Power type energy storage system based on complementation of advantages and disadvantages of multiple battery cells

Abstract

The invention relates to a power type energy storage system based on advantage and disadvantage complementation of multiple battery cells, which comprises an energy storage energy management controller EMS module, an energy storage converter PCS module, a high-rate battery cluster module and a low-rate battery cluster module, and is characterized in that the high-rate battery cluster module is electrically connected with a BMS1 module; when the power type energy storage system based on the multi-cell advantage and disadvantage complementation is used, the high-rate battery cluster module and the low-rate battery cluster module are adopted to form an electric energy storage system to be used in a matched mode, the requirement of the high-rate battery cluster module for electric energy loads is met, the utilization rate of the high-rate battery cluster module is increased, and the utilization rate of the high-rate battery cluster module and the utilization rate of the low-rate battery cluster module are increased. According to the system, the low-rate battery cluster module is isolated from the high-rate battery cluster module through the DC / DC module, and the problem of inter-cluster consistency generated when the battery clusters are connected in parallel is avoided due to the fact that the low-rate battery cluster module is isolated from the high-rate battery cluster module through the DC / DC module.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage systems, and in particular to a power-type energy storage system based on complementary advantages and disadvantages of multiple battery cells. Background Art

[0002] The energy storage system is mainly composed of energy storage cells and a new battery management system BMS, energy storage converter PCS modules, and energy management system energy storage energy management controller EMS modules. It is used to store a large amount of electrical energy and continuously and slowly discharge and charge at low power, so as to achieve the purpose of peak shaving and valley filling for large power grids and smooth out power grid fluctuations. In the actual application scenarios of energy storage systems, such as mines, construction sites, ports, oil fields, etc., there are many high-power electricity demands. For example, the peak power required for the start-up of an electric equipment with a rated power of 200kW can be as high as 1MW, and the power consumption is very high. However, this type of equipment does not work continuously for a long time, but works for a dozen seconds and rests for dozens of minutes, and has low power consumption. Therefore, the current solution for this type of application scenario is to use a high-power diesel generator to drive such a high-power load, and the diesel generator cannot discharge at full power instantaneously. Usually, a 2MW diesel generator is required to drive a 1MW impact load. Multiple high-power diesel generators must be installed on site in parallel to drive the load. Therefore, the procurement cost, installation cost, and use cost of the diesel generator are extremely high. In addition, the noise is loud, the carbon emissions are large, and the air pollution is serious. Therefore, in actual use, energy storage is gradually used to replace diesel generators.

[0003] However, the design of existing traditional energy storage systems is basically based on energy storage. For example, the lithium iron phosphate or sodium ion batteries commonly used for energy storage have a low discharge rate. If you want to discharge at a high rate, you must stack the batteries in multiples. Therefore, this type of energy storage battery is generally large in size and weight, and difficult to transport. The diesel generator sets on site need to be replaced with multiple large energy storage containers. Although it is more environmentally friendly and has certain economic benefits, its cost is still high because it uses more battery cells, and it occupies a large area, is difficult to construct and transport, and has high costs. Summary of the invention

[0004] The purpose of the present invention is to provide a power-type energy storage system based on the complementary advantages and disadvantages of multiple battery cells, which can greatly reduce the overall size of the energy storage system and meet the power supply needs of larger loads.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A power-type energy storage system based on complementary advantages and disadvantages of multiple battery cells, the energy storage system comprising:

[0007] Energy storage energy management controller EMS module, the energy storage energy management controller EMS module controls the power consumption and charging of the energy storage system;

[0008] An energy storage converter PCS module, wherein the energy storage converter PCS module comprises an AC side and a DC side, and the AC side of the energy storage converter PCS module is connected to an external power load;

[0009] High-rate battery cluster modules to cope with the impact of high-power loads;

[0010] Low-rate battery cluster modules for storing electrical energy;

[0011] DC bus, used for transmitting DC power in the energy storage system;

[0012] DC / DC module, which transmits the electric energy between the low-rate battery cluster module and the DC bus in both directions;

[0013] The charging module transfers the external electric energy of the energy storage system to the DC bus;

[0014] DC / DC power supply, which converts the high-voltage DC power of the DC bus into the low-voltage power required by the equipment in the energy storage system;

[0015] A BMS1 module, wherein the BMS1 module is electrically connected to the high-rate battery cluster module to control the high-rate battery cluster module;

[0016] A BMS2 module, wherein the BMS2 module is electrically connected to the low-rate battery cluster module to control the low-rate battery cluster module;

[0017] Battery relay 1, two ends of the battery relay 1 are electrically connected to the DC bus and the DC side of the energy storage converter PCS module respectively.

