Photovoltaic inverter

Abstract

The utility model discloses a photovoltaic inverter. The photovoltaic inverter comprises a first fuse module and an inverter circuit. The first end of the first fuse module is used for being connected with a direct current source, and the second end of the first fuse module is connected with at least one of the positive input end and the negative input end of the inverter circuit; the first fuse module comprises a trigger device and an actuating mechanism; the trigger device is used for triggering the action mechanism under the condition that the current flowing through the first fuse module is greater than the rated current of the first fuse module and is less than twice of the rated current of the first fuse module; and the actuating mechanism is used for disconnecting the connection between the first end of the first fuse module and the first fuse module so as to disconnect the connection between the direct current source and the inverter circuit. In the embodiment of the invention, the fuse module is fused under the condition that the current is greater than the rated current of the fuse module and less than two times of the rated current, so that the action range of the fuse module is expanded, and the safety of the whole inverter is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to power supply technical field especially relates to a photovoltaic inverter. BACKGROUND

[0002] The photovoltaic inverter usually adopts the fuse to avoid the damage of short circuit or overcurrent to the photovoltaic inverter whole machine.

[0003] However, the fuse used in the photovoltaic inverter may fail to fuse in the case that the short circuit current is small, and further causes damage to the photovoltaic inverter whole machine. SUMMARY

[0004] Based on the above problems, the utility model provides a photovoltaic inverter, expands the action range of the fuse in the photovoltaic inverter, and improves the safety of the photovoltaic inverter whole machine.

[0005] The utility model embodiment discloses the following technical scheme:

[0006] Firstly, the application embodiment provides a photovoltaic inverter, which comprises a first fuse module and an inverter circuit.

[0007] The first end of the first fuse module is used for connecting a direct current source, and the second end of the first fuse module is connected to at least one of the positive input end and the negative input end of the inverter circuit.

[0008] The first fuse module comprises a trigger device and an action mechanism, and the trigger device is connected to the action mechanism.

[0009] The trigger device is used for triggering the action mechanism when the current flowing through the first fuse module is greater than the rated current of the first fuse module and less than or equal to twice the rated current of the first fuse module.

[0010] The action mechanism is used for disconnecting the connection between the first end and the second end of the first fuse module, so as to disconnect the connection between the direct current source and the inverter circuit.

[0011] Optionally, the trigger device comprises a first fuse body.

[0012] The first end of the first fuse body is connected to the first end of the first current-carrying component, the second end of the first fuse body is connected to the first end of the second current-carrying component, the second end of the first current-carrying component and the second end of the second current-carrying component are respectively used as the first end and the second end of the first fuse module, and the first end and the second end of the first fuse body are respectively connected to the first end and the second end of the action mechanism.

[0013] The first melt is configured to melt to trigger the action mechanism when the current flowing through the first fuse module is greater than the rated current of the first fuse module and less than or equal to twice the rated current of the first fuse module.

[0014] Optionally, the action mechanism comprises a first power device and a first active device.

[0015] The first end of the first power device is connected to the first end of the first melt, and the second end of the first power device is connected to the second end of the first melt.

[0016] The first power device is configured to generate an electric arc when the first melt melts, and to push the first active device based on the electric arc.

[0017] The first active device is configured to disconnect the connection between the first end and the second end of the first fuse module, so as to disconnect the connection between the DC source and the inverter circuit.

[0018] Optionally, the trigger device comprises a meltable component.

[0019] The first end of the meltable component is connected to the first end of the second melt, and the second end of the meltable component is connected to the first end of the action mechanism; wherein the second end of the second melt serves as the first end of the first fuse module, and the second end of the action mechanism serves as the second end of the first fuse module.

[0020] The meltable component is configured to melt to trigger the action mechanism when the current flowing through the first fuse module is greater than the rated current of the first fuse module and less than or equal to twice the rated current of the first fuse module.

[0021] Optionally, the action mechanism comprises a second power device and a second active device.

[0022] The first end of the second power device is connected to the first end of the meltable component through the second active device; wherein the second end of the second power device serves as the second end of the power mechanism.

[0023] The second power device is configured to contract when the meltable component melts, so as to displace the second active device.

