Energy system and control method thereof, power conversion device and combiner box

Abstract

The embodiment of the invention provides an energy system, a control method thereof, a power conversion device and a combiner box. The system comprises a plurality of positive pole bus lines and a plurality of negative pole bus lines which are used for connecting direct current energy modules; a circuit protection unit is arranged between the positive pole bus line and the direct current positive pole bus, and / or a circuit protection unit is arranged between the negative pole bus line and the direct current negative pole bus; the direct current energy modules connected between any positive electrode bus line and any negative electrode bus line form a module group; the module group comprises: a single module group comprising a DC energy module; or a composite module group comprising a plurality of direct-current energy modules; the withstand current of any direct-current energy module of the composite module group is greater than or equal to the fault current formed by the other direct-current energy modules. Therefore, the risk that the direct-current energy module is damaged after faults such as reverse connection or short circuit can be reduced.

Description

TECHNICAL FIELD

[0001] The embodiments in the specification relate to the technical field of power electronics, and particularly relate to an energy system and a control method thereof, a power conversion device, and a busbar. BACKGROUND

[0002] Currently, some energy systems are provided with multiple direct-current energy modules for producing direct-current electricity. For example, the multiple direct-current energy modules can be photovoltaic strings or energy storage batteries, etc. The direct-current electricity produced by the direct-current energy modules usually needs to be converted into alternating-current electricity by a power conversion device and then integrated into a power grid.

[0003] However, when a reverse connection or a short circuit fault occurs in a direct-current energy module, a fault current may be formed between the remaining direct-current energy modules and the faulty direct-current energy module, and there is a risk of equipment damage.

[0004] Therefore, there is a technical problem in the prior art that the equipment is easily damaged after a reverse connection or a short circuit fault occurs in a direct-current energy module. SUMMARY

[0005] The embodiments in the specification provide an energy system and a control method thereof, a power conversion device, and a busbar, which can reduce the risk of equipment damage after a reverse connection or a short circuit fault occurs in a direct-current energy module to a certain extent.

[0006] The embodiments in the specification provide an energy system, comprising: a plurality of positive busbar lines for connecting to a direct-current positive busbar, and a plurality of negative busbar lines for connecting to a direct-current negative busbar; a circuit protection unit is arranged between the positive busbar line and the direct-current positive busbar, and a circuit protection unit is arranged between the negative busbar line and the direct-current negative busbar; the positive busbar line and the negative busbar line are further used for connecting a plurality of direct-current energy modules; wherein the direct-current energy modules connected between any positive busbar line and any negative busbar line form a module group; the module group comprises: a single module group comprising only one direct-current energy module; or a composite module group comprising a plurality of direct-current energy modules; wherein the withstand current of any direct-current energy module included in the composite module group is greater than or equal to the fault current that can be formed by the remaining direct-current energy modules in the composite module group.

[0007] In some embodiments, the circuit protection unit comprises a switching unit; the energy system further comprises a controller; and the controller is configured to control the switching unit to be disconnected in the case of a fault occurring in a direct-current energy module.

[0008] In some embodiments, among the plurality of positive bus lines, at least one positive bus line is connected with a plurality of direct current energy modules, and the plurality of direct current energy modules are also respectively connected with different negative bus lines, so that the plurality of direct current energy modules form a plurality of the single module groups.

[0009] In some embodiments, among the plurality of positive bus lines, a first positive bus line connected with two positive bus sub-lines; the two positive bus sub-lines of the first positive bus line are respectively used to connect one direct current energy module; wherein the first positive bus line and the plurality of negative bus lines form two single module groups.

[0010] In some embodiments, among the plurality of positive bus lines, a second positive bus line connected with three positive bus sub-lines; the three positive bus sub-lines of the second positive bus line are respectively used to connect one direct current energy module; wherein the second positive bus line and the plurality of negative bus lines form three single module groups.

[0011] In some embodiments, among the plurality of positive bus lines, a third positive bus line connected with four positive bus sub-lines; the four positive bus sub-lines of the third positive bus line are respectively used to connect one direct current energy module; wherein the third positive bus line and the plurality of negative bus lines form four single module groups.

[0012] In some embodiments, among the plurality of negative bus lines, at least one negative bus line is connected with a plurality of direct current energy modules, and the plurality of direct current energy modules are also respectively connected with different positive bus lines, so that the plurality of direct current energy modules form a plurality of the single module groups.

[0013] In some embodiments, among the plurality of negative bus lines, a first negative bus line connected with two negative bus sub-lines; the two negative bus sub-lines of the first negative bus line are respectively used to connect one direct current energy module; wherein the first negative bus line and the plurality of positive bus lines form two single module groups.

[0014] In some embodiments, among the plurality of negative bus lines, a second negative bus line connected with three negative bus sub-lines; the three negative bus sub-lines of the second negative bus line are respectively used to connect one direct current energy module; wherein the second negative bus line and the plurality of positive bus lines form three single module groups.

[0015] In some embodiments, the plurality of negative bus bars comprises: a third negative bus bar connected with four negative sub-bus bars; the four negative sub-bus bars of the third negative bus bar are respectively connected with one direct current energy module; wherein the third negative bus bar and the plurality of positive bus bars form four single module groups.

[0016] In some embodiments, the plurality of positive bus bars comprises: a fourth positive bus bar connected with two positive sub-bus bars; the two positive sub-bus bars of the fourth positive bus bar are respectively connected with one direct current energy module; wherein the fourth positive bus bar and the plurality of negative bus bars form a composite module group comprising two direct current energy modules.

[0017] In some embodiments, the plurality of positive bus bars comprises: a fifth positive bus bar connected with three positive sub-bus bars; the three positive sub-bus bars of the fifth positive bus bar are respectively connected with one direct current energy module; wherein the fifth positive bus bar and the plurality of negative bus bars form one single module group and one composite module group comprising two direct current energy modules; or, the fifth positive bus bar and the plurality of negative bus bars form one composite module group comprising three direct current energy modules.

[0018] In some embodiments, the plurality of positive bus bars comprises: a sixth positive bus bar connected with four positive sub-bus bars; the four positive sub-bus bars of the sixth positive bus bar are respectively connected with one direct current energy module; wherein the sixth positive bus bar and the plurality of negative bus bars form one composite module group comprising two direct current energy modules and two single module groups; or, the sixth positive bus bar and the plurality of negative bus bars form two composite module groups each comprising two direct current energy modules; or, the sixth positive bus bar and the plurality of negative bus bars form one composite module group comprising three direct current energy modules and one single module group; or, the sixth positive bus bar and the plurality of negative bus bars form one composite module group comprising four direct current energy modules.

[0019] In some embodiments, the plurality of negative bus bars comprises: a fourth negative bus bar connected with two negative sub-bus bars; the two negative sub-bus bars of the fourth negative bus bar are respectively connected with one direct current energy module; wherein the fourth negative bus bar and the plurality of positive bus bars form a composite module group comprising two direct current energy modules.

[0020] In some embodiments, the plurality of negative bus bars comprises: a fifth negative bus bar connected with three negative bus sub-lines; the three negative bus sub-lines of the fifth negative bus bar are connected with one direct current power module respectively; wherein the fifth negative bus bar and the plurality of positive bus bars form a single module group and a composite module group comprising two direct current power modules; or the negative bus bar and the plurality of positive bus bars form a composite module group comprising three direct current power modules.

[0021] In some embodiments, the plurality of negative bus bars comprises: a sixth negative bus bar connected with four negative bus sub-lines; the four negative bus sub-lines of the sixth negative bus bar are connected with one direct current power module respectively; wherein the sixth negative bus bar and the plurality of positive bus bars form a composite module group comprising two direct current power modules and two single module groups; or the sixth negative bus bar and the plurality of positive bus bars form two composite module groups each comprising two direct current power modules; or the sixth negative bus bar and the plurality of positive bus bars form a composite module group comprising three direct current power modules and a single module group; or the sixth negative bus bar and the plurality of positive bus bars form a composite module group comprising four direct current power modules.

[0022] In some embodiments, the controller is further configured to control the switch unit to be disconnected in the case that the power conversion device of the energy system fails.

[0023] The embodiments of the present disclosure provide a power conversion device, comprising: a plurality of positive bus bars and a plurality of negative bus bars; the plurality of positive bus bars and the plurality of negative bus bars are used to connect a plurality of direct current power modules; a positive bus bar is connected to a direct current positive bus through a circuit protection unit, and a negative bus bar is connected to a direct current negative bus through a circuit protection unit; wherein a direct current power module connected between any positive bus bar and any negative bus bar forms a module group, the module group comprises: a single module group comprising only one direct current power module; or a composite module group comprising a plurality of direct current power modules; wherein the composite module group comprises a direct current power module with a withstand current greater than or equal to a fault current formed by the remaining direct current power modules in the composite module group.

[0024] In some embodiments, the circuit protection unit comprises a switch unit; the power conversion device further comprises a controller; the controller is configured to control the switch unit to be disconnected in the case that a positive bus bar or a negative bus bar generates a fault current.

[0025] In some embodiments, among the plurality of positive bus lines, at least one positive bus line is connected with a plurality of direct current energy modules, and the plurality of direct current energy modules are also respectively connected with different negative bus lines, so that the plurality of direct current energy modules form a plurality of the single module groups.

[0026] In some embodiments, among the plurality of positive bus lines, a first positive bus line connected with two positive bus sub-lines; the two positive bus sub-lines of the first positive bus line are respectively used to connect one direct current energy module; wherein the first positive bus line and the plurality of negative bus lines form two single module groups.

[0027] In some embodiments, among the plurality of positive bus lines, a second positive bus line connected with three positive bus sub-lines; the three positive bus sub-lines of the second positive bus line are respectively used to connect one direct current energy module; wherein the second positive bus line and the plurality of negative bus lines form three single module groups.

[0028] In some embodiments, among the plurality of positive bus lines, a third positive bus line connected with four positive bus sub-lines; the four positive bus sub-lines of the third positive bus line are respectively used to connect one direct current energy module; wherein the third positive bus line and the plurality of negative bus lines form four single module groups.

[0029] In some embodiments, among the plurality of negative bus lines, at least one negative bus line is connected with a plurality of direct current energy modules, and the plurality of direct current energy modules are also respectively connected with different positive bus lines, so that the plurality of direct current energy modules form a plurality of the single module groups.

[0030] In some embodiments, among the plurality of negative bus lines, a first negative bus line connected with two negative bus sub-lines; the two negative bus sub-lines of the first negative bus line are respectively used to connect one direct current energy module; wherein the first negative bus line and the plurality of positive bus lines form two single module groups.

[0031] In some embodiments, among the plurality of negative bus lines, a second negative bus line connected with three negative bus sub-lines; the three negative bus sub-lines of the second negative bus line are respectively used to connect one direct current energy module; wherein the second negative bus line and the plurality of positive bus lines form three single module groups.

[0032] In some embodiments, the third negative bus line is connected with four negative sub-bus lines; the four negative sub-bus lines of the third negative bus line are respectively used for connecting one direct current energy module; wherein, the third negative bus line and the plurality of positive bus lines form four single module groups.

[0033] In some embodiments, the plurality of positive bus lines includes: a fourth positive bus line connected with two positive sub-bus lines; the two positive sub-bus lines of the fourth positive bus line are respectively connected with one direct current energy module; wherein, the fourth positive bus line and the plurality of negative bus lines form a composite module group including two direct current energy modules.

[0034] In some embodiments, the plurality of positive bus lines includes: a fifth positive bus line connected with three positive sub-bus lines; the three positive sub-bus lines of the fifth positive bus line are respectively connected with one direct current energy module; wherein, the fifth positive bus line and the plurality of negative bus lines form one single module group and one composite module group including two direct current energy modules; or, the fifth positive bus line and the plurality of negative bus lines form one composite module group including three direct current energy modules.

