Electrochemical energy storage system and method

Abstract

The invention relates to the field of electrochemical energy storage, and discloses an electrochemical energy storage system and method, and the system comprises a plurality of energy storage units and an EMS module. Each energy storage unit comprises a PCS boosting cabin and a plurality of battery cabins; the PCS boosting cabin comprises an energy storage converter and a high-voltage control box; the battery cabin comprises a lithium battery module, an alternating current confluence cabinet, a direct current confluence cabinet, a BMS module and a power environment monitoring module; wherein one end of the energy storage converter is connected with the lithium battery module through the DC confluence box, and the other end is connected with the power grid through the AC confluence box; the BMS module is connected with the lithium battery module and the high-voltage control box; the EMS module communicates with the BMS module, the energy storage converter, the high-voltage control box and external equipment; the power environment monitoring module is connected with the lithium battery module and the energy storage converter. Through modular design and standardized interfaces, installation is simplified, space is saved, and meanwhile, the safety and reliability of the system are enhanced through an intelligent management system and efficient heat dissipation design.

Description

Technical Field

[0001] The present invention relates to the field of electrochemical energy storage, and in particular to an electrochemical energy storage system and method. Background Art

[0002] At present, electrochemical energy storage technology is one of the most mature and widely used technologies in the field of energy storage, especially in the field of new energy such as electric vehicles, electronic devices, etc. Common electrochemical energy storage technologies include lithium-ion batteries, sodium-ion batteries, all-vanadium flow batteries, and zinc-bromine flow batteries.

[0003] The low-voltage parallel integration technology used in existing electrochemical energy storage systems achieves an increase in power capacity by connecting a large number of energy storage inverters in parallel on the low-voltage AC side, and then connects them to a power grid above 10kV through a transformer for voltage boosting. However, the PCS failure has a large impact range, and the replacement procedures for faulty battery clusters are complicated. Mixing old and new battery clusters will lead to serious circulation and uneven output problems.

[0004] The medium-voltage cascade integration technology used in existing electrochemical energy storage systems generally divides the overall capacity of the system into several power units, which are directly connected in series to a 10kV or higher-level power grid based on a cascade topology structure, without the need for a step-up transformer. However, its technical route is relatively niche. There is no transformer isolation, and the negative ground voltage is high, which will produce a very high common-mode voltage. Personnel cannot enter the AC live state to check the battery data, and the operation and maintenance personnel are at a high risk of electric shock and casualties. There are many power electronic devices and many fault links. There is no transformer isolation, and the negative ground voltage is high. Personnel cannot enter the AC live state, which places high demands on the operation and maintenance personnel. The operation and maintenance costs are very high. The active / reactive response speed is 200ms. The main control cabinet is controlled by the energy storage main control system, and the main control cabinet controls the phase control cabinet and the H-bridge power, and also balances and controls the H-bridge power. There are many power electronic devices, and equipment debugging is difficult and the cycle is long. Summary of the invention

[0005] In view of the above-mentioned technical deficiencies, the technical problem to be solved by the present invention is to provide an electrochemical energy storage system and method, aiming to solve the problems of high cost, low energy density, limited cycle life, insufficient safety and scarce resources in the existing electrochemical energy storage technology, improve the phenomenon of new energy power abandonment, shaving peaks and filling valleys, smooth output, track predicted curves, and improve grid stability and wind power low voltage ride-through capability.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions: The present invention provides an electrochemical energy storage system, including: a plurality of energy storage units and an EMS module; each energy storage unit includes a PCS booster cabin and a plurality of battery cabins; the PCS booster cabin includes an energy storage converter and a high-voltage control box; the battery cabin includes a lithium battery module, an AC combiner cabinet, a DC combiner cabinet, a BMS module and a power environment monitoring module; One end of the energy storage converter is connected to the lithium battery module through a DC junction box, and the other end is connected to the power grid through an AC junction box, for inputting / outputting power; The BMS module is connected to the lithium battery module and is used to monitor and manage the status of the lithium battery module in real time; The BMS module is also connected to the high-voltage control box to control the total positive contactor, total negative contactor, pre-charge circuit, fuse and molded case circuit breaker in the high-voltage control box; The EMS module communicates with the BMS module, the energy storage converter, the high-voltage control box and external devices to control the operation of the energy storage system as a whole; The power environment monitoring module is connected to the lithium battery module and the energy storage converter to monitor temperature and environmental conditions and send the monitoring data to the BMS module.