[0024] The second active device is configured to disconnect the connection between the first end and the second end of the first fuse module, so as to disconnect the connection between the DC source and the inverter circuit.

[0025] Optionally, the power mechanism further comprises a first arc extinguishing device.

[0026] The first arc extinguishing device is connected in parallel with the first current-carrying assembly.

[0027] The first arc extinguishing device is configured to allow current to flow through the first arc extinguishing device in the event that the connection between the first current carrying component and the first fuse is broken.

[0028] Optionally, the first arc extinguishing device further comprises a second arc extinguishing device.

[0029] The first end of the second arc extinguishing device is connected to the second end of the second fuse, and the second end of the second arc extinguishing device is connected to the second end of the second power device.

[0030] The first arc extinguishing device is configured to allow current to flow through the second arc extinguishing device in the event that the connection between the second fuse and the second actuation mechanism is broken.

[0031] Optionally, the first power device comprises a pyrotechnic device, and the first fuse module further comprises a transient voltage suppression diode.

[0032] The first fuse is connected to the pyrotechnic device via the transient voltage suppression diode.

[0033] Optionally, the first fuse module further comprises a resistive device.

[0034] The first fuse is connected to the pyrotechnic device via the resistive device and the transient voltage suppression diode.

[0035] Optionally, the first fuse module comprises at least one of a plurality of parallel fuses and a plurality of series fuses.

[0036] Optionally, the first fuse module further comprises a second fuse module.

[0037] The first end of the first fuse module is configured to be connected to a positive pole of a direct current source, and the second end of the first fuse module is connected to a positive input terminal of an inverter circuit; or the first end of the second fuse module is configured to be connected to a negative pole of the direct current source, and the second end of the second fuse module is connected to a negative input terminal of the inverter circuit.

[0038] The first end of the first fuse module is configured to be connected to a negative pole of a direct current source, and the second end of the first fuse module is connected to a negative input terminal of an inverter circuit; or the first end of the second fuse module is configured to be connected to a positive pole of the direct current source, and the second end of the second fuse module is connected to a positive input terminal of the inverter circuit.

[0039] The second fuse module is configured to break the connection between the direct current source and the inverter circuit in the event that the current flowing through the second fuse module is greater than or equal to twice the rated current of the second fuse module.

[0040] Optionally, the first fuse module further comprises a direct current EMI filter, an alternating current EMI filter, a direct current lightning protection device, an alternating current lightning protection device, and an insulation detection circuit.

[0041] The first end of the DC EMI filter is connected with the first and second fuse modules, the second end of the DC EMI filter is connected with the DC side of the inverter circuit, the AC side of the inverter circuit is connected with the first end of the AC side EMI filter, and the second end of the AC side EMI filter is used for connecting the power grid.

[0042] The DC lightning protection device and the DC insulation detection circuit are connected with the first end of the DC EMI filter, and the AC lightning protection device is connected with the second end of the AC side EMI filter.

[0043] Compared with the photovoltaic inverter in the related art, the fuse module can be fused when the current I flowing through the fuse module is greater than the rated current In of the fuse module, that is, (In BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0045] Figure 1 A structural schematic diagram of a photovoltaic inverter provided by the embodiment of the present application is provided.

[0046] Figure 2 A structural schematic diagram of a fuse module provided by the embodiment of the present application is provided.

[0047] Figure 3 A structural schematic diagram of a fuse provided by the embodiment of the present application is provided.

[0048] Figure 4 Another structural schematic diagram of a fuse provided by the embodiment of the present application is provided.

[0049] Figure 5 An action schematic diagram of a fuse provided by the embodiment of the present application is provided.

[0050] Figure 6 Still another structural schematic diagram of a fuse provided by the embodiment of the present application is provided.

