A multi-port flexible interconnection device based on energy storage converters

Abstract

The utility model provides a kind of multiport flexible interconnection device based on energy storage converter, by integrating energy storage converter inside flexible interconnection device, when single area energy storage equipment distribution transformer fails, another area energy storage equipment distribution transformer can be powered to important load through the device, realize energy interflow between multiple area energy storage equipment;Single flexible interconnection mechanism built-in controller is connected using Ethernet between superior dispatching management system and microgrid management system, built-in controller and energy storage converter use RS485 communication, improve the communication rate between multiple area energy storage equipment and energy interflow efficiency between area energy storage equipment;AC side and DC side of flexible interconnection device can realize equipment self-protection, improve the safety and reliability of equipment.Using the above technical scheme, energy interflow between multiple area energy storage equipment can be realized;Effectively improve the communication rate between multiple area energy storage equipment and energy interflow efficiency between area energy storage equipment;Effectively improve the safety and reliability of equipment.

Description

Technical Field

[0001] This utility model relates to the field of electrochemical energy storage systems and low-voltage power distribution equipment, specifically to a multi-port flexible interconnection device based on an energy storage converter. Background Technology

[0002] With the increasing market demand for large-scale energy storage power stations with high voltage and high power, energy storage converters are being increasingly used in low-voltage power distribution. Energy storage converters (Power Conversion Systems, PCS) enable bidirectional flow of electrical energy between the AC and DC sides through power electronics technology, serving as a crucial link between DC power distribution systems and the high-voltage power grid or loads. They play a significant role in both energy storage and management. Flexible interconnection devices are switches that manage and regulate the electrical energy of multiple low-voltage distribution area energy storage devices, enabling energy sharing among them. They are widely used in AC and DC power distribution systems.

[0003] The multi-port flexible interconnection device based on energy storage converter is a device that combines energy storage converter with flexible DC transmission, and uses power electronics to perform AC / DC conversion of energy padding, so as to realize the power mutual assistance of energy storage devices in multiple low-voltage distribution areas.

[0004] However, existing flexible interconnection devices based on energy storage converters have the following problems: isolation between a single flexible interconnection device and low-voltage AC; lack of self-protection function for a single flexible interconnection device; and difficulty in unifying and coordinating the communication control of multiple flexible interconnection devices, resulting in a slow communication control rate. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of the aforementioned technologies by proposing a multi-port flexible interconnection device based on an energy storage converter. This invention aims to solve the problems of a single flexible interconnection device lacking self-protection functionality and isolation from low-voltage AC, as well as the difficulty in unifying and coordinating multiple flexible interconnection devices.

[0006] This utility model provides a multi-port flexible interconnection device based on an energy storage converter, including two flexible interconnection mechanisms with self-protection and isolation functions. The AC input terminals of the two flexible interconnection mechanisms are respectively connected to a transformer area energy storage device. The DC output terminals of the two flexible interconnection mechanisms are connected in parallel and merged into a DC bus. The two flexible interconnection mechanisms are connected to a control unit through a network cable. The control unit is used to realize energy mutual assistance between transformer area energy storage devices according to the received data signals.

[0007] Preferably, the flexible interconnection mechanism includes two energy storage converters, the AC side of the energy storage converters is connected to an isolation transformer, the isolation transformer is connected to the energy storage equipment in the distribution area, and an AC circuit breaker is provided between the isolation transformer and the energy storage converters and the energy storage equipment in the distribution area. A DC circuit breaker is installed between the energy storage converter and the DC output terminal.

[0008] Preferably, the control unit includes a control system, an execution system, and a monitoring system. The monitoring system is connected to the AC input of the energy storage device in the distribution area to monitor the AC input power of the energy storage device. The monitoring system is connected to the control system, and the control system is connected to the execution system. The control system issues instructions to the execution system based on the monitoring data of the monitoring system, and the execution system controls the circuit to perform scheduling and self-protection.

