Photovoltaic inverter and photovoltaic system
By dividing the photovoltaic inverter into multiple boost inverter power units in parallel, the complex power design of inverter circuits in the prior art is solved, and the standardized design of inverter circuit modules and convenient power expansion are realized.
Patent Information
- Application Number
- CN202421755353.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-23
- Publication Date
- 2025-08-01
- Estimated Expiration
- 2034-07-23
AI Technical Summary
In existing photovoltaic inverters, multiple boost circuits converge on the DC side of the inverter circuit, resulting in large power of the inverter circuit and high design requirements, making it difficult to achieve convenient power expansion.
At least two boost inverter power units are adopted, each unit includes a boost circuit module and an inverter circuit module. The DC side of the inverter circuit module is connected to the boost circuit module, and the AC side of the at least two units is connected in parallel. Power expansion is performed by adding a parallel boost inverter power unit. The parallel inverter circuit module can be standardized.
The power design requirements of the inverter circuit module are reduced, so that the photovoltaic inverter does not need to redesign the inverter circuit module when expanding power, and realizes modularization and low power, which facilitates power expansion.
Smart Images
Figure CN223182031U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of photovoltaic power generation, and particularly relates to a photovoltaic inverter and a photovoltaic system. Background Art
[0002] With the rapid development of photovoltaic technology, the single power of photovoltaic inverters in photovoltaic systems is getting larger and larger. Multiple photovoltaic string boards are converged on the DC side of the inverter circuit through corresponding multiple boost circuits, and then centrally inverted and grid-connected through a unified inverter circuit. Since the photovoltaic inverter in the prior art adopts a scheme of a single unified inverter circuit, multiple boost circuits are converged on the DC side of the inverter circuit, and the power of the inverter circuit is relatively large, which requires a relatively high design requirement for the inverter circuit. Summary of the Utility Model
[0003] The utility model provides a photovoltaic inverter and a photovoltaic system, which can reduce the power design requirement of the inverter circuit module and facilitate power expansion.
[0004] In a first aspect, an embodiment of the utility model provides a photovoltaic inverter, which includes: at least two boost-inverter power units, each of the boost-inverter power units includes a boost circuit module and an inverter circuit module, the inverter circuit module includes a DC side and an AC side, the DC side of the inverter circuit module is connected to a photovoltaic string through the corresponding boost circuit module, and the AC sides of the at least two boost-inverter power units are connected in parallel.
[0005] According to the photovoltaic inverter of the embodiment of the utility model, the photovoltaic inverter includes at least two boost-inverter power units, each boost-inverter power unit includes a boost circuit module and an inverter circuit module, the DC side of the inverter circuit module is connected to a photovoltaic string through the corresponding boost circuit module, and the AC sides of the at least two boost-inverter power units are connected in parallel. The inverter circuit module only needs to meet the power design requirement of the photovoltaic string connected through the corresponding boost circuit module, so that the boost-inverter power unit is miniaturized and modularized. When power expansion is carried out, only the boost-inverter power units connected in parallel need to be continuously added, that is, a boost-inverter power unit connected to the newly added photovoltaic string is added, and the boost-inverter power unit is connected in parallel with each existing boost-inverter power unit of the photovoltaic inverter on the AC side. The inverter circuit module in each boost-inverter power unit can be designed in a standardized manner, and the photovoltaic inverter no longer needs to redesign the inverter circuit module after power expansion, thus making it more convenient for power expansion.
[0006] According to the foregoing embodiment of the first aspect of the utility model, the photovoltaic inverter further includes: a controller, and the controller is communicatively connected to each of the boost-inverter power units.
[0007] According to any of the foregoing embodiments of the first aspect of the present utility model, the photovoltaic inverter further includes: a filter circuit unit, and the AC sides of the at least two boost-inverting power units are connected in parallel and then connected to the same filter circuit unit.
[0008] According to any of the foregoing embodiments of the first aspect of the present utility model, the filter circuit unit includes at least any one of an LC filter circuit, an LCL filter circuit, a CLC filter circuit, or an LCLC filter circuit.