[0051] Figure 7Another structure diagram of a fuse provided by an embodiment of the present application is shown in FIG. 6;

[0052] Figure 8 Another function diagram of a fuse provided by an embodiment of the present application is shown in FIG. 7;

[0053] Figure 9 Another function diagram of a fuse provided by an embodiment of the present application is shown in FIG. 8;

[0054] Figure 10 Another structure diagram of a fuse provided by an embodiment of the present application is shown in FIG. 9;

[0055] Figure 11 Another structure diagram of a photovoltaic inverter provided by an embodiment of the present application is shown in FIG. 10;

[0056] Figure 12 Another structure diagram of a photovoltaic inverter provided by an embodiment of the present application is shown in FIG. 11;

[0057] Figure 13 Another structure diagram of a photovoltaic inverter provided by an embodiment of the present application is shown in FIG. 12. DETAILED DESCRIPTION

[0058] In order to make the person skilled in the art better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art without creative labor fall within the scope of protection of the present application.

[0059] In the specification and claims of the present application, the terms "first" and "second" and the like are used to distinguish different objects, rather than to describe a specific order of the objects. For example, the first fuse module and the second fuse module are used to distinguish different fuse modules, rather than to describe a specific order of the fuse modules.

[0060] In the embodiments of the present application, the words "exemplary" or "for example" are used to mean serving as an example, instance, or illustration, in any non-limiting and non-exhaustive sense. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or advantageous than other embodiments or design schemes. Rather, the use of the words "exemplary" or "for example" is intended to present related concepts in a concrete manner.

[0061] In the related art, the fuse used in the photovoltaic inverter has the risk of continuous arc burning and destroying the whole machine when the short-circuit current is less than twice the rated nominal current (I < 2In).

[0062] To this end, the utility model discloses a photovoltaic inverter, first fuse module and inverter circuit, the first end of first fuse module is used for connecting direct current source, and the second end of first fuse module connects at least one end of positive input end and negative input end of inverter circuit, first fuse module includes trigger device and action mechanism, wherein, trigger device connects action mechanism, trigger device is used for triggering action mechanism in the current that flows through first fuse module is greater than the rated current of first fuse module and less than two times the rated current of first fuse module, and action mechanism is used for disconnecting the connection between the first end of first fuse module and first fuse module, to disconnect the connection between direct current source and inverter circuit, the first fuse module in the application can disconnect the connection between fuse input end and output end in the case that short circuit current is greater than the rated current of fuse module and less than two times the rated current (In < I < 2In), expand the action range of fuse in photovoltaic inverter, improve the safety of photovoltaic inverter whole machine.

[0063] Referring to Figure 1 , the drawing is a structure schematic diagram of a photovoltaic inverter provided by the utility model embodiment.

[0064] As Figure 1 indicated, the photovoltaic inverter includes: first fuse module 100 and inverter circuit 200;

[0065] The first end of first fuse module 100 is used for connecting direct current source, and the second end of first fuse module 100 connects at least one end of positive input end and negative input end of inverter circuit 200.

[0066] It should be understood that the first fuse module 100 in the embodiment of the application has the following three connection modes: the first connection mode, the photovoltaic inverter includes one first fuse module 100, the first end of the first fuse module 100 is connected to the positive electrode DC+ of the direct current source, and the second end of the first fuse module 100 is connected to the positive input end of the inverter circuit 200;The second connection mode, the photovoltaic inverter includes one first fuse module 100, the first end of the first fuse module 100 is connected to the negative electrode DC- of the direct current source, and the second end of the first fuse module 100 is connected to the negative input end of the inverter circuit 200;The third connection mode, the photovoltaic inverter includes two first fuse modules 100, the first end of the first first fuse module 100 is connected to the positive electrode DC+ of the direct current source, and the second end of the first first fuse module 100 is connected to the positive input end of the inverter circuit 200;The first end of the second first fuse module 100 is connected to the negative electrode DC- of the direct current source, and the second end of the second first fuse module 100 is connected to the negative input end of the inverter circuit 200.

[0067] In a possible implementation, the first fuse module includes a plurality of fuses connected in parallel.

[0068] As shown in a, the first fuse module includes a fuse 1, a fuse 2, and a fuse n. Figure 2 When one of the fuses in the first fuse module fails, the other fuses can play a protective role to ensure that the electrical equipment in the circuit will not be damaged by overload or short circuit and the like, and also improve the safety and reliability of the photovoltaic inverter. In addition, the parallel connection of multiple fuses makes the first fuse module suitable for low-voltage and low-current application scenarios.