[0009] The monitoring system includes an energy meter installed between the energy storage equipment in the distribution area and the AC circuit breaker, that is, the energy meter is placed on the incoming side of the AC circuit breaker; The execution system includes an AC circuit breaker and a DC circuit breaker. The control unit is connected to the AC circuit breaker and the DC circuit breaker respectively. The energy meter is connected to the control unit and provides feedback on energy metering. The control system includes an upper-level energy dispatch management unit, a microgrid system, and a built-in controller. The upper-level energy dispatch management unit is connected to the microgrid system and the built-in controller via network cables. The electricity meter monitors and measures the AC power output by the energy storage equipment in the distribution area and feeds it back to the built-in controller. The upper-level energy dispatch management unit makes decisions and issues energy dispatch strategies, which are then sent to the built-in controller for execution through the microgrid system.

[0010] Preferably, the control unit is connected to the energy meter, the built-in controller, and the energy storage converter via an RS communication bus, forming a device-level real-time data interaction network. The network cable is an Ethernet cable.

[0011] Compared with existing technologies, it has the following beneficial effects: This invention provides a multi-port flexible interconnection device based on an energy storage converter. By integrating the energy storage converter within the flexible interconnection device, when a transformer in a single energy storage area fails, another transformer can supply power to critical loads via this device, achieving energy sharing among multiple energy storage devices in different areas. The built-in controller of each flexible interconnection device connects to the upper-level dispatch management system and microgrid management system via Ethernet, while the built-in controller communicates with the energy storage converter via RS, improving the communication rate and energy sharing efficiency among multiple energy storage devices in different areas. The AC and DC sides of the flexible interconnection device can achieve self-protection, improving the safety and reliability of the equipment. Using the above technical solution, energy sharing among multiple energy storage devices in different areas can be achieved; the communication rate and energy sharing efficiency among multiple energy storage devices in different areas can be effectively improved; and the safety and reliability of the equipment can be effectively enhanced. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only preferred embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 This is a schematic diagram of the overall layout of the flexible interconnection device of this utility model; Figure 2 This is a diagram showing the internal power flow layout of a single flexible interconnection mechanism of this utility model; Figure 3 This is a schematic diagram illustrating the power energy scheduling and functions of a single flexible interconnection device of this utility model; Figure 4 This is a schematic diagram of the power energy scheduling of a single flexible interconnection device according to this utility model; Figure 5 This is a layout diagram of multiple sets of flexible interconnection devices operating in parallel according to this utility model.

[0013] In the diagram, 1-flexible interconnection mechanism; 11-energy storage converter; 12-isolation transformer; 13-AC circuit breaker; 14-DC circuit breaker; 2-area energy storage equipment; 3-DC bus; 4-control unit; 411-upper-level energy dispatch management unit; 412-microgrid system; 42-built-in controller; 43-energy meter; 44-RS485 communication bus; 45-network cable; 5-DC load. Detailed Implementation

[0014] To better understand the structure, functional features, and advantages of this utility model, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings: Example: like Figures 1 to 5 As shown, this utility model provides a multi-port flexible interconnection device based on an energy storage converter 11, including two flexible interconnection mechanisms 1 with self-protection and isolation functions. The AC input terminals of the two flexible interconnection mechanisms 1 are respectively connected to a transformer area energy storage device 2. The DC output terminals of the two flexible interconnection mechanisms 1 are connected in parallel and merged into a DC bus 3. The two flexible interconnection mechanisms 1 are connected to a control unit 4 through a network cable 45. The control unit 4 is used to realize energy mutual assistance between the transformer area energy storage devices 2 according to the received data signals.

[0015] Figures 1 to 5In this context, "single unit" refers to a single flexible interconnection mechanism 1. This device consists of two identical units, and each flexible interconnection mechanism 1 can operate independently. A single flexible interconnection mechanism 1 is suitable for a single three-phase four-wire energy storage converter 11 with a power output of 125kW or less. Two flexible interconnection mechanisms 1 can regulate the AC / DC power of two low-voltage distribution area energy storage devices 2 (AC400V / AC690V) and a DC microgrid (DC750V / DC1000V / DC1500V) up to 250kW. Simultaneously, when paired with a DC-DC converter on the DC side, it can provide DC power supply and energy conversion for DC equipment such as DC charging piles, electrochemical energy storage battery packs, and industrial and commercial energy storage cabinets. Two flexible interconnection mechanisms 1, the DC bus 3 of the distribution area energy storage devices 2, and the control unit 4 constitute a flexible interconnection device. Multiple such devices can be connected in parallel. See [link to relevant documentation]. Figure 5 While connecting the energy storage device 2 in the distribution area, the DC bus 3 is connected in parallel, enabling DC energy flow between the DC load 5 and the flexible interconnection device. This can provide greater power to the DC bus 3, ensuring the power needs of multiple downstream loads. The connection method is relatively flexible and convenient.