[0018] The present invention also includes the following features:

[0019] The energy storage energy management controller EMS module is electrically connected to the energy storage inverter PCS module, BMS1 module, BMS2 module, and DC / DC module, and the energy storage inverter PCS module is electrically connected to the BMS1 module. The outer surface of the energy storage energy management controller EMS module is provided with an IO module, and the external power-off instruction transmits the signal to the energy storage energy management controller EMS module through the input port of the IO module. The energy storage energy management controller EMS module is electrically connected to the liquid cooling unit, dehumidification air conditioner, temperature and humidity sensor, touch screen and 4G module, and the liquid cooling unit, dehumidification air conditioner, temperature and humidity sensor, touch screen and 4G module are all arranged in the energy storage system equipment, and the energy storage energy management controller EMS module is powered by the DC side battery of the energy storage inverter PCS module, which cancels the traditional UPS power supply mode for auxiliary control equipment, reduces costs, and solves the problem of low power and easy power feeding of UPS.

[0020] The DC side of the energy storage converter PCS module, the high-rate battery cluster module, the low-rate battery cluster module, the DC / DC power supply and the charging module are all coupled to one end of the DC bus. A battery relay 1 is provided between the DC side of the energy storage converter PCS module and the DC bus. The high-rate battery cluster module and the charging module are directly connected to the DC bus. A battery relay 2 and a DC / DC module are connected in series between the low-rate battery cluster module and the DC bus in sequence. A control switch is provided at the connection between the DC / DC power supply and the DC bus.

[0021] The discharge rate of the high-rate battery cluster module used in the energy storage system is higher than 2P, so that it can cope with the impact of high-power loads. The high-rate battery cluster module adopts nickel-metal hydride batteries and lithium titanate batteries, and its safety factor is much higher than that of lithium iron phosphate batteries. The energy storage inverter PCS module is arranged between the AC and DC sides of the energy storage system to realize bidirectional energy conversion.

[0022] The low-rate battery cluster module uses a battery cluster with a discharge rate lower than 1P. The low-rate battery cluster module is made of lithium iron phosphate batteries and is used to store electrical energy. The DC / DC module bidirectionally transfers electrical energy between the low-rate battery cluster module and the DC bus. At the same time, the charging and discharging power of the low-rate battery is completely controlled by the energy storage energy management controller EMS module, and constant power charging and discharging can be performed.

[0023] The power ratio of the high-rate battery to the low-rate battery is less than 1:5, and the discharge rate ratio of the high-rate battery to the low-rate battery is greater than 10:1. Compared with a battery cluster composed entirely of low-rate batteries, its energy storage and power supply capabilities are stronger, and compared with a battery cluster composed entirely of high-rate batteries, its own volume is smaller and more convenient for practical application.

[0024] The DC / DC power supply is arranged at one end of the DC bus to realize the conversion of the high-voltage DC power of the DC bus to low-voltage power. The low-voltage power output end of the DC / DC power supply is electrically connected to the energy storage energy management controller EMS module, the switch, the dehumidification air conditioner, the temperature and humidity sensor, the touch screen and the 4G module, so as to provide low-voltage power for the above-mentioned equipment to prevent the equipment from being damaged by external high-voltage DC power.

[0025] The DC / DC module is arranged on the connection circuit between the high-rate battery cluster module and the low-rate battery cluster module to achieve isolation of the high-rate battery cluster module and the low-rate battery cluster module, effectively avoiding the problem that the consistency difference between clusters will increase significantly after multiple rounds of charge and discharge due to the influence of factors such as internal impedance, location, temperature, cluster consistency, etc. caused by direct parallel connection of multiple battery clusters after long-term use.

[0026] It also includes an energy control step, a power-on step, and a power-off step, wherein the energy control step performs the following specific steps:

[0027] S1. Set the primary and secondary lower limits of SOC1 of the BMS1 module and the primary and secondary lower limits of SOC2 of the BMS2 module, as well as the DC / DC module charging and discharging power and the charging module charging power in the energy storage energy management controller EMS module system, and then start the system;

[0028] S2: When the external load starts to consume electricity, the energy storage converter PCS module discharges, and the high-rate battery cluster module instantly responds to the load's power demand and starts to discharge. At this time, the low-rate battery cluster module cannot respond in time, so it will not be impacted by the large load.

[0029] S3. If the SOC1 of the BMS1 module is greater than its first-level lower limit, and the BMS2 module is greater than its first-level lower limit, the energy storage energy management controller EMS module controls the DC / DC module to discharge, and the electric energy flows from the low-rate battery to the DC bus until the load stops using electricity. This is to avoid long-term high-power discharge of the high-rate battery, to spread the thermal effect, and to prevent the high-rate battery from rapidly decreasing in power.