[0069] In a possible implementation, the first fuse module includes a plurality of fuses connected in series.

[0070] As shown in b, the first fuse module includes a fuse 1, a fuse 2, and a fuse n. Figure 2 When one of the fuses in the first fuse module fails, the other fuses can play a protective role to ensure that the electrical equipment in the circuit will not be damaged by overload or short circuit and the like, and also improve the safety and reliability of the photovoltaic inverter. In addition, the series connection of multiple fuses makes the first fuse module suitable for high-voltage and high-current application scenarios.

[0071] The first fuse module includes a trigger device 110 and an action mechanism 120; wherein the trigger device 110 is connected to the action mechanism 120.

[0072] The trigger device 110 is configured to trigger the action mechanism 120 when the current flowing through the first fuse module 100 is greater than the rated current of the first fuse module 100 and less than twice the rated current of the first fuse module 100; and the action mechanism 120 is configured to disconnect the connection between the first end and the second end of the first fuse module 100 to disconnect the connection between the direct current source and the inverter circuit 200.

[0073] For example, the current flowing through the first fuse module 100 is I, and the rated current of the first fuse module 100 is In. If In < I < 2In, the trigger device 110 in the embodiment of the present application triggers the action mechanism 120, so that the action mechanism 120 disconnects the connection between the first end and the second end of the first fuse module.

[0074] The photovoltaic inverter described in this application embodiment can blow fuses when the current I flowing through the fuse module is greater than the rated current In of the fuse module, but less than twice the rated current 2In of the fuse module (In < I < 2In). This expands the effective range of the fuse module in the photovoltaic inverter, avoids damage to the entire photovoltaic inverter caused by the short-circuit current I (In < I < 2In), and improves the safety of the entire inverter.

[0075] The following description will focus on the two different structures of the fuse in the first fuse module.

[0076] It should be noted that in the accompanying drawings of this application, 1 represents the first end and 2 represents the second end.

[0077] The first structure, the first fuse module 100 includes: a triggering device and an actuation mechanism.

[0078] like Figure 3 As shown, the triggering device 110 includes a first melt 1110; the actuating mechanism 120 includes a first power device 1210 and a first moving device 1220.

[0079] The first end of the first fusible element 1110 is connected to the first end of the first current-carrying component 130, and the second end of the first current-carrying component 130 serves as the first end of the first fuse module 100. The second end of the first fusible element 1110 is connected to the first end of the second current-carrying component 140, and the second end of the second current-carrying component 140 serves as the second end of the first fuse module 100. The first and second ends of the first fusible element 1110 are respectively connected to the first and second ends of the first power device 1210.

[0080] The first fuse 1110 is used to melt the first fuse 1110 when the current flowing through the first fuse module 100 is greater than the rated current of the first fuse module 100 and less than or equal to twice the rated current of the first fuse module 100, by accumulating heat. The first power device 1210 is used to generate an electric arc based on the melting of the first fuse 1110 and to generate a thrust based on the electric arc to drive the first movable device 1220. The first movable device 1220 is used to disconnect the connection between the first end and the second end of the first fuse module 100 based on the thrust, so as to disconnect the connection between the DC source and the inverter circuit.

[0081] In one possible implementation, such as Figure 4 As shown, the first power device 1210 is a gunpowder device, and the first moving part 1220 can be a cone-shaped object.

[0082] For ease of understanding, this application provides a schematic diagram of the function of a fuse, as shown in the embodiment. Figure 5 As shown. In Figure 5In the embodiment, the first fuse melts, so that an arc is generated at two ends of the pyrotechnic device due to a voltage difference, the pyrotechnic device is ignited inside due to the arc, and then the pyrotechnic device explodes to generate a thrust; the thrust drives the conical object to fall, cuts off the current-carrying path (a current path formed by the first fuse, the first current-carrying component and the second current-carrying component), and disconnects the connection between the first end and the second end of the first fuse module, so as to disconnect the connection between the direct current source and the inverter circuit.

