Short-circuit protection system of photovoltaic inverter, photovoltaic inverter system and optical storage system

Abstract

The invention belongs to the technical field of short-circuit protection of photovoltaic inverters, and particularly relates to a short-circuit protection system of a photovoltaic inverter, a photovoltaic inverter system and an optical storage system. The short-circuit protection system of the photovoltaic inverter comprises at least two photovoltaic power supplies which are connected in parallel and are used for outputting a direct-current source; the boosting module comprises at least two boosting units, and the input end of each boosting unit is electrically connected with the output end of the corresponding photovoltaic power supply so as to improve the output voltage of the boosting unit and transmit the output voltage to the inverter; the photovoltaic power supply protection module is connected to the input line / output line of the boosting unit or the output bus of the boosting module and is used for controlling the connection or disconnection of the line; the photovoltaic power supply protection module comprises a current detection unit which is connected in series with an output bus and is used for detecting the magnitude of the current on the output bus; and the output cut-off unit is used for controlling on and off of the input line / output line or the output bus of the boosting unit.

Description

Technical Field

[0001] The present invention belongs to the technical field of short-circuit protection of photovoltaic inverters, and in particular relates to a short-circuit protection system of a photovoltaic inverter, a photovoltaic inverter system, and a photovoltaic storage system. Background Art

[0002] Photovoltaic inverters are inverters that can convert the variable DC voltage generated by photovoltaic (PV) solar panels into AC power at the mains frequency, which can be fed back to the commercial power transmission system or used for off-grid power grids. Photovoltaic inverters are one of the important system balancers in photovoltaic array systems and can be used with general AC-powered equipment. Solar photovoltaic inverters have special functions for photovoltaic arrays, such as maximum power point tracking and islanding protection.

[0003] Traditional solar photovoltaic inverters have no internal PV DC input devices. Usually, when the internal devices fail, a short circuit fault will occur, which will cause the PV DC input to have a continuous short circuit and burn the panel, resulting in rapid aging, decay and damage of the photovoltaic panel. At the same time, due to the internal short circuit of the inverter, components may burn and explode, and even worse, fire and other safety accidents may occur due to excessive current. Summary of the invention

[0004] In view of the shortcomings of the prior art described above, an object of the present invention is to provide a short-circuit protection system for a photovoltaic inverter, which is used to cut off the output circuit of the photovoltaic power supply, thereby effectively preventing the spread of faults or accidents and the problem of continuous burning of photovoltaic power supply boards due to short circuit.

[0005] To achieve the above-mentioned purpose and other related purposes, the present invention provides a short-circuit protection system for a photovoltaic inverter, comprising: at least two photovoltaic power sources connected in parallel for outputting a direct current source; a boost module comprising at least two boost units, and the input end of each of the boost units is electrically connected to the output end of the corresponding photovoltaic power source to increase its output voltage and transmit it to an inverter; a photovoltaic power protection module connected to the input line / output line of the boost unit, or the output bus of the boost module, for controlling the conduction or disconnection of the line; wherein the photovoltaic power protection module comprises: a current detection unit connected in series to the output bus, for detecting the current on the output bus; and an output cutoff unit, for controlling the conduction and disconnection of the input line / output line of the boost unit, or the output bus.

[0006] According to a specific embodiment of the present invention, the photovoltaic power protection module further includes: a short circuit control unit, which is used to control the output cut-off unit to work according to the detection result of the current detection unit.

[0007] According to a specific embodiment of the present invention, the positive output end of the photovoltaic power source is connected to the positive line of the input line of the boost unit, and the negative output end is connected to the negative line of the input line of the boost unit; the negative lines of the output lines of all the boost units are collected into a negative bus of the output bus, and the positive lines of the output lines of all the boost units are collected into a positive bus of the output bus.

[0008] According to a specific embodiment of the present invention, the output disconnection unit is provided on the negative line of at least one of the input lines and / or the negative bus.

[0009] According to a specific embodiment of the present invention, if there is a negative line of the input line that is not provided with the output cut-off unit, the negative output terminal of the photovoltaic power supply corresponding to the negative line without the output cut-off unit is short-circuited to the negative output terminal of the photovoltaic power supply corresponding to the negative line with the output cut-off unit, so that the conduction and shutdown of the negative line without the output cut-off unit can be controlled by the output cut-off unit on the negative line with the output cut-off unit.

