Power conversion device

Abstract

To provide a power conversion device converting DC power output from a DC power supply into AC power.SOLUTION: A power conversion device includes a power storage section storing DC power output from a DC power supply and an inverter section converting DC power output from the power storage section into AC power and outputting the converted AC power.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power conversion device. [Background technology]

[0002] DC power is output from DC power sources such as solar power generation systems, wind power generation systems, biopower generation systems, fuel cells, and lithium-ion batteries. On the other hand, the power transmitted to a typical home is AC power, and many electrical appliances use AC power as input power. Summary of the Invention [Problem to be solved by the invention]

[0003] At least one object of the present invention is to provide a power conversion device that converts DC power output from a DC power supply into AC power. [Means for solving the problem]

[0004] The object of the present invention is to [1] A power conversion device including a power storage unit that stores DC power output from a DC power source, and an inverter unit that converts the DC power output from the power storage unit into AC power and outputs the AC power; [2] The power conversion device according to [1], further comprising a control unit, wherein the inverter unit is capable of outputting power supplied from a commercial power source, and when power is not supplied from the commercial power source to the inverter unit, the control unit controls the power conversion device to be supplied from a DC power source; [3] The power conversion device according to [1] or [2], wherein the storage unit stores power supplied from a commercial power source, and includes a rectifier with a protection circuit for protecting the storage unit, and the rectifier with a protection circuit is connected so as to be located between the commercial power source and the storage unit; [4] The power conversion device according to any one of [1] to [3] above, wherein the DC power source is a solar power generation device, a wind power generation device, a biological power generation device, a fuel cell, and / or a lithium ion battery; [5] The power conversion device according to any one of [1] to [4], which includes two or more power storage units, the DC power supply has two or more system outputs, and one power storage unit is connected to each output of the DC power supply; [6] The power conversion device according to any one of [1] to [5], comprising two or more power storage units and two or more inverter units, wherein one inverter unit is connected to one power storage unit; [7] The power conversion device according to any one of [1] to [5], comprising two or more power storage units and two or more inverter units, each power storage unit being connected to two or more inverter units, and capable of supplying power from two or more power storage units to one inverter unit; This is achieved by: [Effects of the Invention]

[0005] According to the present invention, it is possible to provide a power conversion device that converts DC power output from a DC power supply into AC power. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a block diagram showing a configuration of a power conversion device according to an embodiment of the present invention; [Figure 2] 1 is a block diagram showing a configuration of a power conversion device according to an embodiment of the present invention; [Figure 3] 1 is a block diagram showing a configuration of a power conversion device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments as long as they do not contradict the spirit of the present invention.

[0008] Fig. 1 is a block diagram showing the configuration of a power conversion device according to an embodiment of the present invention. The power conversion device 1 shown in Fig. 1 includes inverter units 11 (11a and 11b), power storage units 12 (12a and 12b), rectifiers 13 with protection circuits (13a and 13b), a control unit 14, an operation unit 15, and switch circuits 16 (16a and 16b).

[0009] The power conversion device 1 is electrically connected on the input side to a commercial power supply 2 and also electrically connected to a DC power supply 3. The power conversion device 1 can receive power from the commercial power supply 2 and the DC power supply 3. Furthermore, the power conversion device 1 may be electrically connected on the output side to a load device or the like.

[0010] 1, the commercial power supply 2 and inverter units 11 (11a and 11b), the inverter units 11 (11a and 11b) and output terminals, the commercial power supply 2 and rectifier devices with protection circuits 13 (13a and 13b), the rectifier devices with protection circuits 13 (13a and 13b) and power storage units 12 (12a and 12b), the DC power supply 3 and switch circuits 16 (16a and 16b), the switch circuits 16 (16a and 16b) and power storage units 12 (12a and 12b), and the power storage units 12 (12a and 12b) and inverter units 11 (11a and 11b) are each electrically connected by conductors or the like. In FIG. 1, gray solid arrows indicate electrical connections.

[0011] 1, the control unit 14 is connected to the DC power supply 3, the inverter units 11 (11a and 11b), the operation unit 15, and the external shutdown A contact via communication and / or electrical communication. The control unit 14 may be connected to the DC power supply 3, the inverter units 11 (11a and 11b), the operation unit 15, and the external shutdown A contact via wire or wireless communication. The connection between the control unit 14, the DC power supply 3, the inverter units 11 (11a and 11b), the operation unit 15, and the external shutdown A contact may enable transmission and reception of signals or information. In FIG. 1, the black dashed arrows indicate the connection between the control unit 14, the DC power supply 3, the inverter units 11 (11a and 11b), the operation unit 15, and the external shutdown A contact.