[0016] As another embodiment, such as Figure 1 and Figure 2 As shown, the flexible interconnection mechanism 1 of this application includes an energy storage converter 11, an isolation transformer 12 connected to the AC side of the energy storage converter 11, an isolation transformer 12 connected to the substation energy storage device 2, an AC circuit breaker 13 is provided between the isolation transformer 12 and the energy storage converter 11 and the substation energy storage device 2; a DC circuit breaker 14 is provided between the energy storage converter 11 and the DC output terminal.

[0017] On the AC side, a single flexible interconnection mechanism 1 is equipped with two levels of AC protection. The breaking capacity of the AC circuit breaker 13 protects the energy storage converter 11 and the equipment itself. An isolation transformer 12 is also installed. It will not affect the AC grid due to its own failure or power mismatch, and has the function of isolating the AC grid. On the DC side, each flexible interconnection mechanism 1 has two DC circuit breakers 14 installed on the DC side of the two two-day energy storage converters 11, which can provide self-protection for the two DC outputs respectively.

[0018] As another embodiment, such as Figures 2 to 4 As shown, the control unit 4 of this application includes a control system, an execution system, and a monitoring system. The monitoring system is connected to the AC input of the energy storage device 2 in the distribution area to monitor the AC input power of the energy storage device 2 in the distribution area. The monitoring system is connected to the control system, and the control system is connected to the execution system. The control system issues instructions to the execution system based on the monitoring data of the monitoring system, and the execution system controls the circuit to perform scheduling and self-protection.

[0019] The monitoring system includes an energy meter 43 installed between the energy storage device 2 in the transformer area and the AC circuit breaker 13, that is, the energy meter 43 is placed on the incoming side of the AC circuit breaker 13. The execution system includes an AC circuit breaker 13 and a DC circuit breaker 14. The control unit 4 is connected to the AC circuit breaker 13 and the DC circuit breaker 14 respectively. The energy meter 43 is connected to the control unit and provides feedback on energy metering. The control system includes a higher-level energy dispatch management unit 411 and a microgrid system 412. The higher-level energy dispatch management unit 411, the microgrid system 412, and the built-in controller 42 are all connected via network cable 45. The electricity meter 43 monitors and meters the AC power output from the energy storage device 2 in the distribution area and feeds it back to the built-in controller 42. The higher-level energy dispatch management unit 411 makes decisions and issues energy dispatch strategies, which are then sent to the built-in controller 42 for execution via the microgrid system 412. The control unit 4 is connected to the electricity meter 43, the built-in controller 42, and the energy storage converter 11 via an RS485 communication bus 44, forming a device-level real-time data interaction network. Network cable 45 is an Ethernet cable.

[0020] The upper-level energy dispatch management unit 411 is an energy management controller or a central control server. The built-in controller 42 is the controller built into the energy storage device. The microgrid system 412 is the microgrid controller. The built-in controller 42 of the flexible interconnection device is connected to the upper-level control unit 4 and the microgrid system 412 via Ethernet. The microgrid management system can send control signals such as start-up, shutdown, fault protection, power flow direction, and power setting to the built-in controller 42 for the energy storage converter 11, thereby controlling the energy supply and mutual assistance between the low-voltage AC distribution area energy storage device 2 and the DC microgrid. The RS485 communication bus 44 has a faster response speed than the network cable 45, enabling control signals to be sent to the built-in controller 42 and the AC circuit breaker 13 in a very short time. Ethernet can meet the transmission of large amounts of data, facilitating the rapid flow and processing of energy dispatch commands.

