An energy storage system

Abstract

The present invention provides an energy storage system, comprising a cabinet, a front cover, several battery packs, an electrical control system, an energy management module, an energy storage converter, and a battery pack oil-cooling circulation system. The battery pack is an oil-immersed battery pack, and the front cover is provided to seal the front side of the cabinet. The cabinet is divided from one end to the other into an AC side control area, an AC / DC inverter area, a battery pack area, and a liquid cooling system area. The electrical control system is placed in the cabinet's AC side control area, the energy management module and the energy management module are both placed in the cabinet's AC / DC inverter area, with the energy management module positioned above the energy storage converter. Several battery packs are placed in the cabinet's battery pack area, and the oil tank and oil cooler of the battery pack oil-cooling circulation system are placed in the cabinet's liquid cooling system area. The present invention has a compact layout, good heat dissipation, and high safety.

Description

Technical Field

[0001] The present invention relates to an energy storage system. Background Art

[0002] With technological advancements and the continuous development of energy storage technology, the application areas of energy storage products are becoming increasingly broad, and each application area has specific requirements for their use. When energy storage products are used in grid frequency regulation, they must meet the requirements of fast response frequency regulation and rapid charging and discharging. However, the energy storage products currently on the market cannot fully meet these requirements due to their low charge and discharge rates. Furthermore, the heat dissipation performance of current energy storage products is poor, posing significant safety risks. Therefore, the design of energy storage systems has become a major research topic. Summary of the Invention

[0003] The present invention aims to provide an energy storage system with a compact layout, good heat dissipation effect and high safety. When load changes cause the grid frequency to change, the energy storage system of the present invention can quickly respond to the grid frequency to achieve a primary frequency modulation effect.

[0004] The present invention is achieved through the following solutions:

[0005] An energy storage system includes a cabinet, a front cover, several battery packs, and an electrical control system. It also includes an energy management module (EMU), an energy storage converter (PCS), and a battery pack oil cooling circulation piping system. The battery pack is an oil-immersed battery pack. The cabinet is a square structure with an open front and a hollow interior. The front cover is a matching seal that covers the front of the cabinet. The cabinet is divided from one end to the other into an AC side control area, an AC / DC inverter area, a battery pack area, and a liquid cooling system area.

[0006] The electrical control system is placed in the AC side control area of ​​the cabinet. The energy management module EMU and the energy storage converter PCS are both placed in the AC / DC inverter area of ​​the cabinet, with the energy management module EMU placed above the energy storage converter PCS. The number of energy storage converters is the same as the number of battery pack layers, with one energy storage converter corresponding to one battery pack layer. Several battery packs are placed in the battery pack area of ​​the cabinet in two rows and several layers. Several battery packs are interconnected. The oil tank and oil cooler in the battery pack oil cooling circulation pipeline system are placed in the liquid cooling system area of ​​the cabinet.

[0007] The electrical control system is connected to the energy management module (EMU), the energy storage converter (PCS), the battery pack, and the oil cooler in the battery pack's oil cooling circulation system. The battery pack's battery management system is connected to the energy management module (EMU) and the energy storage converter (PCS). The energy management module (EMU) is connected to the energy storage converter (PCS) and the oil cooler in the battery pack's oil cooling circulation system. Connections between these components can be made through communication connections, wiring harness connections, or other methods.

[0008] The electrical control system is used to provide power to the energy management module EMU, the energy storage converter PCS, the battery pack, and the oil cooler in the battery pack oil cooling circulation pipeline system.

[0009] The energy management module EMU is used to receive the voltage, current, temperature data of the battery pack, the fault information of the battery pack and the data measured by the first flow meter in the oil cooling circulation pipeline system of the battery pack transmitted by the battery management system of the battery pack, obtain the battery pack state of charge SOC and health state SOH according to the received voltage and current data, control the start and stop of the battery pack oil cooling circulation pipeline system according to the received temperature data, including starting and stopping the oil cooler, opening or closing the first switch valve, the second switch valve and the third switch valve, etc., send corresponding instructions to the corresponding energy storage converter PCS according to the received battery pack fault information, and transmit the received relevant data information to the external control host.

[0010] The energy storage converter PCS is used to receive and execute corresponding instructions issued by the energy management module EMU, and the corresponding instructions include controlling the converter to charge or discharge the battery and shut down.

[0011] The battery pack oil cooling circulation pipeline system is used to realize the circulation flow of oil in the battery pack.

[0012] The number of battery packs can be adjusted as needed, and the connection between battery packs can be all series, all parallel, or a combination of series and parallel. The voltage sensor, current sensor, and temperature sensor within the battery pack are used to detect the voltage, current, and temperature data within the corresponding battery pack, respectively. The battery pack is generally equipped with a battery management system, which is used to receive the voltage, current, and temperature data of the battery pack and transmit the data to the energy management module. It is also used to monitor the battery pack for fault conditions and transmit the corresponding fault information of the battery pack to the energy management module (EMU) in real time.

[0013] Furthermore, the cabinet also includes a fire protection system, housed in the battery pack area and atop the liquid cooling system area. The fire protection system is connected to the energy management module (EMU) and the electrical control system, respectively. These connections can be via communications, wiring harnesses, or other methods. The electrical control system provides power to the fire protection system. The fire protection system monitors fire conditions within the cabinet and transmits them to the EMU. It also receives fire control instructions from the EMU and initiates firefighting actions accordingly. Upon receiving the fire control information transmitted by the fire protection system, the EMU analyzes and classifies the fire conditions, feeding this information back to an external control host. Based on the fire control classification, the EMU issues fire control instructions and shutdown commands to the fire protection system and the energy storage converter (PCS). The PCS executes the shutdown command from the EMU. The fire control classification can be set as needed and pre-entered into the EMU. The type and specifications of the fire protection system can be selected from existing fire protection systems on the market.

