Converter for photovoltaic system

Abstract

Converter for a photovoltaic system, comprehensive: at least one unidirectional DC-DC conversion stage, at least one first connection part which is electrically connected to the at least one unidirectional DC-DC conversion part, wherein the at least one first connection part is suitable for being electrically connected to a photovoltaic panel, at least one bidirectional DC-DC conversion section, which is connected in parallel with the output of the unidirectional DC-DC conversion section, at least one second connection part which is electrically connected to the at least one bidirectional DC-DC conversion part, wherein the at least one second connection part is suitable for being electrically connected to a photovoltaic panel or an energy storage device, and a housing that covers the at least one unidirectional DC-DC conversion part and the at least one bidirectional DC-DC conversion part, exposing the at least one first terminal part and the at least one second terminal part.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Chinese Patent Application No. 202422173763.8 filed on Sept. 5, 2024, the disclosure of which is incorporated herein by reference. FIELD OF INVENTION

[0002] The present disclosure relates to a current transformer and in particular to a transformer for a photovoltaic system. BACKGROUND OF THE INVENTION

[0003] Generally speaking, a solar power generation system requires a converter for the solar module. Since the solar module can only output electrical energy but not absorb electrical energy, a unidirectional converter is typically provided for the solar module. If an energy storage device such as rechargeable batteries needs to be installed on the power generation system, an additional bidirectional converter must be purchased. This requires more space and is more expensive. SUMMARY OF THE INVENTION

[0004] The purpose of the disclosure is to provide a converter for photovoltaic systems that has a smaller volume, less cost, and a more flexible connection configuration.

[0005] According to the above purpose, the present disclosure provides a converter for photovoltaic systems comprising: at least one unidirectional DC-DC conversion part, at least one first connection part, at least one bidirectional DC-DC conversion part, at least one second connection part, and a housing. The at least one first connection part is electrically connected to the at least one unidirectional DC-DC conversion part, and the at least one first connection part is suitable for being electrically connected to a photovoltaic panel. The at least one bidirectional DC-DC conversion part is connected in parallel with the output of the unidirectional DC-DC conversion part. The at least one second connection part is electrically connected to the at least one bidirectional DC-DC conversion part, and the at least one second connection part is suitable for being electrically connected to a photovoltaic panel or an energy storage device.The housing covers the at least one unidirectional DC-DC conversion part and the at least one bidirectional DC-DC conversion part and exposes the at least one first connection part and the at least one second connection part.

[0006] According to one embodiment of the present disclosure, the converter for the photovoltaic system further comprises a DC-AC conversion part electrically connected to the at least one unidirectional DC-DC conversion part and the at least one bidirectional DC-DC conversion part to provide an AC output.

[0007] According to one embodiment of the present disclosure, the converter for the photovoltaic system further comprises a control part for controlling an electrical connection between the at least one bidirectional DC-DC conversion part and the photovoltaic panel or the energy storage device.

[0008] According to one embodiment of the present disclosure, the control part is further for controlling an electrical connection between the at least one unidirectional DC-DC conversion part and the photovoltaic panel.

[0009] According to one embodiment of the present disclosure, the converter for the photovoltaic system further comprises a first switch part for switching the electrical connection between the at least one unidirectional DC-DC conversion part and the photovoltaic panel.

[0010] According to one embodiment of the present disclosure, the converter for the photovoltaic system further comprises a second switch part for switching an electrical connection between the at least one bidirectional DC-DC conversion part and the photovoltaic panel or the energy storage device.

[0011] According to one embodiment of the present disclosure, the converter for the photovoltaic system further comprises at least one third terminal part electrically connected to the at least one bidirectional DC-DC conversion part, wherein the at least one third terminal part is adapted to be electrically connected to the energy storage device and the at least one second terminal part is adapted to be electrically connected to the photovoltaic panel.

[0012] According to one embodiment of the present disclosure, the converter for the photovoltaic system further comprises a control part for controlling an electrical connection between the at least one bidirectional DC-DC conversion part and the photovoltaic panel or an electrical connection between the at least one bidirectional DC-DC conversion part and the energy storage device.