[0012] Hereinafter, a description will be given of an embodiment in which power supplied from a commercial power source 2 is output from the power conversion device 1 under normal circumstances, and DC power supplied from a DC power source 3 is converted to AC power by the power conversion device 1 and output in an emergency. The normal circumstances may refer to a state in which power is supplied from the commercial power source 2. The emergency circumstances may refer to a state in which power is not supplied from the commercial power source 2 to the inverter unit 11. Specifically, the state in which power is not supplied from the commercial power source 2 to the inverter unit 11 may be, for example, a state in which power is not supplied from the commercial power source 2 due to a power outage or the like, or a state in which power is supplied from the commercial power source 2 but a conductor or the like inside the power conversion device 1 is broken, preventing power from being supplied from the commercial power source 2 to the inverter unit 11. The power conversion device 1 of the present invention can be used not only when the DC power source 3 is an emergency power source, but also when the DC power source 3 is a normal power source.

[0013] The commercial power source 2 may be a source of power supplied from a power plant to power consumers. The power supplied from the commercial power source 2 may be AC ​​power or DC power. The voltage and frequency of the power supplied from the commercial power source 2 are not particularly limited. The power supplied from the commercial power source 2 may be, for example, 100V AC power.

[0014] As shown in the figure, power input from a commercial power source 2 to a power conversion device 1 is supplied to an inverter unit 11 (11a and 11b) and a rectifier device with a protection circuit 13 (13a and 13b). The inverter unit 11a and the inverter unit 11b are connected in parallel to the commercial power source 2. The rectifier device with a protection circuit 13a and the rectifier device with a protection circuit 13b are connected in parallel to the commercial power source 2.

[0015] In FIG. 1, power input from a commercial power supply 2 is supplied to both inverter units 11a and 11b included in the power conversion device 1. The inverter unit 11 converts input DC power or AC power into AC power and outputs it. The frequency of the AC power output by the inverter unit 11 may be different from the frequency of the input AC power. Note that the inverter unit 11 may output the input AC power without converting it. The inverter unit 11 is capable of outputting power supplied from the commercial power supply 2.

[0016] The AC power output from the inverter unit 11a and the AC power output from the inverter unit 11b may be output to the outside of the power conversion device 1 via output terminals. The power output to the outside of the power conversion device 1 may be supplied to a load device or the like connected to the power conversion device 1. In this case, the output voltage may be, for example, single-phase 100V or single-phase 200V.

[0017] Rectifier 13 with protection circuit is for protecting power storage unit 12. Rectifier 13 with protection circuit may protect power storage unit 12 from overcharging. Rectifier 13 with protection circuit may include, for example, a protection IC, a current detection resistor for monitoring the charging current, a comparator for monitoring the voltage of the power stored in power storage unit 12, and a transistor for receiving a signal from the protection IC when the protection IC detects an abnormality and for conducting or cutting off the charging current to power storage unit 12.

[0018] 1, rectifier device 13a with protection circuit is connected in series with power storage unit 12a, and rectifier device 13b with protection circuit is connected in series with power storage unit 12b. That is, one rectifier device 13 with protection circuit is connected to one power storage unit 12. Furthermore, rectifier device 13 with protection circuit is connected to be located between commercial power source 2 and power storage unit 12.

[0019] The power storage unit 12 stores electric power. The power storage unit 12 is not particularly limited and can be designed as appropriate. The power storage unit 12 may be, for example, a lithium ion battery. The power output by the power storage unit 12 is DC power. In FIG. 1, the power storage unit 12 can store electric power supplied from a commercial power source 2.

[0020] The power stored in the power storage unit 12 does not have to be output to the inverter unit 11 while power is being supplied from the commercial power source 2, and may be output to the inverter unit 11 while power is being supplied from the commercial power source 2. The supply of power from the power storage unit 12 to the inverter unit 11 may be controlled by the control unit 14.

[0021] The rectifier device 13 with a protection circuit may perform control so that the storage unit 12 is not over-discharged and / or over-charged depending on the power charged to the storage unit 12, the power stored in the storage unit 12, etc.

