Bridge arm assembly and optical storage system

Abstract

The utility model belongs to the technical field of optical storage equipment, and particularly relates to a bridge arm assembly and an optical storage system, the bridge arm assembly comprises a plurality of energy storage devices, a plurality of bypass switches and at least one reactor; wherein the output side of each energy storage device is connected with the corresponding bypass switch, and each bypass switch and the reactor are sequentially connected in series; according to the utility model, the energy storage devices can be connected into the bridge arm assemblies through the bypass switches, and each bridge arm assembly can output (N + 1) levels through N energy storage devices, so that multi-level output of the inverter is realized, the harmonic content is low, the quality of output electric energy is good, the energy storage devices are conveniently expanded subsequently, the modular performance is high, the expansion and maintenance are convenient, and the cost is low. And overhaul and maintenance can be carried out without stopping all the equipment.

Description

Technical Field

[0001] The utility model belongs to the technical field of optical storage equipment, and in particular relates to a bridge arm component and an optical storage system. Background Art

[0002] The intermittent and periodic nature of sunlight results in high volatility, unstable output, and a high degree of randomness in photovoltaic power generation. The grid connection of photovoltaic power generation systems can significantly impact the local power grid, hindering its stable and safe operation. Therefore, photovoltaic power generation systems must be used in conjunction with energy storage systems.

[0003] Both photovoltaic power generation systems and energy storage systems use direct current (DC), which must be converted to alternating current (AC) via inverters before being connected to the AC grid. These systems are connected to the DC side via DC / DC converters. Inverters only have two or three levels of power, resulting in low-quality output power and the inability to expand the capacity of the original equipment. If a component of a photovoltaic power generation system or energy storage system fails, all equipment must be shut down to prevent a safety incident or allow for repair and maintenance, which can impact the power grid.

[0004] Therefore, there is an urgent need to develop a new bridge arm component and photovoltaic storage system to solve the above problems. Utility Model Content

[0005] The purpose of the utility model is to provide a bridge arm component and a light storage system.

[0006] In order to solve the above technical problems, the utility model provides a bridge arm assembly, which includes: a plurality of energy storage devices, a plurality of bypass switches and at least one reactor; wherein the output side of each of the energy storage devices is respectively connected to the corresponding bypass switch, and each of the bypass switches and reactors is connected in series in sequence.

[0007] Specifically, the energy storage device includes: a first circuit breaker, a half-bridge circuit, a second circuit breaker, a third circuit breaker, a photovoltaic module and an energy storage module; the first circuit breaker is connected to a bypass switch; the first circuit breaker is connected to the output side of the half-bridge circuit, the photovoltaic module is connected to the input side of the half-bridge circuit via the second circuit breaker, and the energy storage module is connected to the input side of the half-bridge circuit via the third circuit breaker; the first circuit breaker is suitable for controlling the output side of the half-bridge circuit to output or stop output; the second circuit breaker is suitable for controlling the connection and disconnection between the photovoltaic module and the input side of the half-bridge circuit; and the third circuit breaker is suitable for controlling the connection and disconnection between the energy storage module and the input side of the half-bridge circuit.

[0008] Specifically, the energy storage device further includes: a voltage-stabilizing capacitor; the voltage-stabilizing capacitor is connected to the input side of the half-bridge circuit.

[0009] Specifically, the half-bridge circuit includes: two IGBT anti-parallel diodes; and the two IGBT anti-parallel diodes are connected in series.

[0010] Specifically, the photovoltaic module includes: a first DC / DC converter and a photovoltaic unit; the photovoltaic unit is connected to the second circuit breaker through the first DC / DC converter.

[0011] Specifically, the energy storage module includes: a second DC / DC converter and an energy storage battery unit; the energy storage battery unit is connected to the third circuit breaker through the second DC / DC converter.

[0012] On the other hand, the utility model provides a photovoltaic storage system, which includes: an A-phase circuit, a B-phase circuit, a C-phase circuit and a filter circuit; wherein two bridge arm components as described above are provided in each of the A-phase circuit, the B-phase circuit and the C-phase circuit; the A-phase circuit, the B-phase circuit and the C-phase circuit output three-phase electricity through the filter circuit.

[0013] Specifically, the two bridge arm components in the A-phase circuit are set in opposite directions, and the two bridge arm components in the A-phase circuit are connected; the two bridge arm components in the B-phase circuit are set in opposite directions, and the two bridge arm components in the B-phase circuit are connected; the two bridge arm components in the C-phase circuit are set in opposite directions, and the two bridge arm components in the C-phase circuit are connected; two groups of bridge arm components set in the same direction are formed in the A-phase circuit, the B-phase circuit, and the C-phase circuit, and the corresponding bridge arm components in each group are connected to each other.