[0035] In some embodiments, the plurality of positive bus lines includes: a sixth positive bus line connected with four positive sub-bus lines; the four positive sub-bus lines of the sixth positive bus line are respectively connected with one direct current energy module; wherein, the sixth positive bus line and the plurality of negative bus lines form one composite module group including two direct current energy modules and two single module groups; or, the sixth positive bus line and the plurality of negative bus lines form two composite module groups respectively including two direct current energy modules; or, the sixth positive bus line and the plurality of negative bus lines form one composite module group including three direct current energy modules and one single module group; or, the sixth positive bus line and the plurality of negative bus lines form one composite module group including four direct current energy modules.

[0036] In some embodiments, the plurality of negative bus lines includes: a fourth negative bus line connected with two negative sub-bus lines; the two negative sub-bus lines of the fourth negative bus line are respectively connected with one direct current energy module; wherein, the fourth negative bus line and the plurality of positive bus lines form a composite module group including two direct current energy modules.

[0037] In some embodiments, the plurality of negative bus bars comprises: a fifth negative bus bar connected with three negative bus sub-lines; the three negative bus sub-lines of the fifth negative bus bar are connected with one direct current power module respectively; wherein the fifth negative bus bar and the plurality of positive bus bars form one single module group and one composite module group comprising two direct current power modules; or the negative bus bar and the plurality of positive bus bars form one composite module group comprising three direct current power modules.

[0038] In some embodiments, the plurality of negative bus bars comprises: a sixth negative bus bar connected with four negative bus sub-lines; the four negative bus sub-lines of the sixth negative bus bar are connected with one direct current power module respectively; wherein the sixth negative bus bar and the plurality of positive bus bars form one composite module group comprising two direct current power modules and two single module groups; or the sixth negative bus bar and the plurality of positive bus bars form two composite module groups each comprising two direct current power modules; or the sixth negative bus bar and the plurality of positive bus bars form one composite module group comprising three direct current power modules and one single module group; or the sixth negative bus bar and the plurality of positive bus bars form one composite module group comprising four direct current power modules.

[0039] The embodiment of the present specification provides a busbar box, comprising: a plurality of positive bus bars and a plurality of negative bus bars; the plurality of positive bus bars and the plurality of negative bus bars are used to connect a plurality of direct current power modules; a positive bus bar is connected to a direct current positive bus through a circuit protection unit, and a negative bus bar is connected to a direct current negative bus through a circuit protection unit; wherein the direct current power modules connected between any positive bus bar and any negative bus bar form a module group respectively, the module group comprises: a single module group comprising only one direct current power module; or a composite module group comprising a plurality of direct current power modules; wherein the withstand current of any direct current power module in the composite module group is greater than or equal to the fault current formed by the remaining direct current power modules in the composite module group.

[0040] In some embodiments, the circuit protection unit comprises a switching unit; the switching unit is used to be controlled to be opened when a fault current occurs in the corresponding positive bus bar or negative bus bar. In some embodiments, among the plurality of positive bus bars, at least one positive bus bar is connected with a plurality of direct current power modules, and the plurality of direct current power modules are also connected with different negative bus bars respectively, so that the plurality of direct current power modules form a plurality of single module groups.

[0041] In some embodiments, the plurality of positive bus bars comprises: a first positive bus bar connected with two positive sub bus bars; the two positive sub bus bars of the first positive bus bar are respectively connected with one direct current energy module; wherein the first positive bus bar and the plurality of negative bus bars form two single module groups.

[0042] In some embodiments, the plurality of positive bus bars comprises: a second positive bus bar connected with three positive sub bus bars; the three positive sub bus bars of the second positive bus bar are respectively connected with one direct current energy module; wherein the second positive bus bar and the plurality of negative bus bars form three single module groups.

[0043] In some embodiments, the plurality of positive bus bars comprises: a third positive bus bar connected with four positive sub bus bars; the four positive sub bus bars of the third positive bus bar are respectively connected with one direct current energy module; wherein the third positive bus bar and the plurality of negative bus bars form four single module groups.

[0044] In some embodiments, at least one negative bus bar of the plurality of negative bus bars is connected with a plurality of direct current energy modules, and the plurality of direct current energy modules are respectively connected with different positive bus bars, so that the plurality of direct current energy modules form a plurality of single module groups.

[0045] In some embodiments, the plurality of negative bus bars comprises: a first negative bus bar connected with two negative sub bus bars; the two negative sub bus bars of the first negative bus bar are respectively connected with one direct current energy module; wherein the first negative bus bar and the plurality of positive bus bars form two single module groups.

[0046] In some embodiments, the plurality of negative bus bars comprises: a second negative bus bar connected with three negative sub bus bars; the three negative sub bus bars of the second negative bus bar are respectively connected with one direct current energy module; wherein the second negative bus bar and the plurality of positive bus bars form three single module groups.

[0047] In some embodiments, the plurality of negative bus bars comprises: a third negative bus bar connected with four negative sub bus bars; the four negative sub bus bars of the third negative bus bar are respectively connected with one direct current energy module; wherein the third negative bus bar and the plurality of positive bus bars form four single module groups.

[0048] In some embodiments, the plurality of positive bus bars comprises: a fourth positive bus bar connected with two positive sub bus bars; the two positive sub bus bars of the fourth positive bus bar are connected with one direct current energy source module respectively; wherein the fourth positive bus bar and the plurality of negative bus bars form a composite module group comprising two direct current energy source modules.

[0049] In some embodiments, the plurality of positive bus bars comprises: a fifth positive bus bar connected with three positive sub bus bars; the three positive sub bus bars of the fifth positive bus bar are connected with one direct current energy source module respectively; wherein the fifth positive bus bar and the plurality of negative bus bars form one single module group and one composite module group comprising two direct current energy source modules; or the fifth positive bus bar and the plurality of negative bus bars form one composite module group comprising three direct current energy source modules.

[0050] In some embodiments, the plurality of positive bus bars comprises: a sixth positive bus bar connected with four positive sub bus bars; the four positive sub bus bars of the sixth positive bus bar are connected with one direct current energy source module respectively; wherein the sixth positive bus bar and the plurality of negative bus bars form one composite module group comprising two direct current energy source modules and two single module groups; or the sixth positive bus bar and the plurality of negative bus bars form two composite module groups each comprising two direct current energy source modules; or the sixth positive bus bar and the plurality of negative bus bars form one composite module group comprising three direct current energy source modules and one single module group; or the sixth positive bus bar and the plurality of negative bus bars form one composite module group comprising four direct current energy source modules.

[0051] In some embodiments, the plurality of negative bus bars comprises: a fourth negative bus bar connected with two negative sub bus bars; the two negative sub bus bars of the fourth negative bus bar are connected with one direct current energy source module respectively; wherein the fourth negative bus bar and the plurality of positive bus bars form a composite module group comprising two direct current energy source modules.

[0052] In some embodiments, the plurality of negative bus bars comprises: a fifth negative bus bar connected with three negative sub bus bars; the three negative sub bus bars of the fifth negative bus bar are connected with one direct current energy source module respectively; wherein the fifth negative bus bar and the plurality of positive bus bars form one single module group and one composite module group comprising two direct current energy source modules; or the negative bus bar and the plurality of positive bus bars form one composite module group comprising three direct current energy source modules.

[0053] In some embodiments, the plurality of negative bus bars comprises: a sixth negative bus bar connected with four negative bus sub-lines; the four negative bus sub-lines of the sixth negative bus bar are connected with one direct current power source module respectively; wherein, the sixth negative bus bar and the plurality of positive bus bars form a composite module group comprising two direct current power source modules, and two single module groups; or, the sixth negative bus bar and the plurality of positive bus bars form two composite module groups each comprising two direct current power source modules; or, the sixth negative bus bar and the plurality of positive bus bars form a composite module group comprising three direct current power source modules, and one single module group; or, the sixth negative bus bar and the plurality of positive bus bars form a composite module group comprising four direct current power source modules.

[0054] The embodiments of the present disclosure provide a control method of an energy system, comprising: in the case of detecting that a direct current power source module fails, controlling a switch unit in a positive bus bar connected with the direct current power source module to be disconnected, and / or, controlling a switch unit in a negative bus bar connected with the direct current power source module to be disconnected; wherein, the positive bus bar is used to be connected with a direct current positive bus, the negative bus bar is used to be connected with a direct current negative bus; and a direct current power source module connected between any positive bus bar and any negative bus bar forms a module group; the module group comprises: a single module group comprising only one direct current power source module; or, a composite module group comprising a plurality of direct current power source modules; wherein, the composite module group comprises a direct current power source module whose withstand current is greater than or equal to a fault current formed by the remaining direct current power source modules in the composite module group.

[0055] In some embodiments, the control method of the energy system further comprises: in the case of a fault of a power conversion device of the energy system, controlling the switch unit to be disconnected.

[0056] The embodiments provided in the specification provide a plurality of positive busbars for connecting to a direct current positive bus, and a plurality of negative busbars for connecting to a direct current negative bus. A switching unit is provided between the positive busbar and the direct current positive bus, and / or a switching unit is provided between the negative busbar and the direct current negative bus. The positive busbar and the negative busbar are also used to connect a plurality of direct current energy modules; wherein the direct current energy modules connected between any positive busbar and any negative busbar form a module group; the module group includes: a single module group including only one direct current energy module; or a composite module group including a plurality of direct current energy modules. The switching unit is controlled to be opened in the event of a fault of the direct current energy module. After the switching unit is opened, the direct current energy module in the single module group is less likely to form a fault current after a reverse connection or a short circuit, and the direct current energy module in the composite module group is less likely to form a fault current exceeding the withstand current of the direct current energy module after a reverse connection or a short circuit, thereby reducing the risk of damage to the direct current energy module or other equipment. BRIEF DESCRIPTION OF DRAWINGS

[0057] Figure 1a A schematic diagram of an energy system in the related art provided in the specification.

[0058] Figure 1b A schematic diagram of an energy system in the related art provided in the specification.

[0059] Figure 1c A schematic diagram of an energy system in the related art provided in the specification.

[0060] Figure 2 A schematic diagram of an energy system provided in an embodiment of the specification.

[0061] Figure 3a A schematic diagram of the connection relationship between the direct current energy module, the positive busbar and the negative busbar in an energy system provided in an embodiment of the specification.

[0062] Figure 3b A schematic diagram of the connection relationship between the direct current energy module, the positive busbar and the negative busbar in an energy system provided in an embodiment of the specification.

[0063] Figure 3c A schematic diagram of the connection relationship between the direct current energy module, the positive busbar and the negative busbar in an energy system provided in an embodiment of the specification.

[0064] Figure 3d A schematic diagram of the connection relationship between the direct current energy module, the positive busbar and the negative busbar in an energy system provided in an embodiment of the specification.

[0065] Figure 4 A schematic diagram of the connection relationship between the DC power modules and the positive bus line and the negative bus line in the energy system provided for an embodiment of the present specification.

[0066] Figure 5 A schematic diagram of the connection relationship between the DC power modules and the positive bus line and the negative bus line in the energy system provided for an embodiment of the present specification.

[0067] Figure 6 A schematic diagram of the connection relationship between the DC power modules and the positive bus line and the negative bus line in the energy system provided for an embodiment of the present specification.

[0068] Figure 7 A schematic diagram of the connection relationship between the DC power modules and the positive bus line and the negative bus line in the energy system provided for an embodiment of the present specification.