[0022] For example, when rectifier device 13 with protection circuit detects that the voltage of the power stored in power storage unit 12 has reached a predetermined value or higher while power storage unit 12 is being charged from commercial power supply 2, it may cut off the charging current from commercial power supply 2 to power storage unit 12. By cutting off the charging current from commercial power supply 2 to power storage unit 12, it is possible to prevent power storage unit 12 from being overcharged. In this case, the predetermined value may be a value at which power storage unit 12 is thought to be at risk of being overcharged. Note that rectifier device 13 with protection circuit may cut off the charging current from commercial power supply 2 to power storage unit 12 when it detects that the voltage of the power stored in power storage unit 12 has reached a predetermined value or higher.

[0023] Furthermore, for example, when protection circuit-equipped rectifier device 13 detects that the voltage of the power stored in power storage unit 12 has fallen below a predetermined value, it may conduct a charging current from commercial power source 2 to power storage unit 12. By conducting a charging current from commercial power source 2 to power storage unit 12, it is possible to prevent power storage unit 12 from being over-discharged. In this case, the predetermined value may be a value at which power storage unit 12 is thought to be at risk of being over-discharged. Note that protection circuit-equipped rectifier device 13 may conduct a charging current from commercial power source 2 to power storage unit 12 when it detects that the voltage of the power stored in power storage unit 12 has fallen below a predetermined value.

[0024] Rectifier device 13 with a protection circuit may protect power storage unit 12 by a method other than the above. The method for protecting power storage unit 12 is not particularly limited, and any method may be adopted. Rectifier device 13 with a protection circuit may protect power storage unit 12 by a plurality of methods.

[0025] As shown in Figure 1, when the rectifier device 13 with a protection circuit is connected so as to be located between the commercial power source 2 and the storage unit 12, it is possible to use the power supplied from the commercial power source 2 to prevent the storage unit 12 from being over-discharged.

[0026] As described above, during normal operation, the power conversion device 1 can store power in the power storage unit 12 while outputting power supplied from the commercial power source 2. On the other hand, during an emergency, the power conversion device 1 can convert power supplied from the DC power source 3 into AC power and output the AC power instead of the commercial power source 2. The control unit 14 may perform control so that power is supplied from the DC power source 3 to the power conversion device 1 when power is not supplied from the commercial power source 2 to the inverter unit 11.

[0027] The DC power supply 3 may be a DC power supply source. The DC power supply 3 may be, for example, a solar power generation system, a wind power generation system, a biological power generation system, a fuel cell, a lithium-ion battery, or the like. If the DC power supply 3 is a system that generates AC power, such as a wind power generation system, the AC power may be converted into DC power before being input to the power conversion device 1.

[0028] Whether or not power is being supplied from the commercial power source 2 to the inverter unit 11 may be determined by the control unit 14. For example, the control unit 14 may monitor the input power to the inverter unit 11 (11a and 11b) and, when detecting that no power is being input, determine that power is not being supplied from the commercial power source 2 to the inverter unit 11. Alternatively, although not shown, the control unit 14 may monitor the input power from the commercial power source 2 to the power conversion device 1 and, when detecting that no power is being input, determine that power is not being supplied from the commercial power source 2 to the inverter unit 11. Alternatively, although not shown, the control unit 14 may monitor conductors, etc., connecting the commercial power source 2 and the inverter unit 11 (11a and 11b) inside the power conversion device 1 and, when detecting that no current is flowing, determine that power is not being supplied from the commercial power source 2 to the inverter unit 11.

[0029] "Controlling to supply power from the DC power supply 3 to the power conversion device 1" may mean, for example, controlling to start up the DC power supply 3. In this case, the control unit 14 may control to start up the DC power supply 3 by sending a signal to the DC power supply 3. At this time, the switch circuit 16 may be in a conductive state beforehand. Furthermore, "controlling to supply power from the DC power supply 3 to the power conversion device 1" may mean, for example, controlling to make the switch circuit 16 conductive. In this case, the control unit 14 may control to make the switch circuit 16 conductive by sending a signal to the switch circuit 16. The manner of switching of the switch circuit 16 will be described later.

[0030] If a time lag occurs between the interruption of power supply from commercial power supply 2 and the start of power supply from DC power supply 3, the power stored in power storage unit 12 may be supplied to inverter unit 11 during the period from the interruption of power supply from commercial power supply 2 to the start of power supply from DC power supply 3. For example, when control unit 14 determines that power is not being supplied from commercial power supply 2 to inverter unit 11, control unit 14 may control power to be supplied from power storage unit 12 to inverter unit 11. By supplying the power stored in power storage unit 12 to inverter unit 11 during the period from the interruption of power supply from commercial power supply 2 to the start of power supply from DC power supply 3, it is possible to output AC power from power conversion device 1 without interruption.

