Energy storage system

Abstract

The invention provides an energy storage system which comprises a cabinet body, a front side cover plate, a plurality of battery packs, an electrical control system, an energy management module, an energy storage converter and a battery pack oil cooling circulation pipeline system, the battery packs are oil immersion type battery packs, and the front side cover plate covers the front side of the cabinet body in a matched and closed mode. The interior of the cabinet body is sequentially divided into an alternating current side control area, an alternating current and direct current inversion area, a battery pack area and a liquid cooling system area from one end to the other end, the electrical control system is arranged in the alternating current side control area of the cabinet body, the energy management module and the energy management module are arranged in the alternating current and direct current inversion area of the cabinet body, and the energy management module is arranged above the energy storage converter. A plurality of battery packs are arranged in the battery pack area of the cabinet body, and an oil tank and an oil cooler in the battery pack oil cooling circulation pipeline system are arranged in the liquid cooling system area of the cabinet body. The device is compact in layout, good in heat dissipation effect and high in safety.

Description

Technical Field

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

[0002] With the advancement of science and technology and the continuous development of energy storage technology, the application fields of energy storage products are becoming more and more extensive, and there are some specific requirements for the use of energy storage products in various application fields. When energy storage products are applied in the field of power grid frequency regulation, they need to meet the requirements of fast response frequency regulation and fast charging and discharging. However, the energy storage products on the market currently cannot meet the needs of the power grid frequency regulation field well due to their low charging and discharging rates, and the heat dissipation effect of energy storage products on the market is poor, which poses a great safety hazard. Therefore, how to design an energy storage system has become a major research topic at present. Summary of the invention

[0003] The present invention aims to provide an energy storage system with 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 primary frequency modulation.

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

[0005] An energy storage system, comprising a cabinet, a front cover, a plurality of battery packs and an electrical control system, and also comprising an energy management module EMU, an energy storage converter PCS and a battery pack oil cooling circulation pipeline system, wherein 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 matched to cover the front side of the cabinet, and 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;

[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, and the energy management module EMU is placed above the energy storage converter PCS. The number of energy storage converters is the same as the number of layers of battery packs, one energy storage converter corresponds to one layer of battery packs, and several battery packs are placed in the battery pack area of ​​the cabinet in a manner of two rows and several layers. Several battery packs are connected to each other, and the oil tank and oil cooler in the oil cooling circulation pipeline system of the battery pack are placed in the liquid cooling system area of ​​the cabinet;

[0007] The electrical control system is respectively connected to the energy management module EMU, the energy storage converter PCS, the battery pack, and the oil cooler in the oil cooling circulation pipeline system of the battery pack. The battery management system of the battery pack is respectively connected to the energy management module EMU and the energy storage converter PCS. The energy management module EMU is respectively connected to the energy storage converter PCS and the oil cooler in the oil cooling circulation pipeline system of the battery pack. The connection between the components can be communication connection, wiring harness connection, etc.

[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 state of charge SOC and the state of health SOH of the battery pack according to the received voltage and current data, control the start and stop of the oil cooling circulation pipeline system of the battery pack 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., issue corresponding instructions to the corresponding energy storage inverter PCS according to the received fault information of the battery pack, 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 and designed as needed, and the connection between battery packs can be all connected in series, all connected in parallel, or a combination of series and parallel. The voltage sensor, current sensor, and temperature sensor in the battery pack are used to detect the voltage, current, and temperature data in 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 fault condition of the battery pack and transmit the corresponding fault information of the battery pack to the energy management module EMU in real time.