[0069] Figure 8 A schematic diagram of the fault current caused by the failure of the power conversion device in the energy system provided for an embodiment of the present specification.

[0070] Figure 9 A schematic diagram of the power conversion device provided for an embodiment of the present specification.

[0071] Figure 10 A schematic diagram of the connection relationship between the DC power modules and the positive bus line and the negative bus line in the energy system provided for an embodiment of the present specification.

[0072] Figure 11 A schematic diagram of the energy system provided for an embodiment of the present specification. DETAILED DESCRIPTION

[0073] The technical solutions in the embodiments of the present application will be described clearly and completely in the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments of the present application.

[0074] In the description of the embodiments of the present application, it should be understood that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0075] In order to facilitate the understanding of the technical solutions in the embodiments provided by the present specification, some technical terms involved in the embodiments provided by the present specification will be specifically explained.

[0076] Direct current power modules are units that generate or store direct current. For example, a direct current power module can be a string of photovoltaic assemblies connected in series. Alternatively, a direct current power module can be a string of energy storage cells connected in series. Of course, a direct current power module can also include a single photovoltaic assembly or a single energy storage cell. The embodiments of the present specification are not limited in this regard.

[0077] Direct current positive bus lines and direct current negative bus lines are main lines for collecting and transmitting direct current. Specifically, the direct current positive bus lines and the direct current negative bus lines are used to collect and transmit direct current generated by a plurality of direct current power modules. In some embodiments, the direct current positive bus lines and the direct current negative bus lines can be connected to a power conversion circuit to transmit direct current generated by a plurality of direct current power modules to the power conversion circuit.

[0078] Positive bus lines are branch lines of the direct current positive bus lines. A plurality of positive bus lines are connected to the direct current positive bus lines.

[0079] Negative bus lines are branch lines of the direct current negative bus lines. A plurality of negative bus lines are connected to the direct current negative bus lines.

[0080] Any positive bus line and any negative bus line can be connected to a plurality of direct current power modules to transmit direct current of the plurality of direct current power modules connected thereto to the direct current positive bus lines and the direct current negative bus lines.

[0081] The present specification provides an example of the connection relationship between direct current power modules and a power conversion device in the related art.

[0082] Please refer to Figure 1a . In this example, the direct current power modules are strings of photovoltaic assemblies. N strings of photovoltaic assemblies are connected between the direct current positive bus lines and the direct current negative bus lines. N is a positive integer.

[0083] In this example, when the string of photovoltaic assemblies 1 is reversed, a current loop is formed between the string of photovoltaic assemblies 1 and the parallelly connected strings of photovoltaic assemblies 2 to N. Specifically, the strings of photovoltaic assemblies 2 to N will apply reverse current to the string of photovoltaic assemblies 1.

[0084] Figure 1a The current loop through which the reverse current flows is indicated by the dashed line in

[0085] Please refer to Figure 1b . In this example, the string of photovoltaic assemblies 1 is short-circuited. Similarly, the parallelly connected strings of photovoltaic assemblies 2 to N will apply short-circuit current to the string of photovoltaic assemblies.

[0086] Figure 1b The current loop through which the short-circuit current flows is indicated by the dashed line in FIG. 2. The short-circuit current applied by photovoltaic string 2 and photovoltaic string 3 flows into photovoltaic string 1 through the positive bus and returns from the negative bus. Due to the large short-circuit current, various problems such as overheating can occur, which can also cause photovoltaic string 1 to be damaged.

[0087] Therefore, please refer to Figure 1c In some cases, the photovoltaic string can connect the positive bus and the negative bus through a fuse. When a fault current occurs in the line connected by the DC power module, the fuse is blown to cut off the fault current, thereby reducing the risk of damage to the DC power module.

[0088] To better solve the problem that the DC power module is easily damaged after a fault such as reverse connection or short circuit occurs, the inventors have found through in-depth research and analysis that the key to solving this problem lies in how to avoid the formation of a current loop between DC power modules to some extent. And the inventors have found that one of the cruxes of the formation of a current loop between DC power modules is that in the related art, after the connection is completed, multiple DC power modules are connected in parallel between the positive bus and the negative bus. Under this connection relationship, if a DC power module has a fault such as reverse connection or short circuit, the remaining DC power modules will form a current loop with the faulty DC power module through the positive bus and the negative bus, and generate a fault current.

[0089] Therefore, an embodiment of the present specification proposes an energy system and a control method thereof, a power conversion device, and a busbar box, which can avoid the formation of a current loop when one or more photovoltaic strings among multiple photovoltaic strings connected to the power conversion device or the busbar box are reversely connected or short-circuited. Or, even if a current loop is formed when one or more photovoltaic strings among multiple photovoltaic strings are reversely connected or short-circuited, the maximum short-circuit current in the current loop is not higher than the withstand current of any photovoltaic string. Thus, the risk of damage to the photovoltaic string after a fault such as reverse connection or short circuit occurs can be reduced.

[0090] Specifically, an embodiment of the present specification provides an energy system. The energy system comprises: a plurality of positive busbar lines for connecting to a positive bus, and a plurality of negative busbar lines for connecting to a negative bus; a switching unit is provided between the positive busbar line and the positive bus, and / or a switching unit is provided between the negative busbar line and the negative bus; and the positive busbar line and the negative busbar line are further used to connect a plurality of DC power modules.

[0091] Specifically, one end of the plurality of positive busbar lines can be connected to a DC positive busbar. The other end of the plurality of positive busbar lines can be connected to the plurality of DC energy modules. The positive busbar lines can be connected to the positive poles of the plurality of DC energy modules. In some cases, for example, when the DC energy modules are reversely connected, the negative poles of the DC energy modules can also be connected to the positive busbar lines.

[0092] One end of the plurality of negative busbar lines can be connected to a DC negative busbar. The other end of the plurality of negative busbar lines can be connected to the plurality of DC energy modules. The negative busbar lines can be connected to the negative poles of the plurality of DC energy modules. In some cases, for example, when the DC energy modules are reversely connected, the positive poles of the DC energy modules can also be connected to the negative busbar lines.

[0093] The DC positive busbar and the DC negative busbar can be connected to a power conversion circuit. Thus, the positive busbar lines and the negative busbar lines can transmit the DC power of the DC energy modules to the DC positive busbar and the DC negative busbar. Further, the DC power of the DC energy modules can be sent to the power conversion circuit for conversion.

[0094] The power conversion circuit is a circuit for converting the form of electric energy. For example, the power conversion circuit can be an inverter circuit, a DC-DC conversion circuit, etc. The present embodiment is not limited in this regard.

[0095] In some embodiments, referring to Figure 2 , the energy system includes a power conversion device. The DC side of the power conversion device is provided with a plurality of positive busbar lines and a plurality of negative busbar lines. The DC energy modules are connected to the power conversion circuit of the power conversion device through the plurality of positive busbar lines and the plurality of negative busbar lines. The AC side of the power conversion device can be connected to a power grid. The power conversion device is a device for converting the form of electric energy. Specifically, the power conversion device can be an inverter for converting DC power into AC power. Of course, the power conversion device can also be a bidirectional inverter for converting DC power and AC power. Alternatively, the power conversion device can also be a DC-DC converter for converting the DC power provided at the input end of the power conversion device into DC power of different voltage levels. Of course, the power conversion device can also include a bidirectional converter, a power conversion system (PCS), etc. In some embodiments, the power conversion device can also integrate a DC-DC converter and a power conversion system (PCS). The present embodiment is not limited in this regard.

[0096] The DC positive bus and the DC negative bus can be separately designed lines in the energy system. Alternatively, the DC positive bus and the DC negative bus can also be lines in the power conversion device. The present embodiment is not specifically limited here.

[0097] For any DC energy module, a circuit protection unit is arranged between the positive busbar connected by the DC energy module and the DC positive bus, and a circuit protection unit is arranged between the negative busbar connected by the DC energy module and the DC negative bus.

[0098] The circuit protection unit is a component for cutting off fault current, for reducing the risk of damage to equipment in the energy system caused by fault current. Specifically, the circuit protection unit can include a fuse. Alternatively, the circuit protection unit can also include a switching unit. The switching unit includes, but is not limited to, a mechanical switch, a semiconductor switch, etc. Of course, the switching unit can also be a circuit breaker. The present embodiment is not specifically limited here.

[0099] In some embodiments, the circuit protection unit includes a switching unit; the energy system further includes a controller; the controller is configured to control the switching unit to be disconnected in the event of a fault in the DC energy module.

[0100] In the present embodiment, the connection relationship between the plurality of DC energy modules, the plurality of positive busbars and the plurality of negative busbars needs to meet the following conditions to solve the problem that the photovoltaic string is easily damaged after a reverse connection or a short circuit fault occurs.

[0101] Specifically, the DC energy module connected between any positive busbar and any negative busbar forms a module group. That is, when a DC energy module is connected between any pair of positive busbar and negative busbar, the positive busbar and the negative busbar correspond to a module group, and the module group includes the DC energy module connected between the positive busbar and the negative busbar.

[0102] The module group includes: a single module group including only one DC energy module; or a composite module group including a plurality of DC energy modules; wherein the DC energy module included in the composite module group has a withstand current greater than or equal to the fault current formed by the remaining DC energy modules in the composite module group.

[0103] For a single module group, the number of DC energy modules included therein is 1. That is, the DC energy module connected between the pair of positive busbar and negative busbar corresponding to the single module group has only one.

[0104] Since only one DC power module is connected between the positive busbar and the negative busbar, there is no other DC power module connected to the same positive busbar and negative busbar in the single module group. Therefore, after the circuit protection unit between the positive busbar and the DC positive busbar, and the circuit protection unit between the negative busbar and the DC negative busbar are controlled to disconnect the DC power module from the DC busbar, there is no DC power module in parallel with the DC power module in the single module group, and thus it is difficult to form a current loop, thereby reducing the risk of damage to the DC power module or other equipment.

[0105] For example, the energy system includes three DC power modules, as shown in Figure 3a . In this embodiment, the energy system includes a power conversion device, a positive busbar 1 connected to the DC positive busbar of the power conversion device, a positive busbar 2 connected to the DC positive busbar of the power conversion device, a negative busbar 1 connected to the DC negative busbar of the power conversion device, and a negative busbar 2 connected to the DC negative busbar of the power conversion device. In addition, the energy system includes three DC power modules, namely DC power module 1, DC power module 2, and DC power module 3. Among them, DC power module 1+ represents the positive pole of DC power module 1. DC power module 2+ represents the positive pole of DC power module 2. DC power module 3+ represents the positive pole of DC power module 3. DC power module 1- represents the negative pole of DC power module 1. DC power module 2- represents the negative pole of DC power module 2. DC power module 3- represents the negative pole of DC power module 3. In addition, the energy system is provided with a circuit protection unit. The circuit protection unit is a switching unit S1, S2, S3, and S4. S1 represents the switching unit between the positive busbar 1 and the DC positive busbar. S2 represents the switching unit between the positive busbar 2 and the DC positive busbar. S3 represents the switching unit between the negative busbar 1 and the DC negative busbar. S4 represents the switching unit between the negative busbar 2 and the DC negative busbar.

[0106] In this embodiment, the three DC power modules form three single module groups. Among them, DC power module 1 is connected between the positive busbar 1 and the negative busbar 1 to form the first single module group. DC power module 2 is connected between the positive busbar 1 and the negative busbar 2 to form the second single module group. DC power module 3 is connected between the positive busbar 2 and the negative busbar 1 to form the third single module group.

