High-density medium-voltage energy storage system and design method thereof

Abstract

This invention discloses a high-density medium-voltage energy storage system with miniaturized structure and convenient operation and maintenance, and its design method. The method includes: determining the structural composition of the high-density medium-voltage energy storage system; calculating the number of inverter links and the capacity and volume of each energy storage battery cluster in the battery bank, and calculating the heat generation power of each energy storage battery cluster during charging and discharging based on the battery charging and discharging current under rated operating conditions; designing the arrangement of the energy storage battery bank and inverter bank, and the connection scheme with the lowest voltage difference between adjacent energy storage battery clusters; planning the heat dissipation scheme; constructing a container shell with the goals of optimal maintenance space, compact internal structure, and minimal external volume, and installing a fire-fighting module, external interfaces, and a control system. This can reduce the volume of the high-density medium-voltage energy storage system, improve the convenience of operation and maintenance, and enhance the applicability of the equipment in different environments.

Description

Technical Field

[0001] This invention belongs to the technical field of medium-voltage energy storage systems, and relates to a high-density medium-voltage energy storage system with miniaturized structure and convenient operation and maintenance, as well as its design method. Background Technology

[0002] With the continuous development of modern technology, electricity is becoming increasingly important in people's production and daily life. The load changes of various electrical equipment are becoming more and more significant, and the requirements for the stability of power energy are also becoming higher and higher. At the same time, investment in power production infrastructure is also increasing, especially the grid-connected capacity of renewable energy sources such as wind power and photovoltaics, which is increasing year by year.

[0003] To effectively address the challenges posed by power system load shifts and the integration of renewable energy, and to maintain efficient and safe grid operation and a balance between power supply and demand, energy storage systems with charging and discharging capabilities are necessary. As the grid's demands for energy storage system capacity and voltage increase, research into novel high-density medium-voltage energy storage systems has become a new direction for the power energy storage industry.

[0004] High-density medium-voltage energy storage systems require the configuration of energy storage batteries with a capacity of more than 120% on the basis of standard energy storage boxes, converters, control systems, and other safety auxiliary facilities. They also require sufficient insulation and electrical distances under operating voltage conditions. This makes high-density medium-voltage energy storage systems bulky, difficult to transport, and inconvenient to install and maintain, which hinders the promotion and application of high-density medium-voltage energy storage system technology in the power grid.

[0005] Existing high-density medium-voltage energy storage systems typically do not consider inter-cluster voltage and are only applicable to low-voltage energy storage. PCS modules are installed at the bottom of the battery clusters; severe PCS failures or fires could ignite the upper batteries, posing a significant hazard. Air conditioning is installed at the top opening of the container, posing a risk of leaks due to seal aging. The air supply duct passes through two 90-degree bends, resulting in significant air pressure loss. The return air vent is located at the very top of the batteries, making the cooling air circulation path for the bottom PACK the longest, leading to a large difference in heat dissipation between the upper and lower PACKs. Some battery layouts arrange them face-to-face inside the container, with a maintenance passage between the two rows of batteries and a maintenance door at one end of the passage. The disadvantages are that the maintenance passage occupies 30% of the container's volume, increasing the footprint and limiting the power density of the energy storage system. The battery compartment only has one maintenance door at one end, making it difficult to guarantee the safety of maintenance personnel in case of battery failure during maintenance. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a high-density medium-voltage energy storage system with miniaturized structure and convenient operation and maintenance, as well as its design method, thereby reducing the volume of the high-density medium-voltage energy storage system and improving the convenience of operation and maintenance.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A design method for a high-density medium-voltage energy storage system with miniaturized structure and convenient operation and maintenance, the method comprising the following steps:

[0009] Step 1: Determine the structural components of the high-density medium-voltage energy storage system, including energy storage battery packs, converter packs, heat dissipation modules, container shells, fire protection modules, external interfaces, and control systems;

[0010] Step 2: Calculate the number of inverter links and the capacity and volume of each energy storage battery cluster in the energy storage battery pack, and calculate the heat generation power of the energy storage battery cluster.

[0011] Step 3: Based on the number of inverter links and the capacity and volume of each energy storage battery cluster in the energy storage battery pack, install the energy storage battery pack and inverter pack, and achieve the connection with the lowest voltage difference between adjacent energy storage battery clusters in the energy storage battery pack.

[0012] Step 4: Select and match air conditioners and plan a heat dissipation scheme based on the heat generation power of the energy storage battery cluster, and set up heat dissipation modules;

[0013] Step 5: Construct a container shell adapted to the schemes in Steps 1-4 with the goal of optimizing maintenance space and minimizing external volume, and set up fire protection modules, external interfaces and control systems.

