Power supply protection system and protection circuit of string type energy storage converter and energy storage equipment

Abstract

The utility model provides a power supply protection system and protection circuit of a string-type energy storage converter and energy storage equipment. The power supply protection system comprises a conversion module, a control module and a power supply module, wherein the conversion module performs alternating current conversion or direct current conversion on electric energy of the string-type energy storage converter; and the switching module is connected with the conversion module and is used for judging the priority of the electric energy converted by the conversion module and outputting the electric energy. The conversion module is used for carrying out direct current side, energy storage side and alternating current side power supply conversion on the electric energy of the string type energy storage converter, and current can be effectively prevented from flowing backwards to the string type energy storage converter; and the switching module is used for carrying out priority setting on the converted electric energy and outputting the electric energy, so that the complexity of power taking is greatly reduced, data storage and fault information recording can be carried out in time after power failure, and the system has wide applicability.

Description

Technical Field

[0001] The present application relates to the field of energy storage design and application technology, and in particular to a power supply protection system and protection circuit for a string-type energy storage converter. Background Art

[0002] With the widespread adoption of renewable energy and the increasing demand for power system stability, energy storage systems have become critical for balancing supply and demand and improving grid reliability. Existing energy storage systems, due to their integration of multiple battery clusters, present complex power supply requirements and are relatively difficult to store data and record faults after power outages.

[0003] It should be noted that the above introduction to the technical background is merely intended to provide a clear and complete description of the technical solutions of this application and facilitate understanding by those skilled in the art. Simply because these solutions are described in the background technology section of this application, it should not be assumed that the above technical solutions are well known to those skilled in the art. Utility Model Content

[0004] The present application aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, one object of the present application is to provide a power supply protection circuit for a string energy storage converter, comprising:

[0006] A conversion module, which performs AC conversion or DC conversion on the electric energy of the string energy storage converter;

[0007] A switching module is connected to the conversion module, and performs priority judgment on the electric energy converted by the conversion module and outputs the electric energy.

[0008] According to a power supply protection circuit of a string energy storage converter according to one embodiment of the present application, the conversion module includes a first conversion unit, a second conversion unit and a third conversion unit, wherein the first conversion unit is connected to the DC side of the string energy storage converter to perform DC conversion; the second conversion unit is connected to the energy storage side of the string energy storage converter to perform DC / DC conversion; and the third conversion unit is connected to the AC side of the string energy storage converter to perform AC / DC conversion.

[0009] According to the power supply protection circuit of a string energy storage converter in one embodiment of the present application, the first conversion unit includes a first DC / DC converter and a first protection device, wherein the first DC / DC converter is connected to the DC side of the string energy storage converter; and the first protection device is connected to the first DC / DC converter.

[0010] According to a power supply protection circuit of a string energy storage converter according to one embodiment of the present application, the first protection device includes a diode, a load switch, and a rectifier bridge.

[0011] According to the power supply protection circuit of a string energy storage converter in one embodiment of the present application, the second conversion unit includes a second DC / DC converter and a second protection device, wherein the second DC / DC converter is connected to the energy storage side of the string energy storage converter; and the second protection device is connected to the second DC / DC converter.

[0012] According to the power supply protection circuit of the string energy storage converter in one embodiment of the present application, the second protection device includes a diode, a load switch, and a rectifier bridge.

[0013] According to the power supply protection circuit of the string energy storage converter in one embodiment of the present application, the third conversion unit includes an AC / DC converter, wherein the AC / DC converter is connected to the AC side of the string energy storage converter.

[0014] According to a power supply protection circuit of a string energy storage converter according to an embodiment of the present application,

[0015] According to a power supply protection circuit of a string energy storage converter according to one embodiment of the present application, the switching module includes a configuration unit, a mode control unit and a storage unit, wherein the configuration unit is used to set a priority for the electric energy converted by the conversion module; the mode control unit is connected to the configuration unit for setting a priority and transmitting electric energy; the storage unit is connected to the mode control unit for storing operating information of the string energy storage converter.

[0016] Another object of the present application is to propose a power supply protection system for a string energy storage converter, wherein the power supply protection system for the string energy storage converter includes a string energy storage converter device layer and a power supply protection circuit for the string energy storage converter proposed in the present application, wherein the string energy storage converter device layer is connected to the power supply protection circuit of the string energy storage converter.