[0013] According to one embodiment of the present disclosure, the converter for the photovoltaic system further comprises a second switch part for switching an electrical connection between the at least one bidirectional DC-DC conversion part and the photovoltaic panel.

[0014] According to one embodiment of the present disclosure, the converter for the photovoltaic system further comprises a third switch part for switching the electrical connection between the at least one bidirectional DC-DC conversion part and the energy storage device, wherein the second switch part and the third switch part are mutually exclusive.

[0015] According to one embodiment of the present disclosure, the energy storage device comprises a third switch part and a rechargeable battery pack, and the third switch part is for switching an electrical connection between the rechargeable battery pack and the at least one bidirectional DC-DC conversion part, and wherein the second switch part and the third switch part are mutually exclusive.

[0016] Compared with the prior art, the disclosure includes the bidirectional DC-DC conversion part to replace part of the unidirectional DC-DC conversion parts, thereby making the configuration of solar power modules and energy storage devices in the solar power generation system more flexible, occupying less space, and being less costly. DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic structural diagram of a converter for a photovoltaic system according to an embodiment of the present disclosure. Fig. 2a is a schematic structural diagram of a converter for a photovoltaic system according to another embodiment of the present disclosure. Fig. 2b is a schematic structural diagram of a converter for a photovoltaic system according to another embodiment of the present disclosure. Fig. 3 is a circuit diagram of a unidirectional DC-DC conversion part according to an embodiment of the present disclosure. Fig. 4 is a circuit diagram of a unidirectional DC-DC conversion part according to another embodiment of the present disclosure. Fig. 5 is a circuit diagram of a bidirectional DC-DC conversion part according to an embodiment of the present disclosure. Fig. 6 is a circuit diagram of a bidirectional DC-DC conversion part according to another embodiment of the present disclosure.

[0017] Symbol description: 100, 200, 300: converter; CMD: control part; PV1, PV2, PVn: photovoltaic panel; T1: first connection part; T2: second connection part; T3: third connection part; S1: first switch part; S2: second switch part; S3: third switch part; SDD1, SDD2: unidirectional DC-DC conversion part; DDD1: bidirectional DC-DC conversion part; Cap: capacitor; DAC: DC-AC conversion part; GD: grid; CS: enclosure; BT: energy storage device; CL: rechargeable battery pack. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0018] It should be understood that the present disclosure may be subject to various changes in various aspects without departing from the scope of the present disclosure, and the descriptions and diagrams provided therein are essentially for illustrative purposes and not intended to limit the disclosure. In addition, repeated reference symbols and / or labels may be used in various embodiments of the present disclosure. This repetition is for simplicity and clarity and is not intended to limit the relationship between the various embodiments and / or the described appearance structures. In addition, when a component is mentioned as being "connected" or "coupled" to another component, this may refer to a direct connection or coupling to the other component, or there may be intermediate components.While the broad numerical ranges and parameters presented herein are approximate, the values ​​in specific examples are specified as precisely as possible. Furthermore, it should be understood that while terms such as "first," "second," and "third" may be used to describe various components within the scope of the patent application, these components should not be limited by these terms. The components described accordingly in the embodiments are represented by different component symbols.

[0019] It will be Fig. 1, which is a schematic structural diagram of a converter for a photovoltaic system according to an embodiment of the present disclosure. The present disclosure provides a converter 100 for a photovoltaic system, comprising: at least one unidirectional DC-DC conversion part SDD1, at least one first connection part T1, at least one bidirectional DC-DC conversion part DDD1, at least one second connection part T2, and a housing CS. The at least one first connection part T1 is electrically connected to the at least one unidirectional DC-DC conversion part SDD1, and the at least one first connection part T1 is suitable for being electrically connected to a photovoltaic panel PV1. The at least one bidirectional DC-DC converter DDD1 is connected in parallel with the output of the unidirectional DC-DC converter SDD1.The at least one second connection part T2 is electrically connected to the at least one bidirectional DC-DC conversion part DDD1, and the at least one second connection part T2 is adapted to be electrically connected to a photovoltaic panel PVn or an energy storage device BT. The housing CS covers the at least one unidirectional DC-DC conversion part SDD1 and the at least one bidirectional DC-DC conversion part DDD1 and exposes the at least one first connection part T1 and the at least one second connection part T2.