[0014] The present invention further includes the following preferred embodiments:

[0015] Preferably, the structural composition determined in step 1 is as follows:

[0016] The energy storage battery pack includes n energy storage battery clusters, and each energy storage battery cluster includes several battery packs connected in series.

[0017] The converter group comprises n converter units connected in series;

[0018] The heat dissipation module includes several fans, air conditioners, and air supply ducts;

[0019] The fire protection module includes a fire control panel, a fire alarm, and a fire monitoring unit; the fire control panel includes a fire control unit and a fire extinguishing panel.

[0020] The control system includes a converter control unit and a battery management unit;

[0021] The connecting harness includes a primary connecting cable and an optical fiber;

[0022] The external interface includes an external primary input connection terminal, an external primary output connection terminal, and an external secondary connection terminal.

[0023] Preferably, in step 2, the number of converter group links The calculation formula is as follows:

[0024]

[0025] In the formula, Us is the AC input voltage;

[0026] K v This represents the voltage fluctuation value of the power grid.

[0027] K b This refers to the allowable value for grid voltage imbalance.

[0028] K L For inductor voltage drop;

[0029] U DCmin This is the minimum operating voltage of the battery.

[0030] Preferably, in step 2, the heat generation power of each energy storage battery cluster during charging and discharging processes is calculated based on the battery charging and discharging currents under rated operating conditions. The calculation formula is as follows:

[0031] Q=I 2 r

[0032] In the formula, Q is the heating power of the energy storage battery cluster;

[0033] I represents the battery charging or discharging current under rated operating conditions;

[0034] r is the internal resistance of the battery.

[0035] Preferably, in step 3, the installation positions of the energy storage battery group, the inverter group and the energy storage battery cluster are arranged in a topological order according to the number of inverter group links and the capacity and volume of each energy storage battery cluster in the energy storage battery group, so that the voltage difference between each energy storage battery cluster and other adjacent energy storage battery clusters is minimized.

[0036] The converter units within the converter group are connected sequentially using a chain topology scheme, and the inter-terminal voltage gradually increases as the number of converter units increases.

[0037] Furthermore, all converter units in the converter group are arranged in two stacked rows.

[0038] All energy storage battery clusters in the energy storage battery pack are arranged continuously back-to-back with gaps between them;

[0039] The energy storage battery cluster is connected to the DC terminal of the inverter unit via a primary connection cable;

[0040] The primary connection cables are laid in a cross pattern in the gap between the bottom of the energy storage battery cluster and the bottom of the container shell, so as to minimize the voltage difference between adjacent energy storage battery clusters.

[0041] The energy storage battery pack is connected to the battery management unit via optical fiber, and the inverter pack is connected to the inverter control unit via optical fiber.

[0042] Preferably, in step 4, based on the heating power of all energy storage battery clusters and considering the influence of ambient temperature, an air conditioner is selected to ensure that the cooling power of the air conditioner is not less than the heating power of the energy storage battery cluster when the outdoor ambient temperature is highest; and the number of air conditioners is not less than the number of energy storage battery clusters.

[0043] The heat dissipation solution is as follows: two energy storage battery clusters are arranged back to back with a 200mm space reserved. The two sides of the reserved space are then enclosed with insulating covers to form an air supply duct. The fan is installed on the top of the air supply duct.

[0044] The circulating air, as a heat transfer medium, is cooled and blown out by the air conditioner, then sent into the air duct by the fan, and passes through the surface of the battery pack in sequence. After absorbing the heat emitted by the battery pack and heating up, it returns to the air conditioner for cooling.

[0045] Preferably, in step 5, a container shell adapted to the schemes of steps 1-4 is constructed, which is a metal box with multi-sided insulation function welded from steel profiles, and several inspection doors are installed on the outer wall of the container shell, with an air conditioner installed on each inspection door.

[0046] The container shell is equipped with a partition wall to divide the interior into two independent spaces: a battery room and a converter room.

[0047] The energy storage battery pack and the inverter pack are respectively installed in the battery compartment and inverter compartment inside the container shell. The energy storage battery packs are arranged back-to-back along the length of the container shell in sequence. The inverter units of the inverter pack are connected in series from the lower left to the top unit in two columns, then connected laterally to the upper right unit and then down to the lower right unit.

[0048] A steel mesh screen door is installed in the middle of the converter room. The inside of the steel mesh screen is the installation space for the converter, and the outside of the steel mesh screen is the installation space for the control system and the fire alarm control panel.

[0049] Preferably, in step 5, the fire protection module is configured as follows: the fire monitoring unit is installed on the energy storage battery cluster, the fire alarm is installed on the outer wall of the container shell, and the fire extinguishing unit is installed on the top inside the container shell; the fire control unit is connected to both the fire monitoring unit and the fire alarm, and the fire extinguishing host is connected to the fire extinguishing unit.