[0030] S4, if SOC1> its first-level lower limit, and SOC2≤ its first-level lower limit; the energy storage energy management controller EMS module controls the charging module to charge, and the electric energy flows from the outside into the DC bus, first charging the high-rate battery until the high-rate battery is fully charged, that is, SOC1=100%, and then the energy storage energy management controller EMS module controls the DC / DC module to charge, and the electric energy flows from the DC bus into the low-rate battery until the low-rate battery is fully charged, that is, SOC2=100%;

[0031] S5. If SOC1≤the first level lower limit and SOC1>the second level lower limit, then execute the following steps:

[0032] S51. If SOC2> its first-level lower limit at this time, the energy storage energy management controller EMS module controls the DC / DC module to discharge to the DC bus. Conversely, if SOC2≤ its first-level lower limit, the energy storage energy management controller EMS module controls the charging module to charge the DC bus.

[0033] S52, if at this time SOC2 ≤ its first-level lower limit, and SOC2> its second-level lower limit, the energy storage energy management controller EMS module controls the DC / DC power supply to discharge, and the electric energy flows from the low-rate battery to the DC bus. At this time, the low-rate battery and the charging module simultaneously charge the high-rate battery or share the power supply pressure of the high-rate battery;

[0034] S53, if SOC2≤the secondary lower limit at this time, the energy storage energy management controller EMS module controls the DC / DC module to standby;

[0035] S54, the charging module and the low rate battery continue to charge the high rate battery until SOC1> its first level lower limit, then return to S4, otherwise the execution is completed and enters the next step;

[0036] S6. After S5, determine the SOC1 value in the energy storage system:

[0037] S61, if SOC1≤its secondary lower limit, the energy storage energy management controller EMS module controls the energy storage converter PCS module to shut down. At this time, the secondary lower limit is the protection threshold of the high-rate battery. When the battery SOC is lower than this condition, its cycle life will be greatly reduced;

[0038] S62, if SOC2> its secondary lower limit or the charging module has power at this time, the energy storage energy management controller EMS module controls the charging module to charge until SOC1 is fully charged, then the energy storage energy management controller EMS module controls the energy storage converter PCS module to start, and returns to S4;

[0039] S63: If SOC2 ≤ its secondary lower limit and the charging module is in a power-off state, the energy storage energy management controller EMS module controls the system to shut down and starts to execute the power-off process.

[0040] The power-on step includes the following specific operation steps:

[0041] SA1. Manually close the control switch. Before the system is powered on, the entire system is in a power-off state;

[0042] SA2, the DC / DC power supply draws power from the high-rate battery cluster module through the DC bus and outputs 24V DC power, so that the energy storage energy management controller EMS module has power;

[0043] SA3, the energy storage energy management controller EMS module program starts, controls the battery relay 1 to close, at this time the energy storage converter PCS module is powered, and controls the battery relay 2 to close, at this time the DC / DC module is powered;

[0044] SA4, the energy storage energy management controller EMS module controls the battery relay 1 to close, at which time the energy storage converter PCS module has power, and controls the battery relay 2 to close, at which time the DC / DC module has power;

[0045] SA5, the energy storage energy management controller EMS module controls the energy storage converter PCS module to enter the off-grid mode;

[0046] SA6. Complete system power-on.

[0047] The power-off step includes the following specific steps:

[0048] SB1, including manually pressing the power-off button and the energy storage energy management controller EMS module executing S63 to start the power-off process;

[0049] SB2, the energy storage energy management controller EMS module controls the energy storage converter PCS module to shut down;

[0050] SB3, the energy storage energy management controller EMS module controls the battery relay 1 and the battery relay 2 to be disconnected;

[0051] SB4, the energy storage energy management controller EMS module controls the control switch to be disconnected;

[0052] SB5. Complete system power off.

