Power supply system and automatic switching distribution board

Abstract

To provide a power supply system capable of stably supplying power to a load even if failure occurs in a changeover switch for switching between a system output and an independent output.SOLUTION: A power supply system 1A includes a charging / discharging device 11 for charging / discharging a storage battery 12 and an automatic switching distribution panel 20A. The automatic switching distribution panel 20A includes: a first changeover switch SW1 for switching between a first system input end T11 and a first independent input end T12 and connecting them to a first output end T13; a second changeover switch SW2 for switching between a second system input end T21 and a second independence input end T22 and connecting them to a second output end T23; a third changeover switch SW3 for switching between a first system input end T31 and a second input end T32 and connecting them to a third output ends T33; and a control unit 22A for controlling the first changeover switch SW1, the second changeover switch SW2, and the third changeover switch SW3.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power supply system and an automatic switching distribution board. [Background technology]

[0002] A conventional power supply system is a full-load system that can switch between grid output and independent output to supply power to all loads (e.g., electrical appliances) without distinguishing between important loads and general loads (see, for example, Patent Document 1).

[0003] The configuration of a full-load power supply system 1D is shown in Fig. 7. The power supply system 1D includes a power storage system 10 and an automatic switching distribution board 20D. The power supply system 1D switches between the system output from the power grid 2 and the power storage system 10 and the independent output from the power storage system 10 using the automatic switching distribution board 20D, and supplies power to a load 3 such as an electrical appliance connected to a household outlet.

[0004] The power storage system 10 includes a charging / discharging device 11 and a storage battery 12. The charging / discharging device 11 is configured to charge and discharge the storage battery 12, and includes an AC end connected to a system power line L11 and an independent output end connected to a power line for independent output (hereinafter, independent output line L12). The charging / discharging device 11 outputs the discharged power of the storage battery 12 to the system power line L11 (system output) when the power system 2 is energized, and outputs the discharged power of the storage battery 12 to the independent output line L12 (independent output) when the power system 2 is powered.

[0005] The automatic changeover distribution board 20D includes a changeover switch 21D and a control unit 22D that controls the changeover switch 21D. The output side of the automatic changeover distribution board 20D is connected to the load 3 via a general distribution board (not shown). Under the control of the control unit 22D, the changeover switch 21D is connected to the system power line L11 side when the power system 2 is energized, and is connected to the isolated output line L12 side when the power system 2 is powered down. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2019-198203 A Summary of the Invention [Problem to be solved by the invention]

[0007] In the automatic changeover distribution board 20D, a failure that disables changeover switch 21D may occur. For example, if changeover switch 21D becomes unable to changeover while connected to the system power line L11, in the conventional power supply system 1D, the independent output of charge / discharge device 11 cannot be supplied to load 3 during a power outage in the power system 2.

[0008] Furthermore, if changeover switch 21D becomes unable to switch while connected to the independent output line L12 side, conventional power supply system 1D will be unable to supply system output (system power of power system 2 and discharge power output from the AC end of charge / discharge device 11) to load 3 when power system 2 is energized. In this case, since the independent output of charge / discharge device 11 is supplied to load 3 when power system 2 is energized, there is a risk that discovery of a failure in changeover switch 21D will be delayed.

[0009] Furthermore, when an independent output breaker is installed on the independent output line L12, the breaker capacity of the independent output breaker is generally set to a value corresponding to the rated value of the independent output of the charge / discharge device 11, and the rated value of the independent output is smaller than the rated value of the system output of the charge / discharge device 11. For this reason, if the changeover switch 21D becomes unable to be switched while connected to the independent output line L12 side, in the conventional power supply system 1D, the power that can be supplied to the load 3 when the power system 2 is energized is limited to the rated value of the independent output of the charge / discharge device 11, and there is a risk that the frequency of the breaker tripping increases as the load 3 increases.

[0010] The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a power supply system and an automatic switching distribution board that can stably supply power to a load even if a failure occurs in a change-over switch that switches between system output and independent output. [Means for solving the problem]

[0011] In order to solve the above problems, the power supply system according to the present invention comprises: a charging / discharging device including an AC terminal connected to a power grid, a DC terminal connected to a storage battery, and an independent output terminal, the charging / discharging device outputting discharge power of the storage battery from the independent output terminal; an automatic switching distribution board having one side to which the power system and the independent output terminals of the charging / discharging device are connected and the other side to which a load is connected; A power supply system comprising: The automatic switching distribution board is a first changeover switch including a first system input terminal connected to the power system, a first isolated input terminal connected to the isolated output terminal, and a first output terminal, and configured to switch between a state in which the first system input terminal and the first output terminal are electrically connected and a state in which the first isolated input terminal and the first output terminal are electrically connected; a second changeover switch including a second system input terminal connected to the power system, a second independent input terminal connected to the independent output terminal, and a second output terminal, and configured to switch between a state in which the second system input terminal and the second output terminal are conductively connected and a state in which the second independent input terminal and the second output terminal are conductively connected; a third changeover switch including a first input terminal connected to the first output terminal, a second input terminal connected to the second output terminal, and a third output terminal connected to the load, the third changeover switch switching between a state in which the first input terminal and the third output terminal are conductively connected and a state in which the second input terminal and the third output terminal are conductively connected; The power supply device is characterized by comprising a control unit that controls the first changeover switch, the second changeover switch, and the third changeover switch so as to form a power supply path to the load.

[0012] In this configuration, a first power supply path via a first changeover switch and a second power supply path via a second changeover switch are formed in parallel in the automatic changeover distribution board, and the first changeover switch and the second changeover switch are connected to both the power system and the independent output terminal of the charging / discharging device, respectively. Therefore, in this configuration, even if either the first changeover switch or the second changeover switch fails, it is possible to stably supply power to the load via the first power supply path or the second power supply path.

[0013] In the power supply system, The automatic switching distribution board is a fourth changeover switch that is interposed in a first power line that connects the first output terminal and the first input terminal and that switches the first power line between a conductive state and a non-conductive state; a fifth changeover switch that is interposed in a second power line that connects the second output terminal and the second input terminal and that switches the second power line between a conductive state and a non-conductive state; The control unit is The fourth changeover switch and the fifth changeover switch may be controlled so as to bring one of the first power line and the second power line into a conductive state and the other into a non-conductive state.

[0014] In the power supply system, The control unit is When the first changeover switch has a failure that makes it impossible to change over, the fourth changeover switch is controlled to put the first power line into a non-conducting state, and the fifth changeover switch is controlled to put the second power line into a conducting state; In the event of a failure in which the second changeover switch cannot be switched, the fifth changeover switch can be controlled to bring the second power line into a non-conductive state, while the fourth changeover switch can be controlled to bring the first power line into a conductive state.