[0020] Specifically, an output end of the at least one bidirectional DC-DC conversion part DDD1 is connected in parallel with an output end of the unidirectional DC-DC conversion part SDD1. An input end of the at least one bidirectional DC-DC converter DDD1 and an input end of the unidirectional DC-DC converter SDD1 are independent of each other.

[0021] Specifically, the converter 100 may include a plurality of unidirectional DC-DC conversion parts SDD1, SDD2, or a plurality of bidirectional DC-DC conversion parts DDD1, as needed. The second terminal part T2 may have the same structure as the first terminal part T1, but may have different identification features, such as different colors, to indicate to a user that the photovoltaic panel PVn or the energy storage device BT can be electrically connected to the second terminal part T2.

[0022] Specifically, the energy storage device BT includes, for example, a rechargeable battery, a hydrogen energy storage device, and a power generation system consisting of a hydrogen generation module and a hydrogen fuel cell, etc. The energy storage device BT may include a rechargeable storage system that utilizes mechanical energy storage, chemical energy storage, electrochemical energy storage, electrical energy storage, or thermal energy storage. The type of energy storage device is not limited by the disclosure.

[0023] In detail, Fig. 3 or Fig. 4 an embodiment of a circuit diagram of a unidirectional DC-DC conversion part SDD1. Fig. 5 or Fig. Figure 6 shows one embodiment of a circuit diagram of a bidirectional DC-DC conversion part DDD1. However, the disclosure is not limited to these embodiments.

[0024] The converter 100 for the photovoltaic system according to an embodiment of the present disclosure further includes a DC-AC conversion part DAC electrically connected to the at least one unidirectional DC-DC conversion part SDD1 and the at least one bidirectional DC-DC conversion part DDD1 to provide an AC output.

[0025] In detail, the converter 100 further comprises a parallel capacitor C ap and some other devices and converts the DC power into AC power via the DC-AC conversion part DAC to supply it to the grid GD.

[0026] The converter 100 for the photovoltaic system according to an embodiment of the present disclosure further comprises a control part CMD for controlling the electrical connection between the at least one bidirectional DC-DC conversion part DDD1 and the photovoltaic panel PVn or the energy storage device BT.

[0027] In one embodiment of the converter 100 for a photovoltaic system of the present disclosure, the control part CMD also serves to control the electrical connection between at least one unidirectional DC-DC conversion part SDD1 and the photovoltaic panel PV1.

[0028] In one embodiment of the photovoltaic system converter 100 of the disclosure, the control part CMD electrically connects the unidirectional DC-DC conversion part SDD1 / SDD2 to corresponding photovoltaic panels PV1 / PV2 when the photovoltaic panels PV1 to PVn are fully installed.

[0029] Specifically, the control part CMD controls the electrical connection between the at least one unidirectional DC-DC conversion part SDD1 and the photovoltaic panel PV1 and controls the electrical connection between the at least one bidirectional DC-DC conversion part DDD1 and the energy storage device BT to allow the photovoltaic panel PV1 to charge the energy storage device BT through the at least one unidirectional DC-DC conversion part SDD1 and the at least one bidirectional DC-DC conversion part DDD1, or to cause the energy storage device BT to supply AC power to the grid GD through the at least one bidirectional DC-DC conversion part DDD1 and the DC-AC conversion part DAC.

[0030] The converter 100 for a photovoltaic system according to an embodiment of the present disclosure further comprises a first switch part S1 for switching the electrical connection between the at least one unidirectional DC-DC conversion part SDD1 and the photovoltaic panel PV1.