[0014] Furthermore, the battery pack oil cooling circulation piping system includes an oil tank, two oil coolers, a first oil outlet branch pipe, a second oil outlet branch pipe, a first oil return branch pipe, a second oil return branch pipe and an oil return main pipe. The first oil outlet branch pipe, the second oil outlet branch pipe and the first oil return branch pipe are formed by vertically connecting a horizontal pipe and a vertical pipe with one end port closed through an elbow. One end port of the second oil return branch pipe is closed. The two oil coolers are placed side by side above the oil tank. The two oil outlets of the oil tank are connected to the inlets of the two oil coolers through the oil inlet main pipe respectively. The oil ports are connected one by one, and the oil outlets of the two oil coolers are connected one by one to the oil inlets of the horizontal pipes of the first oil outlet branch pipe and the second oil outlet branch pipe respectively through the oil outlet main pipe. The vertical pipes of the first oil outlet branch pipe and the second oil outlet branch pipe are vertically downward and stacked together front to back. A number of oil inlet branch pipes are symmetrically connected to both sides of the vertical pipes of the first oil outlet branch pipe and the second oil outlet branch pipe, and the oil inlet branch pipes are arranged in parallel up and down. The vertical pipe of the first oil return branch pipe and the second oil return branch pipe are symmetrically arranged in the same direction with the closed ends facing upward. The first oil outlet branch pipe and the second oil outlet branch pipe are stacked on both sides of the vertical pipe, and the open end of the second oil return branch pipe is vertically connected to the horizontal pipe of the first oil return branch pipe near the oil outlet. The vertical pipe of the first oil return branch pipe and the side opposite to the second oil return branch pipe are respectively connected to a plurality of oil return branch pipes. The oil outlet of the horizontal pipe of the first oil return branch pipe is connected to the oil inlet of the return oil main pipe, and the oil outlet of the return oil main pipe is connected to the oil inlet of the oil tank. The vertical pipes of the first oil inlet branch pipe and the second oil inlet branch pipe are connected. The vertical pipe of the first oil return branch and the second oil return branch are both placed in front of the two rows of battery packs, and the vertical pipes of the first and second oil inlet branches are both directly opposite the center of the two rows of battery packs. The vertical pipes of the first and second oil return branches are respectively directly opposite the outsides of the two rows of battery packs. The oil inlet branches on the first and second oil inlet branches are connected to the oil inlets of the corresponding battery packs in a one-to-one correspondence, and the oil return branches on the first and second oil return branches are connected to the oil outlets of the corresponding battery packs in a one-to-one correspondence. The two oil coolers, the first on-off valve, the second on-off valve, and the third on-off valve are respectively connected to the EMU, which is used to control the start and stop of the two oil coolers and the opening or closing of the first, second, and third on-off valves. The number and location of the oil inlet branches on the first oil outlet branch pipe and the number and location of the oil inlet branches on the second oil outlet branch pipe can be adjusted as needed, ensuring that the total number of oil inlet branches on the first and second oil outlet branches matches the total number of battery packs and that each oil inlet branch pipe can quickly and easily connect to the oil inlet of the battery pack. The dimensions of the horizontal and vertical pipes of the first and second oil outlet branches can be adjusted as needed. The horizontal pipe dimensions can be designed to ensure that the vertical pipes of the first and second oil outlet branches can be stacked front to back, with the vertical pipes facing the center of the two rows of battery packs. The vertical pipe dimensions can be designed to meet the layout and connection requirements of the oil inlet branches.The distance between the vertical pipe of the first oil return branch pipe, the second oil return branch pipe and the vertical pipes of the first oil outlet branch pipe and the second oil outlet branch pipe stacked together can be adjusted as needed to ensure that the vertical pipe of the first oil return branch pipe and the second oil return branch pipe are facing the outside of the two columns of battery packs respectively. The sizes of the vertical pipe of the first oil return branch pipe and the second oil return branch pipe can be adjusted and designed as needed to meet the layout and connection of the return oil branches. The number of return oil branches on the first oil return branch pipe and the second oil return branch pipe is the same as the number of battery packs in the corresponding columns. The size of the horizontal pipe of the first oil return branch pipe can be adjusted and designed as needed to meet the connection of the second oil return branch pipe.

[0015] Furthermore, a first switch valve is provided on the oil outlet main pipe, a second switch valve is provided on the horizontal pipe of the first oil return branch pipe, and a third switch valve is provided on the open end of the second oil return branch pipe.

[0016] Furthermore, a first flowmeter is provided on the oil inlet branch pipe. This first flowmeter can be used to measure the amount of oil flowing into the corresponding battery pack. The data measured by the first flowmeter is transmitted to the battery management system of the corresponding battery pack, which in turn transmits the received data to the energy management module (EMU).