[0053] The technical effect achieved by the present invention is as follows: by adopting a high-rate battery cluster module and a low-rate battery cluster module to form an electric energy storage system for use in combination, and both are controlled by an energy storage energy management controller EMS module, under the same power and power requirements, it not only has the high-rate battery cluster module to meet the demand for electric energy load, but also has a volume advantage that traditional high-rate battery cluster modules do not have, which brings many conveniences for transportation and on-site applications, and has very significant commercial advantages. In addition, the system isolates the low-rate battery cluster module from the high-rate battery cluster module through a DC / DC module, which can avoid the low-rate battery from being affected by the impact of high-power loads, and can also allow the low-rate battery cluster module and the high-rate battery cluster module to be filled and discharged, and SOC calibration can be performed to avoid the consistency problem between clusters when the battery clusters are connected in parallel. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is the electrical architecture diagram of a power-type energy storage system based on the complementary advantages and disadvantages of multiple battery cells;

[0055] Figure 2 This is a communication architecture diagram of a power-type energy storage system based on the complementary advantages and disadvantages of multiple cells;

[0056] Figure 3 It is a strategic flow chart of a power-type energy storage system based on the complementary advantages and disadvantages of multiple battery cells;

[0057] Figure 4 It is a power-on flow chart of a power-type energy storage system based on the complementary advantages and disadvantages of multiple battery cells;

[0058] Figure 5 It is a power-off flowchart of a power-type energy storage system based on the complementary advantages and disadvantages of multiple battery cells. DETAILED DESCRIPTION

[0059] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is specifically described in conjunction with the following embodiments. It should be understood that the following text is only used to describe one or several specific embodiments of the present invention, and does not strictly limit the scope of protection of the specific claims of the present invention. As used herein, the terms "parallel" and "perpendicular" are not limited to their strict geometric definitions, but include tolerances for reasonable and inconsistent machining or human errors;

[0060] Combination Figures 1 to 5 As shown, the specific features of the power-type energy storage system based on the complementary advantages and disadvantages of multiple cells are described in detail below:

[0061] A power-type energy storage system based on the complementary advantages and disadvantages of multiple battery cells, the energy storage system comprising:

[0062] Energy storage energy management controller EMS module, the energy storage energy management controller EMS module controls the power consumption and charging of the energy storage system;

[0063] The energy storage converter PCS module includes an AC side and a DC side, and the AC side of the energy storage converter PCS module is connected to an external power load;

[0064] High-rate battery cluster modules to cope with the impact of high-power loads;

[0065] Low-rate battery cluster modules for storing electrical energy;

[0066] DC bus, used for transmitting DC power in the energy storage system;

[0067] DC / DC module, which transmits the electric energy between the low-rate battery cluster module and the DC bus in both directions;

[0068] The charging module transfers the external electric energy of the energy storage system to the DC bus;

[0069] DC / DC power supply, which converts the high-voltage DC power of the DC bus into the low-voltage power required by the equipment in the energy storage system;

[0070] BMS1 module, the BMS1 module is electrically connected to the high-rate battery cluster module and controls the high-rate battery cluster module;

[0071] BMS2 module, the BMS2 module is electrically connected to the low-rate battery cluster module to control the low-rate battery cluster module;

[0072] Battery relay 1, two ends of the battery relay 1 are electrically connected to the DC bus and the DC side of the energy storage converter PCS module respectively.

[0073] When the multi-cell power-type energy storage system with complementary advantages and disadvantages is first used, battery relay 1, battery relay 2 and the operating switch are all closed, and the energy storage inverter PCS module is connected to the grid or off-grid. When the system needs high-power discharge, the energy storage inverter PCS module first transmits the power demand to the high-rate battery cluster module. The high-rate battery cluster module is responsible for instantaneous high power output to meet the application requirements of the load. The low-rate battery cluster module is responsible for storing energy for the system and discharges when the high-rate battery or system needs electricity. For example, when the power of the high-rate battery cluster module is low, the energy storage energy management controller EMS module can control the low-rate battery cluster module to charge the high-rate battery cluster module through the DC bus, thereby avoiding the low-rate battery from being discharged. At the same time, when the power of the high-rate battery cluster module or the low-rate battery cluster module is too low, the energy storage energy management controller EMS module can also control the charging module to power the entire system and charge the high-rate battery cluster module and the low-rate battery cluster module.

[0074] Preferably, the DC side of the energy storage inverter PCS module, the high-rate battery cluster module, the low-rate battery cluster module, the DC / DC power supply and the charging module are all coupled to one end of the DC bus, a battery relay 1 is provided between the DC side of the energy storage inverter PCS module and the DC bus, the high-rate battery cluster module and the charging module are directly connected to the DC bus, a battery relay 2 and a DC / DC module are connected in series between the low-rate battery cluster module and the DC bus, and a control switch is provided at the connection between the DC / DC power supply and the DC bus.