[0010] According to a specific embodiment of the present invention, the output cutoff unit is also provided on the positive line or the negative line of the output line.

[0011] According to a specific embodiment of the present invention, the output cut-off unit is provided on the positive line of each of the input lines.

[0012] According to a specific embodiment of the present invention, an output cutoff unit is provided on the negative line of the input line, the positive line / negative line of the output line, or the positive bus / negative bus.

[0013] According to a specific embodiment of the present invention, the output cut-off unit adopts an electromagnetic relay, a DC / AC contactor, an IGBT tube or a MOSFET tube.

[0014] A photovoltaic inverter system comprises the short-circuit protection system of the photovoltaic inverter described above, and an inverter module, the input end of which is electrically connected to the output bus of the boost module in the short-circuit protection system of the photovoltaic inverter, and is used to convert the DC source transmitted by the boost module into an AC source and transmit it to a power grid.

[0015] A photovoltaic storage system comprises the photovoltaic inverter system described above.

[0016] The present invention is to avoid the failure of the DC side components in the inverter system, which causes the input voltage of the inverter to be reversely loaded to both ends of the photovoltaic power supply, resulting in the short-circuit current continuously burning the photovoltaic power supply, greatly reducing the service life of the photovoltaic panel, and even causing safety accidents. Therefore, by setting an output switching unit between the photovoltaic power supply and its corresponding boost unit, when a short-circuit current occurs, its conduction loop is cut off in time to prevent the short-circuit current from flowing to the photovoltaic power supply. Furthermore, in order to protect the entire DC side, the output cut-off unit can also be set at the output end of the DC side, which greatly reduces the loss of the short-circuit current to the DC side. The present invention effectively prevents the problem of continuous burning of the photovoltaic power supply due to short circuit and the spread of faults or accidents, and correspondingly improves the service life of the photovoltaic panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic structural diagram of a specific embodiment of a short-circuit protection system for a photovoltaic inverter provided by the present invention;

[0018] Figure 2 A circuit schematic diagram of a first specific embodiment of a short-circuit protection system for a photovoltaic inverter provided by the present invention;

[0019] Figure 3 A circuit schematic diagram of a second specific embodiment of a short-circuit protection system for a photovoltaic inverter provided by the present invention;

[0020] Figure 4 A circuit schematic diagram of a third specific embodiment of a short-circuit protection system for a photovoltaic inverter provided by the present invention;

[0021] Figure 5 A circuit schematic diagram of a fourth specific embodiment of a short-circuit protection system for a photovoltaic inverter provided by the present invention;

[0022] Figure 6 A circuit schematic diagram of a fifth specific embodiment of a short-circuit protection system for a photovoltaic inverter provided by the present invention;

[0023] Figure 7 A circuit schematic diagram of a sixth specific embodiment of a short-circuit protection system for a photovoltaic inverter provided by the present invention;

[0024] Figure 8 A circuit schematic diagram of a seventh specific embodiment of a short-circuit protection system for a photovoltaic inverter provided by the present invention;

[0025] Fig. 9 A circuit schematic diagram of an eighth specific embodiment of a short-circuit protection system for a photovoltaic inverter provided by the present invention;

[0026] Fig.10A circuit schematic diagram of a ninth specific embodiment of a short-circuit protection system for a photovoltaic inverter provided by the present invention;

[0027] Fig.11 The present invention provides a circuit diagram of a photovoltaic inverter system according to a specific embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0029] It should be noted that the illustrations provided in the following embodiments are only used to illustrate the basic concept of the present invention in a schematic manner, and thus the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0030] First of all, it should be noted that in order to enable those skilled in the art to better understand the present application, some professional terms in the embodiments of the present application are explained accordingly.

[0031] Photovoltaic power source uses the principle of photovoltaic effect to directly convert solar energy into electrical energy through photovoltaic panels. The direct current generated by the photovoltaic power source is converted into alternating current that meets the requirements of the municipal power grid through a grid-connected inverter and then directly connected to the public power grid.