[0107] For example, the energy system includes three DC power modules, as shown in Figure 3b . Figure 3b Compared with Figure 3a, the DC power module 1 is reversely connected. At this time, the fault current appears. Specifically, the fault current includes the reverse current applied to the DC power module 1 by the DC power module 2 and the DC power module 3. At this time, the controller controls the switch units S1, S2, S3 and S4 to be open. After the switch units are open, no loop is formed between the DC power module 2 or the DC power module 3 and the DC power module 1. Thus, the risk of damaging the DC power module can be reduced.

[0108] In some embodiments, referring to Figure 3c , the circuit protection unit arranged between the positive bus line and the DC positive bus and the circuit protection unit arranged between the negative bus line and the DC negative bus can be fuses. Wherein, U1, U2, U3 and U4 are fuses. Correspondingly, when the DC power module 1 is reversely connected, the reverse current applied to the DC power module 1 by the DC power module 2 can pass through the fuses U3 and U4, and the reverse current applied to the DC power module 1 by the DC power module 3 can pass through U1 and U2. Thus, the fuses through which the reverse current flows can be fused, so that the reverse current is cut off. Similarly, when the DC power module 1 is short-circuited, the fuses can also be fused to cut off the short-circuit current.

[0109] Compared with the related art, in which a fuse is arranged for each DC power module. In this embodiment, the technical effect of protecting the DC power module and the equipment in the power conversion device can be achieved while arranging a smaller number of fuses.

[0110] In some embodiments, referring to Figure 3d , the circuit protection unit arranged between the positive bus line and the DC positive bus is a switch unit, and the circuit protection unit arranged between the negative bus line and the DC negative bus is a fuse. Correspondingly, when the fault current appears, the switch units S1 and S2 are controlled to be open. And the fuse is fused due to the fault current, thereby protecting the DC power module and the equipment in the power conversion device.

[0111] In some embodiments, when the controller identifies that the DC power module is faulty (for example, the DC power module is reversely connected), the controller can also only open the switch element between the positive bus line and the DC positive bus to which the faulty DC power module is connected, and the switch element between the negative bus line and the DC negative bus to which the DC power module is connected. This allows part of the DC power modules to work normally to provide power to the DC positive bus and the DC negative bus.

[0112] It should be understood that the energy system provided in the embodiments of the present specification can include any number of DC power modules. The any number of DC power modules form a single module group or a composite module group. The embodiments are not limited specifically herein.

[0113] In some embodiments, among the multiple positive bus lines, at least one positive bus line is connected to multiple DC power modules, and the multiple DC power modules are also connected to different negative bus lines, so that the multiple DC power modules form multiple single module groups.

[0114] That is, in this embodiment, a positive busbar is connected to multiple DC power modules, but the negative busbars connected to these multiple DC power modules are different.

[0115] For example, consider an energy system comprising four DC power modules. Please refer to [link to relevant documentation]. Figure 4 In this embodiment, the energy system includes four DC power modules: DC power module 1, DC power module 2, DC power module 3, and DC power module 4. DC power module 4+ represents the positive terminal of DC power module 4, and DC power module 4- represents the negative terminal of DC power module 4.

[0116] In this configuration, positive busbar 1 connects to two DC power modules, specifically the positive terminals of DC power module 1 and DC power module 2. The negative terminal of DC power module 1 is connected to negative busbar 1, and the negative terminal of DC power module 2 is connected to negative busbar 2. This ensures that only DC power module 1 is connected between positive and negative busbar 1, and only DC power module 2 is connected between positive and negative busbar 2. Therefore, DC power module 1 and DC power module 2 each form a single module group.

[0117] Similarly, the positive busbar 2 is connected to DC power modules 3 and 4. DC power modules 3 and 4 are also connected to the negative busbar 1 and negative busbar 2, respectively. Thus, DC power modules 3 and 4 each form a single module group.

[0118] For example, consider an energy system containing six DC power modules. Please refer to [link to relevant documentation]. Figure 5 . Figure 5 The provided embodiment of the energy system includes six DC power modules: DC power module 1, DC power module 2, DC power module 3, DC power module 4, DC power module 5, and DC power module 6. DC power module 5+ represents the positive terminal of DC power module 5. DC power module 5- represents the negative terminal of DC power module 5. DC power module 6+ represents the positive terminal of DC power module 6. DC power module 6- represents the negative terminal of DC power module 6. Furthermore, this embodiment of the energy system also includes six switching units: S1, S2, S3, S4, S5, and S6.

[0119] The positive electrode bus line 1 is connected with three direct current energy modules, specifically, the positive electrode of the direct current energy module 1, the positive electrode of the direct current energy module 2 and the positive electrode of the direct current module 3. The negative electrode of the direct current energy module 1 is connected to the negative electrode bus line 1. The negative electrode of the direct current energy module 2 is connected to the negative electrode bus line 3. The negative electrode of the direct current energy module 3 is connected to the negative electrode bus line 2. This makes the direct current energy module connected between the positive electrode bus line 1 and the negative electrode bus line 1 only the direct current energy module 1, the direct current energy module connected between the positive electrode bus line 1 and the negative electrode bus line 2 only the direct current energy module 3, and the direct current energy module connected between the positive electrode bus line 1 and the negative electrode bus line 3 only the direct current energy module 2. Thus, the direct current energy module 1, the direct current energy module 2 and the direct current energy module 3 form a single module group respectively.

[0120] Similarly, the positive electrode bus line 2 is connected with the direct current energy module 4 and the direct current energy module 5. And the direct current energy module 4 and the direct current energy module 5 are also connected to the negative electrode bus line 1 and the negative electrode bus line 2 respectively. Thus, the direct current energy module 4 and the direct current energy module 5 form a single module group respectively.

[0121] Similarly, only the direct current energy module 6 is connected between the positive electrode direct current energy module 3 and the negative electrode bus line 1. Thus, the direct current energy module 6 can also form a single module group.

[0122] In some embodiments, the plurality of positive electrode bus lines includes: a first positive electrode bus line connected with two positive electrode bus sub-lines; the two positive electrode bus sub-lines of the first positive electrode bus line are used for connecting a direct current energy module respectively; wherein the first positive electrode bus line and the plurality of negative electrode bus lines form two single module groups.

[0123] The positive electrode bus sub-line is a connecting line for connecting the direct current energy module, so as to connect the direct current energy module to the positive electrode bus line. Wherein one positive electrode bus sub-line is used for connecting one direct current energy module. Correspondingly, the first positive electrode bus line can connect two direct current energy modules through two positive electrode bus sub-lines.

[0124] Please refer to Figure 4 , the positive electrode bus line 1 and the positive electrode bus line 2 are both first positive electrode bus lines.

[0125] In this embodiment, the positive electrode bus line 1 connects the direct current energy module 1 and the direct current energy module 2 through two positive electrode bus sub-lines. The direct current energy module 1 and the direct current energy module 2 are also connected to different negative electrode bus lines, forming two single module groups.

[0126] In this embodiment, the positive busbar 2 is connected to the DC power module 3 and the DC power module 4 through two positive sub-busbars. The DC power module 3 and the DC power module 4 are also connected to different negative busbars, forming two single module groups.

[0127] In some embodiments, the plurality of positive busbars includes a second positive busbar connected to three positive sub-busbars; the three positive sub-busbars of the second positive busbar are respectively connected to one DC power module; and the second positive busbar and the plurality of negative busbars form three single module groups.

[0128] The second positive busbar can be connected to three DC power modules through the three positive sub-busbars.

[0129] Please refer to Figure 5 , Figure 5 In this embodiment, the positive busbar 1 is the second positive busbar.

[0130] In this embodiment, the positive busbar 1 is connected to the DC power module 1, the DC power module 2 and the DC power module 3 through three positive sub-busbars. The DC power module 1, the DC power module 2 and the DC power module 3 are also connected to different negative busbars, forming three single module groups.

[0131] In this embodiment, the positive busbar 2 is the first positive busbar. In this embodiment, the positive busbar 2 is connected to the DC power module 4 and the DC power module 5 through two positive sub-busbars. The DC power module 4 and the DC power module 5 are also connected to different negative busbars, forming two single module groups.

[0132] In this embodiment, the DC power module 6 is connected between the positive busbar 3 and the negative busbar 1, forming a single module group.

[0133] In some embodiments, the plurality of positive busbars includes a third positive busbar connected to four positive sub-busbars; the four positive sub-busbars of the third positive busbar are respectively connected to one DC power module; and the third positive busbar and the plurality of negative busbars form four single module groups.

[0134] The third positive busbar can be connected to four DC power modules through the four positive sub-busbars.

[0135] Please refer to Figure 6 , which takes nine DC power modules as an example. Figure 6 In this embodiment, the positive busbar 1 is the third positive busbar.

[0136] In this embodiment, the positive busbar 1 connects the DC power modules 1, 2, 3 and 4 through four positive busbar sub-lines. The DC power modules 1, 2, 3 and 4 are also connected to different negative busbars, forming four single module groups.

[0137] In this embodiment, the positive busbar 2 and 3 are the first positive busbar.

[0138] Specifically, the positive busbar 2 connects the DC power modules 5 and 6 through two positive busbar sub-lines. The DC power modules 5 and 6 are also connected to different negative busbars, forming two single module groups. In addition, the positive busbar 3 connects the DC power modules 7 and 8 through two positive busbar sub-lines. The DC power modules 7 and 8 are also connected to different negative busbars, forming two single module groups.

[0139] In this embodiment, the DC power module 9 is connected between the positive busbar 4 and the negative busbar 1, forming a single module group.

[0140] In some embodiments, among the plurality of negative busbars, at least one negative busbar is connected to a plurality of DC power modules, and the plurality of DC power modules are also respectively connected to different positive busbars, so that the plurality of DC power modules form a plurality of single module groups.

[0141] That is, a certain negative busbar is connected to a plurality of DC power modules, but the plurality of DC power modules are connected to different positive busbars.

[0142] For example, please refer to Figure 4 . The negative busbar 1 is connected to two DC power modules, specifically the negative of the DC power module 1 and the negative of the DC power module 3. The positive of the DC power module 1 is connected to the positive busbar 1, and the positive of the DC power module 3 is connected to the positive busbar 2. Thus, the DC power module 1 and the DC power module 3 form a single module group respectively.

[0143] Similarly, the negative busbar 2 is connected to the DC power module 2 and the DC power module 4. In addition, the DC power module 2 and the DC power module 4 are also respectively connected to the positive busbar 1 and the positive busbar 2. Thus, the DC power module 2 and the DC power module 4 form a single module group respectively.

[0144] In some embodiments, the plurality of negative bus lines comprises: a first negative bus line connected with two negative bus sub-lines; the two negative bus sub-lines of the first negative bus line are respectively used for connecting one direct current energy module; wherein the first negative bus line and the plurality of positive bus lines form two single module groups.

[0145] The negative bus sub-line is a connecting line for connecting the direct current energy module, so as to connect the direct current energy module to the negative bus line. One negative bus sub-line is used for connecting one direct current energy module. Correspondingly, the first negative bus line can connect two direct current energy modules through two negative bus sub-lines.

[0146] Please refer to Figure 4 , the negative bus line 1 and the negative bus line 2 are both first negative bus lines.

[0147] In this embodiment, the negative bus line 1 connects the direct current energy module 1 and the direct current energy module 3 through two negative bus sub-lines. The direct current energy module 1 and the direct current energy module 3 are also connected to different positive bus lines, forming two single module groups.

[0148] In this embodiment, the negative bus line 2 connects the direct current energy module 2 and the direct current energy module 4 through two negative bus sub-lines. The direct current energy module 2 and the direct current energy module 4 are also connected to different positive bus lines, forming two single module groups.