[0007] Furthermore, the lithium battery module is composed of a plurality of battery cells connected in series or in parallel to form a battery module, a plurality of battery modules form a battery cluster, and a plurality of battery clusters form a battery system.

[0008] Furthermore, the energy storage unit also includes a self-power supply system, a temperature control system, a ventilation system, a video monitoring system, a fire alarm system, a door-controlled lighting, a fire protection system and a lighting system.

[0009] Furthermore, the energy storage unit adopts a modular design, and modules can be increased or decreased according to capacity requirements.

[0010] Furthermore, the battery system meets the 1500Vdc voltage platform and is compatible with 1000V and 1500V voltage levels.

[0011] Furthermore, the battery system and the energy storage converter can be completely decoupled, allowing their configuration to be increased or decreased respectively.

[0012] Furthermore, a human-machine interface is included for interacting with the EMS module.

[0013] An electrochemical energy storage method, comprising: The BMS module collects the status information of the lithium battery module in real time and sends it to the EMS module; The EMS module receives and monitors data from the BMS module and controls the charging and discharging of the battery through the energy storage converter. At the same time, the EMS module also receives data from the high-voltage control box. When a battery abnormality is detected, the circuit is cut off through the high-voltage control box. The power environment monitoring module monitors the temperature and environmental conditions and sends them to the BMS module, and controls the temperature control system and ventilation system through the BMS module; When the main power supply fails, the EMS module controls the self-powered system to provide emergency power.

[0014] The beneficial effects of the present invention are: 1. Modular design and standardized interfaces are adopted to simplify the installation and commissioning process, facilitate on-site layout and transportation, which not only improves system efficiency but also reduces land occupation.

[0015] 2. Real-time monitoring and optimization of system status through intelligent management system, combined with efficient heat dissipation design and multiple protection mechanisms, to ensure safe and stable operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A topological diagram of an electrochemical energy storage system provided in an embodiment of the present invention.

[0018] Figure 2 This is a main wiring diagram of an electrochemical energy storage system.

[0019] Figure 3 Schematic diagram of the modular design of lithium battery modules. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Example

[0022] like Figure 1~Figure 3As shown, this embodiment provides an electrochemical energy storage system, including: a plurality of energy storage units and an EMS module; each energy storage unit includes a PCS booster cabin and a plurality of battery cabins; the PCS booster cabin includes an energy storage inverter and a high-voltage control box; the battery cabin includes a lithium battery module, an AC junction box, a DC junction box, a BMS module and a power environment monitoring module; wherein one end of the energy storage inverter is connected to the lithium battery module through the DC junction box, and the other end is connected to the power grid through the AC junction box for input / output power; the BMS module is connected to the lithium battery module for real-time monitoring and management of the status of the lithium battery module; the BMS module is also connected to the high-voltage control box to control the total positive contactor, the total negative contactor, the pre-charge circuit, the fuse and the molded case circuit breaker in the high-voltage control box; the EMS module communicates with the BMS module, the energy storage inverter, the high-voltage control box and external equipment for overall control of the operation of the energy storage system; the power environment monitoring module is connected to the lithium battery module and the energy storage inverter for monitoring temperature and environmental conditions, and sending the monitoring data to the BMS module.