[0031] Specifically, the first switch part S1 can be a circuit breaker or a manual switch. The circuit breaker can be controlled by the control part CMD. Manual switches are operated by the user. Specifically, the first switch part S1 primarily serves to protect the converter 100 and personnel by disconnecting the electrical connection between the converter 100 and the photovoltaic panel PV1 during installation or disassembly of the photovoltaic panel PV1.

[0032] The converter 100 for a photovoltaic system according to an embodiment of the present disclosure further comprises a second switch part S2 for switching the electrical connection between the at least one bidirectional DC-DC conversion part DDD1 and the photovoltaic panel PV1 or the energy storage devices BT.

[0033] Specifically, the second switch part S2 can be a circuit breaker or a manual switch. The circuit breaker can be controlled by the control part CMD. Manual switches are operated by the user. Specifically, when the second connection part T2 is electrically connected to the photovoltaic panel PVn, the second switch part S2 mainly serves to protect the converter 100 and personnel by disconnecting the electrical connection to the photovoltaic panel PVn during installation or disassembly of the photovoltaic panel PVn. When the second connection part T2 is electrically connected to the energy storage device BT, the second switch part S2 mainly serves to switch so that the energy storage device BT supplies power to the converter 100 or the converter 100 charges the energy storage device BT.

[0034] With reference to Fig. 2a is Fig. 2a shows a schematic structural diagram of a converter 200 for a photovoltaic system according to another embodiment of the present disclosure. The converter 200 for the photovoltaic system according to an embodiment of the present disclosure further comprises at least one third connection part T3 electrically connected to the at least one bidirectional DC-DC conversion part DDD1, wherein the at least one third connection part T3 is adapted to be electrically connected to the energy storage device BT, and the at least one second connection part T2 is adapted to be electrically connected to the photovoltaic panel PVn.

[0035] In particular, the at least one third connection part T3 may have a different shape, structure or color than the at least one second connection part T2 in order to prevent the user from incorrectly connecting the energy storage device BT or the photovoltaic panel PVn.

[0036] In one embodiment of the disclosure, the converter 200 for the photovoltaic system further comprises a control part CMD for controlling the electrical connection between the at least one bidirectional DC-DC conversion part DDD1 and the photovoltaic panel PVn or between the at least one bidirectional DC-DC converter DDD1 and the energy storage device BT.

[0037] Specifically, if the at least one third terminal part T3 is electrically connected to the energy storage device BT and the at least one second terminal part T2 is electrically connected to the photovoltaic panel PVn, since both the at least one third terminal part T3 and the at least one second terminal part T2 are electrically connected to the at least one bidirectional DC-DC conversion part DDD1, it is necessary to control such that only one of the energy storage device BT and the photovoltaic panel PVn can be electrically connected to the at least one bidirectional DC-DC conversion part DDD1 in order to prevent the energy storage device BT from supplying power to the photovoltaic panel PVn or to prevent the photovoltaic panel PVn from being erroneously supplied with power when the user wants to charge the energy storage device BT by the at least one bidirectional DC-DC converter DDD1.

[0038] The converter 200 for the photovoltaic system according to an embodiment of the present disclosure further comprises a second switch part S2 for switching the electrical connection between the at least one bidirectional DC-DC conversion part DDD1 and the photovoltaic panel PVn.

[0039] The converter 200 for the photovoltaic system according to an embodiment of the present disclosure further comprises a third switch part S3 for switching the electrical connection between the at least one bidirectional DC-DC conversion part DDD1 and the energy storage device BT. Operation of the second switch part S2 and operation of the third switch part S3 are mutually exclusive.

[0040] With reference to Fig. 2b is Fig.2b shows a schematic structural diagram of a converter 300 for a photovoltaic system according to another embodiment of the present disclosure. In one embodiment of the converter 300 for the photovoltaic system of the present disclosure, the energy storage device BT comprises a third switch part S3 and a rechargeable battery pack CL. The third switch part S3 serves to switch an electrical connection between the rechargeable battery pack CL and the at least one bidirectional DC-DC conversion part DDD1. Operation of the second switch part S2 and operation of the third switch part S3 are mutually exclusive.