[0149] In some embodiments, the plurality of negative bus lines comprises: a second negative bus line connected with three negative bus sub-lines; the three negative bus sub-lines of the second negative bus line are respectively used for connecting one direct current energy module; wherein the second negative bus line and the plurality of positive bus lines form three single module groups.

[0150] The second negative bus line can connect three direct current energy modules through three negative bus sub-lines.

[0151] Please refer to Figure 5 , Figure 5 In the negative bus line 1 is the second negative bus line.

[0152] In this embodiment, the negative bus line 1 connects the direct current energy module 1, the direct current energy module 4 and the direct current energy module 6 through three negative bus sub-lines. The direct current energy module 1, the direct current energy module 4 and the direct current energy module 6 are also connected to different positive bus lines, forming three single module groups.

[0153] In this embodiment, the negative busbar 2 is a first negative busbar. Specifically, the negative busbar 2 connects the DC power module 3 and the DC power module 5 through two negative sub-busbars. The DC power module 3 and the DC power module 5 are also connected to different positive busbars, forming two single module groups.

[0154] In this embodiment, the DC power module 2 is connected between the negative busbar 3 and the positive busbar 1, forming a single module group.

[0155] In some embodiments, the plurality of negative busbars includes a third negative busbar connected with four negative sub-busbars, and the four negative sub-busbars of the third negative busbar are respectively used to connect one DC power module. The third negative busbar and the plurality of positive busbars form four single module groups.

[0156] The third negative busbar can connect four DC power modules through four negative sub-busbars.

[0157] Please refer to Figure 6 , Figure 6 In this embodiment, the negative busbar 1 is a third negative busbar.

[0158] In this embodiment, the negative busbar 1 connects the DC power module 1, the DC power module 5, the DC power module 7 and the DC power module 9 through four negative sub-busbars. The DC power module 1, the DC power module 5, the DC power module 7 and the DC power module 9 are also connected to different positive busbars, forming four single module groups.

[0159] In this embodiment, the negative busbar 2 and the negative busbar 3 are first negative busbars.

[0160] Specifically, the negative busbar 2 connects the DC power module 2 and the DC power module 6 through two negative sub-busbars. The DC power module 2 and the DC power module 6 are also connected to different positive busbars, forming two single module groups. In addition, the negative busbar 3 connects the DC power module 3 and the DC power module 8 through two negative sub-busbars. The DC power module 3 and the DC power module 8 are also connected to different positive busbars, forming two single module groups.

[0161] In this embodiment, the DC power module 4 is connected between the negative busbar 4 and the positive busbar 1, forming a single module group.

[0162] For a composite module group, the number of DC power modules included in the composite module group is greater than 1. In addition, the withstand current of any DC power module included in the composite module group is greater than or equal to the fault current that can be formed by the remaining DC power modules in the composite module group.

[0163] The plurality of DC power modules in the composite module group are connected in parallel between the same pair of positive busbar and negative busbar. Therefore, when one or several DC power modules are in reverse connection or short circuit, a fault current will be generated.

[0164] The fault current can be the reverse current provided by the remaining DC power modules to the DC power module which is in reverse connection. Of course, the fault current can also be the short circuit current flowing from the remaining DC power modules to the DC power module which is in short circuit. In some embodiments, the fault current formed by the remaining DC power modules can be the sum of the reverse current and the short circuit current of the remaining DC power modules.

[0165] Since the withstand current of any DC power module included in the composite module group is greater than or equal to the fault current formed by the remaining DC power modules in the composite module group, when the switch unit between the positive busbar and the DC positive bus, and / or the switch unit between the negative busbar and the DC negative bus is disconnected, the fault current flowing through the corresponding positive busbar and negative busbar formed by the plurality of DC power modules included in the composite module group will not exceed the withstand current of any DC power module, so that the DC power module is not easily damaged.

[0166] For example, the energy system contains six DC power modules, please refer to Figure 7 In this embodiment, the positive busbar 1 and the negative busbar 1 are connected with three DC power modules. The positive busbar 1 and the negative busbar 1 are specifically connected with the DC power module 1, the DC power module 2 and the DC power module 3, and form a composite module group. The DC power module 4, the DC power module 5 and the DC power module 6 form a single module group respectively.

[0167] In this embodiment, the positive busbar 2 is the first positive busbar. The negative busbar 2 is the first negative busbar. The DC power module 4, the DC power module 5 and the DC power module 6 form a single module group respectively.

[0168] Figure 7 In the current loop, the reverse current of the DC power module 2 and the DC power module 3 flows along the direction of the dashed line when the DC power module 1 is in reverse connection. It is assumed that the reverse current of the DC power module 2 is I2, and the reverse current of the DC power module 3 is I3. The fault current formed by the remaining DC power modules can be the sum of I2 and I3. If the withstand current of the DC power module 1 is greater than the sum of I2 and I3, the risk of damage to the DC power module 1 can be reduced.

[0169] Therefore, when the withstand current of any DC power module included in the composite module group is greater than or equal to the fault current that can be formed by the remaining DC power modules in the module group, the risk of damage to the DC power module due to faults such as reverse connection or short circuit can be reduced to a certain extent.

[0170] In some embodiments, the plurality of positive bus lines includes: a fourth positive bus line connected with two positive bus sub-lines; the two positive bus sub-lines of the fourth positive bus line are respectively connected with one DC power module; and the fourth positive bus line and the plurality of negative bus lines form a composite module group including two DC power modules. Specifically, the two DC power modules connected by the fourth positive bus line are also connected with the same negative bus line. Among the two DC power modules included in the composite module group, the withstand current of any DC power module is not less than the fault current that can be formed by the short circuit current or the reverse flow current of the other DC power module.

[0171] In some embodiments, the plurality of positive bus lines includes: a fifth positive bus line connected with three positive bus sub-lines; the three positive bus sub-lines of the fifth positive bus line are respectively connected with one DC power module; and the fifth positive bus line and the plurality of negative bus lines form a single module group and a composite module group including two DC power modules, or form a composite module group including three DC power modules.

[0172] Specifically, the three DC power modules connected by the fifth positive bus line can also be connected with the same negative bus line to form a composite module group including three DC power modules. Among the three DC power modules included in the composite module group, the withstand current of any DC power module is not less than the fault current that can be formed by the short circuit current or the reverse flow current of the other two DC power modules. For example, the withstand current of any DC power module is not less than the sum of the short circuit current or the reverse flow current of the other two DC power modules.

[0173] Alternatively, among the three DC power modules connected by the fifth positive bus line, two DC power modules are connected with the same negative bus line, and the third DC power module is connected with a different negative bus line, forming a composite module group and a single module group. Among the two DC power modules included in the composite module group, the withstand current of any DC power module is not less than the fault current that can be formed by the short circuit current or the reverse flow current of the other DC power module.

[0174] In some embodiments, the plurality of positive bus bars comprises: a sixth positive bus bar connected with four positive bus sub-lines; the four positive bus sub-lines of the sixth positive bus bar are connected with one direct current power module respectively; wherein, the sixth positive bus bar and the plurality of negative bus bars form a composite module group comprising two direct current power modules and two single module groups; or, the sixth positive bus bar and the plurality of negative bus bars form two composite module groups each comprising two direct current power modules; or, the sixth positive bus bar and the plurality of negative bus bars form a composite module group comprising three direct current power modules and one single module group; or, the sixth positive bus bar and the plurality of negative bus bars form a composite module group comprising four direct current power modules.

[0175] Specifically, among the four direct current power modules connected with the sixth positive bus bar, two direct current power modules are connected with the same negative bus bar, and the other two direct current power modules are connected with different negative bus bars, thereby forming one composite module group and two single module groups. The composite module group comprises two direct current power modules, and the withstand current of any one of the direct current power modules is not less than the fault current formed by the short circuit current or the backflow current of the other direct current power module.

[0176] Alternatively, among the four direct current power modules connected with the sixth positive bus bar, two direct current power modules are connected with the same negative bus bar, and the other two direct current power modules are connected with another negative bus bar, thereby forming two composite module groups. Each composite module group comprises two direct current power modules. Among the two direct current power modules comprised by any one of the composite module groups, the withstand current of any one of the direct current power modules is not less than the fault current formed by the short circuit current or the backflow current of the other direct current power module.

[0177] Alternatively, among the four direct current power modules connected with the sixth positive bus bar, three direct current power modules are connected with the same negative bus bar, and the other direct current power module is connected with a different negative bus bar, thereby forming one composite module group and one single module group. Among the composite module group comprising three direct current power modules, the withstand current of any one of the direct current power modules is not less than the fault current formed by the other two direct current power modules.

[0178] Alternatively, the four direct current power modules connected with the sixth positive bus bar can be connected with the same negative bus bar, thereby forming a composite module group comprising four direct current power modules. Among the four direct current power modules comprised by the composite module group, the withstand current of any one of the direct current power modules is not less than the fault current formed by the other three direct current power modules. For example, the withstand current of any one of the direct current power modules is not less than the sum of the short circuit current or the backflow current of the other three direct current power modules.

[0179] In some embodiments, the plurality of negative bus bars comprises: a fourth negative bus bar connected with two negative sub-bus bars; the two negative sub-bus bars of the fourth negative bus bar are connected with one direct current energy module respectively; wherein the fourth negative bus bar and the plurality of positive bus bars form a composite module group comprising two direct current energy modules. Specifically, the two direct current energy modules connected with the fourth negative bus bar are also connected with the same positive bus bar. Among the two direct current energy modules comprised in the composite module group, the withstand current of any one direct current energy module is not less than the fault current formed by the short circuit current or the backflow current of the other direct current energy module.

[0180] In some embodiments, the plurality of negative bus bars comprises: a fifth negative bus bar connected with three negative sub-bus bars; the three negative sub-bus bars of the fifth negative bus bar are connected with one direct current energy module respectively; wherein the fifth negative bus bar and the plurality of positive bus bars form a single module group and a composite module group comprising two direct current energy modules; or the negative bus bar and the plurality of positive bus bars form a composite module group comprising three direct current energy modules.

[0181] Specifically, the three direct current energy modules connected with the fifth negative bus bar can also be connected with the same positive bus bar to form a composite module group comprising three direct current energy modules. Among the three direct current energy modules comprised in the composite module group, the withstand current of any one direct current energy module is not less than the fault current formed by the other two direct current energy modules.

[0182] Alternatively, among the three direct current energy modules connected with the fifth negative bus bar, two direct current energy modules are connected with the same positive bus bar, and the third direct current energy module is connected with a different positive bus bar, forming a composite module group and a single module group. Among the two direct current energy modules comprised in the composite module group, the withstand current of any one direct current energy module is not less than the fault current formed by the short circuit current or the backflow current of the other direct current energy module.

[0183] In some embodiments, the plurality of negative bus bars comprises: a sixth negative bus bar connected with four negative bus sub-lines; the four negative bus sub-lines of the sixth negative bus bar are connected with one direct current energy module respectively; wherein, the sixth negative bus bar and the plurality of positive bus bars form a composite module group comprising two direct current energy modules, and two single module groups; or, the sixth negative bus bar and the plurality of positive bus bars form two composite module groups each comprising two direct current energy modules; or, the sixth negative bus bar and the plurality of positive bus bars form a composite module group comprising three direct current energy modules, and a single module group; or, the sixth negative bus bar and the plurality of positive bus bars form a composite module group comprising four direct current energy modules.

[0184] Specifically, among the four direct current energy modules connected with the sixth negative bus bar, two direct current energy modules are connected with the same positive bus bar, and the other two direct current energy modules are connected with different positive bus bars, thereby forming a composite module group and two single module groups. The composite module group comprises two direct current energy modules, and the withstand current of any one of the direct current energy modules is not less than the fault current formed by the short circuit current or the backflow current of the other direct current energy module.