[0083] In a possible implementation, the first power device 1210 can be an expansion device. In the embodiment, the first fuse melts, so that an arc is generated at two ends of the expansion device due to a voltage difference, the expansion device is exploded inside due to the arc, and then a thrust is generated; the thrust drives the conical object to fall, cuts off the current-carrying path, and disconnects the connection between the first end and the second end of the first fuse module, so as to disconnect the connection between the direct current source and the inverter circuit 200.

[0084] It should be noted that the first movable device in the foregoing embodiments is only exemplary. In addition to the conical object, other sharp objects such as blades can also be used to cut off the current-carrying path.

[0085] In addition, the embodiment provides another structural diagram of a fuse, as shown in Figure 6 .

[0086] In the embodiment, the fuse is melted when the current I flowing through the fuse module is greater than the rated current In of the fuse module and less than twice the rated current 2In of the fuse module (In < I < 2In), so as to expand the application range of the fuse module in the photovoltaic inverter, avoid the short-circuit current I in the range of In < I < 2In from damaging the photovoltaic inverter, and improve the safety of the inverter.

[0087] Figure 6 The fuse shown in the embodiment includes a first fuse 1110, a first power device 1210, a first movable device 1220, a transient voltage suppression diode 150, a resistor device 160, a first current-carrying component 130, a second current-carrying component 140 and a first arc extinguishing device 170.

[0088] The first end of the first fuse 1110 is connected to the first end of the first current-carrying component 130, the second end of the first fuse 1110 is connected to the first end of the second current-carrying component 140, and the second end of the first current-carrying component 130 and the second end of the second current-carrying component 140 are respectively the first end and the second end of the first fuse module 100; the first end of the first fuse 1110 is connected to the second end of the first fuse 1110 through the first power device 1210, the resistor device 150 and the transient voltage suppression diode 160; and the first arc extinguishing device 170 is connected in parallel with the first current-carrying component 130.

[0089] Exemplarily, the first arc extinguishing device 170 in the embodiment of the present application can be a fuse.

[0090] In the embodiment, the transient voltage suppression diode connected between the first fuse and the first power device can prevent the ignition device in the first power device from failing to ignite due to excessive arc voltage, thereby improving the reliability of the fuse. The ignition device can be a resistance wire.

[0091] Further, the resistor connected in series in the loop between the first fuse and the first power device can prevent the ignition device in the powder device from deteriorating, thereby improving the reliability of the powder device.

[0092] It should be noted that the connection points of the first arc extinguishing device and the first current-carrying component are located on the two sides of the first movable device in the vertical direction, so that after the passage of the first current-carrying component is cut off, the current can flow to the first arc extinguishing device, thereby playing a role in extinguishing the arc and improving the safety of the fuse module by one level of the breaking voltage grade of the fuse module. In addition, in the embodiment, the first fuse module can be applied to a relatively high application scenario of the breaking voltage grade by connecting the first arc extinguishing device in parallel.

[0093] The second structure, the first fuse module 100 includes a trigger device and an action mechanism.

[0094] As shown in Figure 7 The trigger device includes a fusible component 1120, and the action mechanism 120 includes a second power device 1250 and a second movable device 1260. The second end of the second power device 1250 is connected to the second end of the first fuse module 100 and is fixed, and the first end of the second power device 1250 is connected to the first end of the fusible component 1120 through the second movable device 1260. The second end of the second fuse 160 is connected to the first end of the first fuse module 100 and is fixed.

[0095] The fusible component 1120 is used to accumulate heat to melt the fusible component 1120 when the current flowing through the first fuse module 100 is greater than the rated current of the first fuse module 100 and less than twice the rated current of the first fuse module 100. The melting point of the fusible component 1120 is lower than the melting point of the second fuse.

[0096] The second power device 1250 is used to reverse contraction based on the melting of the fusible component 1120, and the second movable device 1260 is used to disconnect the connection between the first end and the second end of the first fuse module 100 based on the reverse contraction of the second movable device, so as to disconnect the connection between the direct current source and the inverter circuit 200.

[0097] Exemplarily, the meltable component 1120 can be low-temperature solder or low-temperature alloy wire or the like. The low-temperature solder and the low-temperature alloy wire have a melting point lower than the melting point of the first and second melts.