[0023] Specifically, the lithium battery module is composed of multiple battery cells connected in series or in parallel to form a battery module, multiple battery modules form a battery cluster, and multiple battery clusters form a battery system. This embodiment uses a total of 51 energy storage units, of which 49 energy storage units are: 1 PCS booster cabin with a capacity of 5175kW + 6 battery cabins with a capacity of 3440kWh; the remaining 2 energy storage units are: Figure 2 The PCS booster cabin shown is 1 with a capacity of 5175kW + 4 with a capacity of 3096kWh; the PCS booster cabin includes 3 energy storage converters with a DC voltage of 1000-1500V, an AC voltage of 690V, a DC load switch of 1500V / 2500A, and a DC fuse of 1500V / 3000A; a transformer consisting of a lightning arrester, a live display device, an electromagnetic lock, a vacuum circuit breaker, and an isolating / earthing switch; a battery cabin It is a 3096kW lithium iron phosphate battery box with a single-compartment configuration. Each battery compartment contains 10 battery clusters. The capacity of a single cluster is 309.6kWh. The battery pack is configured as 384S1P. The battery cell specification is 3.2V, 280Ah. The junction box is a 1500V system with 5 inputs and 3 outputs. The fuse is 1500V / 420A. The DC converter voltage range is 500-1500V, the load switch is 1500V / 250A, and the fuse is 1500V / 250A.

[0024] Preferably, the energy storage unit adopts a modular and prefabricated cabin design, and the modules can be increased or decreased according to capacity requirements; in addition, the prefabricated cabin can be transported as a whole, supports MW-level expansion, is compatible with PCS from different manufacturers, and can match energy storage products with different rates, such as 1h, 2h, 3h, and 4h systems.

[0025] like Figure 3As shown, the modular design has battery current sharing control, meets the 1500Vdc voltage platform, and is compatible with 1000V and 1500V voltage levels, supports liquid cooling, its width is compatible with the battery size, supports multiple machines in parallel, and can be increased or decreased according to capacity needs. According to the standard size and standard profile of the battery design, it is compatible with the installation of batteries and various sub-components, and the internal matching can be configured according to the capacity. It integrates system secondary power distribution, monitoring, and communication control, and can expand black start power supply and AC / DC redundant power supply functions. The large pack design integrates 114 batteries, which greatly improves the battery capacity density. The peripheral wiring harness greatly reduces water cooling and heat dissipation, and the battery temperature is more uniform; the battery system and energy storage inverter can be completely decoupled, allowing for separate increase and decrease of configuration.

[0026] Furthermore, the energy storage unit also includes a self-powered system for providing emergency power when the main power fails; a temperature control system for maintaining the operating temperature of the lithium battery module within an appropriate range; a ventilation system for ensuring air circulation in the prefabricated cabin to prevent overheating; a video monitoring system for real-time monitoring of the interior of the prefabricated cabin; a fire alarm system for detecting fire risks and giving timely alarms; a door-controlled lighting system for controlling the access control and lighting of the prefabricated cabin; a fire protection system for extinguishing fires in the event of a fire; and a lighting system for providing lighting in the prefabricated cabin. A human-machine interface HMI is used for pre-EMS module interaction, monitoring, and controlling the operation of the energy storage system.

[0027] The energy storage unit integrates secondary power distribution, monitoring, and communication control functions, and can expand black start power supply and AC / DC redundant power supply functions. Among them: the secondary power distribution function includes distributing power to various subsystems; the monitoring function includes real-time monitoring of the battery system, energy storage inverter, BMS module and other systems; the communication control function includes a communication interface with external devices to achieve data exchange and remote control; the black start power supply function can provide emergency power supply when the main power supply fails; the AC / DC redundant power supply function ensures the stability and reliability of the system.

[0028] The present embodiment also provides an electrochemical energy storage method, including: when starting, the EMS module performs a self-check to ensure that each component is working properly; the BMS module collects the status information of the lithium battery module (such as voltage, current, temperature, etc.) in real time, and sends the data to the EMS module; the EMS module receives and monitors the data from the BMS module, the PCS booster cabin and the high-voltage control box to fully grasp the operating status of the system; based on factors such as grid demand, renewable energy power generation, load demand, etc., the EMS module optimizes the charging and discharging strategy of the energy storage system and controls the charging or discharging operation of the battery through the PCS converter; when the BMS module detects battery abnormalities such as overtemperature, overvoltage and undervoltage, the circuit is cut off through the total positive contactor, total negative contactor, pre-charge circuit, fuse and molded case circuit breaker in the high-voltage control box to protect the battery from damage; the power environment monitoring module continuously monitors the temperature and environmental conditions of the battery cabin, and sends the monitoring data to the BMS module; the BMS module controls the temperature control system and ventilation system according to these data to maintain a suitable working environment; When the system detects any fault or abnormality, the EMS module automatically triggers the corresponding alarm mechanism and takes necessary measures such as stopping charging and discharging, isolating the faulty unit, etc.; the EMS module exchanges data with external devices through Ethernet or other communication interfaces to achieve remote monitoring and control functions; in the event of a main power failure, the EMS module controls the self-powered system to provide emergency power for key equipment.