[0009] According to any of the foregoing embodiments of the first aspect of the present utility model, in each of the boost-inverting power units, the boost circuit module and the inverting circuit module are directly connected.
[0010] According to any of the foregoing embodiments of the first aspect of the present utility model, each of the boost-inverting power units further includes a DC bus, and the boost circuit module is connected to the inverting circuit module through the DC bus.
[0011] According to any of the foregoing embodiments of the first aspect of the present utility model, the boost circuit module includes a maximum power point tracking sub-module.
[0012] According to any of the foregoing embodiments of the first aspect of the present utility model, the boost circuit module includes at least any one of a two-level boost circuit, a symmetric three-level boost circuit, or a flying capacitor three-level boost circuit.
[0013] According to any of the foregoing embodiments of the first aspect of the present utility model, the inverting circuit module includes at least any one of a two-level inverting circuit, a TNPC inverting circuit, an INPC inverting circuit, or an ANPC inverting circuit.
[0014] In a second aspect, an embodiment of the present utility model provides a photovoltaic system, which includes: a photovoltaic string; and a photovoltaic inverter according to any of the foregoing embodiments of the first aspect of the present utility model, and the DC side of the inverting circuit module of the boost-inverting power unit of the photovoltaic inverter is connected to the photovoltaic string through a corresponding boost circuit module.
[0015] A photovoltaic system according to an embodiment of the present utility model, its photovoltaic inverter includes at least two boost-inverting power units. Each boost-inverting power unit includes a boost circuit module and an inverting circuit module. The DC side of the inverting circuit module is connected to a photovoltaic string through the corresponding boost circuit module, and the AC sides of at least two boost-inverting power units are connected in parallel. The inverting circuit module only needs to meet the power design requirements of the photovoltaic string connected through the corresponding boost circuit module, making the boost-inverting power unit smaller in power and modular. When expanding the power, only need to continue adding parallel boost-inverting power units, that is, add a boost-inverting power unit connected to the newly added photovoltaic string and connect this boost-inverting power unit in parallel with each existing boost-inverting power unit of the photovoltaic inverter on the AC side. The inverting circuit module in each boost-inverting power unit can be designed standardly. After the power of the photovoltaic inverter is expanded, there is no need to redesign the inverting circuit module, thus making it more convenient to expand the power. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.
[0017] Figure 1 FIG. is a schematic structural diagram of an embodiment of the photovoltaic inverter of the present utility model;
[0018] Figure 2 FIG. is a schematic structural diagram of an alternative embodiment of the photovoltaic inverter of the present utility model.
[0019] The realization of the purpose, functional features and advantages of the present utility model will be further described with reference to the embodiments and the drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, rather than all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present utility model.
[0021] It should be noted that all directional indications in the embodiments of the present utility model, such as up, down, left, right, front, back... are only used to explain the relative positional relationship and movement conditions between components in a specific posture as shown in the drawings. If the specific posture changes, the directional indications will also change accordingly.
[0022] In addition, the descriptions involving "first", "second", etc. in the present utility model are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.
[0023] Figure 1 FIG. is a schematic structural diagram of an embodiment of a photovoltaic inverter according to the present utility model. The photovoltaic inverter 100 includes at least two boost-inverter power units 110. Each boost-inverter power unit 110 includes a boost circuit module and an inverter circuit module. The inverter circuit module includes a DC side and an AC side. The DC side of the inverter circuit module is connected to a photovoltaic string through the corresponding boost circuit module, and the AC sides of at least two boost-inverter power units 110 are connected in parallel.
