Parallel H-bridge unit, stage parallel H-bridge energy storage system and power system

Abstract

The utility model relates to a parallel H-bridge unit, a stage parallel H-bridge energy storage system and a power system. The parallel H-bridge unit comprises a plurality of single H-bridge units which are connected in parallel, and each single H-bridge unit comprises an H-bridge structure formed by a plurality of switch elements. By adopting the parallel H-bridge unit, large current can be realized through a small-current switch element.

Description

Technical Field

[0001] The present application relates to the field of circuit technology, and in particular to a parallel H-bridge unit, a multi-stage parallel H-bridge energy storage system, and a power system. Background Art

[0002] With the continuous improvement of new energy technologies, energy storage systems are developing towards larger capacity and higher power, and the current level of energy storage systems is also constantly improving.

[0003] However, the rated voltage and rated current of switching elements such as insulated gate bipolar transistors (IGBTs) and metal-oxide-semiconductor field-effect transistors (MOSFETs) are relatively low, and their direct application cannot meet the energy storage needs of large currents.

[0004] Therefore, how to realize a high-current energy storage converter through a low-current switching element is a key research topic for those skilled in the art. Utility Model Content

[0005] Based on this, it is necessary to provide a parallel H-bridge unit, a parallel H-bridge energy storage system and a power system that can achieve high current through low current switching elements to address the above technical problems.

[0006] In a first aspect, the present application provides a parallel H-bridge unit, comprising a plurality of mutually parallel single H-bridge units, each of which comprises an H-bridge structure composed of a plurality of switching elements.

[0007] In one embodiment, a single H-bridge unit includes four switching elements, each of which is located in one of the four bridge arms of the H-bridge structure.

[0008] In a second aspect, the present application further provides a single-phase parallel H-bridge energy storage system, comprising a first terminal unit, a second terminal unit, m energy storage units, and m-1 parallel H-bridge units of any of the above items, where m≥2;

[0009] The first terminal unit is connected to the first energy storage unit, the m energy storage units are alternately connected to the m-1 parallel H-bridge units, and the second terminal unit is connected to the last energy storage unit.

[0010] In one embodiment, the left bridge arm of each single H-bridge unit is connected to the previous energy storage unit, and the right bridge arm of each single H-bridge unit is connected to the next energy storage unit.

[0011] In one embodiment, the energy storage unit includes a capacitor or a battery.

[0012] In one embodiment, the terminal unit includes a plurality of switch pairs connected in parallel, each switch pair includes a plurality of switch elements connected in series, each switch pair is connected to an external circuit, and the terminal unit includes a first terminal unit and a second terminal unit.

[0013] In one embodiment, the external circuit includes a power grid or a load.

[0014] In a third aspect, the present application also provides a three-phase parallel-connected H-bridge energy storage system, comprising three single-phase parallel-connected H-bridge energy storage systems as described above.

[0015] In one embodiment, the system is a three-phase delta-connected energy storage system; three single-phase parallel H-bridge energy storage systems are connected end to end, and the first terminal unit of each single-phase parallel H-bridge energy storage system is respectively connected to one phase of the three-phase power grid.

[0016] In one embodiment, each phase of the system further includes a first reactor and a second reactor; the first end of the first reactor is connected to a phase in the power grid, the second end of the first reactor is connected to the first end of the second reactor, and the second end of the second reactor is connected to the first terminal unit of a single-phase parallel H-bridge energy storage system; the second terminal unit of each single-phase parallel H-bridge energy storage system is connected to the first end of the second reactor of another phase.

[0017] In a fourth aspect, the present application further provides a power system, which includes a cascaded parallel H-bridge energy storage system as described above.

[0018] In the above-mentioned parallel H-bridge unit, since each single H-bridge unit includes an H-bridge structure composed of multiple switching elements, the current level of the single H-bridge unit will be higher than the current level of a single switching element. The parallel H-bridge unit includes multiple single H-bridge units connected in parallel. Therefore, after connecting multiple single H-bridge units in parallel, the current level of the parallel H-bridge unit can be further increased. In this way, a larger current can be achieved through a small current switching element. Moreover, because all units share the same control signal, control is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of a parallel H-bridge unit in one embodiment;

[0020] Figure 2 Schematic diagram of a monomer H-bridge unit in one embodiment;

[0021] Figure 3 is a schematic diagram of yet another parallel H-bridge unit in one embodiment;

