A commercial and industrial energy storage device

Abstract

This invention provides an industrial and commercial energy storage device, including a battery module, a power control module, and a power conversion module. The battery module is connected to the power conversion module and, under the control of the power control module, is connected to the power grid, allowing the grid to charge the batteries in the battery module or discharge the battery module to the grid. The battery module includes a high-voltage DC-DC boost module, which comprises a battery pack formed by series and parallel connection of secondary batteries and a DC / DC boost power supply module. The DC power output from the battery pack is boosted by the DC / DC boost power supply module and then connected to the power conversion module. In this invention, because a DC / DC boost power supply module is used, only a few batteries are needed in the battery pack, overcoming the shortcomings of current industrial and commercial energy storage devices that rely on multi-stage series connection of batteries to boost voltage for PCS (Power Conversion System), resulting in high maintenance costs.

Description

Technical Field

[0001] This utility model relates to the field of industrial and commercial energy storage equipment. Background Technology

[0002] With the adjustment of national energy storage policies, the growth rate of user-side energy storage has increased significantly. Under the new policies, the energy storage industry is entering a stage of market competition. Technological innovation in energy storage system integration will become one of the driving forces for profitability in the industrial and commercial energy storage industry.

[0003] Currently, commercial and industrial energy storage equipment integration can be broadly categorized into battery modules, power conversion modules, and power control modules. The capacity of commercial and industrial energy storage batteries is generally between one hundred and several hundred kilowatt-hours. To avoid a series of risks associated with battery clusters composed of multiple cells connected in series, the consistency of cells within the same group (consistency of parameters such as cell capacity and internal resistance) is extremely important to prevent premature failure of a single cell from affecting the entire battery pack. The requirement for battery consistency eliminates the possibility of using other types or low-cost cells in a single energy storage device, increasing the BOM cost of the energy storage system (BOM cost, or Bill of Material cost, refers to the cost directly related to the hardware product, which is the expense incurred for each finished product. It has different specific meanings and importance in different industries and scenarios, and includes multiple cost components). Furthermore, if maintenance is needed on a single cell during later use, the entire battery pack must be replaced, further increasing the equipment's operating costs. Because a single battery pack contains a large number of cells, there are relatively more potential risk points within the pack. If one cell experiences thermal runaway, it can affect many other cells in the pack, increasing the probability and danger of a fire.

[0004] Currently, commercial and industrial energy storage cells are connected in series to reach several hundred or even thousands of volts before being converted from AC to DC by a power generation system (PCS) for grid connection or user supply. Due to considerations of integration and cost control, the number of cells connected in series in commercial and industrial energy storage systems has been increasing in recent years. From the initial 16 cells / pack, to the current 24 or 32 cells / pack, the voltage of a single battery pack has increased from 48V to 102V, and the weight has increased from approximately 100 kg to 200 kg. This model, which relies on multi-stage series connection of batteries to increase voltage for PCS use, has many disadvantages: First, maintenance costs are high. When a cell fails, the system cabinet must stop operating, waiting for the replacement of the entire battery pack containing that cell. Since a single battery pack weighs 100-200 kg, replacing such a heavy pack requires specialized lifting equipment and a suitable site, making the process time-consuming and labor-intensive. This leads to several issues: First, it increases the overall cost of using and maintaining the energy storage equipment. Second, the cost of assembling the battery cells is high. The multi-stage series connection of batteries requires a high degree of consistency in the internal resistance, voltage, and capacity of the cells, further increasing the procurement and usage costs. The need for cell consistency and selection also increases manufacturing costs for cell manufacturers. Third, there are relatively greater safety risks. Because the battery pack has a large number of cells connected in series, and the consistency requirements are high, the risk of thermal runaway and subsequent fires increases.

[0005] Here, PCS stands for Power Conversion System, a bidirectional current-controlled conversion device that connects an energy storage battery system to the power grid or load. Its core function is to control the charging and discharging process of the energy storage battery, thereby converting AC to DC power. It consists of hardware and software components for power, control, protection, and monitoring, and is available in single-phase and three-phase configurations. A single-phase PCS typically consists of a bidirectional DC-DC step-up / step-down converter and a DC / AC converter. Utility Model Content

[0006] This invention addresses the shortcomings of current industrial and commercial energy storage devices that rely on multi-stage series connection of batteries to boost voltage for PCS, resulting in high maintenance costs. It provides an industrial and commercial energy storage device in which the battery pack uses only a few individual batteries and utilizes a DC / DC boost power module to boost the voltage.

[0007] The technical solution adopted by this utility model to achieve its technical objective is as follows: an industrial and commercial energy storage device, including a battery module, a power control module, and a power conversion module; the battery module is connected to the power conversion module and connected to the power grid under the control of the power control module, so as to charge the battery in the battery module or discharge the battery module to the power grid; the battery module includes a high-voltage DC boost module, which includes a battery pack formed by secondary batteries connected in series and parallel and a DC / DC boost power supply module, and the DC power output from the battery pack is boosted by the DC / DC boost power supply module and then connected to the power conversion module.