[0013] Furthermore, 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 EMU and the electrical control system respectively. The connection method between the fire protection system and the energy management module EMU and the electrical control system can be communication connection, wiring harness connection, etc. The electrical control system provides power to the fire protection system. The fire protection system is used to monitor the fire situation in the cabinet and transmit the corresponding fire situation to the energy management module EMU, and is also used to receive the relevant fire protection processing instructions issued by the energy management module EMU and start the relevant fire protection actions according to the instructions; after receiving the corresponding fire situation transmitted by the fire protection system, the energy management module EMU analyzes and classifies the fire situation, and at the same time feeds back the corresponding information to the external control host, and issues the corresponding fire protection processing instructions and shutdown instructions to the fire protection system and the energy storage converter PCS according to the fire rating situation, and the energy storage converter PCS executes after receiving the shutdown instruction sent by the energy management module EMU. The fire rating can be set as needed and entered into the EMU in advance. The type and specification of the fire protection system can be selected from the fire protection systems in the existing market as needed.

[0014] Furthermore, 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, wherein 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 a closed port at one end through an elbow, and one end of the second oil return branch pipe is closed. The two oil coolers are arranged side by side above the oil tank, and the two oil outlets of the oil tank are respectively connected to the inlets of the two oil coolers through the oil inlet main pipe. The oil ports are connected in a one-to-one correspondence, and the oil outlets of the two oil coolers are respectively connected in a one-to-one correspondence with the oil inlets of the horizontal pipes of the first oil outlet branch pipe and the second oil outlet branch pipe 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 the two 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 position 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, and the vertical pipe of the first oil return branch pipe and the side opposite to the second oil return branch pipe are respectively connected with 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, the oil outlet of the return oil main pipe is connected to the oil inlet of the oil tank, and the vertical pipes of the first oil inlet branch pipe and the second oil inlet branch pipe are connected to the oil inlet of the oil tank. , 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, 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, the oil inlet branch pipes on the first oil inlet branch pipe and the second oil inlet branch pipe are connected to the oil inlet of the corresponding battery pack in a one-to-one correspondence, and the oil return branch pipes on the first oil return branch pipe and the second oil return branch pipe are connected to the oil outlet of the corresponding battery pack in a one-to-one correspondence. The two oil coolers, the first switch valve, the second switch valve, and the third switch valve are respectively connected to the EMU for communication, and the EMU 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. The number and location of the oil inlet branch pipes on the first oil outlet branch pipe and the number and location of the oil inlet branch pipes on the second oil outlet branch pipe can be adjusted and designed as needed, so that the total number of the oil inlet branch pipes of the first oil outlet branch pipe and the second oil outlet branch pipe is the same as the total number of battery packs and each oil inlet branch pipe can be quickly and conveniently connected to the oil inlet of the battery pack one by one. The size of the horizontal pipe and the vertical pipe of the first oil outlet branch pipe and the second oil outlet branch pipe can be adjusted and designed as needed. The size of the horizontal pipe can be so that the vertical pipes of the first oil outlet branch pipe and the second oil outlet branch pipe can be stacked together front and back and the vertical pipe is directly opposite the middle position of the two rows of battery packs. The size of the vertical pipe can meet the layout and connection of the oil inlet branch pipes.The distances 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 directly facing the outsides 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 ensure the arrangement 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 ensure 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 flow meter is provided on the oil inlet branch pipe. The first flow meter can be used to measure the amount of oil flowing into the corresponding battery pack. The data measured by the first flow meter is transmitted to the battery management system of the corresponding battery pack, and the battery management system then 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 outlet 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 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 two oil coolers through an oil inlet main pipe. The oil cooling and heat dissipation system is placed in the liquid cooling system of the cabinet. Area, the shielded pump, tubular cooler, and plate heat exchanger are respectively connected to the energy management module EMU for communication, and 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, and 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 make corresponding processing according to 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 not directly connected to the oil inlet of the two oil coolers through the oil inlet main pipe. The viscosity of the oil used in oil-immersed battery packs is relatively high and the flow rate is relatively large. 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 can pass through the plate heat exchanger smoothly and cool down quickly. The pipe diameter size can generally be selected as 32mm.