[0017] Furthermore, it also includes an oil cooling and heat dissipation system, which includes a shielded pump, a tubular cooler, a plate heat exchanger, an oil inlet pipe and an oil outflow pipe. The shielded pump, the tubular cooler and the plate heat exchanger are connected in sequence through connecting pipes to form an oil cooling channel. The oil inlet pipe is connected to the inlet of the shielded pump, and the oil outflow pipe is connected to the outlet of the plate heat exchanger. A filter is provided on the oil inlet pipe, and the oil inlet pipe is connected to the oil outlet of the oil tank. The oil outflow pipe is connected to the oil inlets of the two oil coolers through the oil inlet main pipe. The oil cooling and heat dissipation system is placed in the liquid cooling system of the cabinet In this area, the shielded pump, tubular cooler, and plate heat exchanger are respectively connected to the energy management module EMU for communication. The energy management module EMU is used to control the start and stop of the shielded pump, tubular cooler, and plate heat exchanger. The first pressure sensor, second pressure sensor, and second flow meter are respectively connected to the energy management module EMU for communication. The energy management module EMU is used to receive and monitor the data measured by the first pressure sensor, the second pressure sensor, and the second flow meter, and perform corresponding processing based on the relevant data received. The data measured by the first pressure sensor is the first pressure value, the data measured by the second pressure sensor is the second pressure value, and the data measured by the second flow meter is the second flow value. In this solution, the oil outlet of the oil tank is directly connected to the oil inlets of the two oil coolers without passing through the oil inlet main pipe. The oil used in oil-immersed battery packs has a high viscosity and a large flow rate. Therefore, when selecting a plate heat exchanger, a plate heat exchanger with a smooth inner wall of the pipe and a larger pipe diameter is generally selected. The specific size of the pipe diameter of the plate heat exchanger can be selected according to needs to ensure that the oil used in the oil-immersed battery pack passes through the plate heat exchanger smoothly and is quickly cooled. The pipe diameter can generally be selected as 32mm.

[0018] Furthermore, a first pressure sensor is installed in the oil inlet pipe between the oil tank outlet and the filter, a second pressure sensor is installed in the oil outlet pipe, and a second flowmeter is installed in the oil outlet pipe between the plate heat exchanger and the second pressure sensor. The first pressure sensor is used to measure the pressure of the oil in the oil inlet pipe, and the second pressure sensor is used to measure the pressure of the oil in the oil outlet pipe. The second flowmeter is used to measure the flow rate of oil flowing from the plate heat exchanger into the oil outflow pipe.

[0019] Furthermore, an oil replenishment pipe is connected to the oil inlet pipe between the filter and the canned motor pump. The oil replenishment pipe allows for replenishment of oil in the battery pack as needed. Typically, an oil inlet valve is provided on the oil replenishment pipe, which is opened when oil replenishment is required.

[0020] Furthermore, the battery pack includes a box body, a cover plate, one or more battery pack mounting shells, a lower guide plate, an upper guide plate and several battery packs, the battery pack mounting shell is a frame structure with both top and bottom open, and a plurality of parallel baffles and a certain distance apart are respectively provided on the top and bottom of the battery pack mounting shell, the baffle on the top of the battery pack mounting shell is spatially parallel to the baffle on the bottom, that is, the placement direction of the baffle on the top of the battery pack mounting shell is consistent with that of the baffle on the bottom of the battery pack mounting shell, the lower guide plate is an inverted U-shaped through-groove structure, the top of the lower guide plate is provided with several oil inlet holes, the upper guide plate is a U-shaped groove structure with one end closed and the other end open, the bottom of the upper guide plate is provided with several oil outlet holes, an oil outlet, a positive electrode port and a negative electrode port are provided at the upper position of one end surface of the box body, an oil inlet is provided at the lower position of one end surface of the box body, the lower guide plate is provided on the bottom of the box body and the two ends of the lower guide plate are close to each other The top of the oil pump is installed in the oil pumping station, and the bottom of the oil pumping station is installed in the oil pumping station. The number, location, size, and shape of the oil inlet holes on the lower guide plate can be adjusted as needed. The oil inlet holes should be positioned to ensure they align with the gaps between two adjacent battery packs. This allows oil to flow smoothly between the battery packs after entering through the oil inlet holes in the lower guide plate, thereby removing heat generated by each battery pack, reducing the temperature of each battery pack, and minimizing temperature differences between battery packs. The number, location, size, and shape of the oil outlet holes on the upper guide plate can be adjusted as needed. The number of battery pack mounting housings can be adjusted as needed, as can the number and spacing between baffles on the top and bottom of the battery pack mounting housings. The number of battery packs can be adjusted as needed, and the battery packs can be connected individually in series, in parallel, or in a combination of series and parallel. The specific connection method can be adjusted as needed.

[0021] Furthermore, notches are respectively provided at the closed end and the tops of both sides of the upper guide plate.

[0022] Furthermore, the bottom of the open end of the upper guide plate is provided with an oil collecting groove which protrudes downward and has an open outer end and is flush with the open end of the upper guide plate, and the oil collecting groove is connected to the oil outlet of the box; the top of one end or both ends of the lower guide plate is provided with a buffer groove which protrudes upward near the end.