[0008] Furthermore, in the aforementioned industrial and commercial energy storage equipment: in the battery module, the main control board for the series-parallel connection of battery cells is integrated inside the high-voltage DC boost module.

[0009] Furthermore, in the aforementioned industrial and commercial energy storage equipment: the power conversion module is a PCS that controls the charging and discharging process of the battery pack.

[0010] Furthermore, the aforementioned industrial and commercial energy storage equipment also includes a power regulation system. The power regulation system is connected to the main control board and PCS of the battery cells via CAN. When the industrial and commercial energy storage equipment needs to start, stop, increase, or decrease power, the power regulation system notifies the PCS and each main control board of the battery cells via CAN. The main control board of the battery cells then controls the high-voltage DC boost module to work in coordination with the PCS to start or stop the DC / DC boost power module, or increase or decrease the power output.

[0011] Furthermore, in the aforementioned industrial and commercial energy storage equipment: the main control board for the series-parallel connection of the battery cells includes a monitoring module for real-time monitoring of the parameters of its paired battery cells, the parameters including the real-time temperature and voltage of the battery cells.

[0012] Furthermore, in the aforementioned industrial and commercial energy storage equipment: the battery pack consists of four lithium-ion batteries connected in series to form a 12V battery pack.

[0013] Furthermore, in the aforementioned industrial and commercial energy storage equipment: the high-voltage DC boost module has an input range of 10-16V / DC and an output voltage that is adjustable from 600-950VDC.

[0014] In this invention, because a DC / DC boost power module is used, only a few batteries are needed in the battery pack, overcoming the shortcomings of current industrial and commercial energy storage equipment that rely on multi-stage series connection of batteries to increase voltage for PCS use, resulting in high maintenance costs.

[0015] In addition, it also has the following characteristics:

[0016] 1. Battery pack consistency is not required; battery packs from different brands can be mixed and matched, and new and used, or various types of retired cells can be used together to form battery packs. This solves various problems caused by battery pack inconsistencies and reduces the risk of fire. It also addresses the issue of where to dispose of a large number of retired automotive power cells, extending their lifespan.

[0017] 2. Based on extensive data analysis of battery cell fire incidents, there are three stages in which a battery cell fire caused by overvoltage or overcurrent at the input and output: the initial abnormal stage, the risk accumulation stage, and the risk outbreak stage. The battery cell temperature exhibits different characteristics at each stage. This patent monitors the battery cell temperature in real time. When a risk signal appears in a battery cell (in the initial abnormal stage), the input and output paths of all four cells in that battery pack can be immediately disconnected, and the module's connection to the input bus can be severed, isolating the risk. This does not affect system operation and significantly reduces the risk of battery cell fires.

[0018] 3. For later maintenance, only the high-voltage DC boost module needs to be replaced, which will not affect the use of the system. The weight is greatly reduced, maintenance is simple, and the cost is low.

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0020] Appendix Figure 1 This is a circuit diagram of Embodiment 1 of the present invention. Detailed Implementation

[0021] Example 1 Figure 1 As shown, it is an industrial and commercial energy storage device used by industrial and commercial enterprises. Industrial and commercial enterprises use this energy storage device to charge from the external power grid during off-peak hours (when electricity prices are lower), and use the PCS to supply power to the enterprise's internal power grid during peak hours (when electricity prices are higher) in order to save on electricity costs.

[0022] This embodiment of an industrial and commercial energy storage device includes, like current common energy storage devices, a battery module, a power control module, and a power conversion module. The battery module is connected to the power conversion module and, under the control of the power control module, is connected to the power grid, allowing the grid to charge the batteries in the battery module or discharge the battery module to the grid. The battery module includes a high-voltage DC-DC boost module, which comprises a battery pack formed by series and parallel connection of secondary batteries and a DC / DC boost power supply module. The battery pack outputs a 12V battery pack consisting of four lithium-ion batteries connected in series. The DC / DC boost power supply module has an input range of 10-16V / DC and an adjustable output voltage of 600-950VDC.

[0023] like Figure 1As shown, in this embodiment, the high-voltage DC-DC boost module consists of four lithium-ion battery cells connected in series to form a 12V battery pack, plus a DC / DC boost power supply module. The main control board, which integrates the series and parallel connections of the battery cells, is located inside the high-voltage DC-DC boost module. The input range of the high-voltage DC-DC boost module is 10-16V / DC, completely covering the operating voltage range of the lithium-ion battery pack, and the output voltage is adjustable from 600-950V / DC.