[0018] Furthermore, the oil inflow pipeline is provided with a first pressure sensor at a position between the oil outlet of the oil tank and the filter, the oil outflow pipeline is provided with a second pressure sensor, and the oil outflow pipeline is provided with a second flowmeter at a position between the plate heat exchanger and the second pressure sensor. The first pressure sensor is used to measure the pressure value of the oil in the oil inflow pipeline, and the second pressure sensor is used to measure the pressure value of the oil in the oil outflow pipeline. The second flowmeter can be used to measure the flow rate of the oil flowing from the plate heat exchanger into the oil outflow pipeline.

[0019] Furthermore, the oil inlet pipeline is connected to an oil replenishment pipeline at a position between the filter and the shielded pump. The oil replenishment pipeline can be used to replenish the oil of the battery pack as needed. Generally, an oil inlet valve is provided on the oil replenishment pipeline, and the oil inlet valve can be opened when oil replenishment is needed.

[0020] Further, 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 the top and the bottom open, and the top and the bottom of the battery pack mounting shell are respectively provided with several parallel baffles spaced a certain distance apart, 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 and the baffle on the bottom of the battery pack mounting shell is consistent, 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 through 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 through 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 arranged on the bottom of the box body and the two ends of the lower guide plate are close to The battery packs are fixed on both ends of the box body, the lower guide plate is connected with the oil inlet of the box body, 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, a plurality of battery packs are evenly divided according to the number of battery pack mounting shells and are arranged side by side and in layers in each battery pack mounting shell, the gap between two adjacent battery packs is opposite to the corresponding through hole on the lower guide plate, a plurality of battery packs are connected to each other, the positive terminal and the negative terminal of the plurality of battery packs connected to each other are connected to the positive port and the negative port on the box body correspondingly, 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 with the oil outlet of the box body, the box body is filled with oil, the liquid level of the oil is higher than the plane where the tops of the plurality of battery packs connected to each other are located and lower than the plane where the bottoms of the upper guide plate are located, and the box body and the cover plate are matched and closed together. The number, location, size and shape of the oil inlet holes on the lower guide plate can be adjusted and designed as needed. The location of the oil inlet holes can ensure that the oil inlet holes are directly opposite to the gap between the corresponding two adjacent battery groups, so that the oil can flow smoothly between the battery groups after entering through the oil inlet holes of the lower guide plate, thereby smoothly taking away the heat generated by each battery group, reducing the temperature of each battery group, and reducing the temperature difference between each battery group. The number, location, size and shape of the oil outlet holes on the upper guide plate can be adjusted and designed as needed. The number of battery pack mounting shells can be adjusted and designed as needed, and the number of baffles on the top and bottom of the battery pack mounting shell and the distance between the baffles can be adjusted and designed as needed. The number of battery packs can be adjusted and designed as needed. The connection method between each battery pack can be a single series or parallel connection, or a combination of series and parallel connection. The specific connection method can be adjusted and designed as needed.

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

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

[0023] The energy storage system of the present invention has a compact layout, good heat dissipation effect, and high safety. When the load changes and causes 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. The cabinet in the energy storage system of the present invention has the functions of waterproofing, heat preservation, corrosion resistance, fire prevention, sand resistance, shock resistance, and ultraviolet protection, and its protection level is IP54. The battery pack used in the present invention has good heat dissipation. The oil in the oil tank passes through a cooling device, i.e., 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, and then enters from the oil inlet through hole of the lower guide plate and flows through each battery pack from bottom to top through the gap between each adjacent battery pack. Finally, the oil rises and collects in the upper guide plate, and enters the oil outlet of the box body through the oil collecting groove of the upper guide plate, and then flows back to the oil tank from the oil outlet of the box body, thus completing a circulation flow of the oil. The circulation flow direction of the oil in the oil-immersed battery pack is relatively regular, and the temperature difference between each battery pack in the battery pack can be quickly and effectively reduced, thereby ensuring the use performance and safety performance 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 outflowing from 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 operation safety of the entire energy storage system. The battery pack oil cooling circulation pipeline system adopted by the present invention has a compact and beautiful pipeline 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 It is a partial schematic diagram of the energy storage system in Example 1;

[0026] Figure 3 It is a structural schematic diagram in 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 diagram of the structure of the battery pack installation housing in Example 1;

[0029] FIG4( c ) is a schematic structural diagram of the lower guide plate in Example 1;

[0030] FIG4( 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 is further described below in conjunction with embodiments and 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, including a cabinet 1, a front cover (not shown in the figure), 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 side of the cabinet 1. The cabinet 1 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.