[0023] The energy storage system of the present invention features a compact layout, excellent heat dissipation, and high safety. When load changes cause grid frequency changes, the energy storage system can quickly respond to the grid frequency and implement primary frequency modulation. The cabinet in the energy storage system of the present invention is waterproof, heat-insulating, corrosion-resistant, fire-resistant, sand-resistant, shock-resistant, and UV-resistant, achieving an IP54 protection rating. The battery pack used in the present invention has good heat dissipation. The oil in the oil tank passes through a cooling device, namely an oil cooler or a combination of an oil cooler and an oil cooling and heat dissipation system, and then enters the lower guide plate from the oil inlet of the box body, then enters from the oil inlet through the lower guide plate and flows from the gap between each adjacent battery group from bottom to top through each battery group. Finally, the oil rises and collects in the upper guide plate, enters the oil outlet of the box body through the oil collecting groove of the upper guide plate, and flows back to the oil tank from the oil outlet of the box body. In this way, a circulation of the oil is completed. The circulation direction of the oil in the oil-immersed battery pack is relatively regular, which can quickly and effectively reduce the temperature difference between the battery groups in the battery pack, ensuring the performance and safety of the battery pack. The present invention adopts an oil cooling and heat dissipation system, which can quickly and effectively reduce the temperature of the circulating oil out of the battery pack, so that the temperature of the oil is lower when it re-enters the circulation flow, thereby effectively reducing the temperature of the battery pack, ensuring the normal use of the entire energy storage system, and improving the operational safety of the entire energy storage system. The battery pack oil cooling circulation piping system adopted in the present invention has a compact and beautiful piping layout, which can prevent oil backflow, making the structural layout of the entire energy storage system more beautiful and compact, and improving space utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the structure of the energy storage system (excluding the front cover plate) in Example 1;

[0025] Figure 2 This is a partial schematic diagram of the energy storage system in Example 1;

[0026] Figure 3 This is a schematic structural diagram of Example 1;

[0027] FIG4( a ) is a schematic diagram of the overall structure of the battery pack (excluding the cover plate) in Example 1;

[0028] FIG4( b ) is a schematic structural diagram of the battery pack mounting housing in Example 1;

[0029] Figure 4(c) is a schematic structural diagram of the lower guide plate in Example 1;

[0030] Figure 4(d) is a schematic structural diagram of the upper guide plate in Example 1;

[0031] Figure 5 This is a schematic diagram of the structure of the oil cooling and heat dissipation system in Example 2. DETAILED DESCRIPTION

[0032] The present invention will be further described below with reference to the embodiments and the accompanying drawings, but the present invention is not limited to the description of the embodiments.

[0033] Example 1

[0034] An energy storage system, such as Figure 1 、 Figure 2 As shown, Figure 1 、 Figure 2 The complete battery pack oil cooling circulation piping system is not shown in the figure, and includes a cabinet 1, a front cover (not shown), sixteen battery packs 2, an electrical control system 3, an energy management module EMU 4, an energy storage converter PCS 5, a battery pack oil cooling circulation piping system 7, and a fire protection system 6. The battery pack 2 is an oil-immersed battery pack. The cabinet 1 is a square structure with an open front and a hollow interior. The front cover is matched to cover the front of the cabinet 1. The interior of the cabinet 1 is divided from one end to the other into an AC side control area, an AC / DC inverter area, a battery pack area, and a liquid cooling system area.

[0035] The electrical control system 3 is placed in the AC side control area of ​​the cabinet 1. The energy management module EMU 4 and the energy storage converter PCS 5 are both placed in the AC / DC inverter area of ​​the cabinet 1, and the energy management module EMU 4 is placed above the energy storage converter PCS 5. The number of energy storage converters PCS 5 is the same as the number of layers of battery packs 2, that is, the number of energy storage converters PCS 5 is eight, and one energy storage converter PCS 5 corresponds to one layer of battery pack 2. Sixteen battery packs 2 are placed in the battery pack area of ​​the cabinet 1 in two rows of eight layers. In this embodiment, two battery packs 2 on the same layer are connected in series, and then eight layers of battery packs 2 are connected in parallel. The oil tank 701 and the oil cooler 702 in the battery pack oil cooling circulation pipeline system 7 are placed in the liquid cooling system area of ​​the cabinet 1. The fire protection system 6 is placed on top of the battery pack area and the liquid cooling system area of ​​the cabinet 1.

[0036] The electrical control system 3 is respectively connected to the energy management module EMU 4, the energy storage converter PCS 5, the battery pack 2, the oil cooler 702 in the battery pack oil cooling circulation pipeline system 7, and the fire protection system 6. The battery management system of the battery pack 2 is respectively communicated with the energy management module EMU 4 and the energy storage converter PCS 5. The energy management module EMU 4 is respectively communicated with the energy storage converter PCS5, the oil cooler 702 in the battery pack oil cooling circulation pipeline system 7, and the fire protection system 6.

[0037] The electrical control system is used to provide power to the energy management module EMU, energy storage converter PCS, battery pack, oil cooler in the battery pack oil cooling circulation pipeline system, and fire protection system.

[0038] The energy management module EMU is used to receive the battery pack voltage, current, temperature data, battery pack fault information and data measured by the first flow meter in the battery pack oil cooling circulation pipeline system transmitted by the battery management system of the battery pack, and obtain the battery pack state of charge SOC and health state SOH according to the received voltage and current data. It controls the start and stop of the battery pack oil cooling circulation pipeline system according to the received temperature data, including starting and stopping the oil cooler, opening or closing the first switch valve, the second switch valve and the third switch valve, etc. It sends corresponding instructions to the corresponding energy storage converter PCS according to the received battery pack fault information, and transmits the received relevant data information to the external control host.

[0039] The energy storage converter PCS is used to receive and execute corresponding instructions issued by the energy management module EMU. The corresponding instructions include controlling the converter to charge or discharge the battery and shut down.

[0040] The battery pack oil cooling circulation pipeline system is used to realize the circulation of oil in the battery pack.