[0032] Example 1

[0033] See also Figure 1 , 2As shown, a short-circuit protection system for a photovoltaic inverter includes: at least two photovoltaic power sources 10 are set in parallel to output DC sources to increase the output current. In this embodiment, two photovoltaic power sources 10 are connected in parallel to output DC power to the inverter. Specifically, multiple photovoltaic power sources 10 can be set in parallel to output DC power according to actual needs, which all belong to the protection scope of this embodiment. At the same time, since the output voltage of the DC source is relatively small, it is necessary to boost the output voltage thereof, and transmit the boosted DC voltage to the inverter. Therefore, a boost module 20 is also included, and the boost module 20 includes at least two boost units 21, and each boost unit 21 is connected to a photovoltaic power source 10 to increase the output voltage of each photovoltaic power source 10. Among them, the positive output end of the photovoltaic power source 10 is connected to the positive line of the input line of the boost unit 21, and the negative output end is connected to the negative line of the input line of the boost unit 21. The negative lines of the output lines of all the boost units 21 are gathered into a negative bus of the output bus, and the positive lines of the output lines of all the boost units 21 are gathered into a positive bus of the output bus.

[0034] Specifically, in this embodiment, the boost unit 21 is preferably a BOOST boost circuit, and the input end of the BOOST boost circuit is connected to the output end of the photovoltaic power source 10, and the output end is used to connect the inverter to achieve boosting and direct current transmission. However, in the traditional photovoltaic inverter system, no segmented device is set between the photovoltaic power source and the BOOST boost circuit. When the switch tube in the BOOST boost circuit fails, a short circuit fault will occur, so that the energy storage capacitor at the input end of the inverter reversely charges the photovoltaic power source, thereby causing the photovoltaic panel to continue to burn, accelerating the aging and decay of the photovoltaic panel life and even damage. What's more, due to the excessive short circuit circuit, safety accidents such as fire are caused.

[0035] Therefore, in this embodiment, a photovoltaic power protection module 30 is provided to effectively prevent the occurrence of faults and accidents. The photovoltaic power protection module 30 is connected to the input line / output line of the boost unit 21, or the output bus of the boost module 20, so as to timely cut off the line between the photovoltaic power source 10 and the boost module 20 to prevent the short-circuit current from flowing to the photovoltaic power source 10. Specifically, the photovoltaic power protection module 30 includes: a current detection unit, which is connected in series to the output bus of the boost module 20 to detect the change value of the current on the output bus. In this embodiment, the current detection unit adopts a current sensor, which is connected in series to the negative bus of the output bus to detect whether the current value on the negative bus exceeds a preset threshold. An output cut-off unit is used to control the conduction and disconnection of the input line / output line of the boost unit 21, or the output bus, so as to timely cut off the line between the photovoltaic power source 10 and the boost unit 21 when a short-circuit current occurs, so as to prevent the short-circuit current from flowing to the photovoltaic power source 10. A short-circuit control unit is used to control the output cut-off unit to work according to the detection result of the current detection unit. In this embodiment, the short-circuit control unit can be a comparator or an MCU control chip, which is connected to the current detection unit. When the current value collected by the current detection unit exceeds a preset threshold, a control signal is sent to the output cut-off unit to cut off the line at its location. Correspondingly, the output cut-off unit can be a switch tube, whose control electrode is connected to the output end of the short-circuit control unit, and the short-circuit control unit can control the on and off of the switch tube by outputting high and low level signals. It should be noted that the output cut-off unit is not limited to the switch tube described in this embodiment, and components that can control the on and off of the line are all within the protection scope, such as electromagnetic relays, DC / AC contactors, etc. The switch tube can also be an IGBT tube or a MOSFET tube.

[0036] Wherein, the output cut-off unit is at least arranged on the negative line of the input line of the boost unit, such as Figure 2 As shown, the output cut-off unit K1 is connected in series between the negative output terminal of the photovoltaic power source 10 and the negative input terminal of the boost unit 21. And because the current detection unit R1 detects the current on the negative bus of the boost module 20, and it is necessary to cut off the line between each photovoltaic power source 10 and the boost unit 21, the negative output terminal of another photovoltaic power source 10 is short-circuited to the negative output terminal of the photovoltaic power source 10 provided with the output cut-off unit K1, so that two photovoltaic power sources 10 can share one output cut-off unit K1. Preferably, as Figure 2As shown, the negative output terminal of another photovoltaic power source 10 is short-circuited to the rear side of the output cut-off unit K1. If it is short-circuited to the front side of the output cut-off unit K1, the output cut-off unit K1 will be short-circuited, making it unable to control the conduction and disconnection of the input line between the photovoltaic power source 10 and the boost unit 21.