[0075] Preferably, when implementing the energy storage system, the energy storage converter PCS module is used for bidirectional energy conversion on the AC and DC sides of the energy storage system, and the discharge rate of the high-rate battery cluster module used in the energy storage system is higher than 2P, so that it can cope with the impact of high-power loads and improve the adaptability of the energy storage system to different intensities and complexities. Specifically, the high-rate battery cluster module can adopt nickel-hydrogen batteries, lithium titanate batteries and other similar batteries, and its discharge rate can be as high as 10P, and its safety factor is much higher than that of lithium iron phosphate batteries. Such high-rate batteries have the characteristics of high safety factor, high discharge rate and low energy density, and its energy density is usually much lower than that of lithium iron phosphate. However, the cycle life of nickel-hydrogen batteries is affected by the depth of discharge, i.e., DOD. The lower the discharge depth, i.e., shallow charge and discharge, its cycle life can reach 100,000 times, while the cycle life of the lithium titanate battery cluster is as high as 25,000 times, which is much higher than the cycle life of 5,000 times of lithium iron phosphate batteries, which can significantly improve the service life of the system, and the service life is longer and more stable.

[0076] More specifically, the low-rate battery cluster module used in the energy storage system is a battery cluster with a discharge rate lower than 1P, which can be made of lithium iron phosphate batteries for storing electrical energy, and the DC / DC module is used to bidirectionally transfer electrical energy between the low-rate battery cluster module and the DC bus. At the same time, the charging and discharging power of the low-rate battery is completely controlled by the energy storage energy management controller EMS module, and constant power charging and discharging can be performed.

[0077] The high-rate batteries of the above-mentioned high-rate battery cluster module can support 10C-15C discharge. A 100kWh high-rate battery can meet the power demand of a 1MW high-power load, making up for the defects of low discharge rate and weak power output energy of lithium iron phosphate batteries. At the same time, low-rate batteries can charge high-rate batteries or share power consumption through the DC bus, store electrical energy for the system, and make up for the defects of low energy density and small storage capacity of high-rate batteries such as nickel-hydrogen batteries.

[0078] Specifically, compared with a high-power energy storage system composed entirely of low-rate batteries, the power required by high-rate batteries is only 1 / 10 or even 1 / 20. At the same time, compared with an energy storage system composed entirely of high-rate batteries, the energy density of low-rate batteries is much higher than that of high-rate batteries, and the price is significantly lower. Therefore, under the same power and power requirements, this system has absolute volume, weight and cost advantages, which brings many conveniences to transportation and on-site applications and has very significant commercial advantages.

[0079] The charging module is used to transfer the external electric energy of the energy storage system to the DC bus to realize the transmission of electric energy.

[0080] The above-mentioned DC / DC power supply is used to convert the high-voltage direct current of the DC bus into the low-voltage power required by energy storage energy management controller EMS modules, switches and other auxiliary control equipment. For example, 1000V can be converted into 24Vdc, thereby ensuring the power demand of energy storage energy management controller EMS modules, switches and other equipment, and preventing the equipment from being damaged by external high-voltage direct current.

[0081] Preferably, the energy storage management controller EMS module is electrically connected to the energy storage inverter PCS module, BMS1 module, BMS2 module, and DC / DC module, and the energy storage inverter PCS module is electrically connected to the BMS1 module. The outer surface of the energy storage management controller EMS module is provided with an IO module, and the external power-off instruction can transmit the signal to the energy storage management controller EMS module through the input port of the IO module. At the same time, the energy storage management controller EMS module is electrically connected to the liquid cooling unit, dehumidification air conditioner, temperature and humidity sensor, touch screen and 4G module, and the liquid cooling unit, dehumidification air conditioner, temperature and humidity sensor, touch screen and 4G module are all arranged in the energy storage system equipment, and the energy storage management controller EMS module is powered by the DC side battery of the energy storage inverter PCS module, which cancels the traditional UPS power supply mode for auxiliary control equipment, reduces costs, and solves the problem of low power and easy power feeding of UPS.

[0082] A DC / DC module is set between the high-rate battery cluster module and the low-rate battery cluster module in the above-mentioned energy storage system for isolation, which can effectively avoid the influence of factors such as internal impedance, location, temperature, cluster consistency, etc. caused by direct parallel connection of multiple battery clusters after long-term use. Furthermore, after multiple rounds of charge and discharge, the consistency difference between clusters will increase significantly, and many battery clusters cannot be fully charged or discharged, resulting in SOC jumps and a significant reduction in system power. It is necessary to manually calibrate the SOC of each battery cluster one by one on a regular basis.