[0041] The fire protection system monitors fire conditions within the cabinet and transmits these conditions to the energy management module (EMU). It also receives fire control instructions from the EMU and initiates firefighting actions accordingly. Upon receiving these fire control instructions, the EMU analyzes and classifies the fire conditions, feeds this information back to the external control host, and issues fire control and shutdown instructions to the fire protection system and the energy storage converter (PCS) based on the fire classification. The PCS executes the shutdown instructions after receiving them. Fire classifications can be configured as needed and entered into the EMU in advance.

[0042] like Figure 3As shown, the battery pack oil cooling circulation pipeline system 7 includes an oil tank 701, two oil coolers 702, a first oil outlet branch pipe 703, a second oil outlet branch pipe 704, a first oil return branch pipe 705, a second oil return branch pipe 706 and an oil return main pipe 707. The first oil outlet branch pipe 703, the second oil outlet branch pipe 704 and the first oil return branch pipe 705 are formed by vertically connecting a horizontal pipe and a vertical pipe with one end port closed through an elbow. One end port of the second oil return branch pipe 706 is closed. The two oil coolers 702 are placed side by side above the oil tank 701. The two oil outlets of the oil tank 701 are connected to the oil inlets of the two oil coolers 702 through the oil inlet main pipe 708, and the oil outlets of the two oil coolers 702 are connected to the oil inlets of the two oil coolers 702 through the oil outlet main pipe 708. 09 is connected to the oil inlet of the horizontal pipe of the first oil outlet branch pipe 703 and the second oil outlet branch pipe 704 in a one-to-one correspondence. The vertical pipes of the first oil outlet branch pipe 703 and the second oil outlet branch pipe 704 are vertically downward and stacked together front to back. Four oil inlet branch pipes 710 are symmetrically connected to both sides of the vertical pipes of the first oil outlet branch pipe 703 and the second oil outlet branch pipe 704, and the oil inlet branch pipes 710 are arranged in parallel up and down, that is, the total number of oil inlet branch pipes 710 on the first oil outlet branch pipe 703 and the second oil outlet branch pipe 704 is sixteen. A first flow meter is provided on the oil inlet branch pipe 710 (the first flow meter is not shown in the figure). The vertical pipe of the first return oil branch pipe 705 and the second return oil branch pipe 706 are symmetrically arranged in a stacked manner with the closed ends facing upward. 704, and the second return oil branch pipe 706 is connected to both sides of the vertical pipe of the first oil outlet branch pipe 703 and the second oil outlet branch pipe 704, and one end of the opening of the second return oil branch pipe 706 is vertically connected to the position of the horizontal pipe of the first return oil branch pipe 705 near the oil outlet, and the vertical pipe of the first return oil branch pipe 705 and the side opposite to the second return oil branch pipe 706 are respectively connected with eight return oil branch pipes 711, the oil outlet of the horizontal pipe of the first return oil branch pipe 705 is connected to the oil inlet of the return oil main pipe 707, and the oil outlet of the return oil main pipe 707 is connected to the oil inlet of the oil tank 701, the oil outlet main pipe 709 is provided with a first switch valve 712, the horizontal pipe of the first return oil branch pipe 705 is provided with a second switch valve 713, and one end of the opening of the second return oil branch pipe 706 is provided with The third switch valve 714, the vertical pipes of the first oil inlet branch pipe 703 and the second oil inlet branch pipe 704, the vertical pipes of the first oil return branch pipe 705 and the second oil return branch pipe 706 are all placed in front of the two rows of battery packs 2, and the vertical pipes of the first oil inlet branch pipe 703 and the second oil inlet branch pipe 704 are both facing the middle position of the two rows of battery packs 2, the vertical pipes of the first oil return branch pipe 705 and the second oil return branch pipe 706 are respectively facing the outside of the two rows of battery packs 2, the oil inlet branch pipes 710 on the first oil inlet branch pipe 703 and the second oil inlet branch pipe 704 are connected one-to-one with the oil inlets of the corresponding battery packs 2, and the oil return branch pipes 711 on the first oil return branch pipe 705 and the second oil return branch pipe 706 are connected one-to-one with the oil outlets of the corresponding battery packs 2.The two oil coolers, the first switch valve, the second switch valve, and the third switch valve are respectively communicated with the energy management module EMU, which is used to control the start and stop of the two oil coolers and open or close the first switch valve, the second switch valve, and the third switch valve.