[0017] Another object of the present application is to provide an energy storage device, which includes the power supply protection system of the string energy storage converter proposed in the present application.

[0018] In this application, the electric energy of the string energy storage converter is converted into three types of power supply: DC side, energy storage side and AC side through a conversion module, and the backflow of current to the string energy storage converter can be effectively prevented; the converted electric energy is prioritized and output through a switching module, which greatly reduces the complexity of power supply, and can store data and record fault information in time after a power outage, and has wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the structure of the power supply protection circuit of the string energy storage converter provided in an embodiment of the present application;

[0020] Figure 2 A schematic diagram of the structure of a conversion module provided according to an embodiment of the present application;

[0021] Figure 3 Schematic diagram of the structure of the switching module provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0022] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0023] The power supply protection system and protection circuit of the string energy storage converter according to the embodiment of the present application are described below with reference to the accompanying drawings.

[0024] Figure 1 This is a structural diagram of the power supply protection circuit of the string energy storage converter provided in the embodiment of the present application, as shown in FIG. Figure 1 As shown, the power supply protection circuit of the string energy storage inverter in the embodiment of the present application includes but is not limited to a conversion module and a switching module, wherein the conversion module converts the electric energy of the string energy storage inverter into AC or DC; the switching module is connected to the conversion module, and performs priority judgment on the electric energy converted by the conversion module and outputs the electric energy.

[0025] It should be noted that the main components of a string energy storage converter include the DC side, energy storage side, AC side, control system, communication module, and other key components. The DC side is the input end of the energy storage converter, responsible for receiving and converting electrical energy from the battery pack. The DC side includes components such as the DC bus (as the main channel for power transmission, it requires low resistance and good conductivity) and inductors (primarily used to filter high-frequency pulsating current on the DC side, ensure smooth DC voltage output, and regulate the rate of current change to improve system responsiveness).

[0026] The energy storage side includes energy storage capacitors (which, as energy storage elements, have the ability to quickly charge and discharge, helping to balance voltage fluctuations on the DC side and provide a stable power supply). Therefore, the conversion module's energy conversion on the energy storage side of the string energy storage converter includes energy conversion on the energy storage capacitors.

[0027] The AC side is the output of the string energy storage converter, responsible for converting the inverted DC power into AC output. Therefore, the conversion module converts the AC power of the string energy storage converter into AC power. In grid-connected mode, the AC side typically provides 220V three-phase AC power, and the conversion module can collect any phase of the AC power to prepare for the next step of priority determination and power output.

[0028] The control system of the string energy storage converter is responsible for monitoring and controlling the operation of the entire energy storage device. It mainly includes a main control unit (responsible for real-time monitoring of the system's operating status and adjusting the power conversion and control strategy according to user needs), a measurement unit (used for real-time measurement and sampling of parameters such as voltage, current, and frequency), and a protection unit (including overcurrent protection, short-circuit protection, overvoltage protection, undervoltage protection, etc., used to protect the safe operation of the energy storage converter and the entire energy storage device). In this embodiment, the control system monitors the operating status of the conversion module, including parameters such as DC operating voltage, maximum DC power, maximum DC current, environmental indicators, operating temperature, storage temperature, relative humidity, altitude, rated power, rated voltage, rated power, output harmonics, power factor, wiring method, maximum efficiency, overload capacity, etc. during the power conversion process in real time to ensure the safe operation of AC conversion and DC conversion.

[0029] The communication module of the string energy storage converter is used for communication, monitoring and remote control with the host computer, which can realize remote monitoring and control of the string energy storage converter and improve the reliability and safety of the entire energy storage equipment.

[0030] Other key components of a string energy storage converter include IGBT modules and rectifiers. The IGBT module regulates voltage, current, and frequency, and its efficiency directly impacts the power conversion efficiency of the string energy storage converter. The rectifier converts AC power from the grid into DC power for storage in batteries or energy storage devices. While not required for all string energy storage converters, it may be present in some applications and should be configured accordingly. This section will not be discussed in detail.