[0022] Figure 4Schematic diagram of a single-phase parallel H-bridge energy storage system in one embodiment;

[0023] Figure 5 Schematic diagram of yet another single-phase parallel H-bridge energy storage system in one embodiment;

[0024] Figure 6 Schematic diagram of yet another single-phase parallel H-bridge energy storage system in one embodiment;

[0025] Figure 7 Schematic diagram of two three-phase parallel-connected H-bridge energy storage systems in one embodiment;

[0026] Figure 7 (a) Schematic diagram of a delta-connected parallel H-bridge energy storage system;

[0027] Figure 7 (b) is a schematic diagram of a star-connected parallel H-bridge energy storage system;

[0028] Figure 8 Schematic diagram of another three-phase parallel H-bridge energy storage system in one embodiment;

[0029] Figure 9 is a schematic diagram of two power systems in one embodiment;

[0030] Figure 9 (a) is a schematic diagram of a power system including a single-phase parallel H-bridge energy storage system;

[0031] Figure 9 (b) is a schematic diagram of a power system including a three-phase parallel H-bridge energy storage system.

[0032] Description of reference numerals:

[0033] 100-parallel H-bridge unit, 101-monomeric H-bridge unit, 101a-monomeric H-bridge unit, 101b-monomeric H-bridge unit, 101c-monomeric H-bridge unit, 201-switching element, 201a-switching element, 201b-switching element, 201c-switching element, 201d-switching element, 400-single-phase parallel H-bridge energy storage system, 400a-single-phase parallel H-bridge energy storage system, 400b-single-phase parallel H-bridge energy storage system, 400c-single-phase parallel H-bridge energy storage system System, 401-first terminal unit, 402-second terminal unit, 403-energy storage unit, 500-three-phase parallel H-bridge energy storage system, 801-first inductor, 801a-first inductor, 801b-first inductor, 801c-first inductor, 802-second inductor, 802a-second inductor, 802b-second inductor, 802c-second inductor, 803-grid, 803a-grid, 803b-grid, 803c-grid, 900-power system. DETAILED DESCRIPTION

[0034] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the accompanying drawings. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present disclosure.

[0035] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application include direct and indirect connections (couplings) unless otherwise specified. In the description of this application, it should be understood that the orientations or positional relationships indicated by the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to this application.

[0036] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0037] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly attached to the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only.

[0038] In the following embodiments, although terms such as "first," "second," and the like may be used to describe various components, these components are not necessarily limited to the above terms. The above terms are used only to distinguish one component from another. It will also be understood that expressions used in the singular include plural expressions, unless the singular expression has a significantly different meaning in the context. In addition, in the following embodiments, it will also be understood that the terms "including" and / or "having" used herein indicate the presence of the stated features or components, but do not exclude the presence or addition of one or more other features or components.

[0039] In the following embodiments, when a layer, region, or element is “connected,” it can be interpreted that the layer, region, or element is not only directly connected but also connected via other constituent elements interposed therebetween. For example, when a layer, region, element, etc. is described as being connected or electrically connected, the layer, region, element, etc. can be connected or electrically connected not only directly or directly but also via another layer, region, element, etc. interposed therebetween.

[0040] It is understood that “at least one” refers to one or more, “a plurality” refers to two or more, and “at least a portion of an element” refers to a portion or all of an element.

[0041] It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0043] As described in the background technology, at present, with the continuous improvement of new energy technologies, energy storage systems are developing towards larger capacity and higher power. In order to adapt to this trend, the voltage and current levels of energy storage converters are also constantly improving.

[0044] However, the rated voltage and rated current of switching elements such as insulated gate bipolar transistors (IGBTs) and metal-oxide-semiconductor field-effect transistors (MOSFETs) are relatively low, and their direct application cannot meet the energy storage needs of large currents.

[0045] Therefore, how to achieve a high-current, high-voltage energy storage converter using low-current, low-voltage switching elements is a technical problem that needs to be solved urgently. To address this issue, it is necessary to provide a parallel H-bridge unit. This parallel H-bridge unit will be described below.

[0046] Figure 1 FIG. 1 is a schematic diagram of a parallel H-bridge unit in one embodiment, as shown in FIG. Figure 1 As shown, the parallel H-bridge unit 100 includes a plurality of mutually parallel monomer H-bridge units 101. Figure 1 For example, the monomer H-bridge unit 101 includes a monomer H-bridge unit 101a, a monomer H-bridge unit 101b, and a monomer H-bridge unit 101c. The monomer H-bridge unit 101a, the monomer H-bridge unit 101b, and the monomer H-bridge unit 101c are connected in parallel. Figure 1 Three single H-bridge units 101 are used as an example, but the present embodiment is not limited thereto. The number of single H-bridge units 101 in the parallel H-bridge unit 100 only needs to be greater than two.