[0083] Specifically, the energy management controller EMS module controls the charging module to supply power to the entire system, and the specific energy control steps for charging the high-rate battery cluster module and the low-rate battery cluster module are as follows:

[0084] S1. Set the primary and secondary lower limits of SOC1 of the BMS1 module and the primary and secondary lower limits of SOC2 of the BMS2 module, as well as the DC / DC module charging and discharging power and the charging module charging power in the energy storage energy management controller EMS module system, and then start the system;

[0085] S2: When the external load consumes electricity, the energy storage converter PCS module discharges, and the high-rate battery responds to the load's power demand instantly and starts to discharge. At this time, the low-rate battery cannot respond in time, so it will not be impacted by the large load.

[0086] S3. If the SOC1 of the BMS1 module is greater than its first-level lower limit, and the SOC1 of the BMS2 module is greater than its first-level lower limit, the energy storage energy management controller EMS module controls the DC / DC module to discharge, and the electric energy flows from the low-rate battery to the DC bus until the load stops using electricity. This is to avoid long-term high-power discharge of the high-rate battery, to share the thermal effect, and to avoid a rapid drop in the power of the high-rate battery.

[0087] S4. If SOC1> its first-level lower limit, and SOC2≤ its first-level lower limit, the energy storage energy management controller EMS module controls the charging module to charge, and electric energy flows from the outside into the DC bus to charge the high-rate battery first until the high-rate battery is fully charged, that is, SOC1=100%. Then the energy storage energy management controller EMS module controls the DC / DC module to charge, and electric energy flows from the DC bus into the low-rate battery until the low-rate battery is fully charged, that is, SOC2=100%.

[0088] S5. If SOC1≤the first level lower limit and SOC1>the second level lower limit, then execute the following steps:

[0089] S51. If SOC2> its first-level lower limit at this time, the energy storage energy management controller EMS module controls the DC / DC module to discharge to the DC bus. Conversely, if SOC2≤ its first-level lower limit, the energy storage energy management controller EMS module controls the charging module to charge the DC bus.

[0090] S52, if at this time SOC2 ≤ its first-level lower limit, and SOC2> its second-level lower limit, the energy storage energy management controller EMS module controls the DC / DC power supply to discharge, and the electric energy flows from the low-rate battery to the DC bus. At this time, the low-rate battery and the charging module simultaneously charge the high-rate battery or share the power supply pressure of the high-rate battery;

[0091] S53, if SOC2≤the secondary lower limit at this time, the energy storage energy management controller EMS module controls the DC / DC module to standby;

[0092] S54, the charging module and the low rate battery continue to charge the high rate battery until SOC1> its first level lower limit, then return to S4, otherwise the execution is completed and enters the next step;

[0093] S6. After S5, determine the SOC1 value in the energy storage system:

[0094] S61, if SOC1≤its secondary lower limit, the energy storage energy management controller EMS module controls the energy storage converter PCS module to shut down. At this time, the secondary lower limit is the protection threshold of the high-rate battery. When the battery SOC is lower than this condition, its cycle life will be greatly reduced;

[0095] S62, if SOC2> its secondary lower limit or the charging module has power at this time, the energy storage energy management controller EMS module controls the charging module to charge until SOC1 is fully charged, then the energy storage energy management controller EMS module controls the energy storage converter PCS module to start, and returns to S4;

[0096] S63: If SOC2 ≤ its secondary lower limit and the charging module is in a power-off state, the energy storage energy management controller EMS module controls the system to shut down and starts to execute the power-off process.

[0097] Preferably, during the use of the energy storage system, the power-on step includes the following specific operation steps:

[0098] SA1. Manually close the control switch. Before the system is powered on, the entire system is in a power-off state;

[0099] SA2, the DC / DC power supply draws power from the high-rate battery cluster module through the DC bus and outputs 24V DC power, so that the energy storage energy management controller EMS module has power;

[0100] SA3, the energy storage energy management controller EMS module program starts, controls the battery relay 1 to close, at this time the energy storage converter PCS module is powered, and controls the battery relay 2 to close, at this time the DC / DC module is powered;

[0101] SA4, the energy storage energy management controller EMS module controls the battery relay 1 to close, at which time the energy storage converter PCS module has power, and controls the battery relay 2 to close, at which time the DC / DC module has power;

[0102] SA5, the energy storage energy management controller EMS module controls the energy storage converter PCS module to enter the off-grid mode;

[0103] SA6. Complete system power-on.

[0104] Specifically, during the use of the energy storage system, the power-off step includes the following specific steps:

[0105] SB1, including manually pressing the power-off button and the energy storage energy management controller EMS module executing S63 to start the power-off process;

[0106] SB2, the energy storage energy management controller EMS module controls the energy storage converter PCS module to shut down;

[0107] SB3, the energy storage energy management controller EMS module controls the battery relay 1 and the battery relay 2 to be disconnected;

[0108] SB4, the energy storage energy management controller EMS module controls the control switch to be disconnected;

[0109] SB5. Complete system power off.

