Intelligent string type container energy storage system

Abstract

The invention discloses an intelligent string type container energy storage system. The system is composed of a battery system, a battery management system, a heat management system, a fire extinguishing system, a PCS system and an energy storage controller which are integrally mounted and fixed in a container body. According to the energy storage system, one-cluster-one-management is achieved through an energy storage system string-type framework, the battery clusters are connected with the PCS in series and then connected with the PCS in parallel, the series-parallel mismatching problem of the system is solved, all battery packs achieve 100% discharging, one-pack-one-optimization of the system is achieved, the battery packs are balanced and consistent, maximum charging and discharging of the single battery packs are achieved, one battery pack optimizer is integrated in each battery pack, and the energy storage efficiency is improved. The optimizers are connected in parallel with the battery cells, and the optimizers in the battery cluster are directly connected in series, so that the service life of the battery cells in the life cycle is prolonged by 10%, and the available capacity is improved; the energy storage system is high in reliability, convenient to maintain and higher in system safety, each battery cluster independently controls charging and discharging, the situation that the discharge capacity is affected by bias current is avoided, meanwhile, single-cluster fault isolation is achieved, fault diffusion and system whole disabling are avoided, and the safety performance is further improved.

Description

Technical Field

[0001] The present invention belongs to the field of new energy technology, in particular to the field of energy storage equipment design technology, and specifically relates to an intelligent string container energy storage system. Background Art

[0002] Due to the uncertainty and instability of renewable energy generation, how to effectively store and utilize these energies has become an important challenge. Energy storage technology is one of the important means to solve this problem. The current energy storage technology is still a simple energy storage and discharge mode, which has low energy utilization efficiency, high system failure rate and maintenance cost, and low security and stability of the power grid.

[0003] Traditional centralized energy storage systems have a "barrel effect". In traditional centralized solutions, the capacity of the energy storage system may decay exponentially, and the system "barrel effect" is obvious. Its battery modules are directly connected in parallel, and the voltage is forced to be balanced. When charging, if one battery cell is fully charged, all parallel battery clusters must stop charging. Similarly, when discharging, if one battery cell is empty, all parallel battery clusters must stop discharging. The overall life of the system depends on the battery with the shortest life. The battery pack cannot reach 100% DOD.

[0004] The traditional centralized design has negative problems caused by the bias current between clusters. In the traditional centralized design, the battery clusters are directly connected in parallel and then in series with the PCS. Because the discharge depth between clusters is inconsistent, the bias current between clusters is formed, the system cannot be fully charged or discharged, resulting in loss of available capacity.

[0005] Traditional centralized designs have negative safety issues. In traditional centralized designs, a circulation current is formed between parallel battery clusters, causing the battery cells to be overcharged. The increased voltage can easily cause an internal short circuit, which can easily cause fire accidents. In many energy storage accidents previously reported by the media, the formation of a circulation current between parallel battery clusters in the energy storage system is also one of the main causes.

[0006] Therefore, designing an intelligent string container energy storage system can realize intelligent management of the energy storage system, achieve optimal management of the energy storage system through algorithm optimization, and achieve efficient utilization of energy and energy conservation and emission reduction; it can realize modular management of the energy storage system, reduce the failure rate and maintenance cost of the energy storage system, and improve the reliability and stability of the energy storage system; it can support and balance the power grid, meet the power grid's demand for energy, and improve the safety and stability of the power grid. Summary of the invention

[0007] The present invention discloses an intelligent string container energy storage system based on the deficiencies of the prior art. The purpose of the present invention is to provide an energy storage system that can support and balance the power grid and improve the safety and stability of the power grid.

[0008] The present invention is achieved through the following technical solutions:

[0009] An intelligent string container energy storage system, characterized by: consisting of a battery system, a battery management system, a thermal management system, a fire protection system, a PCS system and an energy storage controller installed and fixed in a container body;

[0010] Battery system: It uses lithium iron phosphate batteries, including several independent battery packs, which are connected to form a battery group. Each battery group is connected in series with the PCS and then in parallel.