[0047] Each single H-bridge unit 101 includes an H-bridge structure composed of multiple switching elements ( Figure 1The switching elements may include, but are not limited to, insulated gate bipolar transistors (IGBTs) and metal-oxide-semiconductor field-effect transistors (MOSFETs).

[0048] Optionally, k switching elements may be connected in parallel and / or in series and positioned in the arms of the H-bridge structure, where k is an integer greater than or equal to 1. Furthermore, optionally, the number of switching elements in each arm of the H-bridge structure may be different. For example, the upper left arm and the lower right arm of the H-bridge structure may each include one switching element, and the lower left arm and the upper right arm may each include two switching elements connected in parallel, although this embodiment does not impose any limitation thereto.

[0049] In the above embodiment, since each single H-bridge unit 101 includes an H-bridge structure composed of multiple switching elements, the current level of the single H-bridge unit 101 is higher than the current level of a single switching element. The parallel H-bridge unit 100 includes multiple single H-bridge units 101 connected in parallel. Therefore, after connecting multiple single H-bridge units 101 in parallel, the current level of the parallel H-bridge unit 100 can be further increased. In this way, a larger current can be achieved through a small current switching element.

[0050] Figure 2 is a schematic diagram of a monomer H-bridge unit in one embodiment, such as Figure 2 As shown, in an exemplary embodiment, optionally, the single H-bridge unit 101 includes four switching elements 201 , which are sequentially denoted as switching element 201 a , switching element 201 b , switching element 201 c , and switching element 201 d .

[0051] The switch elements 201 are located in the four arms of the H-bridge structure. That is, the switch elements 201a, 201b, 201c and 201d are located in the upper left arm, lower left arm, upper right arm and lower right arm of the H-bridge unit 200, respectively.

[0052] In the above embodiment, since the single H-bridge unit 101 includes four switching elements 201, each switching element 201 is located in four bridge arms of the H-bridge structure. Therefore, the H-bridge structure can be realized by multiple switching elements 201, which is beneficial to improving the current level of parallel H-bridge units.

[0053] Figure 3 FIG. 1 is a schematic diagram of another parallel H-bridge unit in an embodiment, as shown in FIG. Figure 3As shown, the parallel H-bridge unit 100 includes three single H-bridge units connected in parallel. Each single H-bridge unit 101 includes four switching elements. The four switching elements constitute an H-bridge structure, and the four switching elements are respectively located in four bridge arms of the H-bridge structure.

[0054] Figure 4 Schematic diagram of a single-phase parallel H-bridge energy storage system in one embodiment. In one embodiment, Figure 4 As shown, a single-phase parallel H-bridge energy storage system 400 is provided, which includes a first terminal unit 401, a second terminal unit 402, m energy storage units 403 and m-1 parallel H-bridge units 100 as any of the above items, m≥2.

[0055] The energy storage unit 403 is used to charge and discharge externally to provide voltage to the external. The energy storage unit 403 may include an energy storage element, such as a battery or a capacitor. The first terminal unit 401 and the second terminal unit 402 are used to connect to an external circuit.

[0056] In the single-phase parallel H-bridge energy storage system 400 , the first terminal unit 401 is connected to the first energy storage unit 403 , m energy storage units 403 are alternately connected to m−1 parallel H-bridge units 100 , and the second terminal unit 402 is connected to the last energy storage unit 403 .

[0057] Figure 5 FIG. 1 is a schematic diagram of another single-phase parallel H-bridge energy storage system in one embodiment. Figure 5 Take m=2 as an example, Figure 5 As shown, when m=2, the single-phase parallel H-bridge energy storage system 400 may include a first terminal unit 401, a first energy storage unit 403, a parallel H-bridge unit 100, a second energy storage unit 403 and a second terminal unit 402 connected in sequence from left to right.