[0014] Specifically, the filtering circuit includes: three LCL filters; the three LCL filters are respectively connected to the A-phase circuit, the B-phase circuit, and the C-phase circuit.

[0015] Specifically, corresponding filter capacitors in the three LCL filters are connected to each other.

[0016] The beneficial effect of the present invention is that the energy storage device can be connected to the bridge arm assembly through the bypass switch. Each bridge arm assembly has N energy storage devices and can output (N+1) levels, so that the inverter can output through multiple levels, with low harmonic content and good output power quality. By facilitating the subsequent expansion of the energy storage device, the present invention has high modularity, is easy to expand and maintain, and can carry out inspection and maintenance without shutting down all equipment.

[0017] Other features and advantages of the present invention will be set forth in the following description, and in part will become apparent from the description, or may be understood by practicing the present invention.

[0018] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 This is a schematic diagram of the circuit structure of an optional implementation of the bridge arm assembly of the utility model;

[0021] Figure 2 This is a schematic diagram of the circuit structure of another optional embodiment of the bridge arm assembly of the present utility model;

[0022] Figure 3 It is a circuit diagram of the energy storage device of the utility model;

[0023] Figure 4 It is a circuit diagram of the optical storage system of the utility model.

[0024] In the picture:

[0025] 1. Energy storage device; 2. First DC / DC converter; 3. Second DC / DC converter; 4. Bridge arm assembly;

[0026] K1, bypass switch; L1, reactor; S1, first circuit breaker; S2, second circuit breaker; S3, third circuit breaker; PV1, photovoltaic unit; BAT1, energy storage battery unit; C1, voltage stabilizing capacitor. DETAILED DESCRIPTION

[0027] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0028] Example 1, in this embodiment, as Figures 1 to 3 As shown, this embodiment provides a bridge arm assembly 4, which includes: a plurality of energy storage devices 1, a plurality of bypass switches K1 and at least one reactor L1; wherein the output side of each of the energy storage devices 1 is respectively connected to the corresponding bypass switch K1, and each of the bypass switches K1 and the reactor L1 is connected in series in sequence.

[0029] In this embodiment, the energy storage device 1 can be connected to the bridge arm assembly 4 through the bypass switch K1. Each bridge arm assembly 4 has N energy storage devices 1 and can output (N+1) power levels, thereby realizing multi-level output of the inverter, low harmonic content, and good output power quality. By facilitating subsequent expansion of the energy storage device 1, it has high modularity and is easy to expand and maintain, and can be repaired and maintained without shutting down all equipment.

[0030] Specifically, to facilitate later expansion while the system is powered, some expansion ports can be reserved. Specifically, a bypass switch K1 is connected in series to the bridge arm, and port ports are provided on both sides of the bypass switch K1. When expansion is needed, the bypass switch K1's plug-in port is simply removed and disconnected.

[0031] Specifically, to prevent waveform distortion and increased harmonic content caused by overmodulation, the number N of energy storage devices 1 in each bridge arm component 4 must at least meet the condition: N*Ud / 2>Um, where Ud is the given voltage on the input side of the half-bridge circuit, which can be jointly controlled by the first DC / DC converter 2, the second DC / DC converter 3, the bridge arm component 4 modulation strategy, and the inverter control strategy; Um is the phase voltage amplitude on the grid side.

[0032] Specifically, when the bridge arm assembly 4 is operating normally, each bridge arm assembly 4 requires N energy storage devices 1 to remain functioning properly, but the actual number of energy storage devices 1 in each bridge arm assembly 4 is greater than N. At the same time, the switching of the bridge arm assembly 4 is performed according to the input voltage of the energy storage device 1. For example, if N1 energy storage devices 1 are required to be switched on, when the bridge arm current causes the energy storage device 1 to charge, the N1 energy storage devices 1 with a lower voltage are switched on; when the bridge arm current causes the energy storage device 1 to discharge, the N1 energy storage devices 1 with a higher voltage are switched on.

[0033] In this embodiment, the energy storage device 1 includes: a first circuit breaker S1, a half-bridge circuit, a second circuit breaker S2, a third circuit breaker S3, a photovoltaic module and an energy storage module; the first circuit breaker S1 is connected to the bypass switch K1; the first circuit breaker S1 is connected to the output side of the half-bridge circuit, the photovoltaic module is connected to the input side of the half-bridge circuit via the second circuit breaker S2, and the energy storage module is connected to the input side of the half-bridge circuit via the third circuit breaker S3; the first circuit breaker S1 is suitable for controlling the output side of the half-bridge circuit to output or stop output; the second circuit breaker S2 is suitable for controlling the connection and disconnection between the photovoltaic module and the input side of the half-bridge circuit; the third circuit breaker S3 is suitable for controlling the connection and disconnection between the energy storage module and the input side of the half-bridge circuit.