[0050] The external interface is configured as follows: external primary input connection terminals and external primary output connection terminals are respectively installed on both sides of the external wall of the container shell, and external secondary connection terminals are installed on the external wall of the container shell; the external primary input connection terminals and external primary output connection terminals are respectively connected to the AC terminals of the first and last converter units of the converter group;

[0051] The control system is installed inside the container shell and connected to external secondary connection terminals.

[0052] Preferably, the primary input connection terminal and the external primary output connection terminal are each equipped with a movable protective cover.

[0053] Preferably, the high-density medium-voltage energy storage system comprises an energy storage battery pack, a converter pack, a heat dissipation module, a container shell, a fire protection module, an external interface, and a control system.

[0054] Among them, the energy storage battery pack and the inverter pack are installed according to the number of inverter pack links and the capacity and volume of each energy storage battery cluster in the energy storage battery pack, and the connection between adjacent energy storage battery clusters in the energy storage battery pack is minimized.

[0055] The heat dissipation module is configured based on a heat dissipation scheme obtained by selecting an air conditioner according to the heat generation power of the energy storage battery cluster.

[0056] The container shell, fire-fighting modules, external interfaces, and control systems were constructed and installed with the goal of maximizing maintenance space and minimizing external volume.

[0057] The beneficial effects of this invention are compared with those of the prior art:

[0058] This invention first determines the structural composition of a high-density medium-voltage energy storage system, including energy storage battery packs, inverter packs, connecting harnesses, heat dissipation modules, a container shell, a fire suppression module, external interfaces, and a control system. Then, it calculates the number of inverter pack links and the capacity and volume of each energy storage battery cluster in the battery pack, and calculates the heat generation power of each energy storage battery cluster during charging and discharging based on the battery charging and discharging currents under rated operating conditions. Based on a primary topology scheme, it designs the layout and connection scheme of the energy storage battery packs and inverter packs; it plans a heat dissipation scheme, setting up heat dissipation modules, heat dissipation methods, and paths; by constructing a container shell adapted to the above design scheme, and aiming for optimal maintenance space, compact internal structure, and minimal external volume, it sets up the fire suppression module, external interfaces, and control system, improving the equipment's applicability in different environments. Specifically:

[0059] In the high-density medium-voltage energy storage system designed in this invention, the energy storage battery clusters are arranged sequentially back to back. The energy storage battery group and the converter group are connected in one step to make full use of the space at the bottom of the cluster and adopt a cross-laying scheme to minimize the voltage difference between adjacent battery clusters. The front and rear battery clusters can share the cooling air duct, which greatly reduces the required safety distance between battery clusters and improves the space utilization rate.

[0060] The high-density medium-voltage energy storage system designed in this invention does not involve internal maintenance access channels. Each energy storage battery cluster has a maintenance door designed on the container wall, thus eliminating the need for a centralized maintenance access channel inside the container. Its volume is significantly reduced compared to conventional designs. Furthermore, installation, wiring, and maintenance work can be performed without entering the container, significantly improving operational convenience. The air conditioner of this invention is installed on the maintenance door of the container facing the battery cluster, saving space requirements. Simultaneously, a fan installed at the top of the air duct delivers cool air from the air conditioner into the battery cluster through the air supply duct to cool the battery pack. Attached Figure Description

[0061] Figure 1 This is a flowchart of the design method of the present invention;

[0062] Figure 2 This is a schematic diagram of the high-density medium-pressure energy storage system designed in this invention;

[0063] Figure 3 This is a schematic diagram of the layout and connection of the high-density medium-pressure energy storage system designed in this invention;

[0064] Figure 4 This is a schematic diagram of the internal layout of the container designed according to the present invention;

[0065] Figure 5 This is a schematic diagram of the side sectional view of the box body designed in this invention;

[0066] in, Figure 2-5 The reference numerals in the attached diagram are as follows: 1-energy storage battery pack, 2-inverter pack, 3-primary connection cable, 4-energy storage battery cluster, 5-fan, 6-air supply duct, 7-external primary input connection terminal, 8-container shell, 9-external secondary connection terminal, 10-control system, 11-fire control panel, 12-fire alarm, 13-external primary output connection terminal, 14-inverter unit, 15-access door, 16-air conditioner, 17-fire extinguishing unit, 18-fire monitoring unit, 19-battery pack, 20-circulating air. Detailed Implementation

[0067] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, other embodiments obtained by those skilled in the art without creative effort are all within the protection scope of this invention.