[0058] Figure 6 FIG. 1 is a schematic diagram of another single-phase parallel H-bridge energy storage system in one embodiment. Figure 6 The figure shows a case where the energy storage unit 403 includes energy storage unit 1, energy storage unit 2, energy storage unit 3, ..., energy storage unit m, and the parallel H-bridge unit 100 includes parallel H-bridge unit 1, parallel H-bridge unit 2, ..., parallel H-bridge unit m-1. Figure 6 As shown, the single-phase parallel H-bridge energy storage system 400 may include a first terminal unit 401, energy storage unit 1, parallel H-bridge unit 1, energy storage unit 2, parallel H-bridge unit 2, ..., energy storage unit m-1, parallel H-bridge unit m-1, energy storage unit m, and a second terminal unit 402, which are connected in sequence from left to right.

[0059] In the above embodiment, since the single-phase cascaded parallel H-bridge energy storage system 400 includes a first terminal unit 401, a second terminal unit 402, m energy storage units 403, and m-1 parallel H-bridge units 100, where m≥2; the first terminal unit 401 is connected to the first energy storage unit 403, the m energy storage units 403 are alternately connected to the m-1 parallel H-bridge units 100, and the second terminal unit 402 is connected to the last energy storage unit 403, the parallel H-bridge units 100 can be connected in series, thereby improving the voltage level of the single-phase cascaded parallel H-bridge energy storage system 400, so as to achieve a higher voltage through a low-voltage switching element.

[0060] In an exemplary embodiment, optionally, the left bridge arm of each single H-bridge unit 101 is connected to the previous energy storage unit 403, and the right bridge arm of each single H-bridge unit 101 is connected to the next energy storage unit 403. That is, the left bridge arm of each single H-bridge unit 101 in the i-th parallel H-bridge unit 100 is connected to the i-th energy storage unit, and the right bridge arm of each single H-bridge unit 101 in the i-th parallel H-bridge unit 100 is connected to the i+1-th energy storage unit, where i is an integer from 1 to m-1.

[0061] For example, Figure 5 For example, the left bridge arm of each single H-bridge unit 101 in the parallel H-bridge unit 100 is connected to the first energy storage unit 403 , and the right bridge arm of each single H-bridge unit 101 in the parallel H-bridge unit 100 is connected to the second energy storage unit 403 .

[0062] by Figure 6 For example, the left bridge arm of each single H-bridge unit 101 in the parallel H-bridge unit 1 is connected to the energy storage unit 1, and the right bridge arm of each single H-bridge unit 101 in the parallel H-bridge unit 1 is connected to the energy storage unit 2. The left bridge arm of each single H-bridge unit 101 in the parallel H-bridge unit 2 is connected to the energy storage unit 2, and the right bridge arm of each single H-bridge unit 101 in the parallel H-bridge unit 2 is connected to the energy storage unit 3. The rest is similar and will not be repeated here.

[0063] In the above embodiment, since the left bridge arm of each single H-bridge unit 101 is connected to the previous energy storage unit 403, and the right bridge arm of each single H-bridge unit 101 is connected to the next energy storage unit 403, adjacent parallel H-bridge units 100 can share the same energy storage unit 403. This not only makes the single-phase parallel H-bridge energy storage system 400 more compact and saves hardware costs, but also allows the parallel H-bridge units 100 to be connected in series through the energy storage unit 403, thereby improving the current and voltage levels of the parallel H-bridge energy storage system 400.

[0064] In an exemplary embodiment, optionally, the energy storage unit 403 includes a capacitor or a battery. Figure 5 or Figure 6 For example, the energy storage unit 403 may include a capacitor.

[0065] In the above embodiment, since the energy storage unit 403 includes a capacitor or a battery, the energy storage unit 403 can be charged and discharged to provide voltage to the outside.

[0066] In an exemplary embodiment, please refer to Figure 5 and Figure 6 Optionally, the terminal unit includes a plurality of switch pairs connected in parallel, each switch pair includes a plurality of switch elements 201 connected in series, and each switch pair is connected to an external circuit.

[0067] In this embodiment, the terminal unit includes a first terminal unit 401 and a second terminal unit 402. That is, the first terminal unit 401 and the second terminal unit 402 each include a plurality of switch pairs connected in parallel.

[0068] For example, please refer to Figure 5 or Figure 6 Taking the first terminal unit 401 as an example, the first terminal unit 401 may include three switch pairs connected in parallel, each switch pair including two switch elements 201 connected in series, and each switch pair is connected to an external circuit. The second terminal unit 402 is similar and will not be described in detail here.

[0069] Optionally, the external circuit includes a power grid or a load. The load can be any form of electrical equipment, and this embodiment does not limit it.

