65.

[0119] The reason is that when PW1 is removed, the output voltage of the first voltage conversion unit 63 becomes unstable unless PW2 determines the output voltage independently. The removal of PW1 by PW2 can be detected, for example, when PW2 no longer receives EXT (insertion of own unit complete) from PW1 or CT1.

[0120] [Other Modifications] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is not limited to the above-described embodiments, but includes all modifications within the scope of equivalents to the configurations described in the claims.

[0121] In the above-described embodiment, the device employing the power supply system having redundant power supply units that adjust output voltages for load balancing may be not only the communication device 1, but also a computer device such as a server or other electronic device. In the above-described embodiment, the first and second power supply systems 8A, 8B are not limited to commercial power sources, and may be power generation devices or power storage devices that supply DC power. [Explanation of symbols]

[0122] 1 Communication equipment (electronic equipment) 2. Case 3 Backplane 4 Control unit (load) 5 Line unit (load) 6 Power Supply Unit 6A 1st power supply unit 6B Second power supply unit 7 Fan unit (load) 8A 1st power supply system 8B Second power supply system 21 Front opening 22 Rear opening 30 Backplane 31 Connector 32 Ventilation hole 33 Management signal line 34 DC distribution line 35 Monitoring signal line 35A 1st signal line 35B 2nd signal line 35C 3rd signal line 40 Circuit Board 41 Connector 42 Signal Processing Section 43 CPU 44 memory 45 Communication processing unit 46 Management Port 47 Power supply section 48 Diode OR Circuit 50 Circuit Board 51 Connector 52 Signal processing section 53 CPU 54 memory 55 Switch section 56 external ports 57 Power supply section 58 Diode OR Circuit 60 Circuit Board 61 Connector 62 Signal Processing Unit 63 First voltage conversion unit 64 Second voltage conversion unit 65 Voltage Sensor 70 Circuit Board 71 Connector 72 Signal Processing Section 73 Cooling fan 74 Power supply section 75 Diode OR circuit

Claims

1. A power supply system including first and second power supply units that supply DC power to a load through a diode OR circuit, The first power supply unit a power conversion unit that converts power from the first power distribution system into DC power; The second power supply unit is a power conversion unit that converts power from the second power distribution system into DC power; The first and second power supply units are The power conversion unit can be controlled by a reference voltage value acquired through inter-unit communication, one of the first and second power supply units serving as a master node repeatedly notifies the other of the slave node of its own reference voltage value; a power supply system in which, when notified of the reference voltage value, the unit that is the slave node updates the output voltage of the power conversion unit of the slave node to the reference voltage value.

2. The first and second power supply units are Each can be connected to a different connector on the backplane. The power supply system of claim 1, which determines whether its own node type is a master node or a slave node based on information representing its own connection position and information representing the connection position of the other party received through unit-to-unit communication.

3. The first and second power supply units are 3. The power supply system according to claim 2, wherein the power supply system determines whether its own node type is a master node or a slave node in response to an instruction received from the control unit through inter-unit communication.

4. The control unit The power supply system according to claim 3 , wherein an instruction to stop the repeated notification of the reference voltage value is transmitted to the unit that is the master node.

5. The slave node 5. The power supply system according to claim 2, wherein when removal of the master node from the backplane is detected, the power supply system switches its own node type to a master node.

6. The slave node 5. The power supply system according to claim 1, wherein, when notification of the reference voltage value from the master node is interrupted, whether or not to use the reference voltage value is determined depending on the amount of time that has elapsed since the notification was interrupted.

7. 1. An inter-unit communication method performed in a power supply system including first and second power supply units that supply DC power to a load through a diode OR circuit, comprising: a step in which one of the first and second power supply units, which is a master node, repeatedly notifies the unit, which is a slave node, of its own reference voltage value; a step in which, when the reference voltage value is notified, the unit that is the slave node updates the output voltage of its own power conversion unit to the reference voltage value.

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