[0068] like Figure 1 As shown, Embodiment 1 of the present invention provides a design method for a high-density medium-voltage energy storage system with miniaturized structure and convenient operation and maintenance. In a preferred but non-limiting embodiment of the present invention, the method includes the following steps 1-5:

[0069] Step 1: Determine the structural composition of the high-density medium-voltage energy storage system, including energy storage battery pack 1, converter pack 2, connecting harness, heat dissipation module, container shell 8, fire protection module, external interface and control system 10;

[0070] More preferably, the determined structural composition is as follows:

[0071] The energy storage battery pack 1 includes n energy storage battery clusters 4, and each energy storage battery cluster 4 includes several battery PACK19 connected in series; that is, the energy storage battery pack 1 is an energy storage battery array composed of several energy storage battery clusters 4.

[0072] The converter group 2 includes n converter units 14 connected in series, where n is a positive integer, calculated and rounded from the grid-side voltage and the lowest voltage value after the battery cluster is discharged.

[0073] The heat dissipation module includes several fans 5, air conditioners 16, and air supply ducts 6;

[0074] The fire protection module includes a fire control panel 11, a fire alarm 12, and a fire monitoring unit 18; the fire control panel 11 includes a fire control unit and a fire extinguishing panel.

[0075] The control system 10 includes a converter control unit and a battery management unit;

[0076] The connecting harness includes a primary connecting cable 3 and an optical fiber;

[0077] The external interface includes an external primary input connection terminal 7, an external primary output connection terminal 13, and an external secondary connection terminal 9.

[0078] Step 2: Calculate the number of links in converter group 2 and the capacity and volume of each energy storage battery cluster 4 in energy storage battery group 1, and calculate the heat generation power of energy storage battery cluster 4.

[0079] Calculate the number of inverter links and the capacity and volume of each energy storage battery cluster 4 in the energy storage battery pack, and calculate the heat generation power of each energy storage battery cluster 4 during the charging and discharging process based on the battery charging and discharging current under rated operating conditions.

[0080] More preferably, the number of converter group links The calculation formula is as follows:

[0081]

[0082] In the formula, Us is the AC input voltage;

[0083] K v The value for grid voltage fluctuation is taken as 1.15;

[0084] K b This refers to the allowable value for grid voltage imbalance.

[0085] K L For the inductor voltage drop, take 1.08;

[0086] U DCmin This is the minimum operating voltage of the battery.

[0087] The heat generation power of each energy storage battery cluster during charging and discharging processes is calculated based on the battery charging and discharging currents under rated operating conditions. The calculation formula is as follows:

[0088] Q=I 2 r

[0089] In the formula, Q is the heating power of the energy storage battery cluster;

[0090] I represents the battery charging or discharging current under rated operating conditions;

[0091] r is the internal resistance of the battery.

[0092] Step 3: Based on the number of links in the converter group 2 and the capacity and volume of each energy storage battery cluster 4 in the energy storage battery group 1, install the energy storage battery group 1 and the converter group 2, and achieve the connection with the lowest voltage difference between adjacent energy storage battery clusters 4 in the energy storage battery group 1.

[0093] More preferably, the arrangement and connection scheme of the designed energy storage battery pack 1 and inverter pack 2 is as follows:

[0094] Based on the number of links in converter group 2 and the capacity and volume of each energy storage battery cluster 4 in energy storage battery group 1, the installation positions of energy storage battery group 1, converter group 2 and energy storage battery cluster 4 are sequentially corresponding in topological order, so that the voltage difference between each energy storage battery cluster 4 and other adjacent energy storage battery clusters 4 is minimized, thereby reducing the installation distance between each energy storage battery cluster 4 and improving the space utilization rate.

[0095] The converter units 14 in converter group 2 are connected sequentially in a chain topology, and the inter-terminal voltage gradually increases as the number of converter units 14 increases. The closer the adjacent converter units 14 are, the lower their inter-terminal voltage, and vice versa.

[0096] Furthermore, all converter units 14 in converter group 2 are arranged in two stacked columns.

[0097] All energy storage battery clusters 4 in the energy storage battery pack 1 are arranged continuously back to back with gaps.

[0098] The energy storage battery cluster 4 is connected to the DC terminal of the inverter unit 14 via a primary connection cable 3;

[0099] The primary connection cable 3 is laid crosswise in the gap between the bottom of the energy storage battery cluster 4 and the bottom of the container shell 8, so as to minimize the voltage difference between adjacent energy storage battery clusters 4.

[0100] The energy storage battery pack 1 is connected to the battery management unit via optical fiber, and the inverter pack 14 is connected to the inverter control unit via optical fiber.

[0101] That is, the AC terminals of each converter unit 14 are connected in series, and the DC terminal of each converter unit 14 is connected to a group of energy storage battery clusters 4.

[0102] The primary connection cable 3 is made of medium- and high-voltage flame-retardant silicone rubber flexible cable, with copper terminals installed at both ends.