[0110] Specifically, the power ratio of the high-rate battery to the low-rate battery is less than 1:5.

[0111] Furthermore, the discharge rate ratio of the high rate battery to the low rate battery is higher than 10:1.

Claims

1. A power-type energy storage system based on the complementary advantages and disadvantages of multiple battery cells, characterized by: The energy storage system comprises: Energy storage energy management controller EMS module, the energy storage energy management controller EMS module controls the power consumption and charging of the energy storage system; An energy storage converter PCS module, wherein the energy storage converter PCS module comprises an AC side and a DC side, and the AC side of the energy storage converter PCS module is connected to an external power load; High-rate battery cluster modules to cope with the impact of high-power loads; Low-rate battery cluster modules for storing electrical energy; DC bus, used for transmitting DC power in the energy storage system; DC / DC module, which transmits the electric energy between the low-rate battery cluster module and the DC bus in both directions; The charging module transfers the external electric energy of the energy storage system to the DC bus; DC / DC power supply, which converts the high-voltage DC power of the DC bus into the low-voltage power required by the equipment in the energy storage system; A BMS1 module, wherein the BMS1 module is electrically connected to the high-rate battery cluster module to control the high-rate battery cluster module; A BMS2 module, wherein the BMS2 module is electrically connected to the low-rate battery cluster module to control the low-rate battery cluster module; Battery relay 1, two ends of the battery relay 1 are electrically connected to the DC bus and the DC side of the energy storage converter PCS module respectively.

2. The power-type energy storage system based on complementary advantages and disadvantages of multiple batteries according to claim 1 is characterized in that: The energy storage energy management controller EMS module is electrically connected to the energy storage converter PCS module, BMS1 module, BMS2 module, and DC / DC module, and the energy storage converter PCS module is electrically connected to the BMS1 module. The outer surface of the energy storage energy management controller EMS module is provided with an IO module. The energy storage energy management controller EMS module is electrically connected to the liquid cooling unit, dehumidification air conditioner, temperature and humidity sensor, touch screen and 4G module, and the liquid cooling unit, dehumidification air conditioner, temperature and humidity sensor, touch screen and 4G module are all arranged in the energy storage system equipment, and the energy storage energy management The EMS module of the energy storage controller is powered by the DC side battery of the energy storage converter PCS module. The DC side of the energy storage converter PCS module, the high-rate battery cluster module, the low-rate battery cluster module, the DC / DC power supply and the charging module are all coupled to one end of the DC bus. A battery relay 1 is provided between the DC side of the energy storage converter PCS module and the DC bus. The high-rate battery cluster module and the charging module are directly connected to the DC bus. A battery relay 2 and a DC / DC module are sequentially connected in series between the low-rate battery cluster module and the DC bus. A control switch is provided at the connection between the DC / DC power supply and the DC bus.

3. The power-type energy storage system based on complementary advantages and disadvantages of multiple batteries according to claim 1 is characterized in that: The high-rate battery cluster module used in the energy storage system has a discharge rate higher than 2P, and the high-rate battery cluster module adopts nickel-hydrogen batteries and lithium titanate batteries.

4. The power-type energy storage system based on complementary advantages and disadvantages of multiple batteries according to claim 1 is characterized in that: The low-rate battery cluster module adopts a battery cluster with a discharge rate lower than 1P. The low-rate battery cluster module is made of lithium iron phosphate batteries, and the charge and discharge power of the low-rate battery is completely controlled by the energy storage energy management controller EMS module.

5. The power-type energy storage system based on complementary advantages and disadvantages of multiple batteries according to claim 1 is characterized in that: The power ratio of the high-rate battery to the low-rate battery is less than 1:5, and the discharge rate ratio of the high-rate battery to the low-rate battery is greater than 10:

1.

6. The power-type energy storage system based on complementary advantages and disadvantages of multiple batteries according to claim 1 is characterized in that: The DC / DC power supply is arranged at one end of the DC bus, and the low-voltage electrical output end of the DC / DC power supply is electrically connected to the energy storage energy management controller EMS module, the switch, the dehumidification air conditioner, the temperature and humidity sensor, the touch screen and the 4G module.

7. The power-type energy storage system based on complementary advantages and disadvantages of multiple battery cells according to claim 1 is characterized in that: The DC / DC module is arranged on a connection circuit between the high-rate battery cluster module and the low-rate battery cluster module.