[0043] As shown in FIG4(a), the battery pack 2 includes a box body 21, a cover plate (the cover plate is not shown in FIG4(a)), two battery pack mounting shells 23, a lower guide plate 24, an upper guide plate 25 and a plurality of battery packs 22. In this embodiment, the single battery in the battery pack is nickel-hydrogen D6000. As shown in FIG4(b), the battery pack mounting shell 23 is a frame structure with both the top and the bottom open. A plurality of parallel baffles 231 spaced apart are provided on the top and the bottom of the battery pack mounting shell 23. The baffles 231 on the top of the battery pack mounting shell 23 are spatially parallel to the baffles 231 on the bottom, that is, the baffles 231 on the top of the battery pack mounting shell 23 are placed in the same direction as the baffles 231 on the bottom of the battery pack mounting shell 23, as shown in FIG4(c). ) (the lower guide plate in FIG4 (c) is in an inverted placement state), the lower guide plate 24 is an inverted U-shaped through-groove structure, and a plurality of oil inlet holes 241 are provided on the top of the lower guide plate 24, and a buffer groove 242 protruding upward is provided at a position near the end of the top of one end of the lower guide plate 24. As shown in FIG4 (d), the upper guide plate 25 is a U-shaped groove structure with one end closed and the other end open, and a plurality of oil outlet holes 251 are provided at the bottom of the upper guide plate 25, and an oil collecting groove 252 protruding downward and open at the bottom of the open end of the upper guide plate 25 is provided, which is flush with the end of the open end of the upper guide plate 25, and the closed end and the top of both sides of the upper guide plate 25 are respectively provided with notches 253. An oil outlet 211, a positive electrode port 212 and a negative electrode port 213 are provided. An oil inlet 214 is provided at a lower position on one end surface of the box body 21. A lower guide plate 24 is provided on the bottom of the box body 21 and both ends of the lower guide plate 24 are closely fixed on both ends of the box body 21. The lower guide plate 24 is connected to the oil inlet 214 of the box body 21. Two battery pack mounting shells 23 are placed side by side on the top of the lower guide plate 24 and fixed in the box body 21. Several groups of battery packs 22 are evenly divided according to the number of battery pack mounting shells 23 and are respectively arranged side by side and in layers in each battery pack mounting shell 22. The gap between two adjacent battery packs 22 is opposite to the corresponding through hole 241 on the lower guide plate 24. Several groups of battery packs 22 are connected to each other. In this embodiment, the plurality of battery packs 22 in the same battery pack mounting housing 23 are first connected in parallel to the battery packs 22 in the same row and then to the upper and lower battery packs 22 in series. Thereafter, the battery packs 22 connected in the two battery pack mounting housings 23 are connected in series. The positive terminals and negative terminals of the plurality of battery packs 22 connected together are correspondingly connected to the positive port 212 and the negative port 213 on the box body 21. The upper guide plate 25 is fixed on the top of the two battery pack mounting housings 23 and the open end of the upper guide plate 25 is close to the inner side surface of the end where the oil outlet 211 of the box body 21 is located. The oil collecting groove 252 of the upper guide plate 25 is connected to the oil outlet 211 of the box body 21 at the open end. The box body 21 is filled with oil (the oil outlet is not shown in the figure).The oil level is higher than the top plane of the interconnected battery packs 22 and lower than the bottom plane of the upper guide plate 25. The box body 21 and the cover plate are sealed together.

[0044] The control and protection strategy of the energy storage system in Example 1 includes:

[0045] The battery management system of the S1 battery pack obtains the voltage, current and temperature data of the battery pack in real time, and transmits the obtained data to the corresponding energy management module EMU in real time. After receiving the relevant data, the energy management module EMU processes the voltage and current data to obtain the charge retention SOC and health state SOH of the corresponding battery pack, and judges the obtained charge retention SOC, health state SOH and temperature of the battery pack. If the temperature data of the battery pack exceeds the preset maximum temperature value, the energy management module EMU controls the battery pack oil cooling circulation pipeline system to start to realize the circulation of oil in the battery pack, including starting the oil cooler, opening the first switch valve, the second switch valve and the third switch valve, etc., until the battery pack is The temperature data drops below the preset maximum temperature value of the battery pack; if the charge retention SOC of a battery pack is lower than the preset SOC requirement value, the energy management module EMU controls the electrical control system to recharge the battery pack until the charge retention SOC of the battery pack reaches the preset SOC requirement value; if the health status SOH of a battery pack is lower than the preset SOH requirement value, the energy management module EMU feeds back the health status SOH of the battery pack to the external control host and issues a shutdown command to the energy storage converter PCS, which executes the command after receiving it; the maximum temperature value, SOC requirement value, and SOH requirement value of the battery pack can be designed as needed and pre-entered into the EMU;

[0046] The battery management system of the S2 battery pack monitors the fault conditions of the battery pack in real time and transmits the corresponding fault information of the battery pack to the energy management module EMU in real time. The energy management module EMU processes the fault information received from the battery pack and issues corresponding instructions to the corresponding energy storage converter PCS. At the same time, the received relevant information is transmitted to the external control host. The instructions for different fault conditions can be designed according to needs and pre-entered into the energy management module EMU. Specific instructions include alarm, power reduction, shutdown, etc.

[0047] The S3 fire protection system monitors the fire situation in the cabinet in real time and transmits the corresponding fire situation to the energy management module EMU. After receiving the corresponding fire situation transmitted by the fire protection system, the energy management module EMU analyzes and classifies the fire situation, and feeds back the corresponding information to the external control host. According to the fire classification, it issues corresponding fire protection processing instructions and shutdown instructions to the fire protection system and the energy storage converter PCS. The fire protection system receives the relevant fire protection processing instructions from the energy management module EMU and initiates the relevant fire protection actions according to the instructions. The energy storage converter PCS executes after receiving the shutdown instruction sent by the energy management module EMU. The fire classification can be set as needed and pre-entered into the energy management module EMU;

[0048] Steps S1, S2, and S3 are performed synchronously.