[0041] Specifically, the second switch part S2 or the third switch part S3 can be a circuit breaker or a manual switch. The circuit breaker can be controlled by the control part CMD. Manual switches are operated by the user. To prevent the energy storage device BT from supplying power to the photovoltaic panel PVn, the operation of the second switch part S2 and the third switch part S3 excludes each other. That is, when the second switch part S2 is connected (on), the third switch part S3 is disconnected (off), and when the second switch part S2 is disconnected (off), the third switch part S3 is connected (on).

[0042] Compared with the prior art, the disclosure includes the bidirectional DC-DC conversion part to replace part of the unidirectional DC-DC conversion parts, thereby making the configuration of solar power modules and the energy storage device in the solar power generation system more flexible, space-saving, and less costly.

[0043] The disclosure may be modified in many ways by persons skilled in the art who are familiar with this technology, without, however, departing from the intended protection within the scope of the patent application. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] CN 202422173763.8

[0001]

Claims

[1] Converter for a photovoltaic system, comprising: at least one unidirectional DC-DC conversion part, at least one first connection part electrically connected to the at least one unidirectional DC-DC conversion part, wherein the at least one first connection part is suitable for being electrically connected to a photovoltaic panel, at least one bidirectional DC-DC conversion part connected in parallel with the unidirectional DC-DC conversion part, at least one second connection part electrically connected to the at least one bidirectional DC-DC conversion part, wherein the at least one second connection part is suitable for being electrically connected to a photovoltaic panel or an energy storage device, and a housing covering the at least one unidirectional DC-DC conversion part and the at least one bidirectional DC-DC conversion part and exposing the at least one first terminal part and the at least one second terminal part. [2] The converter for the photovoltaic system according to claim 1, further comprising a DC-AC conversion part electrically connected to the at least one unidirectional DC-DC conversion part and the at least one bidirectional DC-DC conversion part to provide an AC output. [3] The converter for the photovoltaic system according to claim 1, further comprising a control part for controlling an electrical connection between the at least one bidirectional DC-DC conversion part and the photovoltaic panel or the energy storage device. [4] The converter for the photovoltaic system according to claim 3, wherein the control part further serves to control an electrical connection between the at least one unidirectional DC-DC conversion part and the photovoltaic panel. [5] The converter for the photovoltaic system according to claim 4, further comprising a first switch part for switching the electrical connection between the at least one unidirectional DC-DC conversion part and the photovoltaic panel. [6] The converter for the photovoltaic system according to claim 3, further comprising a second switch part for switching an electrical connection between the at least one bidirectional DC-DC conversion part and the photovoltaic panel or the energy storage device. [7] The converter for the photovoltaic system according to claim 1, further comprising at least one third terminal part electrically connected to the at least one bidirectional DC-DC conversion part, wherein the at least one third terminal part is adapted to be electrically connected to the energy storage device and the at least one second terminal part is adapted to be electrically connected to the photovoltaic panel. [8] The converter for the photovoltaic system according to claim 7, further comprising a control part for controlling an electrical connection between the at least one bidirectional DC-DC conversion part and the photovoltaic panel or an electrical connection between the at least one bidirectional DC-DC conversion part and the energy storage device. [9] The converter for the photovoltaic system according to claim 7, further comprising a second switch part for switching an electrical connection between the at least one bidirectional DC-DC conversion part and the photovoltaic panel. [10] The converter for the photovoltaic system according to claim 9, further comprising a third switch part for switching an electrical connection between the at least one bidirectional DC-DC conversion part and the energy storage device, wherein the second switch part and the third switch part are mutually exclusive. [11] The converter for the photovoltaic system according to claim 9, wherein the energy storage device comprises a third switch part and a rechargeable battery pack, and the third switch part is for switching an electrical connection between the rechargeable battery pack and the at least one bidirectional DC-DC conversion part, and wherein the second switch part and the third switch part are mutually exclusive.

Images