[0021] As another embodiment, such as Figure 1 and Figure 5 As shown, the two DC outputs are connected by power copper busbars. When used in parallel, the DC power is relatively large, representing the combined power of the two flexible interconnection mechanisms 1. The load configuration is as follows: Firstly, when used in conjunction with industrial and commercial energy storage cabinets, a single unit can be regarded as two energy storage converters 11 that share a common DC connection but not a common AC connection, thereby serving as a battery management system (BMS) or energy management system (EMS) at the PACK battery pack cluster level. Secondly, it can be used in conjunction with a power router (SST). A power router is usually an energy conversion device that uses a DAB circuit with a high-frequency transformer. A flexible interconnected single cabinet can use the power module in the SST as a DC load 5, or as a DC load 5 of the SST, thereby realizing bidirectional energy flow. Third, introduce a DC-DC converter to be directly connected to a DC 750V new energy electric vehicle charging pile; Fourth, connect to energy storage photovoltaic equipment, and feed electrical energy back to the AC grid through photovoltaic power generation and flexible interconnection mechanism 1; Fifth, the two internal flexible interconnection mechanisms 1 can be used as constant DC voltage sources, with constant voltage output at the DC side voltage level of the flexible interconnection mechanism 1.

[0022] The above description is merely a preferred embodiment of this utility model and does not constitute any limitation on this utility model. Any person skilled in the art can make many possible variations and modifications to the technical solution of this utility model, or modify it into equivalent embodiments, without departing from the scope of the technical solution of this utility model. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technology of this utility model without departing from the scope of the technical solution of this utility model shall fall within the protection scope of this technical solution.

Claims

1. A multi-port flexible interconnection device based on an energy storage converter, characterized in that... It includes two flexible interconnection mechanisms (1) with self-protection and isolation functions. The AC input terminals of the two flexible interconnection mechanisms (1) are respectively connected to a transformer area energy storage device (2). The DC output terminals of the two flexible interconnection mechanisms (1) are connected in parallel and merged into a DC bus (3). The two flexible interconnection mechanisms (1) are connected to a control unit (4) through a network cable (45). The control unit (4) is used to realize energy mutual assistance between the transformer area energy storage devices (2) according to the received data signals.

2. The multi-port flexible interconnection device based on an energy storage converter according to claim 1, characterized in that, The flexible interconnection mechanism (1) includes two energy storage converters (11). The AC side of the energy storage converters (11) is connected to an isolation transformer (12). The isolation transformer (12) is connected to the distribution area energy storage device (2). An AC circuit breaker (13) is provided between the isolation transformer (12), the energy storage converters (11), and the distribution area energy storage device (2). A DC circuit breaker (14) is provided between the energy storage converter (11) and the DC output terminal.

3. The multi-port flexible interconnection device based on an energy storage converter according to claim 2, characterized in that, The control unit (4) includes a control system, an execution system and a monitoring system. The monitoring system is connected to the AC input of the energy storage device (2) in the distribution area to monitor the AC input power of the energy storage device (2). The monitoring system is connected to the control system, and the control system is connected to the execution system. The control system issues instructions to the execution system based on the monitoring data of the monitoring system, and the execution system controls the circuit to perform scheduling and self-protection.

4. The multi-port flexible interconnection device based on an energy storage converter according to claim 3, characterized in that, The monitoring system includes an energy meter (43) installed between the energy storage device (2) in the transformer area and the AC circuit breaker (13), that is, the energy meter (43) is placed on the incoming side of the AC circuit breaker (13); The execution system includes an AC circuit breaker (13) and a DC circuit breaker (14). The control unit (4) is connected to the AC circuit breaker (13) and the DC circuit breaker (14) respectively. The energy meter (43) is connected to the control unit (4) to provide feedback on energy metering. The control system includes an upper-level energy dispatch management unit (411), a microgrid system (412), and a built-in controller (42). The upper-level energy dispatch management unit (411), the microgrid system (412), and the built-in controller (42) are all connected through the network cable (45). The electricity meter (43) monitors and measures the AC power output by the energy storage device (2) in the distribution area and feeds it back to the built-in controller (42). The upper-level energy dispatch management unit (411) makes decisions and issues energy dispatch strategies, which are sent to the built-in controller (42) through the microgrid system (412) for execution.

5. The multi-port flexible interconnection device based on an energy storage converter according to claim 4, characterized in that, The control unit (4) is connected to the energy meter (43), the built-in controller (42) and the energy storage converter (11) via an RS485 communication bus (44) to form a device-level real-time data interaction network.

6. The multi-port flexible interconnection device based on an energy storage converter according to claim 4, characterized in that, The network cable (45) is an Ethernet cable.

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