[0037] It should be noted that the above is only a specific embodiment, and the number of photovoltaic power sources 10 and boost units 21 can be set according to actual needs; accordingly, the number of output cut-off units can also be set according to actual costs, and the output switching unit is provided on the negative line of at least one of the input lines and / or the negative bus, and if there is a negative line of the input line without the output cut-off unit, the negative output end of the photovoltaic power source 10 corresponding to the negative line without the output cut-off unit is short-circuited to the negative output end of the photovoltaic power source 10 corresponding to the negative line with the output cut-off unit, so that the conduction and shutdown of the negative line without the output cut-off unit can be controlled by the output cut-off unit on the negative line with the output cut-off unit. For example, in a specific embodiment, three photovoltaic power sources 10 and corresponding three boost units 21 are provided. At this time, only the negative lines of the input lines of two boost units 21 are provided with output disconnection units. Then, the negative input terminal of the photovoltaic power source 10 corresponding to the output disconnection unit is short-circuited to the negative input terminal of any photovoltaic power source 10 corresponding to the output disconnection unit, so that the output disconnection unit of other photovoltaic power sources 10 can be shared, thereby disconnecting the circuit between the photovoltaic power source 10 and the corresponding boost unit 21.

[0038] In a specific embodiment, if Figure 3 , 4 As shown in FIG. 6 , an output switching unit may be added to the positive line of the input line of the boost unit 21 to prevent short-circuit current from flowing through the photovoltaic power source 10 and causing it to be charged, thereby threatening the safety of maintenance personnel and even damaging the circuit structure of the photovoltaic power source 10. Figure 3 , 4 As shown, on the basis that the negative line of the input line of the boost unit 21 is provided with an output cut-off unit K1, an output cut-off unit K2 can be added to the positive line of the input line of any boost unit 21, and can be specifically set according to the importance of each photovoltaic power source 10 and the actual consumption cost. For example, if the two photovoltaic power sources 10 are a brand new photovoltaic power source and an old photovoltaic power source, the output cut-off unit K2 can be set on the positive line of the input line of the corresponding boost unit 21 of the new photovoltaic power source to protect it, without spending more cost to add an output cut-off unit to the positive line of the input line of the corresponding boost unit 21 of the old photovoltaic power source. Preferably, as Figure 6As shown, an output cut-off unit is provided on the positive line of the input line of the corresponding boost unit of each photovoltaic power source 10, so as to protect each photovoltaic power source to the maximum extent and avoid the phenomenon of photovoltaic panel burning.

[0039] Further, if Figure 5 As shown, an output cut-off unit may also be additionally provided on the output line of the boost unit 21. Specifically, the output cut-off unit K2 is not limited to being provided on the positive line of the output line of the boost unit 21, but may also be provided on the negative line of the output line of the boost unit 21. The output cut-off unit is provided on the output line of the boost unit 21 to prevent the short-circuit current from forming a loop inside the boost unit 21, i.e., the BOOST boost circuit, thereby damaging the components therein and causing losses. In this embodiment, it is preferably provided on the positive line of the output line of the boost unit 21 to prevent the short-circuit current from flowing through the inside of the BOOST boost circuit, causing the components therein to be charged and posing a threat to the safety of maintenance personnel.

[0040] In a specific embodiment, if Figure 7 , 8 As shown in Figures 9 and 10, the output cut-off unit is arranged on the output bus of the boost module 20 to directly cut off the impact of the short-circuit current on the DC side. Preferably, in this embodiment, the output cut-off unit K2 is arranged on the negative bus of the output bus of the boost module 20, so as to be arranged on the same side as the current detection unit R1, so as to react more quickly according to the detection result of the current detection unit R1, thereby cutting off the connection line and greatly reducing the impact caused by the short-circuit current. And since the output cut-off unit K2 is arranged on the output bus of the boost module 20, as shown in Figures 9 and 10, the output cut-off unit K2 is arranged on the negative bus of the output bus of the boost module 20, so as to directly cut off the impact of the short-circuit current on the DC side. Figure 7 , 8 As shown, the short-circuit cut-off unit K1 can be arbitrarily set on the positive line or negative line of the input line of the boost unit 21, in order to strengthen the protection of the photovoltaic power source 10. Among them, the output cut-off unit K2 is mainly used to protect the entire DC side to avoid being affected by the short-circuit current. The main purpose of this embodiment is to protect the photovoltaic power source 10. Therefore, when the current detection unit R1 detects the short-circuit current, K1 and K2 are disconnected in turn to give priority to protecting the photovoltaic power source 10, and then to avoid the short-circuit current from damaging the components in the boost module 20, thereby reducing the loss of the circuit. Further, as Fig. 9 As shown, it is preferred that an output cut-off unit K3 is provided on the negative bus of the output bus of the boost module 20, and output cut-off units K2 and K1 are provided on the positive line and negative line of the input line of the boost unit 21, respectively, so as to comprehensively protect the circuit structure and reduce the harm and impact caused by the short-circuit current.