[0015] In the power supply system, The control unit is In the case where the first changeover switch has a failure that makes it impossible to change over when the first system input terminal is connected to the first output terminal, when the power system is in a conducting state, the fourth changeover switch is controlled to make the first power line conductive, In the case where the second selector switch fails to switch when the second independent input terminal is connected to the second output terminal, the fifth selector switch can be controlled to bring the second power line into a conductive state when the power system is in a power outage state.

[0016] In the power supply system, The control unit is a first detection unit that detects a failure of the first changeover switch that makes it impossible to switch in accordance with a voltage in a front stage and a rear stage of the first changeover switch, and controls the fourth changeover switch in accordance with the detection result; The power supply may be configured to include a second detection unit that detects a failure in the second changeover switch that makes it impossible to switch in accordance with the voltages in the upstream and downstream of the second changeover switch, and controls the fifth changeover switch in accordance with the detection result.

[0017] In the power supply system, The automatic switching distribution board is a sixth changeover switch that is interposed in a third power line that connects the third output terminal and the load and that switches the third power line between a conductive state and a non-conductive state; The control unit is When both the first changeover switch and the second changeover switch have a failure that makes them unable to switch, the sixth changeover switch may be controlled to bring the third power line into a non-conducting state.

[0018] In the power supply system, The automatic switching distribution board is The device may be configured to include a failure display unit that notifies a user of a failure by light emitting means, display means or sound means when at least one of the first changeover switch and the second changeover switch has a failure that makes it impossible to switch.

[0019] In order to solve the above problems, the automatic switching distribution board according to the present invention comprises: An automatic switching panel having a power system and a battery charge / discharge device connected to one side and a load connected to the other side, The charging / discharging device includes an independent output terminal that outputs discharge power of the storage battery, The automatic switching distribution board is a first changeover switch including a first system input terminal connected to the power system, a first isolated input terminal connected to the isolated output terminal, and a first output terminal, and configured to switch between a state in which the first system input terminal and the first output terminal are electrically connected and a state in which the first isolated input terminal and the first output terminal are electrically connected; a second changeover switch including a second system input terminal connected to the power system, a second independent input terminal connected to the independent output terminal, and a second output terminal, and configured to switch between a state in which the second system input terminal and the second output terminal are conductively connected and a state in which the second independent input terminal and the second output terminal are conductively connected; a third changeover switch including a first input terminal connected to the first output terminal, a second input terminal connected to the second output terminal, and a third output terminal connected to the load, the third changeover switch switching between a state in which the first input terminal and the third output terminal are conductively connected and a state in which the second input terminal and the third output terminal are conductively connected; The power supply device is characterized by comprising a control unit that controls the first changeover switch, the second changeover switch, and the third changeover switch so as to form a power supply path to the load. Effect of the Invention

[0020] According to the present invention, it is possible to provide a power supply system and an automatic switching distribution board that can stably supply power to a load even if a failure occurs in a changeover switch that switches between grid output and independent output. [Brief description of the drawings]

[0021] [Figure 1] 1 is a diagram showing a power supply system according to a first embodiment of the present invention. [Diagram 2]4 is a state table showing the control states of the switches SW1 to SW5 in the first embodiment. [Diagram 3] FIG. 5 is a diagram showing a power supply system according to a second embodiment of the present invention. [Figure 4] 10 is a state table showing the control states of the switches SW1 to SW5 in the second embodiment. [Diagram 5] FIG. 11 is a diagram showing a power supply system according to a third embodiment of the present invention. [Figure 6] FIG. 11 is a diagram showing an automatic switching distribution board according to a third embodiment of the present invention. [Figure 7] FIG. 1 illustrates a conventional power supply system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a power supply system and an automatic switching distribution board according to the present invention will be described with reference to the accompanying drawings.

[0023] [First embodiment] 1 shows a power supply system 1A according to a first embodiment of the present invention. The power supply system 1A is a home power supply system, and includes a power storage system 10 and an automatic changeover distribution board 20A. The power supply system 1A is a full-load compatible type, and supplies power to a load 3 by switching between the system output of a power grid 2 and / or the power storage system 10 and the independent output of the power storage system 10 using the automatic changeover distribution board 20A.

[0024] The power system 2 is an AC power source that supplies AC system power to a system power line L11 that connects the power system 2 and the power supply system 1A. The power system 2 is connected to the power supply system 1A via, for example, a three-phase three-wire high-voltage power line, a pole-mounted transformer, and a single-phase three-wire low-voltage (AC100 / 200V) power line.

[0025] The load 3 is a general term for devices that consume power. The load 3 includes, for example, electrical appliances such as a refrigerator, an air conditioner, a washing machine, a personal computer, and a television, and these loads 3 are connected, for example, from a household outlet to a single-phase three-wire power line. Since the power supply system 1A is of a full-load compatible type, the load 3 in this embodiment includes all loads without distinguishing between important loads (loads that are desired to operate even during a power outage in the power system 2) and general loads (loads other than important loads). In the case of a power supply system of the important-load compatible type, the load 3 is an important load, and the general load is connected to the system power line L11 without passing through the automatic switching distribution board 20A.

[0026] The power storage system 10 includes a charge / discharge device 11 and a storage battery 12. The power storage system 10 charges the storage battery 12 with inexpensive late-night power supplied from the power grid 2 when the power is on, and uses the power stored in the storage battery 12 during the day, thereby making it possible to save on electricity bills. Furthermore, the power storage system 10 can supply the power stored in the storage battery 12 to the load 3 even during a power outage in the power grid 2.

[0027] The charge / discharge device 11 includes an AC terminal Ta, a DC terminal Tb, an independent output terminal Tc, a switching unit 11a, a power conversion unit 11b, and a control unit 11c.

[0028] The AC terminal Ta is connected to the power system 2 and the automatic switching distribution board 20A via the system power line L11. The DC terminal Tb is connected to the storage battery 12. The independent output terminal Tc is connected to the automatic switching distribution board 20A via a power line for independent output (hereinafter, the independent output line L12).

[0029] The switching unit 11a includes a first switch SW11, a second switch SW12, a third switch SW13, and a fourth switch SW14. When the power system 2 is energized, the switching unit 11a has the first switch SW11 and the second switch SW12 in a closed state (ON state) and the third switch SW13 and the fourth switch SW14 in an open state (OFF state). On the other hand, when the power system 2 is in a power outage, the first switch SW11 and the second switch SW12 in an open state (OFF state) and the third switch SW13 and the fourth switch SW14 in a closed state (ON state). Each of the switches SW11 to SW14 is, for example, configured of a relay that opens and closes under the control of the control unit 11c.