[0185] Or, among the four direct current energy modules connected with the sixth negative bus bar, two direct current energy modules are connected with the same positive bus bar, and the other two direct current energy modules are connected with another positive bus bar, thereby forming two composite module groups. Each composite module group comprises two direct current energy modules. Among the two direct current energy modules comprised by any one of the composite module groups, the withstand current of any one of the direct current energy modules is not less than the fault current formed by the short circuit current or the backflow current of the other direct current energy module.

[0186] Or, among the four direct current energy modules connected with the sixth negative bus bar, three direct current energy modules are connected with the same positive bus bar, and the other direct current energy module is connected with a different positive bus bar, thereby forming a composite module group and a single module group. Among the composite module group comprising three direct current energy modules, the withstand current of any one of the direct current energy modules is not less than the fault current formed by the other two direct current energy modules. Or, the four direct current energy modules connected with the sixth negative bus bar can be connected with the same positive bus bar, thereby forming a composite module group comprising four direct current energy modules. Among the four direct current energy modules comprised by the composite module group, the withstand current of any one of the direct current energy modules is not less than the fault current formed by the other three direct current energy modules. For example, the withstand current of any one of the direct current energy modules is not less than the sum of the short circuit current or the backflow current of the other three direct current energy modules.

[0187] In some embodiments, the energy system further comprises a power conversion device. The controller is further configured to control the switch unit to be opened in the event of a failure of the power conversion device of the energy system. Specifically, when the power conversion device of the energy system fails, a failure current loop can be formed between the power grid and the DC energy modules through the power conversion device. Therefore, the controller can further be configured to control the switch unit to be opened to cut off the failure current loop when the failure current is identified.

[0188] Referring to Figure 8 , the power grid of the energy system is a three-phase power grid. In this embodiment, a short circuit occurs between the negative pole of the DC energy module 2 and the ground, thereby forming a failure current loop through the power conversion device and the power grid. Specifically, the power of the power grid can be backfed to the DC energy module. The failure current loop is shown by the dashed line in Figure 8 . The failure current loop can be cut off by controlling the switch unit to be opened, thereby reducing the risk of damage to the equipment in the DC energy module and the power conversion device to a certain extent.

[0189] Referring to Figure 9 , the present specification also provides a power conversion device, comprising: a plurality of positive bus lines and a plurality of negative bus lines; the plurality of positive bus lines and the plurality of negative bus lines are used to connect a plurality of DC energy modules; a positive bus line is connected to a DC positive bus through a switch unit, and / or a negative bus line is connected to a DC negative bus through a switch unit; wherein the DC energy modules connected between any positive bus line and any negative bus line form a module group, the module group comprises: a single module group comprising only one DC energy module; or a composite module group comprising a plurality of DC energy modules; wherein the withstand current of any DC energy module included in the composite module group is greater than or equal to the failure current that can be formed by the remaining DC energy modules in the composite module group; a controller is configured to control the switch unit to be opened when a failure current occurs in the positive bus line or the negative bus line.

[0190] wherein, Figure 9 In the provided embodiments, K1 to K n , and K n+1 to K 2n are switch units.

[0191] In some embodiments, the power conversion device can further comprise a power conversion circuit. The input side of the power conversion circuit is connected to the DC positive bus and the DC negative bus. The output side of the power conversion circuit is used to connect the power grid. The power grid can be a single-phase power grid or a three-phase power grid. This embodiment is not specifically limited herein.

[0192] In some embodiments, the number of the plurality of positive bus lines and the plurality of negative bus lines can be the same or different. For example, referring toFigure 4 . Figure 4 The number of positive bus lines and negative bus lines in the energy system provided is the same. Please refer to Figure 10 . Figure 10 The number of positive bus lines and negative bus lines in the energy system provided is different. Specifically, Figure 10 In the embodiments provided, there is one positive bus line and two negative bus lines. DC energy modules 1 and DC energy modules 2 form two single module groups.

[0193] In some embodiments, the controller determines that the DC energy module is in an abnormal state when it identifies that the voltage of the DC energy module is greater than a specified threshold value or the current of the DC energy module is greater than a specified threshold value.

[0194] In some embodiments, among the plurality of positive bus lines, at least one positive bus line is connected with a plurality of DC energy modules, and the plurality of DC energy modules are also respectively connected with different negative bus lines, so that the plurality of DC energy modules form a plurality of single module groups.

[0195] In some embodiments, among the plurality of positive bus lines, there is a first positive bus line connected with two positive bus sub-lines; the two positive bus sub-lines of the first positive bus line are respectively used to connect one DC energy module; and the first positive bus line and the plurality of negative bus lines form two single module groups.

[0196] In some embodiments, among the plurality of positive bus lines, there is a second positive bus line connected with three positive bus sub-lines; the three positive bus sub-lines of the second positive bus line are respectively used to connect one DC energy module; and the second positive bus line and the plurality of negative bus lines form three single module groups.

[0197] In some embodiments, among the plurality of positive bus lines, there is a third positive bus line connected with four positive bus sub-lines; the four positive bus sub-lines of the third positive bus line are respectively used to connect one DC energy module; and the third positive bus line and the plurality of negative bus lines form four single module groups.

[0198] In some embodiments, among the plurality of negative bus lines, at least one negative bus line is connected with a plurality of DC energy modules, and the plurality of DC energy modules are also respectively connected with different positive bus lines, so that the plurality of DC energy modules form a plurality of single module groups.

[0199] In some embodiments, the plurality of negative bus lines comprises: a first negative bus line connected with two negative sub-bus lines; the two negative sub-bus lines of the first negative bus line are respectively connected with one direct current energy module; wherein the first negative bus line and the plurality of positive bus lines form two single module groups.

[0200] In some embodiments, the plurality of negative bus lines comprises: a second negative bus line connected with three negative sub-bus lines; the three negative sub-bus lines of the second negative bus line are respectively connected with one direct current energy module; wherein the second negative bus line and the plurality of positive bus lines form three single module groups.

[0201] In some embodiments, the plurality of negative bus lines comprises: a third negative bus line connected with four negative sub-bus lines; the four negative sub-bus lines of the third negative bus line are respectively connected with one direct current energy module; wherein the third negative bus line and the plurality of positive bus lines form four single module groups.

[0202] In some embodiments, the plurality of positive bus lines comprises: a fourth positive bus line connected with two positive sub-bus lines; the two positive sub-bus lines of the fourth positive bus line are respectively connected with one direct current energy module; wherein the fourth positive bus line and the plurality of negative bus lines form a composite module group comprising two direct current energy modules.

[0203] In some embodiments, the plurality of positive bus lines comprises: a fifth positive bus line connected with three positive sub-bus lines; the three positive sub-bus lines of the fifth positive bus line are respectively connected with one direct current energy module; wherein the fifth positive bus line and the plurality of negative bus lines form one single module group and one composite module group comprising two direct current energy modules; or, the fifth positive bus line and the plurality of negative bus lines form one composite module group comprising three direct current energy modules.

[0204] In some embodiments, the plurality of positive bus lines comprises: a sixth positive bus line connected with four positive sub-bus lines; the four positive sub-bus lines of the sixth positive bus line are respectively connected with one direct current energy module; wherein the sixth positive bus line and the plurality of negative bus lines form one composite module group comprising two direct current energy modules and two single module groups; or, the sixth positive bus line and the plurality of negative bus lines form two composite module groups each comprising two direct current energy modules; or, the sixth positive bus line and the plurality of negative bus lines form one composite module group comprising three direct current energy modules and one single module group; or, the sixth positive bus line and the plurality of negative bus lines form one composite module group comprising four direct current energy modules.

[0205] In some embodiments, the plurality of negative bus bars comprises: a fourth negative bus bar connected with two negative sub bus bars; the two negative sub bus bars of the fourth negative bus bar are connected with one direct current energy module respectively; wherein the fourth negative bus bar and the plurality of positive bus bars form a composite module group comprising two direct current energy modules.

[0206] In some embodiments, the plurality of negative bus bars comprises: a fifth negative bus bar connected with three negative sub bus bars; the three negative sub bus bars of the fifth negative bus bar are connected with one direct current energy module respectively; wherein the fifth negative bus bar and the plurality of positive bus bars form a single module group, and a composite module group comprising two direct current energy modules; or the negative bus bar and the plurality of positive bus bars form a composite module group comprising three direct current energy modules.

[0207] In some embodiments, the plurality of negative bus bars comprises: a sixth negative bus bar connected with four negative sub bus bars; the four negative sub bus bars of the sixth negative bus bar are connected with one direct current energy module respectively; wherein the sixth negative bus bar and the plurality of positive bus bars form a composite module group comprising two direct current energy modules, and two single module groups; or the sixth negative bus bar and the plurality of positive bus bars form two composite module groups comprising two direct current energy modules respectively; or the sixth negative bus bar and the plurality of positive bus bars form a composite module group comprising three direct current energy modules, and a single module group; or the sixth negative bus bar and the plurality of positive bus bars form a composite module group comprising four direct current energy modules.

[0208] In some embodiments, the power conversion device can be a multi-channel power conversion device. Wherein the plurality of positive bus bars and the plurality of negative bus bars can correspond to each channel of the power conversion device respectively.

[0209] The related description of the power conversion device can refer to other embodiments in this specification. This embodiment will not be described here.

[0210] One embodiment of the present specification also provides a busbar. The busbar can include: a plurality of positive bus lines and a plurality of negative bus lines; the plurality of positive bus lines and the plurality of negative bus lines are used to connect a plurality of direct current energy modules; the positive bus line is connected to a direct current positive bus through a switch unit, and / or the negative bus line is connected to a direct current negative bus through a switch unit; the switch unit is controlled to be opened when a fault current occurs in the corresponding positive bus line or negative bus line; wherein the direct current energy modules connected between any positive bus line and any negative bus line form a module group respectively, and the module group includes: a single module group including only one direct current energy module; or a composite module group including a plurality of direct current energy modules; wherein the fault current formed by the remaining direct current energy modules in the composite module group is less than or equal to the fault current of any direct current energy module included in the composite module group.

[0211] The busbar can be used to realize the bus connection of the direct current provided by the direct current energy module. The embodiments of the present specification are not limited herein.

[0212] In some embodiments, among the plurality of positive bus lines, at least one positive bus line is connected with a plurality of direct current energy modules, and the plurality of direct current energy modules are also respectively connected with different negative bus lines, so that the plurality of direct current energy modules form a plurality of single module groups.

[0213] In some embodiments, among the plurality of positive bus lines, a first positive bus line connected with two positive bus sub-lines is included; the two positive bus sub-lines of the first positive bus line are respectively used to connect one direct current energy module; wherein the first positive bus line and the plurality of negative bus lines form two single module groups.

[0214] In some embodiments, among the plurality of positive bus lines, a second positive bus line connected with three positive bus sub-lines is included; the three positive bus sub-lines of the second positive bus line are respectively used to connect one direct current energy module; wherein the second positive bus line and the plurality of negative bus lines form three single module groups.

[0215] In some embodiments, among the plurality of positive bus lines, a third positive bus line connected with four positive bus sub-lines is included; the four positive bus sub-lines of the third positive bus line are respectively used to connect one direct current energy module; wherein the third positive bus line and the plurality of negative bus lines form four single module groups.

[0216] In some embodiments, among the plurality of negative bus lines, at least one negative bus line is connected with a plurality of direct current energy modules, and the plurality of direct current energy modules are also respectively connected with different positive bus lines, so that the plurality of direct current energy modules form a plurality of single module groups.