[0024] According to the photovoltaic inverter 100 of the embodiment of the present utility model, the photovoltaic inverter 100 includes at least two boost-inverter power units 110. Each boost-inverter power unit 110 includes a boost circuit module 111 and an inverter circuit module 112. The DC side of the inverter circuit module 112 is connected to the photovoltaic string 200 through the corresponding boost circuit module 111, and the AC sides of at least two boost-inverter power units 110 are connected in parallel. The inverter circuit module 112 only needs to meet the power design requirements of the photovoltaic string 200 connected through the corresponding boost circuit module 111, so that the boost-inverter power unit 110 is miniaturized and modularized. When performing power expansion, only the boost-inverter power unit 110 connected in parallel needs to be added continuously, that is, a boost-inverter power unit 110 connected to the newly added photovoltaic string 200 is added and the boost-inverter power unit 110 is connected in parallel with the existing boost-inverter power units 110 of the photovoltaic inverter 100 on the AC side. The inverter circuit module 112 in each boost-inverter power unit 110 can be designed standardly, and the photovoltaic inverter 100 does not need to redesign the inverter circuit module 112 after power expansion, thus making it more convenient to perform power expansion.
[0025] In some embodiments, the photovoltaic inverter 100 further includes a controller 120, which is communicatively connected to each boost-inverting power unit 110 to control each boost-inverting power unit 110 and communicate with each boost-inverting power unit 110.
[0026] In the above embodiments, all the boost-inverting power units 110 of the photovoltaic inverter 100 are coordinately and uniformly controlled by a single controller 120, thereby reducing the cost of the control scheme of the photovoltaic inverter 100.
[0027] In some embodiments, the photovoltaic inverter 100 further includes a filter circuit unit 130, and the AC sides of at least two boost-inverting power units 110 are connected in parallel and then connected to the same filter circuit unit 130.
[0028] In the above embodiments, all the boost-inverting power units 110 of the photovoltaic inverter 100 are connected in parallel on the AC side and then connected to the same filter circuit unit 130, that is, all the boost-inverting power units 110 of the photovoltaic inverter 100 share a set of filter circuit units 130, reducing the design cost of the filter circuit unit 130. The boost-inverting power units 110 are set as a standardized structure, reducing the design difficulty of the filter circuit unit 130.
[0029] In some embodiments, the filter circuit unit 130 includes a grid-connection switch, and the photovoltaic inverter 100 is connected to the power grid 300 through the grid-connection switch.
[0030] In some embodiments, the filter circuit unit 130 includes at least any one of an LC (inductor-capacitor) filter circuit, an LCL (inductor-capacitor-inductor) filter circuit, a CLC (capacitor-inductor-capacitor) filter circuit, or an LCLC (inductor-capacitor-inductor-capacitor) filter circuit.
[0031] In some embodiments, in each boost-inverting power unit 110, the boost circuit module 111 and the inverting circuit module 112 are directly connected.
[0032] Figure 2 This is a schematic structural diagram of an alternative embodiment of the photovoltaic inverter of the present utility model. In an alternative embodiment, each boost-inverting power unit 110 further includes a DC bus 113, and the boost circuit module 111 is connected to the inverting circuit module 112 through the DC bus 113.
[0033] In some other embodiments, according to the needs of circuit functions, other functional circuits can also be connected between the boost circuit module 111 and the inverting circuit module 112 of each boost-inverting power unit 110.
[0034] In some embodiments, the boost circuit module 111 includes a maximum power point tracking (MPPT) sub-module, such that each boost inverter power unit 110 has at least one path with the function of MPPT.
[0035] In some embodiments, the boost circuit module 111 includes at least any one of a two-level boost circuit, a symmetric three-level boost circuit, or a flying capacitor three-level boost circuit.
[0036] In some embodiments, the inverter circuit module 112 includes at least any one of a two-level inverter circuit, a TNPC (T-type neutral point clamped) inverter circuit, an INPC (I-type neutral point clamped) inverter circuit, or an ANPC (A-type neutral point clamped, or active neutral point clamped) inverter circuit.