[0030] The power conversion unit 11b includes a bidirectional AC / DC inverter and a bidirectional DC / DC converter. The AC side of the bidirectional AC / DC inverter is connected to the opening / closing unit 11a, and the DC side is connected to one DC side of the bidirectional DC / DC converter. The other DC side of the bidirectional DC / DC converter is connected to the DC terminal Tb. The power conversion unit 11b performs charging and discharging operations on the storage battery 12 under the control of the control unit 11c. During charging, the power conversion unit 11b supplies DC charging power to the storage battery 12. During discharging, the power conversion unit 11b extracts DC discharge power from the storage battery 12, converts it to AC power, and outputs it.

[0031] The control unit 11c includes a switching control unit that controls the switching unit 11a, and a power conversion control unit that controls the power conversion unit 11b. The power conversion control unit may be configured, for example, as a digital circuit using a microcontroller or DSP, or may be configured as a circuit combining a digital circuit and an analog circuit. The control unit 11c further includes a detection unit. The detection unit includes, for example, a current sensor and / or a voltage sensor that detects a current value and / or a voltage value required for the control of the control unit 11c.

[0032] The control unit 11c sets the operation mode of the charging / discharging device 11. The operation modes include an interconnected operation mode that is set when the power system 2 is energized, and an independent operation mode that is set when the power system 2 is in a power outage state. In the interconnected operation mode, the control unit 11c closes the first switch SW11 and the second switch SW12 (opens the third switch SW13 and the fourth switch SW14) to cause the power conversion unit 11b to perform a system output from the AC terminal Ta and an independent output from the independent output terminal Tc. On the other hand, in the independent operation mode, the control unit 11c closes the third switch SW13 and the fourth switch SW14 (opens the first switch SW11 and the second switch SW12) to cause the power conversion unit 11b to perform only an independent output from the independent output terminal Tc.

[0033] The storage battery 12 is a stationary storage battery that is installed in a predetermined location and includes at least one secondary battery that is configured to be chargeable and dischargeable, and a battery management system that manages the secondary battery. As the secondary battery, for example, a lithium ion secondary battery is used, but a secondary battery other than a lithium ion secondary battery may also be used.

[0034] An independent output breaker may be provided in the independent output line L12 of the power storage system 10. The breaker capacity of the independent output breaker is set to a value corresponding to the rated value of the independent output of the charging / discharging device 11, and the rated value of the independent output is smaller than the rated value of the system output of the charging / discharging device 11.

[0035] The automatic switching distribution board 20A includes a switch unit 21A and a control unit 22A that controls the switch unit 21A. One side (AC input side) of the automatic switching distribution board 20A is connected to the power system 2 and the power storage system 10 via a system power line L11, and is also connected to the power storage system 10 via an independent output line L12. The other side (AC output side) of the automatic switching distribution board 20A is connected to the load 3 via a general distribution board (not shown).

[0036] The switch section 21A includes a first switch SW1, a second switch SW2, a third switch SW3, a fourth switch SW4, and a fifth switch SW5, and switches between a system output and an independent output. Each of the switches SW1 to SW5 may be formed of at least one relay, or may be formed of at least one semiconductor switch.

[0037] The system output input to the switch unit 21A is AC system power supplied from the power system 2 and / or AC power output from the AC terminal Ta of the charging / discharging device 11. The independent output input to the switch unit 21A is AC power output from the independent output terminal Tc of the charging / discharging device 11.

[0038] The first changeover switch SW1 includes a first system input terminal T11 connected to the system power line L11, a first isolated input terminal T12 connected to the isolated output line L12, and a first output terminal T13 connected to the first power line L1. Under the control of the control unit 22A, the first changeover switch SW1 switches between a state in which the first system input terminal T11 and the first output terminal T13 are conductively connected and a state in which the first isolated input terminal T12 and the first output terminal T13 are conductively connected. That is, the first changeover switch SW1 switches between a state in which the system output is supplied to the first power line L1 and a state in which the isolated output is supplied to the first power line L1.

[0039] The second changeover switch SW2 includes a second system input terminal T21 connected to the system power line L11, a second independent input terminal T22 connected to the independent output line L12, and a second output terminal T23 connected to the second power line L2. Under the control of the control unit 22A, the second changeover switch SW2 switches between a state in which the second system input terminal T21 and the second output terminal T23 are conductively connected and a state in which the second independent input terminal T22 and the second output terminal T23 are conductively connected. That is, the second changeover switch SW2 switches between a state in which the system output is supplied to the second power line L2 and a state in which the independent output is supplied to the second power line L2.

[0040] The third changeover switch SW3 includes a first input terminal T31 connected to the first power line L1, a second input terminal T32 connected to the second power line L2, and a third output terminal T33 connected to the third power line L3. Under the control of the control unit 22A, the third changeover switch SW3 switches between a state in which the first input terminal T31 and the third output terminal T33 are conductively connected (hereinafter referred to as an "upper state") and a state in which the second input terminal T32 and the third output terminal T33 are conductively connected (hereinafter referred to as a "lower state"). That is, the third changeover switch SW3 switches between a state in which the AC power supplied from the first power line L1 is supplied to the third power line L3 (upper state) and a state in which the AC power supplied from the second power line L2 is supplied to the third power line L3 (lower state).

[0041] The fourth changeover switch SW4 is interposed in the first power line L1. The fourth changeover switch SW4 switches between an ON state and an OFF state under the control of the control unit 22A, and when in the ON state, makes the first power line L1 a conductive state, whereas when in the OFF state, makes the first power line L1 a non-conductive state.

[0042] The fifth changeover switch SW5 is interposed in the second power line L2. The fifth changeover switch SW5 switches between an ON state and an OFF state under the control of the control unit 22A, and when in the ON state, makes the second power line L2 a conductive state, whereas when in the OFF state, makes the second power line L2 a non-conductive state.

[0043] The control unit 22A includes a mode determination unit that determines the operation mode of the charge / discharge device 11, a failure determination unit that determines a failure that disables switching of the first changeover switch SW1 and the second changeover switch SW2, and a switch control unit that controls the switches SW1 to SW5.

[0044] The mode determination unit determines the operation mode by communicating with the control unit 11c of the power storage system 10, or by detecting the system power supplied from the power system 2. In the former case, the mode determination unit includes a communication means for communicating with the control unit 11c, and acquires the operation mode from the control unit 11c through the communication means. In the latter case, the mode determination unit includes a voltage sensor, and determines the interconnected operation mode when the voltage of the first system input terminal T11 or the second system input terminal T21 detected by the voltage sensor is within a predetermined normal range, and determines the independent operation mode when the voltage is not within the normal range. The mode determination unit outputs the determined operation mode to the switch control unit.

[0045] The failure determination unit determines whether the first changeover switch SW1 has a failure that prevents it from switching by detecting the voltage at the first output terminal T13 before and after switching of the operating mode using a voltage sensor, and determines whether the second changeover switch SW2 has a failure that prevents it from switching by detecting the voltage at the second output terminal T23 before and after switching of the operating mode.