[0031] After the conversion module processes the power, it performs a corresponding priority determination. In the grid-connected state, the AC power is connected to the string energy storage converter, which operates in rectification or inversion mode, and the conversion module converts the AC power. In the off-grid state, the AC power is disconnected from the string energy storage converter, which operates in inversion mode, and the conversion module converts the DC voltage on the DC side (for example, a 1500V DC power supply). When an extreme fault occurs, the DC side fuse and the AC side fuse blow at the same time. At this time, the conversion module converts the electric energy on the energy storage side. Since the energy storage side is usually set by an energy storage capacitor, and the voltage across the energy storage capacitor will not immediately decay to 0V, sufficient reaction time can be left to save the fault information and the entire operation data. Among them, the voltage of the energy storage capacitor usually decays according to the exponential law. The time constant related to the decay = energy storage constant capacity × equivalent resistance across the energy storage capacitor. Therefore, the parameters of the energy storage capacitor can be set based on specific needs to adjust the time constant to ensure sufficient reaction time.

[0032] During the operation of the power supply protection circuit, when connected to the grid, the switching module usually allows the load to preferentially use the AC power of the string energy storage inverter; when the AC power is off the grid, the switching module adjusts the load to use the DC power of the string energy storage inverter; in extreme fault conditions, when both the DC side and the AC side are blown, the switching module connects to the energy storage power of the string energy storage inverter and can save the load fault information and load operation data in a short time.

[0033] Figure 2 Schematic diagram of the structure of the conversion module provided according to the embodiment of the present application. Figure 2 As shown, the conversion module includes a first conversion unit, a second conversion unit and a third conversion unit, wherein the first conversion unit is connected to the DC side of the string energy storage converter to perform DC / DC conversion. Since the DC voltage on the DC side is usually large, for example, 1500V, and the load voltage is usually 12V, 24V, 36V, 48V, etc., the first conversion unit performs a step-down operation; the second conversion unit is connected to the energy storage side of the string energy storage converter to perform DC / DC conversion. Since the energy storage side is connected in parallel with the DC side, the voltage on the energy storage side is the same as the voltage on the DC side, so the second conversion unit performs a step-down operation; the third conversion unit is connected to the AC side of the string energy storage converter to perform AC / DC conversion.

[0034] Furthermore, if Figure 2As shown, the first conversion unit includes a first DC / DC converter and a first protection device, wherein the first DC / DC converter is connected to the DC side of the string energy storage converter; and the first protection device is connected to the first DC / DC converter. As an example, the first protection device can be a diode, a load switch, or a rectifier bridge, which is used to prevent current backflow. The second conversion unit includes a second DC / DC converter and a second protection device, wherein the second DC / DC converter is connected to the energy storage side of the string energy storage converter; and the second protection device is connected to the second DC / DC converter. As an example, the second protection device can be a diode, a load switch, or a rectifier bridge, which is used to prevent current backflow. The third conversion unit includes an AC / DC converter, wherein the AC / DC converter is connected to the AC side of the string energy storage converter.

[0035] It should be noted that the conversion module includes, but is not limited to, a first conversion unit, a second conversion unit, and a third conversion unit, and may also be configured using an application-specific integrated circuit (ASIC, which is a proprietary application chip designed and manufactured for specific user requirements and specific systems) or an IP core (an IP core is a mature design of a circuit module with independent functions in chip design. This circuit design can be applied to other chip design projects that include this circuit module, thereby reducing the design workload, shortening the design cycle, and improving the success rate of chip design. IP cores are classified into three levels: behavioral level, structural level, and physical level, corresponding to three types of IP cores: soft cores designed with hardware description language, solid cores with complete structural description, and hard cores based on physical description and process verification. The specific configuration forms are not detailed here. As long as the electric energy of the string energy storage converter can be converted into AC or DC, any configuration form of the conversion module is applicable, and is not limited to this embodiment.

[0036] Figure 3 Schematic diagram of the structure of the switching module provided according to the embodiment of the present application. Figure 3As shown, the switching module includes a configuration unit, a mode control unit and a storage unit, wherein the configuration unit is used to set the priority of the electric energy converted by the conversion module. In this embodiment, when connected to the grid, the switching module usually allows the load to give priority to the AC power of the string energy storage converter; the mode control unit is connected to the configuration unit, and is used to set the priority and transmit electric energy, and is used to perform corresponding electric energy mode transmission according to the output instruction of the configuration unit; the storage unit is connected to the mode control unit, and is used to store the operating information of the string energy storage converter, and is used to obtain the fault information and load operation data of the load in a short time when an extreme fault occurs and both the DC side and the AC side are blown.