[0011] Battery management system: The battery management system adopts a two-level architecture; the slave CCU supports 48-channel battery voltage sampling, 4-channel temperature acquisition, DIDO input and output, and realizes functions such as single-cell voltage detection, temperature acquisition, and passive balancing of the battery pack; the slave CCU communicates with the master BCU through CAN bus communication; the master BCU has multiple peripheral access interfaces to realize system voltage detection, temperature acquisition, insulation detection, SOC estimation, current detection, historical data recording, relay control, battery safety protection and alarm;

[0012] Thermal management system: The thermal management system includes a liquid cooling thermal management system and an air conditioning management system; the liquid cooling thermal management system consists of a liquid cooling plate, a liquid cooling unit, liquid cooling pipes, high and low voltage wiring harnesses and coolant; a temperature monitoring point is set in each battery pack to monitor the battery cell temperature in real time, and an over-temperature alarm and fault information push mechanism are set. Over-temperature and under-temperature conditions trigger system shutdown, and temperature data is uploaded to the cloud management system in real time; the air conditioning management system consists of an industrial air conditioner set in the electrical warehouse to adjust the ambient temperature of electrical equipment;

[0013] Fire fighting system: The fire fighting system includes a water fire fighting system and a gas fire fighting system; the water fire fighting system is a fully flooded water sprinkler system installed in the battery compartment; the gas fire fighting system is a perfluorohexanone fire fighting system installed in the battery compartment and the electrical compartment;

[0014] PCS system: includes bidirectional converters using digital control technology, which are modular string-type bidirectional converters. Every three 200kW string-type converters are matched with a 630kVA transformer to form a PCS cabinet. The number of PCS cabinets is matched according to the system capacity.

[0015] Energy storage controller: The energy storage controller hardware adopts X86 architecture, and the software is based on embedded Linux system. It is used for on-site data collection, data processing, statistical analysis, intelligent early warning, optimization and regulation of energy storage, and data interaction with the superior dispatching system.

[0016] The container is further composed of a base frame assembly, a door end assembly, a side wall assembly, a top plate assembly and a battery rack; one side wall is provided with an air inlet and an exhaust device to prevent rainwater, and the other side wall is provided with a port and an air inlet device connected to external water fire fighting; a wire mesh is installed at the door end for exhaust of the liquid cooling unit; and a pressure relief port is installed on the top plate.

[0017] Furthermore, the battery pack liquid cooling plate adopts a "snake-shaped" flow channel, and the coolant adopts 50% water by mass + 50% ethylene glycol by mass.

[0018] Furthermore, the fully flooded water sprinkler system of the water fire fighting system is composed of a nozzle, a smoke and temperature composite detector, a water pipe, and a water pipe joint. A nozzle and a smoke and temperature composite detector are arranged above each battery cluster; the smoke and temperature composite detector automatically triggers the nozzle to spray water on the battery cluster and sound an alarm at the same time; a water fire fighting interface is installed on the side wall of the container for connecting to the fire water supply system of the energy storage power station.

[0019] Furthermore, the perfluorohexanone fire fighting system of the gas fire fighting system is composed of a gas cylinder, a fire extinguishing nozzle, a nozzle, a pipeline, a control panel, a pressure switch, an alarm device and a smoke and temperature composite detector, which is used for fire fighting and detection of the battery compartment, the electrical compartment and the battery pack.

[0020] The container used in the present invention is a 20-foot, 30-foot, 40-foot or 45-foot standard container, or a non-standard container.

[0021] The intelligent string container energy storage system of the present invention is more efficient. The intelligent string architecture realizes one cluster one management. The battery clusters are connected in series with the PCS and then in parallel. The system eliminates the series-parallel mismatch problem. All battery packs achieve 100% discharge. The system optimizes one pack at a time. The battery packs have consistent balance, realizing maximum charge and discharge of a single battery pack. A battery pack optimizer is integrated in each battery pack. The optimizer is connected in parallel with the battery cell. The optimizers in the battery cluster are directly connected in series. The battery cell life is increased by 10% during the life cycle, thereby increasing the available capacity.

[0022] The intelligent string container energy storage system of the present invention has high reliability and is easy to maintain. The modular design of the intelligent string solution can be flexibly deployed, supports the mixed use of new and old batteries, installment power replenishment, on-site replacement, and realizes plug-and-play, eliminating the need for on-site manual adjustment of SOC and extremely simple operation and maintenance.

[0023] The intelligent string container energy storage system of the present invention is safer. Each battery cluster controls charging and discharging independently to avoid bias current affecting the discharge amount. At the same time, single cluster fault isolation is achieved to avoid fault propagation and overall system strike, and safety performance is further improved.

[0024] The intelligent string container energy storage system of the present invention has strong scalability, supports online expansion, and can increase the number of battery modules as needed to meet the needs of different application scenarios.