[0046] When the fourth switch SW4 is in the ON state, the fifth switch SW5 is in the OFF state, and the third switch SW3 is in the UP state, the failure determination unit determines whether the first switch SW1 has a failure that makes it impossible to switch as follows (1) or (2). (1) In the grid-connected operation mode, if the voltage of the first output terminal T13 is within a predetermined first normal range, and if, when switching from the grid-connected operation mode to the independent operation mode, the voltage change at the first output terminal T13 before and after the switching falls outside a predetermined second normal range for a predetermined period of time, the fault determination unit determines that a fault has occurred in which the first change-over switch SW1 is fixed to the first system input terminal T11 side and is unable to be switched. (2) In the independent operation mode, if the voltage of the first output terminal T13 is within a predetermined third normal range, and when switching from the independent operation mode to the interconnected operation mode, the voltage change of the first output terminal T13 before and after the switching is outside a predetermined fourth normal range for a predetermined period of time, the fault judgment unit judges that a fault has occurred in which the first change-over switch SW1 is fixed to the first independent input terminal T12 side and is unable to switch.

[0047] When the fourth changeover switch SW4 is in the OFF state, the fifth changeover switch SW5 is in the ON state, and the third changeover switch SW3 is in the down state, the failure determination unit determines that the second changeover switch SW2 has a failure that makes it impossible to switch as follows (3) or (4). (3) In the grid-connected operation mode, if the voltage of the second output terminal T23 is within a predetermined first normal range, and if, when switching from the grid-connected operation mode to the independent operation mode, the voltage change of the second output terminal T23 before and after the switching is outside a predetermined second normal range for a predetermined period of time, the fault determination unit determines that a fault has occurred in which the second change-over switch SW2 is fixed to the second system input terminal T21 side and cannot be switched. (4) In the independent operation mode, if the voltage of the second output terminal T23 is within a predetermined third normal range, and when switching from the independent operation mode to the interconnected operation mode, the voltage change of the second output terminal T23 before and after the switching is outside a predetermined fourth normal range for a predetermined period of time, the fault judgment unit judges that a fault has occurred in which the second change-over switch SW2 is fixed to the second independent input terminal T22 side and is unable to switch.

[0048] The first to fourth normal ranges can be appropriately set in the control unit 22A based on the rated value of the system output of the charging / discharging device 11, the rated value of the independent output of the charging / discharging device 11, the difference between these rated values, etc. The failure determination unit outputs the determination result to the switch control unit.

[0049] The switch control unit controls the switches SW1 to SW5 based on the determination results of the mode determination unit and the failure determination unit. Specifically, the switch control unit controls the switches SW1 to SW5 as shown in Fig. 2. In the following, a failure that makes switching impossible will simply be referred to as a failure, and the same applies to the second and third embodiments.

[0050] (Status 1-1) In state 1-1, the operation mode of the charge / discharge device 11 is the grid-connected operation mode, and neither the first changeover switch SW1 nor the second changeover switch SW2 has a malfunction.

[0051] In the grid-connected operation mode, a grid output (a grid voltage and / or an AC voltage output from an AC terminal Ta) is applied to the first grid input terminal T11 and the second grid input terminal T21, and an independent output (an AC voltage output from an independent output terminal Tc) is applied to the first independent input terminal T12 and the second independent input terminal T22.

[0052] The control unit 22A sets the first changeover switch SW1 in a state where the first system input terminal T11 and the first output terminal T13 are electrically connected, and sets the second changeover switch SW2 in a state where the second system input terminal T21 and the second output terminal T23 are electrically connected. Furthermore, the control unit 22A sets the fourth changeover switch SW4 in an ON state, the fifth changeover switch SW5 in an OFF state, and the third changeover switch SW3 in an up state, or sets the fourth changeover switch SW4 in an OFF state, the fifth changeover switch SW5 in an ON state, and the third changeover switch SW3 in a down state. The control unit 22A can set in advance whether the switches SW3 to SW5 are in the former state or the latter state.

[0053] (Status 1-2) In state 1-2, the operation mode of the charge / discharge device 11 is the independent operation mode, and neither the first changeover switch SW1 nor the second changeover switch SW2 has a malfunction.

[0054] In the case of the isolated operation mode, no system output is applied to the first system input terminal T11 and the second system input terminal T21, and an isolated output is applied to the first isolated input terminal T12 and the second isolated input terminal T22.

[0055] The control unit 22A sets the first changeover switch SW1 to a state in which the first independent input terminal T12 and the first output terminal T13 are electrically connected, and sets the second changeover switch SW2 to a state in which the second independent input terminal T22 and the second output terminal T23 are electrically connected. Furthermore, the control unit 22A sets the fourth changeover switch SW4 to the ON state, the fifth changeover switch SW5 to the OFF state, and the third changeover switch SW3 to the UP state, or sets the fourth changeover switch SW4 to the OFF state, the fifth changeover switch SW5 to the ON state, and the third changeover switch SW3 to the DOWN state.

[0056] (Status 1-3) In state 1-3, the operation mode of the charging / discharging device 11 is the independent operation mode, the first changeover switch SW1 is broken, and the second changeover switch SW2 is not broken. In state 1-3, the first changeover switch SW1 is broken while being fixed to the first system input terminal T11 side, but even if the first changeover switch SW1 is broken while being fixed to the first independent input terminal T12 side, the control unit 22A performs the same control.

[0057] The control unit 22A sets the second changeover switch SW2 to a state in which the second independent input terminal T22 and the second output terminal T23 are conductively connected, sets the fourth changeover switch SW4 to an OFF state, the fifth changeover switch SW5 to an ON state, and sets the third changeover switch SW3 to a lower state. As a result, the independent output is supplied to the load 3 through a power supply path that passes through the second changeover switch SW2.

[0058] (Status 1-4) In state 1-4, the operation mode of the charge / discharge device 11 is the grid-connected operation mode, the first changeover switch SW1 is broken, and the second changeover switch SW2 is not broken. In state 1-4, the first changeover switch SW1 is broken while being fixed to the first system input terminal T11 side, but even if the first changeover switch SW1 is broken while being fixed to the first isolated input terminal T12 side, the control unit 22A performs the same control.

[0059] The control unit 22A sets the second changeover switch SW2 to a state in which the second system input terminal T21 and the second output terminal T23 are conductively connected, sets the fourth changeover switch SW4 to an OFF state, the fifth changeover switch SW5 to an ON state, and sets the third changeover switch SW3 to a lower state. As a result, the system output is supplied to the load 3 through a power supply path that passes through the second changeover switch SW2.

[0060] (Status 1-5) In state 1-5, the operation mode of the charging / discharging device 11 is the independent operation mode, the second changeover switch SW2 is broken, and the first changeover switch SW1 is not broken. In state 1-5, the second changeover switch SW2 is broken in a state fixed to the second system input terminal T21 side, but even if the second changeover switch SW2 is broken in a state fixed to the second independent input terminal T22 side, the control unit 22A performs the same control.