[0103] Step 4: Select an air conditioner and plan a heat dissipation scheme based on the heat generation power of the energy storage battery cluster 4, and set up heat dissipation modules, heat dissipation methods and paths;

[0104] More preferably, the planned heat dissipation scheme is as follows: based on the heat generation power of all energy storage battery clusters 4 and considering the influence of ambient temperature, air conditioners 16 are selected to ensure that the cooling power of the air conditioners is not less than the heat generation power of the energy storage battery clusters 4 when the outdoor ambient temperature is the highest; and the number of air conditioners 16 is not less than the number of energy storage battery clusters 4.

[0105] The heat dissipation solution is as follows: two energy storage battery clusters 4 are arranged back to back with a 200mm space reserved. The two sides of the reserved space are then enclosed by an insulating cover to form an air supply duct 6. The fan 5 is installed on the top of the air supply duct 6.

[0106] The circulating air 20 is cooled and blown out by the air conditioner 16 as a heat transfer medium. It is then sent into the air supply duct 6 by the fan 5, passes through the surface of the battery PACK9, absorbs the heat emitted by the battery PACK9 and heats up, and then returns to the air conditioner 16 for cooling.

[0107] Each air conditioner 16 is installed on the door panel on the front of the energy storage battery cluster 4, and a partition is installed between the air inlet and outlet of the air conditioner to prevent short circuits in the cooling path.

[0108] By adding a fan between the air conditioner vent and the battery, the airflow direction can be reliably changed, ensuring uniform and consistent heat dissipation from the battery.

[0109] The heat dissipation power is calculated based on the rated charging rate and discharging rate of the energy storage battery pack.

[0110] Step 5: Construct a container shell adapted to the schemes in Steps 1-4 with the goal of optimal maintenance space, compact internal structure, and minimum external volume, and set up fire protection module, external interface and control system 10.

[0111] More preferably, a container shell adapted to the schemes of steps 1-4 is constructed, which is a metal box with six-sided insulation function welded from steel profiles, and several maintenance doors 15 are installed at the required locations on the outer wall of the container shell 8. For example, maintenance doors 15 are opened in the container shell 8 in the length direction opposite to each energy storage battery cluster 4, and air conditioners 16 are installed on each maintenance door 15.

[0112] The container shell is equipped with a partition wall to divide the interior into two independent spaces: a battery room and a converter room.

[0113] The energy storage battery pack 1 and the inverter pack 2 are respectively installed in the battery compartment and inverter compartment inside the container shell 8. The energy storage battery clusters 4 of the energy storage battery pack 1 are arranged back to back along the length of the container shell in sequence. The inverter units 14 of the inverter pack 2 are connected in series from the lower left to the top unit in two columns, then connected laterally to the upper right unit and then down to the lower right unit.

[0114] The primary connection cable is laid crosswise after entering the battery room from the converter room, so as to minimize the voltage between adjacent battery clusters.

[0115] A steel mesh screen door is installed in the middle of the converter room. The inside of the steel mesh screen is the installation space for the converter, and the outside of the steel mesh screen is the installation space for the control system 10 and the fire alarm control panel 11.

[0116] The fire protection module is set up as follows: the fire monitoring unit 18 is installed on the front panel of the energy storage battery cluster 4, the fire alarm 12 is installed on the outer wall of the container shell 8, and the fire extinguishing unit 17 is installed on the top inside the container shell 8; the fire control unit is connected to both the fire monitoring unit 18 and the fire alarm 12, and the fire extinguishing host is connected to the fire extinguishing unit 17.

[0117] The external interface is set up as follows: external primary input connection terminal 7 and external primary output connection terminal 13 are respectively set on both sides of the external wall of the container shell 8, and external secondary connection terminal 9 is set on the external wall of the container shell 8; external primary input connection terminal 7 and external primary output connection terminal 13 are respectively connected to the AC terminals of the first and last two converter units 14 of the converter group 2.

[0118] The control system is configured as follows: the control system 10 is installed inside the container shell 8 and connected to the external secondary connection terminal 9.

[0119] The primary input connection terminal 7 and the external primary output connection terminal 13 are each equipped with a movable protective cover.

[0120] Embodiment 2 of the present invention provides a high-density medium-voltage energy storage system designed according to the above design method. The high-density medium-voltage energy storage system comprises an energy storage battery pack 1, a converter pack 2, a heat dissipation module, a container shell 8, a fire-fighting module, an external interface, and a control system 10.

[0121] Among them, the energy storage battery pack 1 and the inverter pack 2 are installed according to the number of links of the inverter pack 2 and the capacity and volume of each energy storage battery cluster 4 in the energy storage battery pack 1, and the connection between adjacent energy storage battery clusters 4 in the energy storage battery pack 1 is minimized.

[0122] The heat dissipation module is configured based on the heat dissipation scheme obtained by selecting an air conditioner according to the heat generation power of the energy storage battery cluster 4.