[0098] Exemplarily, the second power device 1250 can be a spring or the like, which generates power through deformation.

[0099] In a possible implementation, a structural schematic diagram of the fuse is shown in Figure 8 In Figure 8 , the low-temperature solder (meltable component 1120) melts, disconnecting the connection with the second melt 180; the spring (second power device 1250) reversely contracts the second movable device 1260 based on the melting of the low-temperature solder (meltable component 1120), and disconnects the connection between the first end and the second end of the first fuse module 100 based on the reverse contraction of the spring, to disconnect the connection between the direct-current source and the inverter circuit.

[0100] The photovoltaic inverter provided in the embodiment of the present application melts in the case that the current I flowing through the fuse module is greater than the rated current In of the fuse module and less than twice the rated current 2In of the fuse module (In < I < 2In), thereby expanding the range of the fuse module in the photovoltaic inverter, avoiding the damage of the short-circuit current I (In < I < 2In) to the photovoltaic inverter, and improving the safety of the inverter.

[0101] For the convenience of understanding, another schematic diagram of the action of the fuse is provided in the embodiment of the present application, as shown in Figure 9 .

[0102] In Figure 9 , the second power device 1250 pulls the movable device 1260 to separate from the second melt 180, thereby disconnecting the connection between the first end and the second end of the first fuse module, to disconnect the connection between the direct-current source and the inverter circuit.

[0103] In addition, the embodiment of the present application further provides a fuse, and a corresponding structural schematic diagram is shown in Figure 10 . Figure 10 In , the fuse comprises a meltable component 1120, a second power device 1250, a second movable device 1260, a second melt 180 and a second arc-extinguishing device 190.

[0104] The trigger device includes a fusible component 1120; a second end of the second power device 1250 is connected to a first end of the first fuse module and is fixed, a first end of the second power device 1250 is connected to a first end of the fusible component 1120 through the second movable device 1260, a second end of the fusible component 1120 is connected to a first end of the second fuse 180, and a second end of the second fuse 180 is connected to a second end of the first fuse module and is fixed; the second arc extinguishing device 190 is connected in parallel between the first ends and the second ends of the first fuse module 100 (a first end of the second arc extinguishing device 190 is connected to the first end of the fuse module, that is, the first end of the second arc extinguishing device 190 and the second end of the second fuse 180 are connected to the same terminal, and a second end of the second arc extinguishing device 190 is connected to the second end of the fuse module, that is, the second end of the second arc extinguishing device 190 and the first end of the second power device 1250 are connected to the same terminal).

[0105] For example, the second arc extinguishing device 190 can be a fuse.

[0106] In this embodiment, by connecting the second arc extinguishing device in parallel, the voltage level of the fuse module and the safety of the fuse module can be improved. In addition, the first fuse module can be applied to an application scenario with a relatively high breaking voltage level.

[0107] Referring to Figure 11 , this figure is a structural schematic diagram of another photovoltaic inverter provided by the embodiment of the application.

[0108] As shown in Figure 11 , the photovoltaic inverter includes a first fuse module 100 and a second fuse module 300.

[0109] A first end of the first fuse module 100 is used for connecting a positive electrode DC+ of a direct current source, and a second end of the first fuse module 100 is connected to a positive input end of an inverter circuit 200; a first end of the second fuse module 300 is used for connecting a negative electrode DC- of the direct current source, and a second end of the second fuse module 300 is connected to a negative input end of the inverter circuit.

[0110] The second fuse module 300 is used for disconnecting the connection between the direct current source and the inverter circuit 200 when a current flowing through the second fuse module 300 is greater than or equal to twice the rated current of the second fuse module.

[0111] Referring to Figure 12 , this figure is a structural schematic diagram of still another photovoltaic inverter provided by the embodiment of the application.

[0112] As shown in Figure 12 , the photovoltaic inverter includes a first fuse module 100 and a third fuse module 400.

[0113] The first end of the first fuse module 100 is used for connecting the negative pole DC- of the DC power source, and the second end of the first fuse module 100 is connected to the negative input end of the inverter circuit 200; the first end of the third fuse module 400 is used for connecting the positive pole DC+ of the DC power source, and the second end of the third fuse module 400 is connected to the positive input end of the inverter circuit.