[0031] When power supply from the DC power source 3 to the power conversion device 1 begins, the DC power output from the DC power source 3 and input to the power conversion device 1 is input to the power storage units 12 (12a and 12b) via the switch circuit 16 (16a and 16b) and stored in the power storage units 12 (12a and 12b).

[0032] Switch circuit 16 is used to switch between conducting and blocking current. In Fig. 1, switch circuit 16a is provided on the input side of power storage unit 12a, and switch circuit 16b is provided on the input side of power storage unit 12b. That is, one switch circuit 16 is connected to one power storage unit 12. Corresponding switch circuits 16 and power storage units 12 may be connected in series.

[0033] When switch circuit 16 is in the ON state, the DC power supply 3 and power storage unit 12 are electrically connected, and power is supplied from the DC power supply 3 to the power storage unit 12 corresponding to the switch circuit 16. When switch circuit 16 is in the OFF state, the DC power supply 3 and power storage unit 12 are cut off, and power is not supplied to the power storage unit 12 corresponding to the switch circuit 16. The ON / OFF switching of switch circuit 16 may be controlled by control unit 14. Although not shown, control unit 14 may send a signal to switch switch circuit 16 between ON and OFF.

[0034] 1, the DC power supply 3 has two output systems. Furthermore, one power storage unit 12 is connected to each output of the DC power supply 3 via a switch circuit 16. The manner in which the two switch circuits 16 are switched ON / OFF is not particularly limited and can be designed as appropriate. For example, the control unit 14 may control all switch circuits 16 to be in the OFF state while power is being supplied from the commercial power supply 2, and to be in the ON state when power is no longer being supplied from the commercial power supply 2. Furthermore, for example, when it is determined that an abnormality has occurred in the power storage unit 12 or the inverter unit 11 included in the power conversion device 1, the control unit 14 may control the switch circuit 16 corresponding to the power storage unit 12 or the inverter unit 11 in which the abnormality has occurred to be in the OFF state.

[0035] There is no particular limitation on the number of output systems provided in the DC power supply 3. For example, the number of output systems provided in the DC power supply 3 may be one or two or more. When the DC power supply 3 has two or more output systems, one power storage unit 12 may be connected to each output of the DC power supply 3.

[0036] A protection circuit for protecting power storage unit 12 from over-discharge and / or over-charge may be provided inside power storage unit 12. When power storage unit 12 stores DC power output from DC power supply 3, the protection circuit provided inside power storage unit 12 may protect power storage unit 12 from over-discharge and / or over-charge.

[0037] The power stored in the power storage unit 12 is output to the inverter unit 11. The inverter unit 11 converts the DC power input to the inverter unit 11 into AC power and outputs the converted AC power to the outside of the power conversion device 1 via an output terminal. In FIG. 1, the power storage unit 12a is connected to the inverter unit 11a, and the power storage unit 12b is connected to the inverter unit 11b. That is, the power storage units 12 are connected so that one inverter unit 11 corresponds to one power storage unit 12. The power stored in the power storage unit 12a is output to the inverter unit 11a, and the power stored in the power storage unit 12b is output to the inverter unit 11b.

[0038] Regarding the mode of outputting AC power from inverter unit 11, the above description can be adopted to the extent necessary.

[0039] By making the power conversion device 1 function as described above, even if the supply of power from the commercial power source 2 is interrupted due to a power outage or the like, the power conversion device 1 can continue to output AC power without interruption.

[0040] If the supply of power from the commercial power source 2 is interrupted and an uninterruptible power supply (UPS) equipped with an automatic shutdown function is connected between the power conversion device 1 and the load device, the control unit 14 may send a signal to the uninterruptible power supply (UPS) to safely shut down the load device. For example, in FIG. 1, the signal may be sent via an external shutdown A contact. The uninterruptible power supply (UPS) can safely shut down the load device and restart the load device when power is supplied from the DC power source 3 again.

[0041] Furthermore, the operation unit 15 may be configured to accept operation input from a user. The shape, input contents, etc. of the operation unit 15 are not particularly limited and may be designed as appropriate. For example, an instruction to start and / or stop the power conversion device 1 may be input by operation input to a switch-shaped operation unit 15. Furthermore, an operation input to a panel-shaped operation unit 15 may be configured to set the type of information that the control unit 14 receives from the DC power supply 3. The operation unit 15 may transmit the input signal or information to the control unit 14.