[0025] The benefits of the present invention:

[0026] The intelligent string container energy storage system of the present invention can realize intelligent management of the energy storage system, realize optimal management of the energy storage system through algorithm optimization, and realize efficient utilization of energy and energy conservation and emission reduction. Secondly, the system can realize modular management of the energy storage system, reduce the failure rate and maintenance cost of the energy storage system, and improve the reliability and stability of the energy storage system. The intelligent string container energy storage system can also support and balance the power grid, meet the energy demand of the power grid, and improve the safety and stability of the power grid. In terms of renewable energy, the intelligent string container energy storage system can realize efficient utilization of renewable energy, reduce dependence on traditional energy, and realize environmental protection and sustainable development. In terms of smart home, the intelligent string container energy storage system can realize efficient utilization of household and industrial and commercial energy, reduce energy waste and consumption, improve family comfort and quality of life, and reduce industrial and commercial costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a three-dimensional exploded diagram of the intelligent string container energy storage system of the present invention.

[0028] In the figure, 1 is the thermal management system, 2 is the fire protection system, 3 is the PCS system, 4 is the energy storage controller (EMS), 5 is the battery management system, 6 is the battery system, and 7 is the container. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with specific implementation methods. The specific implementation methods are further descriptions of the principles of the present invention and do not limit the present invention in any way. Technologies that are the same or similar to the present invention do not exceed the scope of protection of the present invention.

[0030] Combined with the attached pictures.

[0031] As shown in the figure, the intelligent string container energy storage system of the present invention includes a battery system, a battery management system, a thermal management system, a fire protection system, a PCS system, an energy storage controller (EMS) and a container.

[0032] Battery system: It uses lithium iron phosphate batteries, including several independent battery packs. The battery packs are connected to form a battery group. Each battery group is connected in series with the PCS and then in parallel. It has the characteristics of high power density, high cycle number, high safety, etc., and a wide operating temperature range.

[0033] Battery Management System: The battery management system (BMS) system adopts a two-level architecture. The slave control CCU supports 48-channel battery voltage sampling, 4-channel temperature acquisition, and DIDO output. It realizes functions such as single cell voltage detection, temperature acquisition, and passive balancing of the battery pack. The slave control communicates with the master control BCU through CAN bus communication. The master control BCU has rich peripheral access to meet the system application requirements. Its core functions include voltage detection, temperature acquisition, insulation detection, SOC estimation, current detection, historical data recording, relay control, battery safety protection and alarm, etc.

[0034] Thermal management system: The thermal management system includes a liquid cooling thermal management system and an air conditioning management system. The liquid cooling thermal management system consists of a liquid cooling plate, a liquid cooling unit, a liquid cooling pipeline, high and low voltage wiring harnesses and a coolant. The battery pack liquid cooling plate adopts a "snake" flow channel, and the coolant adopts 50% water by mass + 50% ethylene glycol by mass. The liquid cooling system uses a certain thermal management strategy to cool or heat the battery pack when the coolant flows through the liquid cooling plate. Ensure that the battery operates in the range of 25℃-45℃ throughout its life cycle to prevent thermal runaway caused by overheating. Temperature monitoring points are deployed inside each battery pack, and temperature data is uploaded to the cloud management system in real time to monitor the temperature status of the battery cell in real time. It is also equipped with an over-temperature alarm and a fault information push mechanism. Over-temperature and low temperature will trigger system shutdown. Industrial air conditioning is configured in the electrical warehouse to adjust the temperature so that the power equipment can operate within a certain temperature range; it can adjust the humidity. Excessive humidity will cause damage and corrosion to the power equipment; it can ensure air quality. The power equipment in the distribution room will generate a lot of heat and dust; it can extend the service life of the power equipment.