[0061] The control unit 22A sets the first changeover switch SW1 to a state in which the first independent input terminal T12 and the first output terminal T13 are conductively connected, the fourth changeover switch SW4 to an ON state, the fifth changeover switch SW5 to an OFF state, and the third changeover switch SW3 to an up state. As a result, the independent output is supplied to the load 3 through a power supply path that passes through the first changeover switch SW1.

[0062] (Status 1-6) In state 1-6, the operation mode of the charging / discharging device 11 is the grid-connected operation mode, the second changeover switch SW2 is broken, and the first changeover switch SW1 is not broken. The second changeover switch SW2 is broken in a state where it is fixed to the second system input terminal T21 side, but even if the second changeover switch SW2 is broken in a state where it is fixed to the second independent input terminal T22 side, the control unit 22A performs the same control.

[0063] The control unit 22A sets the first changeover switch SW1 to a state in which the first system input terminal T11 and the first output terminal T13 are conductively connected, the fourth changeover switch SW4 to an ON state, the fifth changeover switch SW5 to an OFF state, and the third changeover switch SW3 to an up state. As a result, the system output is supplied to the load 3 through a power supply path that passes through the first changeover switch SW1.

[0064] As described above, in the power supply system 1A according to the present embodiment, the first power supply path (first power line L1) via the first changeover switch SW1 and the second power supply path (second power line L2) via the second changeover switch SW2 are formed in parallel in the automatic changeover distribution board 20A, and the first changeover switch SW1 and the second changeover switch SW2 are connected to both the system power line L11 and the independent output line L12, respectively. Therefore, in the power supply system 1A according to the present embodiment, even if either the first changeover switch SW1 or the second changeover switch SW2 fails, it is possible to stably supply power to the load 3 via the first power supply path (first power line L1) or the second power supply path (second power line L2).

[0065] The fault determination unit of this embodiment is configured to detect whether the switches SW1 and SW2 are fixed to the grid power line L11 side or the isolated output line L12 side. However, in the power supply system 1A according to this embodiment, when either the first changeover switch SW1 or the second changeover switch SW2 fails, power is supplied to the load 3 through a power supply path via the other switch that is not faulty. Therefore, if the fault of the switches SW1 and SW2 can be detected, it is not necessary to detect whether the fault is fixed to the grid power line L11 side or the isolated output line L12 side. Therefore, the fault determination unit of this embodiment can be simplified in configuration.

[0066] [Second embodiment] 3 shows a power supply system 1B according to a second embodiment of the present invention. The power supply system 1B includes a power storage system 10 and an automatic switching distribution board 20B. The power storage system 10 has the same configuration as in the first embodiment.

[0067] The automatic switching distribution board 20B includes a switch unit 21B and a control unit 22B that controls the switch unit 21B. The switch unit 21B has the same configuration as the switch unit 21A of the first embodiment.

[0068] The control unit 22B includes a mode determination unit that determines the operation mode of the charging / discharging device 11, a failure determination unit that determines a failure that disables switching of the first changeover switch SW1 and the second changeover switch SW2, and a switch control unit that controls the switches SW1 to SW5. The control unit 22B has the same configuration as the control unit 22A of the first embodiment, except for the control performed by the switch control unit.

[0069] The switch control section controls each of the switches SW1 to SW5 based on the determination results of the mode determination section and the failure determination section. Specifically, the switch control section controls each of the switches SW1 to SW5 as shown in FIG.

[0070] (Status 2-1) In state 2-1, the operation mode of the charge / discharge device 11 is the grid-connected operation mode, and neither the first changeover switch SW1 nor the second changeover switch SW2 is malfunctioning. The control unit 22B sets the first changeover switch SW1 to a state in which the first system input terminal T11 is electrically connected to the first output terminal T13, the second changeover switch SW2 to a state in which the second system input terminal T21 is electrically connected to the second output terminal T23, and sets the fourth changeover switch SW4 to an ON state, the fifth changeover switch SW5 to an OFF state, and the third changeover switch SW3 to an up state.

[0071] (Status 2-2) In state 2-2, the operation mode of the charging / discharging device 11 is the independent operation mode, and neither the first changeover switch SW1 nor the second changeover switch SW2 is faulty. The control unit 22B sets the first changeover switch SW1 to a state in which the first independent input terminal T12 and the first output terminal T13 are conductively connected, the second changeover switch SW2 to a state in which the second independent input terminal T22 and the second output terminal T23 are conductively connected, the fourth changeover switch SW4 to an OFF state, the fifth changeover switch SW5 to an ON state, and the third changeover switch SW3 to a lower state.

[0072] (Status 2-3) State 2-3 is the same as state 1-3 in the first embodiment. That is, the control unit 22B performs the same control as the control unit 22A in the first embodiment.

[0073] (Status 2-4) In state 2-4, the operation mode of the charge / discharge device 11 is the grid-connected operation mode, the first changeover switch SW1 is fixed to the first system input terminal T11 side and is faulty, and the second changeover switch SW2 is not faulty. The control unit 22B sets the second changeover switch SW2 to a state in which the second system input terminal T21 and the second output terminal T23 are conductively connected, the fourth changeover switch SW4 to the ON state, the fifth changeover switch SW5 to the OFF state, and the third changeover switch SW3 to the UP state. As a result, the system output is supplied to the load 3 through the first power supply path via the faulty first changeover switch SW1.

[0074] (Status 2-5) State 2-5 is the same as state 1-5 in the first embodiment. That is, the control unit 22B performs the same control as the control unit 22A in the first embodiment.

[0075] (Status 2-6) State 2-6 is the same as state 1-6 in the first embodiment. That is, the control unit 22B performs the same control as the control unit 22A in the first embodiment.

[0076] (State 2-7) In state 2-7, the operation mode of the charging / discharging device 11 is the independent operation mode, the first changeover switch SW1 is fixed to the first independent input terminal T12 and is faulty, and the second changeover switch SW2 is not faulty. In this case, the control unit 22B performs the same control as in state 2-3 (state 1-3 in the first embodiment) on the switches SW2 to SW5 that are not faulty.

[0077] (State 2-8) In state 2-8, the operation mode of the charge / discharge device 11 is the grid-connected operation mode, the first changeover switch SW1 is fixed to the first isolated input terminal T12 and is faulty, and the second changeover switch SW2 is not faulty. In this case, the control unit 22B performs the same control as in state 1-4 of the first embodiment on the switches SW2 to SW5 that are not faulty.

[0078] (Status 2-9) In state 2-9, the operation mode of the charging / discharging device 11 is the independent operation mode, the second changeover switch SW2 is fixed to the second independent input terminal T22 side and is faulty, and the first changeover switch SW1 is not faulty. The control unit 22B sets the first changeover switch SW1 to a state in which the first independent input terminal T12 and the first output terminal T13 are conductively connected, the fourth changeover switch SW4 to the OFF state, the fifth changeover switch SW5 to the ON state, and the third changeover switch SW3 to the LOW state. As a result, the independent output is supplied to the load 3 through the second power supply path via the failed second changeover switch SW2.