[0123] The container shell, fire-fighting module, external interface and control system 10 were built and set up with the goal of optimal maintenance space, compact internal structure and minimal external volume.

[0124] like Figure 2-5 As shown, the high-density medium-voltage energy storage system includes: energy storage battery pack 1, inverter pack 2, primary connection cable 3, fan 5, air supply duct 6, external primary input connection terminal 7, container shell 8, external secondary connection terminal 9, control system 10, fire control panel 11, fire alarm 12, external primary output connection terminal 13, inverter unit 14, air conditioner 16, fire extinguishing unit 17, fire monitoring unit 18, and circulating air 20.

[0125] The energy storage battery pack 1 comprises n independent energy storage battery clusters 4, with each pair of energy storage battery clusters 4 placed back-to-back with a certain distance between them, such as... Figure 3-4 The order and position shown are arranged from B1 to Bn inside the container shell 8. The space between the two back-to-back energy storage battery clusters 4 is enclosed on both sides by insulating covers to form an air supply duct 6. A fan 5 is installed on the top of the air supply duct 6.

[0126] Each battery cluster 4 includes several battery packs 19, which are individual energy storage battery packs assembled by connecting battery cells in series and cannot be separated.

[0127] Converter group 2 includes n converter units 14, such as Figure 3 As shown, the converter unit 14 is arranged in two columns from bottom to top according to the serial numbers M1 to Mn.

[0128] Each energy storage battery cluster 4 is connected to the DC terminal of the corresponding converter unit 14 via a primary connection cable 3.

[0129] The primary connection cable 3 is laid in the gap between the bottom of the energy storage battery cluster 4 and the bottom of the container shell 8.

[0130] The AC terminals of the first and last two converter units 14 of the converter group 2 are respectively connected to the external primary input connection terminals 7 and the external primary output connection terminals 13 on both sides of the container shell 8.

[0131] The primary input connection terminal 7 and the external primary output connection terminal 13 are installed on both sides of the container shell 8 and are equipped with openable protective covers.

[0132] The control system 10 includes a converter control unit and a battery management unit. The control system 10 is installed inside the container shell 8 and connected to the external secondary connection terminal 9 installed on the outer wall of the container shell 8.

[0133] The fire control panel 11 includes a fire control unit and a fire extinguishing unit. The fire control unit of the fire control panel 11 is connected to the fire monitoring unit 18 installed on the energy storage battery cluster 4 and the fire alarm 12 installed on the outer wall of the container shell 8. The fire extinguishing unit of the fire control panel 11 is connected to the fire extinguishing unit 17 installed on the top of the container shell 8.

[0134] The outer wall of the container shell 8 is equipped with several inspection doors 15, and each inspection door 15 is equipped with an air conditioner 16.

[0135] After being cooled inside the air conditioner 16, the circulating air 20 is blown out from the upper outlet and transported to the air supply duct 6 by the fan 5. It then enters the energy storage battery cluster 4 from the rear, flows over the surface of the battery PACK 19, absorbs the heat dissipated by the battery PACK 19, and after the temperature of the circulating air 20 rises, it flows out from the front of the energy storage battery cluster 4 and is drawn into the air inlet of the air conditioner 16, where it is cooled again inside the air conditioner, completing a heat dissipation cycle.

[0136] The beneficial effects of this invention are compared with those of the prior art:

[0137] This invention first determines the structural composition of a high-density medium-voltage energy storage system, including energy storage battery packs, inverter packs, connecting harnesses, heat dissipation modules, a container shell, a fire suppression module, external interfaces, and a control system. Then, it calculates the number of inverter pack links and the capacity and volume of each energy storage battery cluster in the battery pack, and calculates the heat generation power of each energy storage battery cluster during charging and discharging based on the battery charging and discharging currents under rated operating conditions. Based on a primary topology scheme, it designs the layout and connection scheme of the energy storage battery packs and inverter packs; it plans a heat dissipation scheme, setting up heat dissipation modules, heat dissipation methods, and paths; and by constructing a container shell adapted to the above design scheme, with the goals of optimal maintenance space, compact internal structure, and minimal external volume, it sets up fire suppression modules, external interfaces, and a control system, improving the equipment's applicability in different environments.

[0138] In the high-density medium-voltage energy storage system designed in this invention, the energy storage battery clusters are arranged sequentially back to back. The energy storage battery group and the converter group are connected in one step to make full use of the space at the bottom of the cluster and adopt a cross-laying scheme to minimize the voltage difference between adjacent battery clusters. The front and rear battery clusters can share the cooling air duct, which greatly reduces the required safety distance between battery clusters and improves the space utilization rate.