[0070] In the above embodiment, since the terminal unit includes a plurality of switch pairs connected in parallel, and each switch pair includes a plurality of switch elements 201 connected in series, and each switch pair is connected to an external circuit, the parallel H-bridge unit 100 can be connected to an external circuit, such as a power grid or a load, through the first terminal unit 401 and the second terminal unit 402.

[0071] Figure 7 Schematic diagram of two three-phase parallel H-bridge energy storage systems in one embodiment. In one embodiment, Figure 7 As shown, two three-phase parallel-connected H-bridge energy storage systems 500 are provided. The three-phase parallel-connected H-bridge energy storage system 500 includes three single-phase parallel-connected H-bridge energy storage systems 400 as described above.

[0072] Taking three single-phase parallel H-bridge energy storage systems 400 including a single-phase parallel H-bridge energy storage system 400a, a single-phase parallel H-bridge energy storage system 400b and a single-phase parallel H-bridge energy storage system 400c as an example, please continue to refer to Figure 7 ,like Figure 7As shown in FIG. 5( a ), three single-phase parallel H-bridge energy storage systems 400 a , 400 b and 400 c can be connected in a triangle to form a three-phase parallel H-bridge energy storage system 500 . Figure 7 As shown in FIG. 5( b ), three single-phase cascaded parallel H-bridge energy storage systems 400 a , 400 b and 400 c can also be connected in a star configuration to form a three-phase cascaded parallel H-bridge energy storage system 500 .

[0073] In the above embodiment, since the three-phase cascaded H-bridge energy storage system 500 includes three single-phase cascaded H-bridge energy storage systems 400 as described above, a three-phase cascaded H-bridge energy storage system 500 can be flexibly obtained through the single-phase cascaded H-bridge energy storage systems 400 to be suitable for different application scenarios.

[0074] Figure 8 A schematic diagram of another three-phase parallel H-bridge energy storage system 500 in one embodiment is shown as follows: Figure 8 As shown, in an exemplary embodiment, optionally, the three-phase parallel H-bridge energy storage system 500 is a three-phase delta-connected energy storage system.

[0075] Please continue to refer to Figure 8 Continuing with the example of three single-phase cascaded H-bridge energy storage systems 400, including single-phase cascaded H-bridge energy storage system 400a, single-phase cascaded H-bridge energy storage system 400b, and single-phase cascaded H-bridge energy storage system 400c, the three single-phase cascaded H-bridge energy storage systems 400a, 400b, and 400c are connected end-to-end. Furthermore, the first terminal units 401 in the single-phase cascaded H-bridge energy storage systems 400a, 400b, and 400c are each connected to one phase of a three-phase power grid.

[0076] In the above embodiment, since the three single-phase cascaded H-bridge energy storage systems 400 are connected end to end, and the first terminal unit 401 of each single-phase cascaded H-bridge energy storage system 400 is respectively connected to one phase of the three-phase power grid, a three-phase cascaded H-bridge energy storage system 500 with a three-phase delta connection can be formed by the three single-phase cascaded H-bridge energy storage systems 400.

[0077] Please continue to refer to Figure 8 In an exemplary embodiment, optionally, each phase of the three-phase shunt H-bridge energy storage system 500 further includes a first reactor 801 and a second reactor 802 .

[0078] Among them, the first end of the first inductor 801 is connected to one phase of the power grid, the second end of the first inductor 801 is connected to the first end of the second inductor 802, and the second end of the second inductor 802 is connected to the first terminal unit 401 of the single-phase parallel H-bridge energy storage system 400; the second terminal unit 402 of each single-phase parallel H-bridge energy storage system 400 is connected to the first end of the second inductor 802 of another phase.

[0079] For example, in a case where the three phases of a power grid include 803a, 803b, and 803c, the first end of a first reactor 801a is connected to one phase 803a of the power grid, and the second end of a second reactor 802a is connected to the first terminal unit 401 of a single-phase cascaded parallel H-bridge energy storage system 400a. The second terminal unit 402 of each single-phase cascaded parallel H-bridge energy storage system 400a is connected to the first end of a second reactor 802b of another phase 803b. The same principles apply and are not further detailed here.