[0041] In a specific embodiment, if Fig.10As shown, if the negative line of the input line of the boost unit 21 is not provided with an output cut-off unit, at least the positive line of each input line is provided with an output cut-off unit. Since the positive output terminals of the photovoltaic power source 10 cannot be short-circuited, in order to protect each photovoltaic power source, an output cut-off unit must be provided for each photovoltaic power source to cut off the line between the photovoltaic power source 10 and the boost unit 21. Fig.10 As shown, the positive lines of the input lines of the two photovoltaic power sources 10 corresponding to the boost units 21 are respectively provided with output disconnection units K1 and K2, and on this basis, an output disconnection unit can be further provided on the negative line of the input line of the boost unit 21 or on the output line to enhance the protection effect on the DC side. And since the output disconnection unit is provided on the positive line of the input line of each boost unit 21, when the output disconnection unit is provided on the negative line of the input line, the negative output terminals of the photovoltaic power source 10 do not need to be short-circuited.

[0042] It should be noted that the above are only some embodiments provided herein. This application mainly cuts off the output line of the photovoltaic power source according to the detection of the short-circuit current to avoid the short-circuit current from causing harm to the photovoltaic power source and reducing its service life. Therefore, the setting position of the output cut-off unit is within the protection scope of this application.

[0043] Example 2

[0044] See also Fig.11 As shown, this embodiment also provides a photovoltaic inverter system, including: at least two photovoltaic power sources 10, a boost module 20, a photovoltaic power protection module 30 and an inverter module 40. The boost module also includes at least two boost units 21, and the boost unit 21 is set corresponding to the photovoltaic power source 10.

[0045] In this embodiment, if Fig.11 As shown, the photovoltaic power sources 10 are still arranged in parallel, and the output end of each photovoltaic power source 10 is connected to the input end of the boost unit 21, the output end of the boost unit 21 is connected to the input end of the inverter module 40, and the output end of the inverter module 40 is connected to the power grid to convert the DC power on the DC side into AC power and transmit it to the power grid.

[0046] Among them, the current detection unit R1 of the photovoltaic power protection module 30 is connected in series between the negative output end of the boost module 20 and the negative input end of the inverter module 40; the output cut-off unit K1 is connected in series between the negative output end of the photovoltaic power source 10 and the negative input end of its corresponding boost unit 21; the short-circuit control unit (not shown in the figure) is electrically connected to the current detection unit R1 and the output cut-off unit K1, respectively.

[0047] It should be noted that the boost unit described in this embodiment is a BOOST boost circuit based on the boost unit, and the inverter module 40 is also only a basic inverter circuit. The technical problems solved and the technical means proposed are not limited to the basic circuit described above, and modules with the same functions all fall within the protection scope of this application.