[0139] In the high-density medium-voltage energy storage system designed in this invention, each energy storage battery cluster has an inspection door on the container wall. Therefore, there is no need to reserve a centralized maintenance passage inside the container, significantly reducing its volume compared to conventional designs. Furthermore, installation, wiring, and maintenance work can be performed without entering the container, greatly improving operational convenience. The air conditioner of this invention is installed on the inspection door of the container facing the battery cluster, saving space requirements. Additionally, a fan installed at the top of the air duct delivers cool air from the air conditioner into the battery cluster through the air supply duct to cool the battery pack.

[0140] In this patent, the PCS modules are centrally installed in the PCS room, and the batteries are centrally installed in the battery room. The two are connected by a high-voltage DC cable, which reduces the direct impact between the PCS and the battery cluster and ensures relatively safe operation. The air conditioner is installed on the door facing the battery, eliminating the risk of water leakage. The air conditioner's cool air is delivered directly to the PACK through the top fan of the air duct. The air conditioner's return air vent faces the middle of the battery, ensuring uniform airflow and consistent heat dissipation for each PACK.

[0141] The solution involved in this patent does not involve internal maintenance channels, and the internal space of the container is fully utilized. For energy storage systems of the same capacity, this solution saves more floor space. Moreover, all maintenance in this patent is done from the outside of the container, which ensures the safety of the transportation and maintenance personnel.

[0142] This disclosure can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of this disclosure.

[0143] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by an instruction execution device. Computer-readable storage media can be, for example—but not limited to—electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination of the foregoing. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0144] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0145] Computer program instructions used to perform the operations of this disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, status setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing the status information of the computer-readable program instructions to implement various aspects of this disclosure.

[0146] Various aspects of this disclosure are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0147] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that, when executed by the processor of the computer or other programmable data processing apparatus, they create means for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium that causes a computer, programmable data processing apparatus, and / or other device to operate in a particular manner; thus, the computer-readable medium storing the instructions comprises an article of manufacture that includes instructions for implementing aspects of the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0148] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to perform the functions / actions specified in one or more boxes of a flowchart and / or block diagram.

[0149] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of an instruction containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than those shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0150] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A design method for a high-density medium-voltage energy storage system with miniaturized structure and convenient operation and maintenance, characterized by: The method includes the following steps: Step 1: Determine the structural components of the high-density medium-voltage energy storage system, including energy storage battery packs, inverter packs, connecting harnesses, heat dissipation modules, container shells, fire protection modules, external interfaces, and control systems. Step 2: Calculate the number of inverter links and the capacity and volume of each energy storage battery cluster in the energy storage battery pack, and calculate the heat generation power of the energy storage battery cluster; wherein, the number of inverter links... The calculation formula is as follows: In the formula, Us is the AC input voltage; K v K represents the grid voltage fluctuation value. b K represents the allowable value for grid voltage imbalance. L For inductor voltage drop; U DCmin This is the minimum operating voltage of the battery; Step 3: Based on the number of inverter link segments and the capacity and volume of each energy storage battery cluster in the energy storage battery pack, install the energy storage battery pack and inverter pack, and achieve the connection with the lowest possible voltage difference between adjacent energy storage battery clusters in the energy storage battery pack. This includes: according to the number of inverter link segments and the capacity and volume of each energy storage battery cluster in the energy storage battery pack, the installation positions of the energy storage battery pack, inverter pack, and energy storage battery clusters correspond sequentially in topological order, so that the voltage difference between each energy storage battery cluster and its surrounding adjacent energy storage battery clusters is minimized; the inverter units within the inverter pack adopt a chain topology scheme and are sequentially connected... The voltage between terminals gradually increases with the number of converter units; all converter units in the converter group are arranged in two stacked rows; all energy storage battery clusters in the energy storage battery group are arranged continuously back-to-back with gaps; the DC terminals of the energy storage battery clusters and converter units are connected by primary connection cables; the primary connection cables are laid crosswise in the gap between the bottom of the energy storage battery clusters and the bottom of the container shell to minimize the voltage difference between adjacent energy storage battery clusters; the energy storage battery group is connected to the battery management unit through optical fiber, and the converter group is connected to the converter control unit through optical fiber. Step 4: Select and match air conditioners and plan a heat dissipation scheme based on the heat generation power of the energy storage battery cluster, and set up heat dissipation modules; Step 5: Construct a container shell adapted to the schemes in Steps 1-4 with the goal of optimizing maintenance space and minimizing external volume, and set up fire protection modules, external interfaces and control systems.