[0217] In some embodiments, the plurality of negative bus lines comprises: a first negative bus line connected with two negative sub-bus lines; the two negative sub-bus lines of the first negative bus line are respectively connected with one direct current energy module; wherein the first negative bus line and the plurality of positive bus lines form two single module groups.

[0218] In some embodiments, the plurality of negative bus lines comprises: a second negative bus line connected with three negative sub-bus lines; the three negative sub-bus lines of the second negative bus line are respectively connected with one direct current energy module; wherein the second negative bus line and the plurality of positive bus lines form three single module groups.

[0219] In some embodiments, the plurality of negative bus lines comprises: a third negative bus line connected with four negative sub-bus lines; the four negative sub-bus lines of the third negative bus line are respectively connected with one direct current energy module; wherein the third negative bus line and the plurality of positive bus lines form four single module groups.

[0220] In some embodiments, the plurality of positive bus lines comprises: a fourth positive bus line connected with two positive sub-bus lines; the two positive sub-bus lines of the fourth positive bus line are respectively connected with one direct current energy module; wherein the fourth positive bus line and the plurality of negative bus lines form a composite module group comprising two direct current energy modules.

[0221] In some embodiments, the plurality of positive bus lines comprises: a fifth positive bus line connected with three positive sub-bus lines; the three positive sub-bus lines of the fifth positive bus line are respectively connected with one direct current energy module; wherein the fifth positive bus line and the plurality of negative bus lines form one single module group and one composite module group comprising two direct current energy modules; or, the fifth positive bus line and the plurality of negative bus lines form one composite module group comprising three direct current energy modules.

[0222] In some embodiments, the plurality of positive bus lines comprises: a sixth positive bus line connected with four positive sub-bus lines; the four positive sub-bus lines of the sixth positive bus line are respectively connected with one direct current energy module; wherein the sixth positive bus line and the plurality of negative bus lines form one composite module group comprising two direct current energy modules and two single module groups; or, the sixth positive bus line and the plurality of negative bus lines form two composite module groups each comprising two direct current energy modules; or, the sixth positive bus line and the plurality of negative bus lines form one composite module group comprising three direct current energy modules and one single module group; or, the sixth positive bus line and the plurality of negative bus lines form one composite module group comprising four direct current energy modules.

[0223] In some embodiments, the plurality of negative bus bars comprises: a fourth negative bus bar connected with two negative sub bus bars; the two negative sub bus bars of the fourth negative bus bar are connected with one DC power module respectively; wherein the fourth negative bus bar and the plurality of positive bus bars form a composite module group comprising two DC power modules.

[0224] In some embodiments, the plurality of negative bus bars comprises: a fifth negative bus bar connected with three negative sub bus bars; the three negative sub bus bars of the fifth negative bus bar are connected with one DC power module respectively; wherein the fifth negative bus bar and the plurality of positive bus bars form a single module group, and a composite module group comprising two DC power modules; or, the negative bus bar and the plurality of positive bus bars form a composite module group comprising three DC power modules.

[0225] In some embodiments, the plurality of negative bus bars comprises: a sixth negative bus bar connected with four negative sub bus bars; the four negative sub bus bars of the sixth negative bus bar are connected with one DC power module respectively; wherein the sixth negative bus bar and the plurality of positive bus bars form a composite module group comprising two DC power modules, and two single module groups; or, the sixth negative bus bar and the plurality of positive bus bars form two composite module groups comprising two DC power modules respectively; or, the sixth negative bus bar and the plurality of positive bus bars form a composite module group comprising three DC power modules, and a single module group; or, the sixth negative bus bar and the plurality of positive bus bars form a composite module group comprising four DC power modules.

[0226] The description of the bus box can refer to other embodiments in the specification. This embodiment will not be described in detail here.

[0227] In some embodiments, the energy system is provided with the bus box in any embodiment of the specification. Please refer to Figure 11 The DC power module can be connected to the bus box first, and then connected to the power conversion device through the bus box. This embodiment is not limited here.

[0228] In some embodiments, a bus box or a power conversion device (such as a multi-channel power conversion device) itself can have several positive bus bars and several negative bus bars.

[0229] The plurality of positive busbars and the plurality of negative busbars mentioned in the embodiments of the present specification can be positive busbars and negative busbars in which the direct current energy modules are connected or which can be used to connect the direct current energy modules. That is, in the power conversion device, the busbar box or the photovoltaic system protected in the embodiments of the present specification, a part of the positive busbars and the negative busbars can be idle.

[0230] Of course, the plurality of positive busbars and the plurality of negative busbars mentioned in the embodiments of the present specification can also be positive busbars and negative busbars that meet the connection relationship of the positive busbar, the plurality of negative busbars and the direct current energy module provided in the embodiments of the present specification. The embodiments of the present specification are not specifically limited herein.

[0231] It can be understood that, in the following embodiments, if the circuits, modules, units and the like connected to each other can have transmission of electrical signals or data, it should be understood as "electrically connected", "communicatively connected" and the like.

[0232] It can be understood that the specific examples herein are only to help those skilled in the art better understand the embodiments of the present specification, and not to limit the scope of the present application.

[0233] It can be understood that, in various embodiments in the present specification, the size of the serial number of each process does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present specification.

[0234] It can be understood that the various embodiments described in the present specification can be implemented alone or in combination, and the embodiments of the present specification do not limit this.

[0235] Unless otherwise specified, all technical and scientific terms used in the embodiments of the present specification have the same meanings as those commonly understood by those skilled in the art of the present specification. The terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the scope of the present specification. The term "and / or" used in the present specification includes any and all combinations of one or more of the listed items. The singular forms "a", "an" and "the" used in the embodiments of the present specification and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0236] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this specification.

[0237] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0238] As should be understood from the several embodiments provided in this specification, the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0239] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0240] The above description is merely a specific embodiment of this specification, but the scope of protection of this invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this specification should be included within the scope of protection of this specification. Therefore, the scope of protection of this invention should be determined by the scope of the claims.

Claims

1. An energy system, characterized in that, include: Multiple positive busbars for connecting to the DC positive busbar, and multiple negative busbars for connecting to the DC negative busbar; a circuit protection unit is provided between the positive busbars and the DC positive busbar, and a circuit protection unit is provided between the negative busbars and the DC negative busbar; The positive and negative bus lines are also used to connect multiple DC power modules; wherein, the DC power modules connected between any positive and negative bus lines form a module group; the module group includes: a single module group including only one DC power module; or, a composite module group including multiple DC power modules; wherein, the withstand current of any DC power module included in the composite module group is greater than or equal to the fault current that the other DC power modules in the composite module group can generate.

2. The energy system according to claim 1, characterized in that, The circuit protection unit includes a switching unit; the energy system also includes a controller; the controller is used to control the switching unit to disconnect in the event of a fault in the DC energy module.

3. The energy system according to claim 1, characterized in that, In the plurality of positive bus lines, at least one positive bus line is connected to a plurality of DC power modules, and the plurality of DC power modules are also connected to different negative bus lines, so that the plurality of DC power modules form a plurality of single module groups.

4. The energy system according to claim 3, characterized in that, The plurality of positive busbars includes: a first positive busbar connected to two positive busbar sub-circuits; the two positive busbar sub-circuits of the first positive busbar are respectively used to connect to a DC power module; wherein, the first positive busbar and the plurality of negative busbars form two single module groups; Alternatively, the plurality of positive bus lines may include: a second positive bus line connected to three positive bus sub-lines; the three positive bus sub-lines of the second positive bus line are respectively used to connect to a DC power module; wherein, the second positive bus line and the plurality of negative bus lines form three single module groups; Alternatively, the plurality of positive bus lines may include: a third positive bus line connected to four positive bus sub-lines; the four positive bus sub-lines of the third positive bus line are each used to connect to a DC power module; wherein the third positive bus line and the plurality of negative bus lines form four single module groups.

5. The energy system according to claim 1, characterized in that, In the plurality of negative bus lines, at least one negative bus line is connected to a plurality of DC power modules, and the plurality of DC power modules are also connected to different positive bus lines, so that the plurality of DC power modules form a plurality of single module groups.

6. The energy system according to claim 5, characterized in that, The plurality of negative bus lines include: a first negative bus line connected to two negative bus sub-lines; the two negative bus sub-lines of the first negative bus line are respectively used to connect to a DC power module; wherein, the first negative bus line and the plurality of positive bus lines form two single module groups; Alternatively, the plurality of negative bus lines may include: a second negative bus line connected to three negative bus sub-lines; the three negative bus sub-lines of the second negative bus line are respectively used to connect to a DC power module; wherein, the second negative bus line and the plurality of positive bus lines form three single module groups; Alternatively, the plurality of negative bus lines may include: a third negative bus line connected to four negative bus sub-lines; the four negative bus sub-lines of the third negative bus line are respectively used to connect to a DC power module; wherein, the third negative bus line and the plurality of positive bus lines form four single module groups.

7. The energy system according to claim 1, characterized in that, The plurality of positive busbars includes: a fourth positive busbar connected to two positive busbar sub-circuits; the two positive busbar sub-circuits of the fourth positive busbar are respectively connected to a DC power module; wherein, the fourth positive busbar and the plurality of negative busbars form a composite module group including two DC power modules. Alternatively, the plurality of positive busbars may include: a fifth positive busbar connected to three positive busbar sub-circuits; the three positive busbar sub-circuits of the fifth positive busbar are each connected to a DC power module; wherein the fifth positive busbar and the plurality of negative busbars form a single module group and a composite module group including two DC power modules; or, the fifth positive busbar and the plurality of negative busbars form a composite module group including three DC power modules. Alternatively, the plurality of positive busbars may include: a sixth positive busbar connected to four positive busbar sub-circuits; the four positive busbar sub-circuits of the sixth positive busbar are each connected to a DC power module; wherein the sixth positive busbar and the plurality of negative busbars form a composite module group including two DC power modules and two single module groups; or, the sixth positive busbar and the plurality of negative busbars form two composite module groups each including two DC power modules; or, the sixth positive busbar and the plurality of negative busbars form a composite module group including three DC power modules and one single module group; or, the sixth positive busbar and the plurality of negative busbars form a composite module group including four DC power modules.

8. The energy system according to claim 1, characterized in that, The plurality of negative busbars includes: a fourth negative busbar connected to two negative busbar sub-circuits; the two negative busbar sub-circuits of the fourth negative busbar are respectively connected to a DC power module; wherein, the fourth negative busbar and the plurality of positive busbars form a composite module group including two DC power modules. Alternatively, the plurality of negative bus lines may include: a fifth negative bus line connected to three negative bus sub-lines; the three negative bus sub-lines of the fifth negative bus line are each connected to a DC power module; wherein the fifth negative bus line and the plurality of positive bus lines form a single module group and a composite module group including two DC power modules; or, the negative bus line and the plurality of positive bus lines form a composite module group including three DC power modules. Alternatively, the plurality of negative busbars may include: a sixth negative busbar connected to four negative busbar sub-circuits; the four negative busbar sub-circuits of the sixth negative busbar are each connected to a DC power module; wherein the sixth negative busbar and the plurality of positive busbars form a composite module group including two DC power modules and two single module groups; or, the sixth negative busbar and the plurality of positive busbars form two composite module groups each including two DC power modules; or, the sixth negative busbar and the plurality of positive busbars form a composite module group including three DC power modules and a single module group; or, the sixth negative busbar and the plurality of positive busbars form a composite module group including four DC power modules.

9. The energy system according to claim 2, characterized in that, The controller is also used to control the switching unit to disconnect in the event of a failure in the power conversion device of the energy system.