[0024] In this embodiment, multiple high-voltage DC-DC boost modules are connected in parallel to the inverter input bus for use by the PCS or the inverter. Because the high-voltage DC-DC boost module is a DC / DC boost switching power supply, it has a wide input range and adjustable output voltage and current. The main control board, connected in series and parallel to the battery cells, monitors the temperature and other parameters of the paired cells in real time. The voltage, input, and output current of the battery are completely controlled through the boost module's switching power supply. Therefore, there are no consistency requirements for the lithium-ion battery pack integrated into the energy storage system; cells from any brand can be freely combined, and retired and brand-new cells can be used simultaneously. The high-voltage DC-DC boost module has various protection functions such as overcurrent, overvoltage, and overtemperature protection for input and output, making the equipment more reliable and less prone to risks.

[0025] At the equipment system level, the energy storage device's power regulation system is connected to the main control board of the battery cells and the PCS or inverter via CAN. When the energy storage device needs to start, stop, increase, or decrease power, the power regulation system notifies the inverter and each battery cell series-parallel main control board via CAN. The main control board then controls the high-voltage DC boost module to coordinate with the inverter, causing the boost module to start or stop working, or increase or decrease the power output. This operating mode allows all modules on the PCS / inverter input bus to work in a balanced manner, resulting in more stable voltage and current on the bus, more stable operation of each module and component, and reduced risk of runaway.

[0026] Specifically, in this embodiment, two copper strips or wires extend from the positive and negative input terminals of the inverter PCS of the industrial and commercial energy storage equipment to serve as the inverter input bus. Based on the inverter power, the positive and negative outputs of multiple high-voltage DC boost modules and communication components are connected to the PCS or inverter input bus via screw-locking connections. The bus is isolated from the DC / DC boost switching power supply output of the high-voltage DC boost modules by a switch. At this point, the hardware connection of all important components is complete.

[0027] After the high-voltage DC boost module is connected to the PCS or inverter input bus, the DC / DC boost switching power supply is in a non-operating state by default. The power regulation system in the power control module is powered by the system and is in standby mode. The main control board connected in series and parallel by the battery cells is powered by the lithium-ion battery and is in standby mode.

[0028] When the energy storage device starts up, the power regulation system uses CAN to instruct the main control board of the battery cells to start the DC / DC boost switching power supplies of each high-voltage DC-DC boost module. Once the output voltage of each high-voltage DC-DC boost module's DC / DC boost switching power supply is started and stabilized to the input voltage range required by the PCS or inverter, the power regulation system then uses CAN to instruct the inverter to start working and output AC power for downstream use. When the energy storage device stops up, the power regulation system uses CAN to instruct the inverter to first shut down the AC output, and then uses CAN to instruct the main control board of the battery cells to control the DC / DC boost switching power supplies of the high-voltage DC-DC boost modules to shut down. After each high-voltage DC-DC boost module is completely shut down, the energy storage system outputs a system stop working indicator. When the energy storage system needs to increase or decrease the output power, the power regulation system instructs the main control board of the battery cells to first instruct the high-voltage DC-DC boost modules to increase or decrease the output power, and then instructs the PCS or inverter to increase or decrease the output power as required.

Claims

1. An industrial and commercial energy storage device, comprising a battery module, a power control module, and a power conversion module; wherein the battery module is connected to the power conversion module and, under the control of the power control module, is connected to the power grid, utilizing the power grid to charge the battery in the battery module or for the battery module to discharge to the power grid; characterized in that: The battery module includes a high-voltage DC-DC boost module, which comprises a battery pack formed by connecting secondary batteries in series and parallel, and a DC / DC boost power supply module. The DC power output from the battery pack is boosted by the DC / DC boost power supply module and then connected to a power conversion module.

2. Industrial and commercial energy storage device according to claim 1, characterized in that: In the battery module, the main control board, which connects the battery cells in series and parallel, is integrated inside the high-voltage DC boost module.

3. Industrial and commercial energy storage device according to claim 2, characterized in that: The power conversion module is a PCS that controls the charging and discharging process of the battery pack.

4. Industrial and commercial energy storage device according to claim 3, characterized in that: The power control module includes a power regulation system, which is connected to the main control board and PCS of the battery cells via CAN. When the industrial and commercial energy storage equipment needs to start, stop, increase or decrease power, the power regulation system notifies the PCS and each main control board of the battery cells via CAN. The main control board of the battery cells then controls the high-voltage DC boost module to work in coordination with the PCS to start or stop the DC / DC boost power module, or increase or decrease the power output.

5. Industrial and commercial energy storage device according to claim 4, characterized in that: The main control board for the series-parallel connection of the battery cells includes a monitoring module that monitors the parameters of its paired battery cells in real time, including the real-time temperature and voltage of the battery cells.

6. Industrial and commercial energy storage device according to any of claims 1 to 5, characterized in that: The battery pack consists of four lithium-ion batteries connected in series to form a 12V battery pack.

7. Industrial and commercial energy storage device according to claim 6, characterized in that The high-voltage DC boost module has an input range of 10-16V / DC and an adjustable output voltage of 600-950VDC.

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