[0048] In a specific embodiment, if Fig.11 As shown, the boost unit 21 includes: capacitors C1, C2, diodes D1, D2, inductor L5, and switch tube Q7. Among them, the two ends of capacitor C1 are respectively connected to the positive and negative electrodes of the photovoltaic power source 10; one end of inductor L5 is respectively connected to one end of capacitor C1 and the positive electrode of photovoltaic power source 10, and the other end is respectively connected to the anode of diode D2 and the emitter of switch tube Q7; the collector of switch tube Q7 is respectively connected to the other end of capacitor C1 and the negative electrode of photovoltaic power source 10, and the base is used to connect the control chip; one end of capacitor C2 is connected to the cathode of diode D2, and the other end is connected to the collector of switch tube Q7; the anode of diode D1 is connected to the positive electrode of photovoltaic power source 10, and the other end is connected to one end of capacitor C2. Among them, the two ends of capacitor C2 serve as the output ends of the boost unit. Another boost unit 21 includes: capacitors C3, C4, diodes D4, D5, inductor L6, and switch tube Q78, and the circuit structure is the same as described above, which will not be described in detail here. Further, the positive output ends of the two boost units 21 are connected to the positive input ends of the inverter module 40, and the negative output ends are connected to the negative input ends of the inverter module 40. The inverter module includes: capacitor C6, and switch tubes Q1, Q2, Q3, and Q4. Among them, the two ends of capacitor C6 are respectively connected to the positive output end and the negative output end of the boost module; the emitter of switch tube Q1 is connected to one end of capacitor C6, and the collector is connected to the emitter of switch tube Q3; the collector of switch tube Q3 is connected to the other end of capacitor C6; the emitter of switch tube Q2 is respectively connected to one end of capacitor C6 and the emitter of switch tube Q1, and the collector is connected to the emitter of switch tube Q4; the collector of switch tube Q4 is respectively connected to the other end of capacitor C6 and the collector of switch tube Q3; and the bases of the switches Q1, Q2, Q3, and Q4 are all connected to the control chip. The positive pole of the grid is connected between the collector of the switch tube Q1 and the emitter of the switch tube Q3, and the negative pole is connected between the collector of the switch tube Q2 and the emitter of the switch tube Q4 to obtain alternating current.

[0049] Example 3

[0050] This embodiment also provides a photovoltaic storage system including the photovoltaic inverter system described above, so as to convert solar energy into electrical energy for use.

[0051] In summary, the present invention is to avoid the failure of the DC side components in the inverter system, which causes the input voltage of the inverter to be reversely loaded to both ends of the photovoltaic power supply, resulting in the short-circuit current continuously burning the photovoltaic power supply, greatly reducing the service life of the photovoltaic panel, and even causing safety accidents. Therefore, by setting an output switching unit between the photovoltaic power supply and its corresponding boost unit, when a short-circuit current occurs, its conduction loop is cut off in time to prevent the short-circuit current from flowing to the photovoltaic power supply. Furthermore, in order to protect the entire DC side, the output cut-off unit can also be set at the output end of the DC side, which greatly reduces the loss of the short-circuit current to the DC side. The present invention effectively prevents the problem of continuous burning of the photovoltaic power supply due to short circuit and the spread of faults or accidents, and correspondingly improves the service life of the photovoltaic panel.

[0052] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

[0053] In the description herein, many specific details, such as examples of components and / or methods, are provided to provide a complete understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more of the specific details or with other devices, systems, components, methods, components, materials, parts, etc. In other cases, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

[0054] References throughout this specification to "one embodiment," "an embodiment," or "a specific embodiment" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention, and not necessarily in all embodiments. Thus, various appearances of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout this specification do not necessarily refer to the same embodiment. In addition, the particular features, structures, or characteristics of any specific embodiment of the invention may be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the invention described and illustrated herein may be possible in light of the teachings herein and are to be considered part of the spirit and scope of the invention.

[0055] It should also be understood that one or more of the elements shown in the figures may also be implemented in a more separate or more integrated manner, or even removed because they are inoperable in certain circumstances or provided because they may be useful depending on the application.

[0056] In addition, unless otherwise explicitly indicated, any marking arrows in the drawings should be regarded as exemplary only and not limiting. In addition, unless otherwise indicated, the term "or" used herein is generally intended to mean "and / or". In the case where the term is not clear because it is anticipated that the ability to separate or combine is provided, the combination of components or steps will also be regarded as indicated.

[0057] As used in the description herein and throughout the claims that follow, "a", "an", and "the" include plural references unless otherwise indicated. Likewise, as used in the description herein and throughout the claims that follow, the meaning of "in" includes "in" and "on" unless otherwise indicated.

[0058] The above description of the illustrated embodiments of the present invention (including the contents described in the Abstract) is not intended to be an exhaustive list or to limit the present invention to the precise form disclosed herein. Although specific embodiments of the present invention and examples of the present invention are described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the present invention as will be recognized and appreciated by those skilled in the art. As noted, these modifications may be made to the present invention in accordance with the above description of the embodiments described in the present invention, and these modifications will be within the spirit and scope of the present invention.