[0114] The third fuse module 400 is used for disconnecting the connection between the DC power source and the inverter circuit 200 when the current flowing through the third fuse module 400 is greater than or equal to twice the rated current of the second fuse module.

[0115] Referring to Figure 13 , the figure is a structure schematic diagram of another photovoltaic inverter provided by the embodiment of the application.

[0116] As Figure 13 shown, the photovoltaic inverter comprises a first fuse module 100, a second fuse module 300, an inverter circuit 200, a DC lightning protector 500, a DC insulation detection circuit 600, a DC EMI filter 700, an AC EMI filter 800 and an AC lightning protector 900.

[0117] The first end of the first fuse module 100 is used for connecting the positive pole DC+ of the DC power source, and the second end of the first fuse module 100 is connected to the positive input end of the DC EMI filter 700; the first end of the second fuse module 300 is used for connecting the negative pole DC- of the DC power source, and the second end of the second fuse module 300 is connected to the negative input end of the DC EMI filter 700; the output end of the DC EMI filter 700 is connected to the DC side of the inverter circuit 200, and the AC side of the inverter circuit 200 is connected to the first end of the AC EMI filter 800; the second end of the AC EMI filter 800 is used for connecting the power grid; wherein the DC lightning protector 500 and the DC insulation detection circuit 600 are connected to the input end of the DC EMI filter (the first end of the DC lightning protector 500 is connected to the output end of the first fuse module 100, and the second end of the DC lightning protector 500 is connected to the output end of the second fuse module 300; the first end of the DC insulation detection circuit 600 is connected to the output end of the first fuse module 100, and the second end of the DC insulation detection circuit 600 is connected to the output end of the second fuse module 300); the AC lightning protector 900 is connected to the output end of the AC EMI filter 900 (the three phases of the AC lightning protector 900 are respectively connected to the three-phase output ends of the AC EMI filter 800).

[0118] The DC lightning protector 500 can prevent overvoltage of the DC power source, protect the safety of the equipment, and avoid damage of the equipment caused by short circuit and grounding fault due to lightning; the AC lightning protector 1000 can protect various electrical equipment in the converter station from damage caused by overvoltage.

[0119] The direct current side insulation detection circuit 600 can discover insulation failure and potential hidden dangers in time, further reduce equipment damage and power grid failure rate, and thus achieve the purpose of improving the reliability, stability and safety of the power system.

[0120] The direct current side EMI filter 700 can inhibit the propagation of electromagnetic interference signals and ensure the normal operation of the equipment or system.

[0121] The alternating current side EMI filter 800 can eliminate high-frequency noise on the power line and thus ensure the stable operation of the equipment.

[0122] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A photovoltaic inverter, characterized in that The utility model relates to a DC-AC converter, comprising: a first fuse module and an inverter circuit; a first end of the first fuse module is used for connecting a DC source, and a second end of the first fuse module is connected to at least one of a positive input end and a negative input end of the inverter circuit; the first fuse module comprises a trigger device and an action mechanism, and the trigger device is connected to the action mechanism; the trigger device is used for triggering the action mechanism when a current flowing through the first fuse module is greater than a rated current of the first fuse module and less than or equal to twice the rated current of the first fuse module; the action mechanism is used for disconnecting the connection between the first end and the second end of the first fuse module to disconnect the connection between the DC source and the inverter circuit.

2. The photovoltaic inverter of claim 1, wherein, the trigger device comprises a first fuse body; a first end of the first fuse body is connected to a first end of a first current-carrying component, a second end of the first fuse body is connected to a first end of a second current-carrying component, a second end of the first current-carrying component and a second end of the second current-carrying component are respectively used as the first end and the second end of the first fuse module, and the first end and the second end of the first fuse body are respectively connected to a first end and a second end of the action mechanism; the first fuse body is used for fusing when the current flowing through the first fuse module is greater than the rated current of the first fuse module and less than or equal to twice the rated current of the first fuse module to trigger the action mechanism.