[0042] In the above description, the power conversion device 1 is described as including two inverter units 11, two power storage units 12, two rectifiers with protection circuits 13, and two switch circuits 16. However, the number of inverter units 11, two power storage units 12, two rectifiers with protection circuits 13, and two switch circuits 16 included in the power conversion device 1 is not particularly limited and can be designed as appropriate. For example, the number of inverter units 11, two power storage units 12, two rectifiers with protection circuits 13, and two switch circuits 16 included in the power conversion device 1 may be one or more. The power conversion device 1 may include the same number of inverter units 11, two power storage units 12, two rectifiers with protection circuits 13, and two switch circuits 16, or may include inverter units 11, two power storage units 12, two rectifiers with protection circuits 13, and two switch circuits 16, but at least some of them may have different numbers. The power conversion device 1 may not include the rectifiers with protection circuits 13 and / or the switch circuits 16.

[0043] Furthermore, in the above description, an example of the power conversion device 1 has been described in which the rectifier device with protection circuit 13, the storage unit 12, and the inverter unit 11 are connected in a one-to-one-to-one correspondence between the commercial power source 2 and the output terminal, and the switch circuit 16, the storage unit 12, and the inverter unit 11 are connected in a one-to-one-to-one correspondence between the DC power source 3 and the output terminal. However, the manner of connection of each component between the commercial power source 2 and the output terminal, and the manner of connection of each component between the DC power source 3 and the output terminal are not particularly limited and can be designed as appropriate.

[0044] Furthermore, the power conversion device 1 may include components other than the inverter unit 11, the storage unit 12, the rectifier device 13 with a protection circuit, the control unit 14, the operation unit 15, and the switch circuit 16. The manner of connection of the components included in the power conversion device 1 is not particularly limited and can be designed as appropriate. The manner of connection of the components included in the power conversion device 1 can be determined depending on the type of components included in the power conversion device 1, the number of components, the output voltage of the power conversion device 1, etc.

[0045] Although the above description has been given taking as an example the power conversion device 1 whose output voltage is single-phase 100V or single-phase 200V, the output voltage of the power conversion device 1 is not particularly limited and can be designed as appropriate. For example, the output voltage of the power conversion device 1 may be single-phase three-wire 100V / 200V, three-phase 200V, etc.

[0046] When the output voltage of the power conversion device 1 is single-phase three-wire 100V / 200V, the mode of connection to the output terminals in the power conversion device 1 may be as shown in Fig. 2. Fig. 2 is a block diagram showing the configuration of a power conversion device according to an embodiment of the present invention.

[0047] The power conversion device 1 shown in Fig. 2 is configured to extract power from inverter unit 11a and inverter unit 11b. The line connecting inverter unit 11a and inverter unit 11b functions as a neutral point. An output voltage of 200V is obtained between the two voltage lines, and an output voltage of 100V is obtained between either of the two voltage lines and the neutral point.

[0048] Regarding the connections, functions, and the like of other components in the power conversion device 1 shown in FIG. 2, the explanation for FIG. 1 can be adopted to the extent necessary.

[0049] Furthermore, when the output method of the power conversion device 1 is a three-phase four-wire 200V system, the mode of connection to the output terminals in the power conversion device 1 may be as shown in Fig. 3. Fig. 3 is a block diagram showing the configuration of a power conversion device according to an embodiment of the present invention.

[0050] The power conversion device 1 shown in Fig. 3 includes three inverter units 11 (11a to 11c). The commercial power source 2 and inverter unit 11a are electrically connected, the commercial power source 2 and inverter unit 11b are electrically connected, and the commercial power source 2 and inverter unit 11c are electrically connected. Regarding the manner in which power is supplied from the commercial power source 2 to the three inverter units 11 (11a to 11c), the explanation for Fig. 1 can be adopted to the extent necessary.

[0051] 3, each power storage unit 12 (12a and 12b) is connected to three inverter units 11 (11a to 11c). Also, it is possible to supply power to one inverter unit 11 from two power storage units 12 (12a and 12b).

[0052] Although not shown, a power combining unit may be connected between the power storage units 12 and the inverter units 11. In this case, the power storage units 12a and 12b each output DC power to the power combining unit, and the power combining unit can combine the output DC powers into one DC power. The power combining unit can supply the combined DC power to each of the three inverter units 11 (11a to 11c). In other words, the power conversion device 1 may be able to combine powers output from two or more power storage units 12 and supply the combined power to each of the two or more inverter units 11.