[0080] In the above embodiment, each phase of the three-phase cascaded H-bridge energy storage system 500 further includes a first reactor 801 and a second reactor 802. The first end of the first reactor 801 is connected to a phase in the power grid, the second end of the first reactor 801 is connected to the first end of the second reactor 802, and the second end of the second reactor 802 is connected to the first terminal unit 401 of the single-phase cascaded H-bridge energy storage system 400; the second terminal unit 402 of each single-phase cascaded H-bridge energy storage system 400 is connected to the first end of the second reactor 802 of another phase. It can be seen that the cascaded H-bridge energy storage system can achieve high voltage and high current output by cascading multiple energy storage units, multiple cascaded H-bridge units, and terminal units, thereby facilitating the realization of a high current energy storage converter using low current switching elements.

[0081] Figure 9 FIG. 1 is a schematic diagram of a power system in one embodiment, as shown in FIG. Figure 9 As shown, in one embodiment, a power system 900 is provided, which includes any of the above-mentioned cascaded parallel H-bridge energy storage systems. Figure 9 As shown in FIG. 1( a ), the power system 900 may include a single-phase parallel H-bridge energy storage system 400. Figure 9 As shown in FIG. 8( b ), the power system 900 may include a three-phase parallel H-bridge energy storage system 500 .

[0082] Each module in the energy storage power supply or power system described above can be implemented in whole or in part through software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in hardware form, or can be stored in a computer device memory in software form, so that the processor can call and execute the corresponding operations of each module.

[0083] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0084] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A parallel H-bridge unit, characterized in that: The parallel H-bridge unit (100) comprises a plurality of mutually parallel single H-bridge units (101), and each of the single H-bridge units (101) comprises an H-bridge structure composed of a plurality of switch elements (201).

2. The parallel H-bridge unit according to claim 1, characterized in that: The single H-bridge unit (101) comprises four switch elements (201), and each switch element (201) is located in four bridge arms of the H-bridge structure.

3. A single-phase parallel H-bridge energy storage system, characterized in that: The single-phase parallel H-bridge energy storage system (400) comprises a first terminal unit (401), a second terminal unit (402), m energy storage units (403), and m-1 parallel H-bridge units (100) according to claim 1 or 2, wherein m≥2; The first terminal unit (401) is connected to the first energy storage unit (403), the m energy storage units (403) are alternately connected to the m-1 parallel H-bridge units (100), and the second terminal unit (402) is connected to the last energy storage unit (403).

4. The single-phase parallel H-bridge energy storage system according to claim 3, characterized in that: The left bridge arm of each monomer H-bridge unit (101) is connected to the previous energy storage unit (403), and the right bridge arm of each monomer H-bridge unit (101) is connected to the next energy storage unit (403).

5. The single-phase parallel H-bridge energy storage system according to claim 3, characterized in that: The energy storage unit (403) includes a capacitor or a battery.

6. The single-phase parallel H-bridge energy storage system according to claim 3, characterized in that: The terminal unit includes a plurality of switch pairs connected in parallel, each of the switch pairs includes a plurality of switch elements connected in series, and each of the switch pairs is connected to an external circuit; the terminal unit includes the first terminal unit (401) and the second terminal unit (402).

7. The single-phase parallel H-bridge energy storage system according to claim 6, characterized in that: The external circuit includes a power grid or a load.

8. A three-phase parallel H-bridge energy storage system, characterized in that: The three-phase cascaded parallel H-bridge energy storage system (500) comprises three single-phase cascaded parallel H-bridge energy storage systems (400) according to any one of claims 3 to 7.

9. The three-phase parallel H-bridge energy storage system according to claim 8, characterized in that: The three-phase parallel H-bridge energy storage system (500) is a three-phase delta-connected energy storage system; the three single-phase parallel H-bridge energy storage systems (400) are connected end to end, and the first terminal unit (401) of each single-phase parallel H-bridge energy storage system (400) is respectively connected to one phase of the three-phase power grid.

10. The three-phase parallel H-bridge energy storage system (500) according to claim 9, characterized in that: Each phase of the three-phase cascaded parallel H-bridge energy storage system (500) further includes a first reactor (801) and a second reactor (802); a first end of the first reactor (801) is connected to one phase of the power grid, a second end of the first reactor (801) is connected to a first end of the second reactor (802), and a second end of the second reactor (802) is connected to a first terminal unit (401) of the single-phase cascaded parallel H-bridge energy storage system (400); and a second terminal unit (402) of each single-phase cascaded parallel H-bridge energy storage system (400) is connected to a first end of the second reactor (802) of another phase.

11. A power system, characterized in that: The power system (900) comprises a cascaded parallel H-bridge energy storage system as described in any one of claims 3 to 10.

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