2. The design method for a high-density medium-voltage energy storage system with miniaturized structure and convenient operation and maintenance as described in claim 1, characterized in that: The structural composition determined in step 1 is as follows: The energy storage battery pack includes n energy storage battery clusters, and each energy storage battery cluster includes several battery packs connected in series. The converter group comprises n converter units connected in series; The heat dissipation module includes several fans, air conditioners, and air supply ducts; The fire protection module includes a fire control panel, a fire alarm, and a fire monitoring unit; the fire control panel includes a fire control unit and a fire extinguishing panel. The control system includes a converter control unit and a battery management unit; The connecting harness includes a primary connecting cable and an optical fiber; The external interface includes an external primary input connection terminal, an external primary output connection terminal, and an external secondary connection terminal.

3. The design method for a high-density medium-voltage energy storage system with miniaturized structure and convenient operation and maintenance as described in claim 2, characterized in that: In step 2, the heat generation power of each energy storage battery cluster during charging and discharging processes is calculated based on the battery charging and discharging currents under rated operating conditions. The calculation formula is as follows: Q=I 2 r In the formula, Q is the heating power of the energy storage battery cluster; I represents the battery charging or discharging current under rated operating conditions; r is the internal resistance of the battery.

4. The design method for a high-density medium-voltage energy storage system with miniaturized structure and convenient operation and maintenance as described in claim 2, characterized in that: In step 4, based on the heating power of all energy storage battery clusters and considering the influence of ambient temperature, air conditioners are selected to ensure that the cooling power of the air conditioner is not less than the heating power of the energy storage battery cluster when the outdoor ambient temperature is the highest; and the number of air conditioners is not less than the number of energy storage battery clusters. The heat dissipation solution is as follows: two energy storage battery clusters are arranged back to back with a 200mm space reserved. The two sides of the reserved space are then enclosed with insulating covers to form an air supply duct. The fan is installed on the top of the air supply duct. The circulating air, as a heat transfer medium, is cooled and blown out by the air conditioner, then sent into the air duct by the fan, and passes through the surface of the battery pack in sequence. After absorbing the heat emitted by the battery pack and heating up, it returns to the air conditioner for cooling.

5. The design method for a high-density medium-voltage energy storage system with miniaturized structure and convenient operation and maintenance as described in claim 2, characterized in that: In step 5, a container shell adapted to the schemes in steps 1-4 is constructed. It is a metal box with multi-sided insulation function, which is welded from steel profiles. Several inspection doors are installed on the outer wall of the container shell, and an air conditioner is installed on each inspection door. The container shell is equipped with a partition wall to divide the interior into two independent spaces: a battery room and a converter room. The energy storage battery pack and the inverter pack are respectively installed in the battery compartment and inverter compartment inside the container shell. The energy storage battery packs are arranged back-to-back along the length of the container shell in sequence. The inverter units of the inverter pack are connected in series from the lower left to the top unit in two columns, then connected laterally to the upper right unit and then down to the lower right unit. A steel mesh screen door is installed in the middle of the converter room. The inside of the steel mesh screen is the installation space for the converter, and the outside of the steel mesh screen is the installation space for the control system and the fire alarm control panel.

6. The design method for a high-density medium-voltage energy storage system with miniaturized structure and convenient operation and maintenance as described in claim 5, characterized in that: In step 5, the fire protection module is set up as follows: the fire monitoring unit is installed on the energy storage battery cluster, the fire alarm is installed on the outer wall of the container shell, and the fire extinguishing unit is installed on the top inside the container shell; the fire control unit is connected to both the fire monitoring unit and the fire alarm, and the fire extinguishing host is connected to the fire extinguishing unit. The external interface is configured as follows: external primary input connection terminals and external primary output connection terminals are respectively installed on both sides of the external wall of the container shell, and external secondary connection terminals are installed on the external wall of the container shell; the external primary input connection terminals and external primary output connection terminals are respectively connected to the AC terminals of the first and last converter units of the converter group; The control system is installed inside the container shell and connected to external secondary connection terminals.

7. The design method for a high-density medium-voltage energy storage system with miniaturized structure and convenient operation and maintenance as described in claim 6, characterized in that: The primary input connection terminal and the external primary output connection terminal are each equipped with a movable protective cover.

8. The high-density medium-pressure energy storage system designed by the design method according to any one of claims 1-7, characterized in that: The high-density medium-voltage energy storage system consists of an energy storage battery pack, a converter pack, a heat dissipation module, a container shell, a fire-fighting module, an external interface, and a control system. Among them, the energy storage battery pack and the inverter pack are installed according to the number of inverter pack links and the capacity and volume of each energy storage battery cluster in the energy storage battery pack, and the connection between adjacent energy storage battery clusters in the energy storage battery pack is minimized. The heat dissipation module is configured based on a heat dissipation scheme obtained by selecting an air conditioner according to the heat generation power of the energy storage battery cluster. The container shell, fire-fighting modules, external interfaces, and control systems were constructed and installed with the goal of maximizing maintenance space and minimizing external volume.

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