[0053] The power conversion device 1 shown in Fig. 3 is configured to extract power from inverter unit 11a, inverter unit 11b, and inverter unit 11c. The line connecting inverter unit 11a, inverter unit 11b, and inverter unit 11c functions as a neutral point. An output voltage of 200V is obtained from the three voltage lines.

[0054] Regarding the connections and functions of other components in the power conversion device 1 shown in FIG. 3, the explanation for FIG. 1 can be adopted to the extent necessary.

[0055] When DC power supply 3 is used as a normal power supply, power conversion device 1 may or may not be connected to commercial power supply 2. When DC power supply 3 is used as a normal power supply, the DC current output from DC power supply 3 is stored in power storage unit 12, and the DC power output from power storage unit 12 is converted into AC power by inverter unit 11 and output.

[0056] In this way, by providing a power conversion device that includes a power storage unit that stores DC power output from a DC power supply and an inverter unit that converts the DC power output from the power storage unit into AC power and outputs the AC power, it is possible to provide a power conversion device that converts DC power output from a DC power supply into AC power. Also, even if the DC power output from the DC power supply is unstable, it is possible to stably output AC power.

[0057] Furthermore, in this way, the power conversion device is provided with a control unit, and the inverter unit is capable of outputting power supplied from a commercial power source. When power is not supplied from the commercial power source to the inverter unit, the control unit controls the supply of power from the DC power source to the power conversion device, and thereby, when power is not supplied from the commercial power source, it becomes possible to output AC power using power from the DC power source.

[0058] Furthermore, in this way, the storage unit stores power supplied from a commercial power source, and is provided with a rectifier device with a protection circuit for protecting the storage unit. The rectifier device with a protection circuit is connected so as to be positioned between the commercial power source and the storage unit, thereby making it possible to protect the storage unit using power from the commercial power source.

[0059] Furthermore, since the DC power source is a solar power generation device, a wind power generation device, a biological power generation device, a fuel cell, and / or a lithium ion battery, the DC current output from the solar power generation device, the wind power generation device, the biological power generation device, the fuel cell, and / or the lithium ion battery can be converted into AC power and output.

[0060] Furthermore, in this way, the power conversion device has two or more storage units, the DC power supply has two or more system outputs, and one storage unit is connected to each output of the DC power supply. Therefore, even if an abnormality occurs in, for example, part of the storage units or part of the output of the DC power supply, the power conversion device can be operated using the normal storage units and the output of the DC power supply.

[0061] Furthermore, by having a power conversion device equipped with two or more storage units and two or more inverter units, and connecting one inverter unit to one storage unit, for example, even if an abnormality occurs in one of the storage units, the power conversion device can be operated using a normal storage unit.

[0062] Furthermore, since the power conversion device is equipped with two or more storage units and two or more inverter units, each storage unit is connected to two or more inverter units, and power can be supplied from two or more storage units to one inverter unit, for example, even if an abnormality occurs in one of the storage units, the power conversion device can be operated using a normal storage unit. [Explanation of symbols]

[0063] 1 Power conversion device 2 Commercial power supply 3 DC power supply 11 Inverter section 12 Power storage unit 13 Rectifier with protection circuit 14 Control Unit 15 Control section 16 Switch Circuit

Claims

1. a power storage unit that stores DC power output from a DC power supply; an inverter unit that converts DC power output from the power storage unit into AC power and outputs it; Equipped with Power conversion device.

2. Control unit Equipped with The inverter unit is capable of outputting power supplied from a commercial power source, When power is not supplied from the commercial power supply to the inverter unit, the control unit controls so that power is supplied from the DC power supply to the power conversion device. The power conversion device according to claim 1 .

3. The power storage unit stores power supplied from a commercial power source, Rectifier with protection circuit to protect the storage unit Equipped with The rectifier with a protection circuit is connected so as to be located between the commercial power source and the power storage unit. The power conversion device according to claim 1 or 2.

4. The DC power source is a solar power generator, a wind power generator, a biopower generator, a fuel cell, and / or a lithium ion battery. The power conversion device according to claim 1 or 2.

5. Two or more power storage units are provided, The DC power supply has two or more system outputs, One power storage unit is connected to each output of the DC power supply. The power conversion device according to claim 1 or 2.

6. Two or more power storage units are provided, Two or more inverter units are provided, One inverter unit is connected to one power storage unit. The power conversion device according to claim 1 or 2.

7. Two or more power storage units are provided, Two or more inverter units are provided, Each power storage unit is connected to two or more inverter units, It is possible to supply power to one inverter unit from two or more power storage units. The power conversion device according to claim 1 or 2.

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