[0079] (Status 2-10) In state 2-10, the operation mode of the charge / discharge device 11 is the grid-connected operation mode, the second changeover switch SW2 is fixed to the second isolated input terminal T22 side and is faulty, and the first changeover switch SW1 is not faulty. In this case, the control unit 22B performs the same control as in state 2-6 (state 1-6 in the first embodiment) on the switches SW1, SW3 to SW5 that are not faulty.

[0080] As described above, in the power supply system 1B according to the present embodiment, the first power supply path (first power line L1) via the first changeover switch SW1 and the second power supply path (second power line L2) via the second changeover switch SW2 are formed in parallel in the automatic changeover distribution board 20B, and the first changeover switch SW1 and the second changeover switch SW2 are connected to both the system power line L11 and the independent output line L12, respectively. Therefore, in the power supply system 1B according to the present embodiment, even if either the first changeover switch SW1 or the second changeover switch SW2 fails, it is possible to stably supply power to the load 3 via the first power supply path (first power line L1) or the second power supply path (second power line L2).

[0081] Furthermore, in the power supply system 1B according to this embodiment, when the operation mode of the charging / discharging device 11 is the grid-connected operation mode and the first changeover switch SW1 has a failure while being fixed to the first system input terminal T11 side (in the case of state 2-4), the system output is supplied to the load 3 through the first power supply path via the failed first changeover switch SW1. In this way, by performing the same control as when the first changeover switch SW1 has no failure (in the case of state 2-1) on the switches SW2 to SW5 that have no failure, it is possible to suppress the complication of control.

[0082] Similarly, in the power supply system 1B according to the present embodiment, when the operation mode of the charging / discharging device 11 is the independent operation mode and the second changeover switch SW2 has a failure while being fixed to the second independent input terminal T22 side (in the case of state 2-9), an independent output is supplied to the load 3 through the second power supply path via the failed second changeover switch SW2. In this way, by performing the same control as when the second changeover switch SW2 has no failure (in the case of state 2-2) on the switches SW1 and SW3 to SW5 that have no failure, it is possible to suppress the complication of control.

[0083] [Third embodiment] 5 shows a power supply system 1C according to a third embodiment of the present invention. The power supply system 1C includes a power storage system 10C and an automatic switching distribution board 20C.

[0084] The power storage system 10C includes a charge / discharge device 11C and a storage battery 12. The charge / discharge device 11C differs from the first embodiment in that it performs grid output without performing independent output during grid-connected operation mode (for example, the configuration of the opening / closing unit differs from that of the first embodiment), but otherwise has the same configuration as the first embodiment. The storage battery 12 has the same configuration as the first embodiment.

[0085] The automatic changeover distribution board 20C includes a switch unit 21C and a control unit 22C that controls the switch unit 21C. The switch unit 21C has the same configuration as the switch unit 21A of the first embodiment, except that a sixth changeover switch SW6 is provided on the third power line L3. In this embodiment, the fourth changeover switch SW4, the fifth changeover switch SW5, and the sixth changeover switch SW6 are relay switches (contacts).

[0086] The sixth changeover switch SW6 switches between an ON state and an OFF state under the control of the control unit 22C, and when in the ON state, makes the third power line L3 a conductive state, whereas when in the OFF state, makes the third power line L3 a non-conductive state. The sixth changeover switch SW6 is in the OFF state when both the first changeover switch SW1 and the second changeover switch SW2 are faulty, and is in the ON state when only one of them is faulty or when neither is faulty.

[0087] As shown in FIG. 6, the control unit 22C includes a mode determination unit 23, a switch control unit 24, a first detection unit 25, a second detection unit 26, a failure determination unit 27, and a failure display unit .

[0088] The mode determination unit 23 has the same configuration as the mode determination unit in the first embodiment, and determines the operation mode of the charging / discharging device 11 C. The mode determination unit 23 outputs the determined operation mode to the switch control unit 24.

[0089] The switch control unit 24 controls the switches SW1 to SW3 according to the determination result of the mode determination unit 23 and the presence or absence of a failure in the first changeover switch SW1 and the second changeover switch SW2. Specifically, the switch control unit 24 controls the switches SW1 to SW3 in the same manner as in the first embodiment (as shown in FIG. 2).

[0090] The first detection unit 25 detects whether or not there is a failure in the first changeover switch SW1, and controls the fourth changeover switch SW4 according to the detection result. The first detection unit 25 turns the fourth changeover switch SW4 to the ON state when it has not detected a failure in the first changeover switch SW1, and turns the fourth changeover switch SW4 to the OFF state when it has detected a failure in the first changeover switch SW1.

[0091] The first detection unit 25 includes logic circuits C1 to C5, a transistor TR1, and a drive coil RC1 of the fourth switch SW4. The logic circuit C1 is a NAND circuit, the logic circuits C2, C3, and C5 are an AND circuit, and the logic circuit C4 is an OR circuit, and these logic circuits are configured with analog circuits and / or digital circuits. The transistor TR1 is an NPN-type bipolar transistor, and the drive coil RC1 is connected to the collector of the transistor TR1. An output signal (voltage signal) from a connection point P1 between the transistor TR1 and the drive coil RC1 is output to the failure determination unit 27 and the switch control unit 24. The input sections of the logic circuits C1 to C3 receive signals (system output signal and independent output signal) that have been binarized (for example, input present: 1, no input: 0) depending on whether or not AC power is input by converting the AC power (system output and independent output) into a DC detection signal using detection circuits (system output detection circuit and independent output detection circuit) not shown that are provided on the power lines (system power line L11 and independent output line L12).

[0092] When the charging / discharging device 11C is in the grid-connected operation mode, the voltage signal input from the grid power line L11 to the first detection unit 25 and the second detection unit 26 is a high-level signal, while the voltage signal input from the independent output line L12 to the first detection unit 25 and the second detection unit 26 is a low-level signal. When the charging / discharging device 11C is in the grid-connected operation mode, the voltage signal input from the grid power line L11 to the first detection unit 25 and the second detection unit 26 is a low-level signal, while the voltage signal input from the independent output line L12 to the first detection unit 25 and the second detection unit 26 is a high-level signal.