[0049] Example 2

[0050] An energy storage system, the structure of which is similar to that of the energy storage system of embodiment 1, except that the energy storage system further includes an oil cooling and heat dissipation system 9, such as Figure 5 As shown, the oil cooling and heat dissipation system 9 includes a shielded pump 901, a tubular cooler 902, a plate heat exchanger 903, an oil inlet pipe 904, and an oil outlet pipe 905. In this embodiment, the plate heat exchanger 4 is selected to have a smooth inner wall surface and a pipe diameter of 32 mm. The shielded pump 901, the tubular cooler 902, and the plate heat exchanger 903 are sequentially connected through a connecting pipe 906 to form an oil cooling channel. The oil inlet pipe 904 is connected to the inlet of the shielded pump 901, and the oil outlet pipe 905 is connected to the outlet of the plate heat exchanger 903. A filter 907 is provided on the oil inlet pipe 904. An oil replenishment pipe 908 is connected to the oil inlet pipe 904 between the filter 907 and the shielded pump 901. The oil replenishment pipe 908 is provided with an oil inlet valve ( Figure 5(The oil inlet valve is not shown in the figure), the oil flows into the pipeline 904 and is connected to the oil outlet of the oil tank 701. The oil flows into the pipeline 904 and is provided with a first pressure sensor 909 at a position between the oil outlet of the oil tank 701 and the filter 907. The oil flows out of the pipeline 905 and is provided with a second pressure sensor 910. The oil flows out of the pipeline 905 and is provided with a second flow meter 911 at a position between the plate heat exchanger 903 and the second pressure sensor 910. The oil flows out of the pipeline 905 and is respectively connected to the oil inlets of the two oil coolers through the oil inlet main pipe. The oil cooling and heat dissipation system 9 is placed in the liquid cooling system area of ​​the cabinet. The shielded pump, tubular cooler, plate heat exchanger, and oil inlet valve are respectively connected to the energy management module EMU for communication. The energy management module EMU is used to control the start and stop of the shielded pump, tubular cooler, and plate heat exchanger. The first pressure sensor, the second pressure sensor, and the second flow meter are respectively connected to the energy management module EMU for communication. The energy management module EMU is used to receive and monitor the data measured by the first pressure sensor, the second pressure sensor, and the second flow meter, and perform corresponding processing based on the relevant data received. The data measured by the first pressure sensor is the first pressure value, the data measured by the second pressure sensor is the second pressure value, and the data measured by the second flow meter is the second flow value. In this embodiment, the oil outlet of the oil tank is directly connected to the oil inlets of the two oil coolers without passing through the oil inlet main pipe.

[0051] The control and protection strategy of the energy storage system in Example 2 is basically the same as the steps of the control and protection strategy of the energy storage system in Example 1, except that: in step S1, when the temperature data of the battery pack exceeds the preset maximum temperature value of the battery pack, the following steps are also included: the energy management module EMU controls the start-up of the shielded pump, tubular cooler, and plate heat exchanger in the oil cooling and heat dissipation system.

[0052] The energy management module (EMU) collects and evaluates data from the first pressure sensor, second pressure sensor, and second flowmeter in real time. If the first pressure value falls below a preset first pressure value, the EMU controls the oil inlet valve to open and replenish oil into the oil cooling channel until the first pressure value reaches the preset first pressure value, at which point the EMU controls the oil inlet valve to close. The preset first pressure value can be adjusted as needed and pre-entered into the EMU.

Claims

1. An energy storage system, comprising a cabinet, a front cover, a plurality of battery packs, and an electrical control system, characterized in that: It also includes an energy management module, an energy storage converter, and a battery pack oil cooling circulation piping system. The battery pack is an oil-immersed battery pack. The cabinet is a square structure with an open front and a hollow interior. The front cover plate is matched to cover the front side of the cabinet. The cabinet is divided into an AC side control area, an AC / DC inverter area, a battery pack area, and a liquid cooling system area from one end to the other. The electrical control system is placed in the AC side control area of ​​the cabinet. The energy management module and energy storage converter are both placed in the AC / DC inverter area of ​​the cabinet, with the energy management module placed above the energy storage converter. The number of energy storage converters is the same as the number of battery pack layers, with one energy storage converter corresponding to one battery pack layer. Several battery packs are placed in the battery pack area of ​​the cabinet in two rows and several layers. Several battery packs are interconnected. The oil tank and oil cooler in the battery pack oil cooling circulation pipeline system are placed in the liquid cooling system area of ​​the cabinet. The electrical control system is respectively connected to the energy management module, the energy storage converter, the battery pack, and the oil cooler in the battery pack oil cooling circulation system; the battery management system of the battery pack is respectively connected to the energy management module and the energy storage converter; the energy management module is respectively connected to the energy storage converter and the oil cooler in the battery pack oil cooling circulation system; The battery pack comprises a box body, a cover plate, one or more battery pack mounting shells, a lower guide plate, an upper guide plate and several battery packs, the battery pack mounting shell is a frame structure with both the top and the bottom being open, a plurality of parallel baffles and a certain distance apart are respectively provided on the top and the bottom of the battery pack mounting shell, the baffle on the top of the battery pack mounting shell is spatially parallel to the baffle on the bottom, the lower guide plate is an inverted U-shaped through-groove structure, the top of the lower guide plate is provided with several oil inlet holes, the upper guide plate is a U-shaped groove structure with one end closed and the other end open, the bottom of the upper guide plate is provided with several oil outlet holes, an oil outlet, a positive electrode port and a negative electrode port are provided at the upper position of one end surface of the box body, an oil inlet is provided at the lower position of one end surface of the box body, the lower guide plate is provided on the bottom of the box body and the two ends of the lower guide plate are closely fixed to the two ends of the box body, the lower guide plate and the box body are connected The oil inlet of the body is connected, and more than one battery pack mounting shell is placed side by side on the top of the lower guide plate and fixed in the box body, and several battery packs are evenly divided according to the number of battery pack mounting shells and are respectively arranged side by side and in layers in each battery pack mounting shell, and the gap between two adjacent battery packs is opposite to the corresponding through-hole on the lower guide plate, and several battery packs are connected to each other, and the positive terminal and negative terminal of several battery packs connected to each other are correspondingly connected to the positive port and negative port on the box body, the upper guide plate is fixed on the top of more than one battery pack mounting shell and the open end of the upper guide plate is close to the inner side surface of the end where the oil outlet of the box body is located, the open end of the upper guide plate is connected to the oil outlet of the box body, and the box body is filled with oil, and the liquid level of the oil is higher than the plane where the tops of the several battery packs connected to each other are lower than the plane where the bottom of the upper guide plate is located, and the box body and the cover plate are matched and closed together.