[0035] The electrical control system 3 is arranged 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 arranged 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 the energy storage converter PCS 5 is the same as the number of layers of the battery pack 2, that is, the number of the energy storage converter PCS 5 is eight, one energy storage converter PCS 5 corresponds to one layer of battery pack 2, and sixteen battery packs 2 are arranged in the battery pack area of ​​the cabinet 1 in two rows and 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 arranged in the liquid cooling system area of ​​the cabinet 1, and the fire protection system 6 is arranged 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 inverter 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 inverter PCS 5; the energy management module EMU 4 is respectively communicated with the energy storage inverter 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, the energy storage converter PCS, the battery pack, the oil cooler in the battery pack oil cooling circulation pipeline system, and the fire protection system.

[0038] 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 state of charge SOC and the state of health SOH of the battery pack according to the received voltage and current data, control the start and stop of the oil cooling circulation pipeline system of the battery pack 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., issue corresponding instructions to the corresponding energy storage inverter PCS according to the received fault information of the battery pack, and transmit 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 is used to monitor the fire situation in the cabinet and transmit the corresponding fire situation to the energy management module EMU. It is also used to receive the relevant fire protection processing instructions issued by the energy management module EMU and start the relevant fire protection actions according to the instructions. After receiving the corresponding fire situation transmitted by the fire protection system, the energy management module EMU analyzes and rates the fire situation, and feeds back the corresponding information to the external control host. According to the fire rating, the corresponding fire protection processing instructions and shutdown instructions are issued to the fire protection system and the energy storage converter PCS. The energy storage converter PCS executes after receiving the shutdown instruction sent by the EMU. The fire rating can be set 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 a closed port at one end through an elbow. One end of the second oil return branch pipe 706 is closed. The two oil coolers 702 are arranged 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 the two 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. The 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. The first oil outlet branch pipe 703 and the second oil outlet branch pipe 704 are connected together, and one end of the opening of the second oil return branch pipe 706 is vertically connected to the position of the horizontal pipe of the first oil return branch pipe 705 near the oil outlet. The vertical pipe of the first oil return branch pipe 705 and the side opposite to the second oil return branch pipe 706 are respectively connected with eight oil return branch pipes 711. The oil outlet of the horizontal pipe of the first oil return branch pipe 705 is connected to the oil inlet of the return oil main pipe 707. 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 oil return branch pipe 705 is provided with a second switch valve 713, and one end of the opening of the second oil return branch pipe 706 is provided with a 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 outsides 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 to the oil inlets of the corresponding battery packs 2 in a one-to-one manner, 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 to the oil outlets of the corresponding battery packs 2 in a one-to-one manner.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, and the energy management module EMU 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 a certain distance apart are respectively arranged on the top and the bottom of the battery pack mounting shell 23. The baffle 231 on the top of the battery pack mounting shell 23 is spatially parallel to the baffle 231 on the bottom, that is, the baffle 231 on the top of the battery pack mounting shell 23 is placed in the same direction as the baffle 231 on the bottom, as shown in FIG4(c). ) (the lower guide plate in FIG4(c) is in an inverted position), the lower guide plate 24 is an inverted U-shaped through-groove structure, a plurality of oil inlet through holes 241 are arranged on the top of the lower guide plate 24, and a buffer groove 242 protruding upward is arranged 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, a plurality of oil outlet through holes 251 are arranged 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 arranged, and the oil collecting groove 252 protruding downward and open at the outer end and flush with the end of the open end of the upper guide plate 25 is arranged, and the closed end and the top of both sides of the upper guide plate 25 are respectively provided with notches 253, and the upper position of one end surface of the box body 21 is provided with a buffer groove 242 protruding upward. 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 of one end surface of the box body 21, a lower guide plate 24 is arranged on the bottom of the box body 21 and two ends of the lower guide plate 24 are closely fixed on the two ends of the box body 21, the lower guide plate 24 is connected with the oil inlet 214 of the box body 21, two battery pack mounting shells 23 are arranged side by side on the top of the lower guide plate 24 and fixed in the box body 21, a plurality of battery packs 22 are evenly divided according to the number of battery pack mounting shells 23 and are 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, and a plurality of battery packs 22 are connected to each other. In this embodiment, a plurality of battery packs 22 in the same battery pack mounting shell 23 are first connected in parallel with the same row of battery packs 22 and then connected in series with the upper and lower battery packs 22. After that, the battery packs 22 connected in the two battery pack mounting shells 23 are connected in series with each other. The positive terminal and the negative terminal of the plurality of battery packs 22 connected together are connected to the positive port 212 and the negative port 213 on the box body 21 correspondingly. The upper guide plate 25 is fixed on the top of the two battery pack mounting shells 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, that is, the open end is connected to the oil outlet 211 of the box body 21, and the box body 21 is filled with oil (the oil is not shown in the figure).The liquid level of the oil is higher than the plane where the tops of the several battery groups 22 connected to each other are located and lower than the plane where the bottoms of the upper guide plates 25 are located. The box body 21 is sealed together with the cover plate.