[0093] In the first detection unit 25, the voltage level of the first output terminal T13 of the first changeover switch SW1 is high when the first changeover switch SW1 is not faulty, and is low when the first changeover switch SW1 is faulty. The output of the logic circuit C1 is high regardless of whether the first changeover switch SW1 is faulty or not. When the first changeover switch SW1 is not faulty, the output of the logic circuit C4 is high, the output of the logic circuit C5 is also high, the transistor TR1 is turned on, a current flows through the drive coil RC1, and the fourth changeover switch SW4 is turned on. As a result, the output from the connection point P1 (the voltage level of the connection point P1) is low. On the other hand, when the first changeover switch SW1 is faulty, the output of the logic circuit C4 is low, the output of the logic circuit C5 is also low, the transistor TR1 is turned off, no current flows through the drive coil RC1, and the fourth changeover switch SW4 is turned off. As a result, the output from the connection point P1 is high.

[0094] The second detection unit 26 detects whether or not there is a failure in the second changeover switch SW2, and controls the fifth changeover switch SW5 in accordance with the detection result. The second detection unit 26 turns the fifth changeover switch SW5 to the ON state when it has not detected a failure in the second changeover switch SW2, and turns the fifth changeover switch SW5 to the OFF state when it has detected a failure in the second changeover switch SW2.

[0095] The second detection unit 26 includes logic circuits C6 to C10, a transistor TR2, and a drive coil RC2 of the fifth switch SW5. The logic circuit C6 is a NAND circuit, the logic circuits C7, C8, and C10 are an AND circuit, and the logic circuit C9 is an OR circuit, and these logic circuits are configured with analog circuits and / or digital circuits. The transistor TR2 is an NPN-type bipolar transistor, and the drive coil RC2 is connected to the collector of the transistor TR2. An output signal (voltage signal) from a connection point P2 between the transistor TR2 and the drive coil RC2 is output to the failure determination unit 27 and the switch control unit 24. The input sections of the logic circuits C6 to C8 receive signals (system output signal and independent output signal) that have been binarized (for example, input present: 1, no input: 0) depending on whether or not AC power is input by converting the AC power (system output and independent output) into a DC detection signal using detection circuits (system output detection circuit and independent output detection circuit) not shown that are provided on the power lines (system power line L11 and independent output line L12).

[0096] In the second detection unit 26, the voltage level of the second output terminal T23 of the second changeover switch SW2 is high when the second changeover switch SW2 is not faulty, and is low when the second changeover switch SW2 is faulty. The output of the logic circuit C6 is high regardless of whether the second changeover switch SW2 is faulty or not. When the second changeover switch SW2 is not faulty, the output of the logic circuit C9 is high, the output of the logic circuit C10 is also high, the transistor TR2 is turned on, a current flows through the drive coil RC2, and the fifth changeover switch SW5 is turned on. As a result, the output from the connection point P2 (the voltage level of the connection point P2) is low. On the other hand, when the second changeover switch SW2 is faulty, the output of the logic circuit C9 is low, the output of the logic circuit C10 is also low, the transistor TR2 is turned off, no current flows through the drive coil RC2, and the fifth changeover switch SW5 is turned off. As a result, the output from the connection point P2 is high.

[0097] The failure determination unit 27 sets the sixth changeover switch SW6 to the ON state when it has not detected a failure of the first changeover switch SW1 or when it has not detected a failure of the second changeover switch SW2, and sets the sixth changeover switch SW6 to the OFF state when it has detected failures of both the first changeover switch SW1 and the second changeover switch SW2.

[0098] The fault determination unit 27 includes a logic circuit C11, a transistor TR3, and a drive coil RC3 for the sixth switch SW6. The logic circuit C11 is a NAND circuit, and is configured with an analog circuit and / or a digital circuit. The transistor TR3 is an NPN-type bipolar transistor, and the drive coil RC3 is connected to the collector of the transistor TR3.

[0099] The logic circuit C11 receives an output signal from the connection point P1 and an output signal from the connection point P2. When neither the first changeover switch SW1 nor the second changeover switch SW2 is faulty (when P1 is low level and P2 is low level), when only the first changeover switch SW1 is faulty (when P1 is high level and P2 is low level), or when only the second changeover switch SW2 is faulty (when P1 is low level and P2 is high level), the output of the logic circuit C11 becomes high level, the transistor TR3 turns ON, a current flows through the drive coil RC3, and the sixth changeover switch SW6 turns ON. On the other hand, when both the first changeover switch SW1 and the second changeover switch SW2 are faulty (when P1 is high level and P2 is high level), the output of the logic circuit C11 becomes low level, the transistor TR3 turns OFF, a current does not flow through the drive coil RC3, and the sixth changeover switch SW6 turns OFF.

[0100] The fault display unit 28 is configured to notify a user of a fault when at least one of the first changeover switch SW1 and the second changeover switch SW2 has a fault. In this embodiment, the fault display unit 28 includes a logic circuit C12, a transistor TR4, a light-emitting diode LED1, and a resistor R1. The logic circuit C12 is a NAND circuit, and is configured with an analog circuit and / or a digital circuit. The transistor TR4 is an NPN-type bipolar transistor, and a series circuit of the resistor R1 and the light-emitting diode LED1 is connected to the collector of the transistor TR4. The light-emitting diode LED1 is at least one light-emitting diode that emits visible light.

[0101] The output signal of the logic circuit C4 and the output signal of the logic circuit C9 are input to the logic circuit C12. When the first changeover switch SW1 and the second changeover switch SW2 are not malfunctioning (when the output of C4 is at a high level and the output of C9 is at a high level), the output of the logic circuit C12 is at a low level, the transistor TR4 is turned off, no current flows through the light-emitting diode LED1, and the light-emitting diode LED1 does not emit light. On the other hand, when at least one of the first changeover switch SW1 and the second changeover switch SW2 is malfunctioning (when at least one of the outputs of C4 and C9 is at a low level), the output of the logic circuit C12 is at a high level, the transistor TR4 is turned on, a current flows through the light-emitting diode LED1, and the light-emitting diode LED1 emits light. This allows the user to be notified of the malfunction, and the user can discover the malfunction early.

[0102] In this embodiment, a light-emitting means (light-emitting diode LED1) is used to notify the user that at least one of the first changeover switch SW1 and the second changeover switch SW2 has failed. In addition to or instead of this, a display means such as a touch panel may be used to display the failure, or any audio means may be used to notify the user of the failure by voice.

[0103] [Variations] Although the embodiments of the power supply system and the automatic switching distribution board according to the present invention have been described above, the present invention is not limited to the above-described embodiments.

[0104] The power supply system according to the present invention is a power supply system including a charging / discharging device having an AC terminal connected to a power grid, a DC terminal connected to a storage battery, and an independent output terminal, and outputting discharge power of the storage battery from the independent output terminal, and an automatic changeover distribution board having one side to which the power grid and the independent output terminal of the charging / discharging device are connected and the other side to which a load is connected, wherein the automatic changeover distribution board has a first system input terminal connected to the power grid, a first independent input terminal and a first output terminal connected to the independent output terminal, and a first changeover switch for switching between a state in which the first system input terminal and the first output terminal are conductively connected and a state in which the first independent input terminal and the first output terminal are conductively connected, and a second system input terminal and a second independent output terminal connected to the power grid. the second independent input terminal and the second output terminal connected to the first output terminal, and switching between a state in which the second system input terminal and the second output terminal are conductively connected and a state in which the second independent input terminal and the second output terminal are conductively connected; a third input terminal connected to the first output terminal, a second input terminal connected to the second output terminal, and a third output terminal connected to the load, and switching between a state in which the first input terminal and the third output terminal are conductively connected and a state in which the second input terminal and the third output terminal are conductively connected; and a control unit that controls the first changeover switch, the second changeover switch, and the third changeover switch so that a power supply path to the load is formed.