[0037] It should be noted that the switching module includes but is not limited to a configuration unit, a mode control unit and a storage unit, and can also be set up using a dedicated integrated circuit, an IP core, etc. Its specific setting form will not be described here one by one. As long as the priority of the electric energy converted by the conversion module can be judged and the electric energy can be output, the setting form of any conversion module is applicable and is not limited to this embodiment.

[0038] In particular, according to an embodiment of the present application, the structural schematic diagram of the power supply protection circuit referenced above can be implemented as a power supply protection system for a string energy storage converter, wherein the power supply protection system for the string energy storage converter includes a string energy storage converter device layer and a power supply protection circuit for the string energy storage converter provided in this embodiment, wherein the string energy storage converter device layer is connected to the power supply protection circuit for the string energy storage converter. In particular, according to an embodiment of the present application, the power supply protection system for the string energy storage converter referenced above can be implemented as an energy storage device for balancing the load on a power grid.

[0039] In summary, this embodiment uses a conversion module to perform three power supply conversions on the DC side, energy storage side, and AC side of the electric energy of the string energy storage converter, and can effectively prevent current backflow into the string energy storage converter; the switching module sets the priority of the converted electric energy and outputs the electric energy, greatly reducing the complexity of power acquisition, and can promptly store data and record fault information after a power outage, which has wide applicability.

[0040] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0041] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0042] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0043] 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.

[0044] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0045] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A power supply protection circuit for a string energy storage converter, characterized in that: include: A conversion module, which performs AC conversion or DC conversion on the electric energy of the string energy storage converter; A switching module is connected to the conversion module, and performs priority judgment on the electric energy converted by the conversion module and outputs the electric energy.

2. The power supply protection circuit of the string energy storage converter according to claim 1, characterized in that: The conversion module includes a first conversion unit, a second conversion unit and a third conversion unit, wherein the first conversion unit is connected to the DC side of the string energy storage converter to perform DC / DC conversion; the second conversion unit is connected to the energy storage side of the string energy storage converter to perform DC / DC conversion; and the third conversion unit is connected to the AC side of the string energy storage converter to perform AC / DC conversion.

3. The power supply protection circuit of the string energy storage converter according to claim 2, characterized in that: The first conversion unit includes a first DC / DC converter and a first protection device, wherein the first DC / DC converter is connected to the DC side of the string energy storage converter; and the first protection device is connected to the first DC / DC converter.

4. The power supply protection circuit of the string energy storage converter according to claim 3, characterized in that: The first protection device includes a diode, a load switch, and a rectifier bridge.

5. The power supply protection circuit of the string energy storage converter according to claim 2, characterized in that: The second conversion unit includes a second DC / DC converter and a second protection device, wherein the second DC / DC converter is connected to the energy storage side of the string energy storage converter; and the second protection device is connected to the second DC / DC converter.

6. The power supply protection circuit of the string energy storage converter according to claim 5, characterized in that: The second protection device includes a diode, a load switch, and a rectifier bridge.

7. The power supply protection circuit of the string energy storage converter according to claim 2, characterized in that: The third conversion unit includes an AC / DC converter, wherein the AC / DC converter is connected to the AC side of the string energy storage converter.

8. The power supply protection circuit of the string energy storage converter according to claim 1, characterized in that: The switching module includes a configuration unit, a mode control unit and a storage unit, wherein the configuration unit is used to set the priority of the electric energy converted by the conversion module; the mode control unit is connected to the configuration unit for setting the priority and transmitting electric energy; the storage unit is connected to the mode control unit for storing the operating information of the string energy storage converter.

9. A power supply protection system for a string energy storage converter, characterized in that: It comprises a string energy storage converter device layer and a power supply protection circuit of the string energy storage converter according to any one of claims 1 to 8, wherein the string energy storage converter device layer is connected to the power supply protection circuit of the string energy storage converter.

10. An energy storage device, characterized in that: The energy storage device includes the power supply protection system of the string energy storage converter according to claim 9.

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