8. The power-type energy storage system based on complementary advantages and disadvantages of multiple batteries according to claim 7 is characterized in that: The method comprises an energy control step, a power-on step and a power-off step, wherein the energy control step performs the following specific steps: S1. Set the primary and secondary lower limits of SOC1 of the BMS1 module and the primary and secondary lower limits of SOC2 of the BMS2 module, as well as the DC / DC module charging and discharging power and the charging module charging power in the energy storage energy management controller EMS module system, and then start the system; S2: When the external load starts to consume electricity, the energy storage converter PCS module discharges, and the high-rate battery cluster module instantly responds to the load's power demand and starts to discharge. At this time, the low-rate battery cluster module cannot respond in time and will not be impacted by the large load. S3. If the SOC1 of the BMS1 module is greater than its first-level lower limit, and the SOC1 of the BMS2 module is greater than its first-level lower limit, the energy storage energy management controller EMS module controls the DC / DC module to discharge, and the electric energy flows from the low-rate battery to the DC bus until the load stops using electricity; S4, if SOC1> its first-level lower limit, and SOC2≤ its first-level lower limit; the energy storage energy management controller EMS module controls the charging module to charge, and the electric energy flows from the outside into the DC bus, first charging the high-rate battery until the high-rate battery is fully charged, that is, SOC1=100%, and then the energy storage energy management controller EMS module controls the DC / DC module to charge, and the electric energy flows from the DC bus into the low-rate battery until the low-rate battery is fully charged, that is, SOC2=100%; S5. If SOC1≤the first level lower limit and SOC1>the second level lower limit, then execute the following steps: S51. If SOC2> its first-level lower limit at this time, the energy storage energy management controller EMS module controls the DC / DC module to discharge to the DC bus. Conversely, if SOC2≤ its first-level lower limit, the energy storage energy management controller EMS module controls the charging module to charge the DC bus. S52, if at this time SOC2 ≤ its first-level lower limit, and SOC2> its second-level lower limit, the energy storage energy management controller EMS module controls the DC / DC power supply to discharge, and the electric energy flows from the low-rate battery to the DC bus. At this time, the low-rate battery and the charging module simultaneously charge the high-rate battery or share the power supply pressure of the high-rate battery; S53, if SOC2≤the secondary lower limit at this time, the energy storage energy management controller EMS module controls the DC / DC module to standby; S54, the charging module and the low rate battery continue to charge the high rate battery until SOC1> its first level lower limit, then return to S4, otherwise the execution is completed and enters the next step; S6. After S5, determine the SOC1 value in the energy storage system: S61, if SOC1≤its secondary lower limit, the energy storage energy management controller EMS module controls the energy storage converter PCS module to shut down, and at this time the secondary lower limit is the protection threshold of the high rate battery; S62, if SOC2> its secondary lower limit or the charging module has power at this time, the energy storage energy management controller EMS module controls the charging module to charge until SOC1 is fully charged, then the energy storage energy management controller EMS module controls the energy storage converter PCS module to start, and returns to S4; S63: If SOC2 ≤ its secondary lower limit and the charging module is in a power-off state, the energy storage energy management controller EMS module controls the system to shut down and starts to execute the power-off process.

9. The power-type energy storage system based on complementary advantages and disadvantages of multiple batteries according to claim 8 is characterized in that: The power-on procedure includes the following specific steps: SA1. Manually close the control switch. Before the system is powered on, the entire system is in a power-off state; SA2, the DC / DC power supply draws power from the high-rate battery cluster module through the DC bus and outputs 24V DC power. At this time, the energy storage energy management controller EMS module is powered; SA3, the energy storage energy management controller EMS module program starts, controls the battery relay 1 to close, at this time the energy storage converter PCS module is powered, and controls the battery relay 2 to close, at this time the DC / DC module is powered; SA4, the energy storage energy management controller EMS module controls the battery relay 1 to close, at which time the energy storage converter PCS module has power, and controls the battery relay 2 to close, at which time the DC / DC module has power; SA5, the energy storage energy management controller EMS module controls the energy storage converter PCS module to enter the off-grid mode; SA6. Complete system power-on.

10. The power-type energy storage system based on complementary advantages and disadvantages of multiple battery cells according to claim 9 is characterized in that: The power-off procedure includes the following specific steps: SB1, including manually pressing the power-off button and the energy storage energy management controller EMS module executing S63 to start the power-off process; SB2, the energy storage energy management controller EMS module controls the energy storage converter PCS module to shut down; SB3, the energy storage energy management controller EMS module controls the battery relay 1 and the battery relay 2 to be disconnected; SB4, the energy storage energy management controller EMS module controls the control switch to be disconnected; SB5. Complete system power off.

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