[0105] For example, the power supply systems 1A to 1C according to the above embodiments do not necessarily have to include the fourth changeover switch SW4 and the fifth changeover switch SW5.

[0106] The charge / discharge device of the present invention may be a charge / discharge device (for example, a V2H device) that charges and discharges a storage battery mounted on an electric vehicle or the like.

[0107] The power supply system of the present invention may include a power conversion unit (e.g., a power conditioner device) of a power generation device (e.g., a solar power generation device) that uses renewable energy. When the power conversion unit of the power generation device has an independent output terminal that can output AC power as an independent output, the independent output terminal can be connected to the output side of the automatic switching distribution board (e.g., the third power line L3 in the above embodiment). [Explanation of symbols]

[0108] 1A~1C Power Supply System 2 Power system 3. Load 10, 10C Energy Storage System 11, 11C charge / discharge device 11a Opening and closing section 11b Power conversion section 11c Control section 12 Storage battery 20A~20C automatic switching distribution board 21A~21C Switch section 22A~22C Control section 23 Mode determination section 24 Switch control section 25 First detection section 26 Second detection section 27 Failure determination section 28 Fault display section

Claims

1. a charging / discharging device including an AC terminal connected to a power grid, a DC terminal connected to a storage battery, and an independent output terminal, the charging / discharging device outputting discharge power of the storage battery from the independent output terminal; an automatic switching distribution board having one side to which the power system and the independent output terminals of the charging / discharging device are connected and the other side to which a load is connected; A power supply system comprising: The automatic switching distribution board is a first changeover switch including a first system input terminal connected to the power system, a first isolated input terminal connected to the isolated output terminal, and a first output terminal, the first changeover switch switching between a state in which the first system input terminal and the first output terminal are electrically connected and a state in which the first isolated input terminal and the first output terminal are electrically connected; a second changeover switch including a second system input terminal connected to the power system, a second independent input terminal connected to the independent output terminal, and a second output terminal, the second changeover switch switching between a state in which the second system input terminal and the second output terminal are conductively connected and a state in which the second independent input terminal and the second output terminal are conductively connected; a third changeover switch including a first input terminal connected to the first output terminal, a second input terminal connected to the second output terminal, and a third output terminal connected to the load, the third changeover switch switching between a state in which the first input terminal and the third output terminal are conductively connected and a state in which the second input terminal and the third output terminal are conductively connected; a control unit that controls the first changeover switch, the second changeover switch, and the third changeover switch so as to form a power supply path to the load.

1. A power supply system comprising:

2. The automatic switching distribution board is a fourth changeover switch that is interposed in a first power line that connects the first output terminal and the first input terminal and that switches the first power line between a conductive state and a non-conductive state; a fifth changeover switch that is interposed in a second power line that connects the second output terminal and the second input terminal and that switches the second power line between a conductive state and a non-conductive state, The control unit is The fourth changeover switch and the fifth changeover switch are controlled so as to bring one of the first power line and the second power line into a conductive state and bring the other into a non-conductive state.

2. The power supply system according to claim 1 .

3. The control unit is When the first changeover switch has a failure that makes it impossible to change over, the fourth changeover switch is controlled to put the first power line into a non-conductive state, and the fifth changeover switch is controlled to put the second power line into a conductive state; When the second changeover switch has a failure that makes it impossible to switch, the fifth changeover switch is controlled to put the second power line into a non-conducting state, and the fourth changeover switch is controlled to put the first power line into a conducting state.

3. The power supply system according to claim 2.

4. The control unit is In the case where the first changeover switch has a failure that makes it impossible to change over when the first system input terminal is connected to the first output terminal, when the power system is in a conducting state, the fourth changeover switch is controlled to bring the first power line into a conducting state, In the case where the second selector switch has a failure that makes it impossible to switch when the second independent input terminal is connected to the second output terminal, when the power system is in a power outage state, the fifth selector switch is controlled to make the second power line conductive.

3. The power supply system according to claim 2.

5. The control unit is a first detection unit that detects a failure of the first changeover switch that makes it impossible to switch in accordance with a voltage of a front stage and a rear stage of the first changeover switch, and controls the fourth changeover switch in accordance with the detection result; a second detection unit that detects a failure of the second changeover switch that makes it impossible to switch in accordance with a voltage in a front stage and a rear stage of the second changeover switch, and controls the fifth changeover switch in accordance with the detection result.

3. The power supply system according to claim 2.

6. The automatic switching distribution board is a sixth changeover switch that is interposed in a third power line that connects the third output terminal and the load and that switches the third power line between a conductive state and a non-conductive state; The control unit is When both the first changeover switch and the second changeover switch are in a failure state in which they cannot be switched, the sixth changeover switch is controlled to bring the third power line into a non-conducting state.

2. The power supply system according to claim 1 .

7. The automatic switching distribution board is and a failure display unit that notifies a user of a failure by a light emitting means, a display means, or a sound means when at least one of the first changeover switch and the second changeover switch is in a failure state that makes it impossible to change over.

2. The power supply system according to claim 1 .

8. An automatic switching panel having a power system and a battery charge / discharge device connected to one side and a load connected to the other side, The charging / discharging device includes an independent output terminal that outputs discharge power of the storage battery, The automatic switching distribution board is a first changeover switch including a first system input terminal connected to the power system, a first isolated input terminal connected to the isolated output terminal, and a first output terminal, the first changeover switch switching between a state in which the first system input terminal and the first output terminal are electrically connected and a state in which the first isolated input terminal and the first output terminal are electrically connected; a second changeover switch including a second system input terminal connected to the power system, a second independent input terminal connected to the independent output terminal, and a second output terminal, the second changeover switch switching between a state in which the second system input terminal and the second output terminal are conductively connected and a state in which the second independent input terminal and the second output terminal are conductively connected; a third changeover switch including a first input terminal connected to the first output terminal, a second input terminal connected to the second output terminal, and a third output terminal connected to the load, the third changeover switch switching between a state in which the first input terminal and the third output terminal are conductively connected and a state in which the second input terminal and the third output terminal are conductively connected; a control unit that controls the first changeover switch, the second changeover switch, and the third changeover switch so as to form a power supply path to the load. An automatic switching distribution board characterized by:

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