[0037] An embodiment of the present invention further provides a photovoltaic system, which includes a photovoltaic string 200 and the photovoltaic inverter 100 of any one of the foregoing embodiments. The photovoltaic inverter 100 includes at least two boost inverter power units 110. Each boost inverter power unit 110 includes a boost circuit module and an inverter circuit module. The inverter circuit module includes a DC side and an AC side. The DC side of the inverter circuit module is connected to the photovoltaic string through the corresponding boost circuit module, and the AC sides of at least two boost inverter power units 110 are connected in parallel. The DC side of the inverter circuit module 112 of the boost inverter power unit 110 of the photovoltaic inverter 100 is connected to the photovoltaic string 200 through the corresponding boost circuit module 111.
[0038] For the photovoltaic system according to the embodiment of the present invention, its photovoltaic inverter 100 includes at least two boost inverter power units 110. Each boost inverter power unit 110 includes a boost circuit module 111 and an inverter circuit module 112. The DC side of the inverter circuit module 112 is connected to the photovoltaic string 200 through the corresponding boost circuit module 111, and the AC sides of at least two boost inverter power units 110 are connected in parallel. The inverter circuit module 112 only needs to meet the power design requirements of the photovoltaic string 200 connected through the corresponding boost circuit module 111, such that the boost inverter power unit 110 is miniaturized and modularized. When performing power expansion, only the boost inverter power unit 110 connected in parallel needs to be continuously added, that is, a boost inverter power unit 110 connected to the newly added photovoltaic string 200 is added, and the boost inverter power unit 110 is connected in parallel with the existing boost inverter power units 110 of the photovoltaic inverter 100 on the AC side. The inverter circuit module 112 in each boost inverter power unit 110 can be designed in a standardized manner, and the photovoltaic inverter 100 no longer needs to re-design the inverter circuit module 112 after power expansion, thus making it more convenient for power expansion.
[0039] The above are only the preferred embodiments of the present utility model, and do not thus limit the patent scope of the present utility model. Any equivalent structural transformation made under the concept of the present utility model by using the content of the specification and drawings of the present utility model, or any direct / indirect application in other related technical fields shall be included within the patent protection scope of the present utility model.
Claims
1. A photovoltaic inverter, characterized in that, Comprising: At least two boost-inverting power units, each of the boost-inverting power units comprising a boost circuit module and an inverting circuit module, the inverting circuit module comprising a DC side and an AC side, the DC side of the inverting circuit module being connected to a photovoltaic string through the corresponding boost circuit module, and the AC sides of the at least two boost-inverting power units being connected in parallel.
2. The photovoltaic inverter according to claim 1, wherein Further comprising: A controller, the controller being communicatively connected to each of the boost-inverting power units.
3. The photovoltaic inverter according to claim 1, wherein Further comprising: A filter circuit unit, the AC sides of the at least two boost-inverting power units being connected in parallel and then connected to the same filter circuit unit.
4. The PV inverter according to claim 3, wherein The filter circuit unit comprises at least any one of an LC filter circuit, an LCL filter circuit, a CLC filter circuit or an LCLC filter circuit.
5. The PV inverter according to claim 1, wherein In each of the boost-inverting power units, the boost circuit module is directly connected to the inverting circuit module.
6. The PV inverter according to claim 1, wherein Each of the boost-inverting power units further comprises a DC bus, and the boost circuit module is connected to the inverting circuit module through the DC bus.
7. The photovoltaic inverter according to claim 1, wherein The boost circuit module comprises a maximum power point tracking sub-module.
8. The photovoltaic inverter according to claim 1, wherein, The boost circuit module comprises at least any one of a two-level boost circuit, a symmetric three-level boost circuit or a flying capacitor three-level boost circuit.
9. The photovoltaic inverter according to claim 1, characterized in that, The inverting circuit module comprises at least any one of a two-level inverting circuit, a TNPC inverting circuit, an INPC inverting circuit or an ANPC inverting circuit.
10. A photovoltaic system, characterized in that, Comprising: A photovoltaic string; And A photovoltaic inverter according to any one of claims 1 to 9, the DC side of the inverting circuit module of the boost-inverting power unit of the photovoltaic inverter being connected to the photovoltaic string through the corresponding boost circuit module.