[0034] Specifically, when the energy storage device 1 is completely unable to operate or requires maintenance, the bypass switch K1 is closed and the first circuit breaker S1 is disconnected; when the energy storage module fails or requires maintenance, the third circuit breaker S3 can be disconnected; when the photovoltaic module requires maintenance, the second circuit breaker S2 can be disconnected, thereby achieving complete isolation of the live parts.

[0035] In this embodiment, the energy storage device 1 further includes: a voltage stabilizing capacitor C1; the voltage stabilizing capacitor C1 is connected to the input side of the half-bridge circuit.

[0036] Specifically, when the photovoltaic module or energy storage module of the energy storage device 1 fails, since the voltage-stabilizing capacitor C1 has a certain ability to stabilize voltage and store electrical energy, and the bridge arm current discharges in one and a half cycles and charges in half cycles, it can ensure that the input side voltage of this part of the module is stable within a certain range, and this part of the module is put into operation. When the energy storage device 1 is in the bypass state, when distributing the input and output cut-off signal, the cut-off signal is always distributed to this part of the module. Since the sub-modules on the bridge arm have a certain redundancy, the safe operation of the system can still be guaranteed.

[0037] In this embodiment, the half-bridge circuit includes: two IGBT anti-parallel diodes; and the two IGBT anti-parallel diodes are connected in series.

[0038] In this embodiment, the photovoltaic module includes: a first DC / DC converter 2 and a photovoltaic unit PV1 ; the photovoltaic unit PV1 is connected to a second circuit breaker S2 via the first DC / DC converter 2 .

[0039] Specifically, the photovoltaic unit PV1 may be a photovoltaic cell, and the photovoltaic unit PV1 is connected to the second circuit breaker S2 via the first DC / DC converter 2 .

[0040] Specifically, the first DC / DC converter 2 is a bidirectional DC / DC converter, and its topology includes but is not limited to a BUCK / BOOST converter and a bidirectional LLC resonant converter.

[0041] Specifically, the first DC / DC converter 2 operates in a photovoltaic maximum power mode to maximize the use of photovoltaic power generation.

[0042] In this embodiment, the energy storage module includes: a second DC / DC converter 3 and an energy storage battery unit BAT1 ; the energy storage battery unit BAT1 is connected to a third circuit breaker S3 via the second DC / DC converter 3 .

[0043] Specifically, the energy storage battery unit BAT1 may be a charge-discharge battery, and the energy storage battery unit BAT1 is connected to the third circuit breaker S3 via the second DC / DC converter 3 .

[0044] Specifically, the second DC / DC converter 3 includes but is not limited to a BOOST converter and various variants thereof.

[0045] Example 2, based on Example 1, Figures 1 to 4 As shown, this embodiment provides a photovoltaic storage system, which includes: an A-phase circuit, a B-phase circuit, a C-phase circuit and a filter circuit; wherein two bridge arm components 4 as provided in Example 2 are provided in the A-phase circuit, the B-phase circuit and the C-phase circuit; the A-phase circuit, the B-phase circuit and the C-phase circuit output three-phase electricity through the filter circuit.

[0046] Specifically, the M of the bridge arm assembly 4 XN1 (X=A,B,C) and M XP1 After the terminals are connected, the filter inductor L X3 Connected; M of each bridge arm assembly 4 XP2 Port interconnection, each bridge arm component 4 M XN2 Port interconnection.

[0047] In this embodiment, the two bridge arm components 4 in the A-phase circuit are set in opposite directions, and the two bridge arm components 4 in the A-phase circuit are connected; the two bridge arm components 4 in the B-phase circuit are set in opposite directions, and the two bridge arm components 4 in the B-phase circuit are connected; the two bridge arm components 4 in the C-phase circuit are set in opposite directions, and the two bridge arm components 4 in the C-phase circuit are connected; two groups of bridge arm components 4 set in the same direction are formed in the A-phase circuit, the B-phase circuit, and the C-phase circuit, and the corresponding bridge arm components 4 in each group are connected to each other.

[0048] In this embodiment, the filtering circuit includes: three LCL filters; the three LCL filters are respectively connected to the A-phase circuit, the B-phase circuit, and the C-phase circuit.

[0049] In this embodiment, corresponding filter capacitors in the three LCL filters are connected to each other.