[0035] Fire fighting system: The fire fighting system includes water fire fighting system and gas fire fighting system. The water fire fighting system is a fully flooded water sprinkler system installed in the battery compartment, which is composed of nozzles, smoke and temperature composite detectors, water pipes, water pipe joints, etc., and nozzles and smoke and temperature composite detectors are arranged above each battery cluster; the smoke and temperature composite detector automatically triggers the nozzles to spray water on the battery cluster, and at the same time, an alarm is issued and the relevant fire fighters are notified. A water fire fighting interface is installed on the side wall of the container to connect the fire fighting water supply system of the energy storage power station. The gas fire fighting system is a perfluorohexanone fire fighting system installed in the battery compartment and electrical compartment, which is composed of gas cylinders, fire extinguishing nozzles, nozzles, pipelines, control panels, pressure switches, alarm devices and smoke and temperature composite detectors. It can carry out fire fighting and detection on the battery compartment, electrical compartment and battery pack, and has the characteristics and functions of rapid response, automatic control, high reliability and wide adaptability. The energy storage container needs a fire alarm and fire suppression system to provide protection, timely detect and report fire conditions, take effective measures to control and extinguish fires, and minimize fire hazards. The fire extinguishing agent uses perfluorohexanone. The battery compartment is equipped with an automatic fire alarm system and a gas fire extinguishing system. When a fire is detected in the battery compartment, it can quickly determine and automatically start the fire extinguishing system to extinguish the cabin-level fire in a full flooding manner. At the same time, the fire is reported to the fire control room and the battery management system to minimize the fire hazard. The battery compartment is equipped with a combustible gas detection system and an explosion-proof ventilation system. By real-time monitoring of the concentration of combustible gas and linking the explosion-proof ventilation device, the concentration of combustible gas in the battery compartment is controlled within a safe range. The battery compartment should be equipped with a full flooding water sprinkler system, and a water fire fighting interface should be reserved for connecting to the fire water supply system of the energy storage power station. The battery pack-level fire fighting system includes detectors for the battery pack, spraying, and continuous cooling fire suppression and fire extinguishing devices. The nozzles are arranged in the battery pack to meet the requirements for uniform distribution of the fire extinguishing agent after spraying.

[0036] PCS system: including bidirectional converters using digital control technology; modular string bidirectional converters, every three 200kW string converters are matched with a 630kVA transformer to form a PCS cabinet, and the same number of PCS cabinets are matched according to the system capacity. The bidirectional converter adopts advanced digital control technology, optimizes the control performance, improves the reliability of the system, and realizes grid-connected discharge, grid-connected charging and off-grid operation. The system has a wide DC input range and can better meet the charging and discharging requirements of different battery combinations. At the same time, the energy storage system composed of bidirectional conversion modules is more flexible in structure and power design. Under the condition of equal power output, the diversity of battery group connection is increased and the number of parallel groups of battery groups is reduced. It can better manage the battery and improve the battery life and the economic benefits of the energy storage system.

[0037] Energy Storage Controller (EMS): The local control system hardware adopts X86 architecture, and the software is based on embedded Linux system, which realizes the functions of on-site data collection, data processing, statistical analysis, intelligent early warning, optimization and regulation of energy storage, and completes data interaction with the superior dispatching system.

[0038] Container: The container is mainly composed of the chassis assembly, door end assembly, side wall assembly, roof assembly and battery rack. The left wall is equipped with a rainproof air inlet and exhaust device, and the right wall is equipped with a port and air inlet device connected to the external water fire protection; a steel wire mesh is installed at the door end to facilitate the exhaust of the liquid cooling unit; and a pressure relief port is installed on the roof assembly.

[0039] Working principle: The intelligent string container energy storage system combines the battery system, battery management system, thermal management system, fire protection system, PCS system, energy storage controller (EMS) and container into an energy storage system, and optimizes the management and control of the energy storage system through intelligent control. The battery system uses lithium batteries, which can achieve high energy density and power density, and has a long service life and low maintenance cost. The battery management system has functions such as single cell voltage detection, temperature collection, passive balancing of the battery pack, as well as insulation detection, SOC estimation, current detection, historical data recording, relay control, battery safety protection and alarm. The thermal management system cools or heats the battery pack through a certain thermal management strategy. Temperature monitoring points are deployed inside each battery pack. The temperature data is uploaded to the cloud management system in real time to monitor the temperature status of the battery cell in real time. It is also equipped with an over-temperature alarm and a fault information push mechanism. Over-temperature and low temperature will trigger system shutdown. The fire protection system can detect and report fires in time, take effective measures to control and extinguish fires, and is equipped with an automatic fire alarm system and a gas fire extinguishing system. When a fire is detected, it can quickly judge and automatically start the fire extinguishing system to extinguish the fire at the cabin level in a full flooding manner. At the same time, the fire is reported to the fire control room and the battery management system to minimize the fire hazard. The battery compartment is equipped with a combustible gas detection system and an explosion-proof ventilation system. By real-time monitoring of the concentration of combustible gas and linking the explosion-proof ventilation device, the concentration of combustible gas in the battery compartment is controlled within a safe range. The battery compartment is equipped with a full flooding water sprinkler system, and a water fire protection interface is reserved for connecting the fire water supply system of the energy storage power station. The PCS system realizes grid-connected discharge, grid-connected charging and off-grid operation modes. The energy storage controller (EMS) realizes the functions of on-site data collection, data processing, statistical analysis, intelligent early warning, optimization and regulation of energy storage, and completes data interaction with the superior dispatching system. The container is responsible for the protection and integration of each unit of the system.