[0029] The embodiment of the present invention has AC and DC redundant power supply functions, ensuring that the stability and reliability of the system can be maintained when a single power supply fails, which is achieved by the secondary power distribution system and the backup power supply system. It adopts modular, standardized and intelligent design concepts, and innovative breakthroughs in battery-to-system integration technology, with multiple advantages such as easy layout, easy transportation, easy installation, easy capacity expansion, and easy maintenance. At the same time, this compact design not only reduces the equivalent floor area of ​​the typical layout unit of the system by up to 24.7%, further saving land costs, but also facilitates the layout design and implementation of the project; and the heat dissipation of the battery and power components of the present invention, the heat exchange efficiency is more than 40% higher than that of forced air cooling, which can meet high-protection application environments. The battery temperature rise can be controlled within 15°C. The existing other split designs, installing battery modules on site, will increase project costs and time.

[0030] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An electrochemical energy storage system, characterized in that: include: Several energy storage units and an EMS module; each energy storage unit includes a PCS booster cabin and multiple battery cabins; the PCS booster cabin includes an energy storage converter and a high-voltage control box; the battery cabin includes a lithium battery module, an AC combiner cabinet, a DC combiner cabinet, a BMS module and a power environment monitoring module; One end of the energy storage converter is connected to the lithium battery module through a DC junction box, and the other end is connected to the power grid through an AC junction box, for inputting / outputting power; The BMS module is connected to the lithium battery module and is used to monitor and manage the status of the lithium battery module in real time; The BMS module is also connected to the high-voltage control box to control the total positive contactor, total negative contactor, pre-charge circuit, fuse and molded case circuit breaker in the high-voltage control box; The EMS module communicates with the BMS module, the energy storage converter, the high-voltage control box and external devices to control the operation of the energy storage system as a whole; The power environment monitoring module is connected to the lithium battery module and the energy storage converter to monitor temperature and environmental conditions and send the monitoring data to the BMS module.

2. The electrochemical energy storage system according to claim 1, characterized in that: The lithium battery module is composed of a plurality of battery cells connected in series or in parallel to form a battery module, a plurality of battery modules are composed of a battery cluster, and a plurality of battery clusters are composed of a battery system.

3. The electrochemical energy storage system according to claim 1, characterized in that: The energy storage unit also includes a self-power supply system, a temperature control system, a ventilation system, a video monitoring system, a fire alarm system, a door-controlled lighting, a fire protection system and a lighting system.

4. The electrochemical energy storage system according to claim 1, characterized in that: The energy storage unit adopts a modular design, and modules can be increased or decreased according to capacity requirements.

5. The electrochemical energy storage system according to claim 2, characterized in that: The battery system meets the 1500Vdc voltage platform and is compatible with 1000V and 1500V voltage levels.

6. The electrochemical energy storage system according to any one of claims 1 to 4, characterized in that: The battery system and the energy storage converter can be completely decoupled, allowing the configuration to be increased or decreased respectively.

7. The electrochemical energy storage system according to any one of claims 1 to 4, characterized in that: Also included is a human-machine interface for interacting with the EMS module.

8. A method for using the electrochemical energy storage system according to any one of claims 1 to 7, characterized in that: include: The BMS module collects the status information of the lithium battery module in real time and sends it to the EMS module; The EMS module receives and monitors data from the BMS module and controls the charging and discharging of the battery through the energy storage converter. At the same time, the EMS module also receives data from the high-voltage control box. When a battery abnormality is detected, the circuit is cut off through the high-voltage control box. The power environment monitoring module monitors the temperature and environmental conditions and sends them to the BMS module, and controls the temperature control system and ventilation system through the BMS module; When the main power supply fails, the EMS module controls the self-powered system to provide emergency power.

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