[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 charge retention SOC, health state SOH and temperature of the obtained 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 The temperature data is reduced to 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 supplement the battery pack until the charge retention SOC of the battery pack reaches the preset SOC requirement value; if the health state SOH of a battery pack is lower than the preset SOH requirement value, the energy management module EMU feeds back the health state SOH of the battery pack to the external control host and sends a shutdown command to the energy storage converter PCS, which executes after receiving the command; 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 condition 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 of the battery pack accordingly and issues corresponding instructions to the corresponding energy storage converter PCS, and transmits the received relevant information to the external control host at the same time. The instructions for different fault conditions can be designed according to the needs and pre-entered into the energy management module EMU. The 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 rates the fire situation, and feeds back the corresponding information to the external control host, and issues corresponding fire protection processing instructions and shutdown instructions to the fire protection system and energy storage converter PCS according to the fire classification. The fire protection system receives the relevant fire protection processing instructions issued by 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 instructions 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, whose structure 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. The plate heat exchanger 4 of this embodiment selects a smooth inner wall of the pipe and a pipe diameter of 32 mm. The shielded pump 901, the tubular cooler 902, and the plate heat exchanger 903 are connected in sequence 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. The oil inlet pipe 904 is connected to an oil replenishment pipe 908 at a position between the filter 907 and the shielded pump 901. The oil replenishment pipe 908 is provided with an oil inlet valve ( Figure 5The oil inlet valve is not shown in the figure), the oil inlet pipeline 904 is connected with the oil outlet of the oil tank 701, the oil inlet pipeline 904 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 outflow pipeline 905 is provided with a second pressure sensor 910, the oil outflow pipeline 905 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 outflow pipeline 905 is respectively connected with the oil inlets of the two oil coolers through the oil inlet main pipe, and the oil cooling and heat dissipation system 9 is arranged 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, and 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, and 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 make corresponding processing according to the received relevant data, 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 not directly connected to the oil inlets of the two oil coolers 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 the data measured by the first pressure sensor, the second pressure sensor and the second flow meter in real time and judges the data. If the first pressure value is lower than the preset first pressure value, the energy management module EMU controls the oil inlet valve to open and add oil to the oil cooling channel until the first pressure value reaches the preset first pressure value, at which time the energy management module EMU controls the oil inlet valve to close. The preset first pressure value can be adjusted and designed as needed and pre-entered into the energy management module 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 pipeline 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 the energy storage converter are both placed in the AC / DC inverter area of ​​the cabinet, and the energy management module is placed above the energy storage converter. The number of the energy storage converters is the same as the number of layers of the battery packs, one energy storage converter corresponds to one layer of battery packs, and several battery packs are placed in the battery pack area of ​​the cabinet in a manner of two rows and several layers. Several battery packs are connected to each other, and the oil tank and oil cooler in the oil cooling circulation pipeline system of the battery pack 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 inverter, the battery pack, and the oil cooler in the oil cooling circulation pipeline system of the battery pack; the battery management system of the battery pack is respectively connected to the energy management module and the energy storage inverter; the energy management module is respectively connected to the energy storage inverter and the oil cooler in the oil cooling circulation pipeline system of the battery pack.