Claims

1. An intelligent string container energy storage system, characterized in that: It consists of a battery system, a battery management system, a thermal management system, a fire protection system, a PCS system and an energy storage controller that are fixed in the container. Battery system: It uses lithium iron phosphate batteries, including several independent battery packs, which are connected to form a battery group. Each battery group is connected in series with the PCS and then in parallel. Battery management system: The battery management system adopts a two-level architecture; the slave CCU supports 48-channel battery voltage sampling, 4-channel temperature acquisition, DIDO input and output, and realizes functions such as single-cell voltage detection, temperature acquisition, and passive balancing of the battery pack; the slave CCU communicates with the master BCU through CAN bus communication; the master BCU has multiple peripheral access interfaces to realize system voltage detection, temperature acquisition, insulation detection, SOC estimation, current detection, historical data recording, relay control, battery safety protection and alarm; Thermal management system: The thermal management system includes a liquid cooling thermal management system and an air conditioning management system; the liquid cooling thermal management system consists of a liquid cooling plate, a liquid cooling unit, liquid cooling pipes, high and low voltage wiring harnesses and coolant; a temperature monitoring point is set in each battery pack to monitor the battery cell temperature in real time, and an over-temperature alarm and fault information push mechanism are set. Over-temperature and under-temperature conditions trigger system shutdown, and temperature data is uploaded to the cloud management system in real time; the air conditioning management system consists of an industrial air conditioner set in the electrical warehouse to adjust the ambient temperature of electrical equipment; Fire fighting system: The fire fighting system includes a water fire fighting system and a gas fire fighting system; the water fire fighting system is a fully flooded water sprinkler system installed in the battery compartment; the gas fire fighting system is a perfluorohexanone fire fighting system installed in the battery compartment and the electrical compartment; PCS system: includes bidirectional converters using digital control technology, which are modular string-type bidirectional converters. Every three 200kW string-type converters are matched with a 630kVA transformer to form a PCS cabinet. The number of PCS cabinets is matched according to the system capacity. Energy storage controller: The energy storage controller hardware adopts X86 architecture, and the software is based on embedded Linux system. It is used for on-site data collection, data processing, statistical analysis, intelligent early warning, optimization and regulation of energy storage, and data interaction with the superior dispatching system.

2. The intelligent string container energy storage system according to claim 1 is characterized in that: The container is composed of a base frame assembly, a door end assembly, a side wall assembly, a top plate assembly and a battery rack; one side wall is provided with an air inlet and an exhaust device to prevent rainwater, and the other side wall is provided with a port and an air inlet device connected to external water fire fighting; a wire mesh is installed at the door end for exhaust of the liquid cooling unit; and a pressure relief port is installed on the top plate.

3. The intelligent string container energy storage system according to claim 1 is characterized in that: The battery pack liquid cooling plate adopts a "snake-shaped" flow channel, and the coolant adopts 50% water by mass + 50% ethylene glycol by mass.

4. The intelligent string container energy storage system according to claim 1 is characterized in that: The fully flooded water sprinkler system of the water fire fighting system consists of a nozzle, a smoke and temperature composite detector, a water pipe, and a water pipe joint. A nozzle and a smoke and temperature composite detector are arranged above each battery cluster; the smoke and temperature composite detector automatically triggers the nozzle to spray water on the battery cluster and sound an alarm at the same time; a water fire fighting interface is installed on the side wall of the container for connecting to the fire water supply system of the energy storage power station.

5. The intelligent string container energy storage system according to claim 1 is characterized in that: The perfluorohexanone fire fighting system of the gas fire fighting system is composed of a gas cylinder, a fire extinguishing nozzle, a nozzle, a pipeline, a control panel, a pressure switch, an alarm device and a smoke and temperature composite detector, and is used for fire fighting and detection of a battery compartment, an electrical compartment and a battery pack.

6. The intelligent string container energy storage system according to claim 1 is characterized in that: The container is a standard container of 20 feet, 30 feet, 40 feet or 45 feet, or a non-standard container.

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