10. A power conversion device, characterized in that, include: Multiple positive bus lines and multiple negative bus lines; the multiple positive bus lines and the multiple negative bus lines are used to connect multiple DC power modules; the positive bus lines are connected to the DC positive bus through a circuit protection unit, and the negative bus lines are connected to the DC negative bus through a circuit protection unit; The DC power modules connected between any positive and any negative busbars are each considered as a module group. The module group includes: a single module group consisting of only one DC power module; or a composite module group consisting of multiple DC power modules. The withstand current of any DC power module in the composite module group is greater than or equal to the fault current that the other DC power modules in the composite module group can generate.

11. The power conversion device according to claim 10, characterized in that, The circuit protection unit includes a switching unit; the power conversion device further includes a controller for controlling the switching unit to disconnect when a fault current occurs in the positive or negative busbar.

12. The power conversion device according to claim 10, characterized in that, In the plurality of positive bus lines, at least one positive bus line is connected to a plurality of DC power modules, and the plurality of DC power modules are also connected to different negative bus lines, so that the plurality of DC power modules form a plurality of single module groups.

13. The power conversion device according to claim 12, characterized in that, The plurality of positive busbars includes: a first positive busbar connected to two positive busbar sub-circuits; the two positive busbar sub-circuits of the first positive busbar are respectively used to connect to a DC power module; wherein, the first positive busbar and the plurality of negative busbars form two single module groups; Alternatively, the plurality of positive bus lines may include: a second positive bus line connected to three positive bus sub-lines; the three positive bus sub-lines of the second positive bus line are respectively used to connect to a DC power module; wherein, the second positive bus line and the plurality of negative bus lines form three single module groups; Alternatively, the plurality of positive bus lines may include: a third positive bus line connected to four positive bus sub-lines; the four positive bus sub-lines of the third positive bus line are each used to connect to a DC power module; wherein the third positive bus line and the plurality of negative bus lines form four single module groups.

14. The power conversion device according to claim 10, characterized in that, In the plurality of negative bus lines, at least one negative bus line is connected to a plurality of DC power modules, and the plurality of DC power modules are also connected to different positive bus lines, so that the plurality of DC power modules form a plurality of single module groups.

15. The power conversion device according to claim 14, characterized in that, The plurality of negative bus lines include: a first negative bus line connected to two negative bus sub-lines; the two negative bus sub-lines of the first negative bus line are respectively used to connect to a DC power module; wherein, the first negative bus line and the plurality of positive bus lines form two single module groups; Alternatively, the plurality of negative bus lines may include: a second negative bus line connected to three negative bus sub-lines; the three negative bus sub-lines of the second negative bus line are respectively used to connect to a DC power module; wherein, the second negative bus line and the plurality of positive bus lines form three single module groups; Alternatively, the plurality of negative bus lines may include: a third negative bus line connected to four negative bus sub-lines; the four negative bus sub-lines of the third negative bus line are respectively used to connect to a DC power module; wherein, the third negative bus line and the plurality of positive bus lines form four single module groups.

16. The power conversion device according to claim 10, characterized in that, The plurality of positive busbars includes: a fourth positive busbar connected to two positive busbar sub-circuits; the two positive busbar sub-circuits of the fourth positive busbar are respectively connected to a DC power module; wherein, the fourth positive busbar and the plurality of negative busbars form a composite module group including two DC power modules. Alternatively, the plurality of positive busbars may include: a fifth positive busbar connected to three positive busbar sub-circuits; the three positive busbar sub-circuits of the fifth positive busbar are each connected to a DC power module; wherein the fifth positive busbar and the plurality of negative busbars form a single module group and a composite module group including two DC power modules; or, the fifth positive busbar and the plurality of negative busbars form a composite module group including three DC power modules. Alternatively, the plurality of positive busbars may include: a sixth positive busbar connected to four positive busbar sub-circuits; the four positive busbar sub-circuits of the sixth positive busbar are each connected to a DC power module; wherein the sixth positive busbar and the plurality of negative busbars form a composite module group including two DC power modules and two single module groups; or, the sixth positive busbar and the plurality of negative busbars form two composite module groups each including two DC power modules; or, the sixth positive busbar and the plurality of negative busbars form a composite module group including three DC power modules and one single module group; or, the sixth positive busbar and the plurality of negative busbars form a composite module group including four DC power modules.

17. The power conversion device according to claim 10, characterized in that, The plurality of negative busbars includes: a fourth negative busbar connected to two negative busbar sub-circuits; the two negative busbar sub-circuits of the fourth negative busbar are respectively connected to a DC power module; wherein, the fourth negative busbar and the plurality of positive busbars form a composite module group including two DC power modules. Alternatively, the plurality of negative bus lines may include: a fifth negative bus line connected to three negative bus sub-lines; the three negative bus sub-lines of the fifth negative bus line are each connected to a DC power module; wherein the fifth negative bus line and the plurality of positive bus lines form a single module group and a composite module group including two DC power modules; or, the negative bus line and the plurality of positive bus lines form a composite module group including three DC power modules. Alternatively, the plurality of negative busbars may include: a sixth negative busbar connected to four negative busbar sub-circuits; the four negative busbar sub-circuits of the sixth negative busbar are each connected to a DC power module; wherein the sixth negative busbar and the plurality of positive busbars form a composite module group including two DC power modules and two single module groups; or, the sixth negative busbar and the plurality of positive busbars form two composite module groups each including two DC power modules; or, the sixth negative busbar and the plurality of positive busbars form a composite module group including three DC power modules and a single module group; or, the sixth negative busbar and the plurality of positive busbars form a composite module group including four DC power modules.

18. A junction box, characterized in that, include: Multiple positive busbars and multiple negative busbars; the multiple positive busbars and the multiple negative busbars are used to connect multiple DC power modules; the positive busbars are connected to the DC positive busbar through a circuit protection unit, and / or, the negative busbars are connected to the DC negative busbar through a circuit protection unit; The DC power modules connected between any positive and any negative busbars are each considered as a module group. The module group includes: a single module group consisting of only one DC power module; or a composite module group consisting of multiple DC power modules. The withstand current of any DC power module in the composite module group is greater than or equal to the fault current that the other DC power modules in the composite module group can generate.

19. The combiner box according to claim 18, characterized in that, The circuit protection unit includes a switching unit; the switching unit is used to be controlled to disconnect when a fault current occurs in the corresponding positive or negative bus line.

20. The combiner box according to claim 18, characterized in that, In the plurality of positive bus lines, at least one positive bus line is connected to a plurality of DC power modules, and the plurality of DC power modules are also connected to different negative bus lines, so that the plurality of DC power modules form a plurality of single module groups.

21. The combiner box according to claim 20, characterized in that, The plurality of positive busbars includes: a first positive busbar connected to two positive busbar sub-circuits; the two positive busbar sub-circuits of the first positive busbar are respectively used to connect to a DC power module; wherein, the first positive busbar and the plurality of negative busbars form two single module groups; Alternatively, the plurality of positive bus lines may include: a second positive bus line connected to three positive bus sub-lines; the three positive bus sub-lines of the second positive bus line are respectively used to connect to a DC power module; wherein, the second positive bus line and the plurality of negative bus lines form three single module groups; Alternatively, the plurality of positive bus lines may include: a third positive bus line connected to four positive bus sub-lines; the four positive bus sub-lines of the third positive bus line are each used to connect to a DC power module; wherein the third positive bus line and the plurality of negative bus lines form four single module groups.

22. The combiner box according to claim 18, characterized in that, In the plurality of negative bus lines, at least one negative bus line is connected to a plurality of DC power modules, and the plurality of DC power modules are also connected to different positive bus lines, so that the plurality of DC power modules form a plurality of single module groups.

23. The combiner box according to claim 22, characterized in that, The plurality of negative bus lines include: a first negative bus line connected to two negative bus sub-lines; the two negative bus sub-lines of the first negative bus line are respectively used to connect to a DC power module; wherein, the first negative bus line and the plurality of positive bus lines form two single module groups; Alternatively, the plurality of negative bus lines may include: a second negative bus line connected to three negative bus sub-lines; the three negative bus sub-lines of the second negative bus line are respectively used to connect to a DC power module; wherein, the second negative bus line and the plurality of positive bus lines form three single module groups; Alternatively, a third negative busbar is connected to four negative busbar sub-circuits; the four negative busbar sub-circuits of the third negative busbar are respectively used to connect to a DC power module; wherein, the third negative busbar and the plurality of positive busbars form four single module groups.

24. The combiner box according to claim 18, characterized in that, The plurality of positive busbars includes: a fourth positive busbar connected to two positive busbar sub-circuits; the two positive busbar sub-circuits of the fourth positive busbar are respectively connected to a DC power module; wherein, the fourth positive busbar and the plurality of negative busbars form a composite module group including two DC power modules. Alternatively, the plurality of positive busbars may include: a fifth positive busbar connected to three positive busbar sub-circuits; the three positive busbar sub-circuits of the fifth positive busbar are each connected to a DC power module; wherein the fifth positive busbar and the plurality of negative busbars form a single module group and a composite module group including two DC power modules; or, the fifth positive busbar and the plurality of negative busbars form a composite module group including three DC power modules. Alternatively, the plurality of positive busbars may include: a sixth positive busbar connected to four positive busbar sub-circuits; the four positive busbar sub-circuits of the sixth positive busbar are each connected to a DC power module; wherein the sixth positive busbar and the plurality of negative busbars form a composite module group including two DC power modules and two single module groups; or, the sixth positive busbar and the plurality of negative busbars form two composite module groups each including two DC power modules; or, the sixth positive busbar and the plurality of negative busbars form a composite module group including three DC power modules and one single module group; or, the sixth positive busbar and the plurality of negative busbars form a composite module group including four DC power modules.

25. The combiner box according to claim 18, characterized in that, The plurality of negative busbars includes: a fourth negative busbar connected to two negative busbar sub-circuits; the two negative busbar sub-circuits of the fourth negative busbar are respectively connected to a DC power module; wherein, the fourth negative busbar and the plurality of positive busbars form a composite module group including two DC power modules. Alternatively, the plurality of negative bus lines may include: a fifth negative bus line connected to three negative bus sub-lines; the three negative bus sub-lines of the fifth negative bus line are each connected to a DC power module; wherein the fifth negative bus line and the plurality of positive bus lines form a single module group and a composite module group including two DC power modules; or, the negative bus line and the plurality of positive bus lines form a composite module group including three DC power modules. Alternatively, the plurality of negative busbars may include: a sixth negative busbar connected to four negative busbar sub-circuits; the four negative busbar sub-circuits of the sixth negative busbar are each connected to a DC power module; wherein the sixth negative busbar and the plurality of positive busbars form a composite module group including two DC power modules and two single module groups; or, the sixth negative busbar and the plurality of positive busbars form two composite module groups each including two DC power modules; or, the sixth negative busbar and the plurality of positive busbars form a composite module group including three DC power modules and a single module group; or, the sixth negative busbar and the plurality of positive busbars form a composite module group including four DC power modules.

26. A control method for an energy system, characterized in that, include: In the event of a detected DC power module failure, the switching unit in the positive busbar connected to the DC power module is disconnected, and / or the switching unit in the negative busbar connected to the DC power module is disconnected; wherein the positive busbar is used to connect to the DC positive busbar, and the negative busbar is used to connect to the DC negative busbar; and the DC power modules connected between any positive busbar and any negative busbar form a module group; the module group includes: a single module group comprising only one DC power module; or a composite module group comprising multiple DC power modules; wherein the withstand current of any DC power module in the composite module group is greater than or equal to the fault current that the other DC power modules in the composite module group can generate.

27. The method according to claim 26, characterized in that, The method further includes: In the event of a malfunction in the power conversion device of the energy system, the control switch unit is disconnected.

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