2. An energy storage system according to claim 1, characterized in that: It also includes a fire protection system, which is placed on the top of the battery pack area and the liquid cooling system area of ​​the cabinet. The fire protection system is connected to the energy management module and the electrical control system respectively.

3. The energy storage system according to claim 1, wherein: The battery pack oil cooling circulation pipeline system includes an oil tank, two oil coolers, a first oil outlet branch pipe, a second oil outlet branch pipe, a first oil return branch pipe, a second oil return branch pipe and an oil return main pipe. The first oil outlet branch pipe, the second oil outlet branch pipe and the first oil return branch pipe are formed by vertically connecting a horizontal pipe and a vertical pipe with one end port closed through an elbow. One end port of the second oil return branch pipe is closed. The two oil coolers are placed side by side above the oil tank. The two oil outlets of the oil tank are connected to the oil inlets of the two oil coolers through the oil inlet main pipe. The oil outlets of the two oil coolers are connected one by one with the oil inlets of the first oil outlet branch pipe and the horizontal pipe of the second oil outlet branch pipe respectively through the oil outlet main pipe. The vertical pipes of the first oil outlet branch pipe and the second oil outlet branch pipe are vertically downward and stacked together front to back. A plurality of oil inlet branch pipes are symmetrically connected to both sides of the vertical pipes of the first oil outlet branch pipe and the second oil outlet branch pipe, and the oil inlet branch pipes are arranged in parallel up and down. The vertical pipe of the first oil return branch pipe and the second oil return branch pipe are symmetrically arranged in a stacked manner with the closed ends facing upward. The first oil outlet branch pipe and the second oil outlet branch pipe are connected together on both sides of the vertical pipe, and one open end of the second oil return branch pipe is vertically connected to the horizontal pipe of the first oil return branch pipe near the oil outlet. The vertical pipe of the first oil return branch pipe and the second oil return branch pipe are opposite to each other and are respectively connected to a plurality of oil return branch pipes. The oil outlet of the horizontal pipe of the first oil return branch pipe is connected to the oil inlet of the return oil main pipe, and the oil outlet of the return oil main pipe is connected to the oil inlet of the oil tank. The vertical pipes of the first oil inlet branch pipe and the second oil inlet branch pipe are connected. The vertical pipe of the first oil return branch pipe and the second oil return branch pipe are both placed in front of the two rows of battery packs, and the vertical pipes of the first oil inlet branch pipe and the second oil inlet branch pipe are both facing the middle position of the two rows of battery packs, and the vertical pipe of the first oil return branch pipe and the second oil return branch pipe are respectively facing the outside of the two rows of battery packs, and the oil inlet branches on the first oil inlet branch pipe and the second oil inlet branch pipe are connected to the oil inlets of the corresponding battery packs in a one-to-one manner, and the oil return branches on the first oil return branch pipe and the second oil return branch pipe are connected to the oil outlets of the corresponding battery packs in a one-to-one manner.

4. An energy storage system according to claim 3, characterized in that: The oil outlet main pipe is provided with a first switch valve, the horizontal pipe of the first oil return branch pipe is provided with a second switch valve, and the open end of the second oil return branch pipe is provided with a third switch valve.

5. An energy storage system according to any one of claims 3 to 4, characterized in that: It also includes an oil cooling and heat dissipation system, which includes a shielded pump, a tubular cooler, a plate heat exchanger, an oil inlet pipe and an oil outlet pipe. The shielded pump, tubular cooler and plate heat exchanger are connected in sequence through connecting pipes to form an oil cooling channel. The oil inlet pipe is connected to the inlet of the shielded pump, and the oil outlet pipe is connected to the outlet of the plate heat exchanger. A filter is provided on the oil inlet pipe. The oil inlet pipe is connected to the oil outlet of the oil tank, and the oil outlet pipe is connected to the oil inlets of the two oil coolers through the oil inlet main pipe. The oil cooling and heat dissipation system is placed in the liquid cooling system area of ​​the cabinet.

6. An energy storage system according to claim 5, characterized in that: A first pressure sensor is provided on the oil inlet pipe between the oil outlet of the oil tank and the filter, a second pressure sensor is provided on the oil outflow pipe, and a second flow meter is provided on the oil outflow pipe between the plate heat exchanger and the second pressure sensor.

7. An energy storage system according to claim 6, characterized in that: The oil inlet pipeline is connected to an oil replenishing pipeline at a position between the filter and the shielded pump.

8. The energy storage system according to claim 1, wherein: The closed end and the tops of both sides of the upper guide plate are respectively provided with notches.

9. The energy storage system according to claim 1, wherein: The bottom of the open end of the upper guide plate is provided with an oil collecting groove that protrudes downward and has an open outer end and is flush with the end of the open end of the upper guide plate. The oil collecting groove is connected to the oil outlet of the box; a buffer groove that protrudes upward is provided at a position near the end of the top of one or both ends of the lower guide plate.

Images