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, and is connected to the energy management module and the electrical control system respectively.

3. An energy storage system according to claim 1, characterized in that: 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 a closed end port through an elbow. One end port of the second oil return branch pipe is closed. The two oil coolers are arranged side by side above the oil tank. The two oil outlets of the oil tank are respectively 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, and the oil inlets of the horizontal pipes of the first oil outlet branch pipe and the second oil outlet branch pipe are connected one by one 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 and back. The two sides of the vertical pipes of the first oil outlet branch pipe and the second oil outlet branch pipe are symmetrically connected to a plurality of oil inlet branch pipes, 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 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, and the vertical pipe of the first oil return branch pipe and the second oil return branch pipe are opposite to each other. A plurality of oil return branch pipes are respectively connected, 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, 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, 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, the vertical pipe of the first oil return branch pipe and the second oil return branch pipe are respectively facing the outsides of the two rows of battery packs, the oil inlet branch pipes 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 branch pipes 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, 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 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 two oil coolers through an 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 pipeline between the oil outlet of the oil tank and the filter, a second pressure sensor is provided on the oil outlet pipeline, and a second flow meter is provided on the oil outlet pipeline 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. An energy storage system according to any one of claims 1 to 7, characterized in that: 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 a plurality of battery packs, the battery pack mounting shell being a frame structure with both the top and the bottom open, a plurality of parallel baffles spaced a certain distance apart are respectively arranged 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, a plurality of oil inlet through holes are arranged on the top of the lower guide plate, the upper guide plate is a U-shaped groove structure with one end closed and the other end open, a plurality of oil outlet through holes are arranged on the bottom of the upper guide plate, an oil outlet, a positive electrode port and a negative electrode port are provided at an upper position on one end surface of the box body, an oil inlet is provided at a lower position on one end surface of the box body, the lower guide plate is arranged on the bottom of the box body and the two ends of the lower guide plate are closely fixed on the two ends of the box body, the lower guide plate and the box body are The oil inlet of the box is connected, 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, several groups of 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, the gap between two adjacent battery packs is opposite to the corresponding through hole on the lower guide plate, several groups of battery packs are connected to each other, the positive terminal and the negative terminal of the several groups of battery packs connected to each other are correspondingly connected to the positive port and the negative port on the box, 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 is located, the open end of the upper guide plate is connected to the oil outlet of the box, the box is filled with oil, the liquid level of the oil is higher than the plane where the tops of the several groups of battery packs connected to each other are located and lower than the plane where the bottom of the upper guide plate is located, and the box is sealed together with the cover plate.

9. An energy storage system according to claim 8, characterized in that: The closed end of the upper guide plate and the tops of both sides are respectively provided with notches.

10. An energy storage system according to claim 8, characterized in that: The bottom of the open end of the upper guide plate is provided with an oil collecting groove which protrudes downward and is open at the outer end and is flush with the end of the open end of the upper guide plate, and the oil collecting groove is connected to the oil outlet of the box; a buffer groove which protrudes upward is provided at a position near the end at the top of one or both ends of the lower guide plate.

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