[0050] Specifically, the filter inductor L in the LCL filter X3 One end of the bridge arm assembly 4 is connected to the M x1 (x=N,P) port connection, filter inductor L X3 The other end of the filter inductor L X4 and filter capacitor C X Connected. Filter capacitor C X One end of the filter inductor L X3 , filter inductor L X4 connected, and the three filter capacitors are connected to each other.

[0051] In summary, the utility model can connect the energy storage device to the bridge arm assembly through the bypass switch. Each bridge arm assembly has N energy storage devices and can output (N+1) levels, so that the inverter can output through multiple levels, with low harmonic content and good output power quality. By facilitating the subsequent expansion of energy storage devices, it has high modularity and is easy to expand and maintain, and can be repaired and maintained without shutting down all equipment.

[0052] All components used in this application (parts whose specific structures are not described) are standard components or components known to those skilled in the art. Their structures and principles are readily known to those skilled in the art through technical manuals or routine experimental methods. Furthermore, the software programs referred to in this application are all prior art, and this application does not involve any improvements to the software programs.

[0053] In the description of the embodiments of the present invention, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0054] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating positions or relationships, are based on the positions or relationships shown in the accompanying drawings and are intended solely to facilitate the description of this utility model and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0055] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. There may be other division methods in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed may be through some communication interface, indirect coupling or communication connection of devices or units, which may be electrical, mechanical or other forms.

[0056] The units described as separate components may or may not be physically separate, and 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 these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0057] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0058] Based on the above-mentioned ideal embodiment of the present invention, and in accordance with the above description, relevant personnel can make various changes and modifications without departing from the technical scope of the present invention. The technical scope of the present invention is not limited to the content of the specification, but must be determined according to the scope of the claims.

Claims

1. A bridge arm assembly, characterized in that: include: Several energy storage devices, several bypass switches and at least one reactor; in The output side of each energy storage device is connected to the corresponding bypass switch, and each bypass switch and reactor are connected in series in sequence. The energy storage device includes: a first circuit breaker, a half-bridge circuit, a second circuit breaker, a third circuit breaker, a photovoltaic module and an energy storage module; The first circuit breaker is connected to the bypass switch; The first circuit breaker is connected to the output side of the half-bridge circuit, the photovoltaic module is connected to the input side of the half-bridge circuit via the second circuit breaker, and the energy storage module is connected to the input side of the half-bridge circuit via the third circuit breaker; The first circuit breaker is adapted to control the output side of the half-bridge circuit to output externally or stop outputting; The second circuit breaker is adapted to control the on / off connection between the photovoltaic module and the input side of the half-bridge circuit; The third circuit breaker is suitable for controlling the connection and disconnection between the energy storage module and the input side of the half-bridge circuit.

2. The bridge arm assembly according to claim 1, wherein: The energy storage device further includes: a voltage stabilizing capacitor; The voltage stabilizing capacitor is connected to the input side of the half-bridge circuit.

3. The bridge arm assembly according to claim 1, wherein: The half-bridge circuit includes: two IGBT anti-parallel diodes; The two IGBT anti-parallel diodes are connected in series.

4. The bridge arm assembly according to claim 1, wherein: The photovoltaic module includes: a first DC / DC converter and a photovoltaic unit; The photovoltaic unit is connected to the second circuit breaker via a first DC / DC converter.

5. The bridge arm assembly according to claim 1, wherein: The energy storage module includes: a second DC / DC converter and an energy storage battery unit; The energy storage battery unit is connected to the third circuit breaker via a second DC / DC converter.

6. A solar storage system, characterized in that: include: A phase circuit, B phase circuit, C phase circuit and filter circuit; in Two bridge arm assemblies according to any one of claims 1 to 5 are provided in each of the A-phase circuit, the B-phase circuit, and the C-phase circuit; The A-phase circuit, the B-phase circuit, and the C-phase circuit output three-phase electricity through a filter circuit.

7. The solar storage system according to claim 6, wherein: The two bridge arm components in the A-phase circuit are arranged in opposite directions, and the two bridge arm components in the A-phase circuit are connected; The two bridge arm components in the B-phase circuit are arranged in opposite directions, and the two bridge arm components in the B-phase circuit are connected; The two bridge arm components in the C-phase circuit are arranged in opposite directions, and the two bridge arm components in the C-phase circuit are connected; Two groups of bridge arm components arranged in the same direction are formed in the A-phase circuit, the B-phase circuit and the C-phase circuit, and the corresponding bridge arm components in each group are connected to each other.

8. The solar storage system according to claim 6, wherein: The filtering circuit includes: three LCL filters; The three LCL filters are connected to the A-phase circuit, the B-phase circuit, and the C-phase circuit respectively.

9. The solar storage system according to claim 8, wherein: The corresponding filter capacitors in the three LCL filters are connected to each other.

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