[0059] Systems and methods have been generally described herein as details that aid in understanding the present invention. In addition, various specific details have been given to provide an overall understanding of embodiments of the present invention. However, those skilled in the relevant art will recognize that embodiments of the present invention may be practiced without one or more of the specific details, or may be practiced using other devices, systems, accessories, methods, components, materials, parts, etc. In other cases, well-known structures, materials, and / or operations are not specifically shown or described in detail to avoid confusion with various aspects of embodiments of the present invention.

[0060] Thus, although the invention has been described herein with reference to specific embodiments thereof, freedom of modification, various changes and substitutions are also within the foregoing disclosure, and it should be understood that in some cases, some features of the invention will be employed without the corresponding use of other features without departing from the scope and spirit of the proposed invention. Thus, many modifications may be made to adapt a particular environment or material to the essential scope and spirit of the invention. The invention is not intended to be limited to the specific terms used in the claims below and / or the specific embodiments disclosed as the best mode contemplated for carrying out the invention, but the invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Thus, the scope of the invention will be determined solely by the appended claims.

Claims

1. A short-circuit protection system for a photovoltaic inverter, characterized in that: include: At least two photovoltaic power sources are connected in parallel to output a DC source; A boost module, comprising at least two boost units, wherein the input end of each boost unit is electrically connected to the output end of the photovoltaic power source corresponding thereto, so as to increase the output voltage thereof and transmit it to the inverter; A photovoltaic power supply protection module, connected to the input line / output line of the boost unit, or the output bus of the boost module, for controlling the on or off of the line; Wherein, the photovoltaic power supply protection module comprises: A current detection unit, connected in series to the output bus, for detecting the magnitude of the current on the output bus; The output cut-off unit is used to control the input line / output line of the boost unit, or the on and off of the output bus.

2. The short-circuit protection system for photovoltaic inverter according to claim 1, characterized in that: The photovoltaic power supply protection module also includes: A short circuit control unit is used to control the output cut-off unit to operate according to the detection result of the current detection unit.

3. The short-circuit protection system for photovoltaic inverter according to claim 1, characterized in that: The positive output end of the photovoltaic power source is connected to the positive line of the input line of the boost unit, and the negative output end is connected to the negative line of the input line of the boost unit; the negative lines of the output lines of all the boost units are collected into a negative bus of the output bus, and the positive lines of the output lines of all the boost units are collected into a positive bus of the output bus.

4. The short-circuit protection system for photovoltaic inverter according to claim 3, characterized in that: The output disconnection unit is provided on the negative electrode line of at least one of the input lines and / or the negative electrode bus.

5. The short-circuit protection system for photovoltaic inverter according to claim 4, characterized in that: If there is a negative line of the input line that is not provided with the output cut-off unit, the negative output end of the photovoltaic power supply corresponding to the negative line without the output cut-off unit is short-circuited to the negative output end of the photovoltaic power supply corresponding to the negative line with the output cut-off unit, so that the conduction and shutdown of the negative line without the output cut-off unit can be controlled by the output cut-off unit on the negative line with the output cut-off unit.

6. The short-circuit protection system for photovoltaic inverter according to claim 5, characterized in that: The output cut-off unit is also provided on the positive line or the negative line of the output line.

7. The short-circuit protection system for photovoltaic inverter according to claim 3, characterized in that: The output cut-off unit is provided on the positive line of each input line.

8. The short-circuit protection system for photovoltaic inverter according to claim 7, characterized in that: An output cut-off unit is provided on the negative electrode line of the input line, the positive electrode line / negative electrode line or the positive electrode bus / negative electrode bus of the output line.

9. The short-circuit protection system for photovoltaic inverter according to claim 1, characterized in that: The output cut-off unit adopts an electromagnetic relay, a DC / AC contactor, an IGBT tube or a MOSFET tube.

10. A photovoltaic inverter system, characterized in that: A short-circuit protection system for a photovoltaic inverter comprising any one of claims 1 to 9, and The inverter module has an input end electrically connected to the output bus of the boost module in the short-circuit protection system of the photovoltaic inverter, and is used to convert the DC source transmitted by the boost module into an AC source and transmit it to the power grid.

11. A solar energy storage system, characterized in that: Includes the photovoltaic inverter system as described in claim 10.

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