3. The photovoltaic inverter of claim 2, wherein, the action mechanism comprises a first power device and a first movable device; a first end of the first power device is connected to a first end of the first fuse body, and a second end of the first power device is connected to a second end of the first fuse body; the first power device is used for generating an electric arc when the first fuse body fuses and pushing the first movable device based on the electric arc; the first movable device is used for disconnecting the connection between the first end and the second end of the first fuse module to disconnect the connection between the DC source and the inverter circuit.

4. The photovoltaic inverter of claim 1, wherein, the trigger device comprises a fusible component; a first end of the fusible component is connected to a first end of a second fuse body, and a second end of the fusible component is connected to a first end of the action mechanism; wherein a second end of the second fuse body is used as the first end of the first fuse module, and a second end of the action mechanism is used as the second end of the first fuse module; the fusible component is used for fusing when the current flowing through the first fuse module is greater than the rated current of the first fuse module and less than or equal to twice the rated current of the first fuse module to trigger the action mechanism.

5. The photovoltaic inverter of claim 4, wherein, the action mechanism comprises a second power device and a second movable device; a first end of the second power device is connected to a second end of the fusible component through the second movable device; wherein a second end of the second power device is used as the second end of the action mechanism; the second power device is used for reversely shrinking when the fusible component fuses to displace the second movable device. The second active device is configured to disconnect the connection between the first end and the second end of the first fuse module, so as to disconnect the connection between the direct current source and the inverter circuit.

6. The photovoltaic inverter of claim 3, wherein, Further comprising: The first arc extinguishing device; The first arc extinguishing device is connected in parallel across the first current-carrying component; The first arc extinguishing device is configured to allow current to flow through the first arc extinguishing device in the case that the connection between the first current-carrying component and the first fuse body is disconnected.

7. The photovoltaic inverter of claim 5, wherein, Further comprising: The second arc extinguishing device; The second arc extinguishing device is connected in parallel across the first fuse module; The second arc extinguishing device is configured to allow current to flow through the second arc extinguishing device in the case that the connection between the second fuse body and the action mechanism is disconnected.

8. The photovoltaic inverter of claim 3, wherein, The first power device comprises a powder device, and the first fuse module further comprises a transient voltage suppression diode; The first fuse body is connected to the powder device through the transient voltage suppression diode.

9. The photovoltaic inverter of claim 8, wherein, The first fuse module further comprises a resistor device; The first fuse body is connected to the powder device through the resistor device and the transient voltage suppression diode.

10. The photovoltaic inverter according to any of claims 1 to 9, characterized in that The first fuse module comprises at least one of a plurality of parallel fuses and a plurality of series fuses.

11. The photovoltaic inverter of claim 10, wherein, Further comprising: The second fuse module; The first end of the first fuse module is configured to be connected to the positive pole of the direct current source, and the second end of the first fuse module is connected to the positive input end of the inverter circuit; The first end of the second fuse module is configured to be connected to the negative pole of the direct current source, and the second end of the second fuse module is connected to the negative input end of the inverter circuit, or The first end of the first fuse module is configured to be connected to the negative pole of the direct current source, and the second end of the first fuse module is connected to the negative input end of the inverter circuit; the first end of the second fuse module is configured to be connected to the positive pole of the direct current source, and the second end of the second fuse module is connected to the positive input end of the inverter circuit; The second fuse module is configured to disconnect the connection between the direct current source and the inverter circuit in the case that the current flowing through the second fuse module is greater than or equal to twice the rated current of the second fuse module.

12. The photovoltaic inverter of claim 11, wherein, Further comprising: A direct current EMI filter, an alternating current EMI filter, a direct current lightning protection device, an alternating current lightning protection device, and an insulation detection circuit; The first end of the direct current EMI filter is connected to the first fuse module and the second fuse module, the second end of the direct current EMI filter is connected to the direct current side of the inverter circuit, the alternating current side of the inverter circuit is connected to the first end of the alternating current EMI filter, and the second end of the alternating current EMI filter is configured to be connected to a power grid; The direct current lightning protection device and the insulation detection circuit are connected to the first end of the direct current EMI filter, and the alternating current lightning protection device is connected to the second end of the alternating current EMI filter.

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