The energy storage system is a rather complex structure, which involves the coordinated work of components and systems in multiple different technical fields. From the battery technology itself, to the energy conversion and management system, to the auxiliary systems such as smart cloud monitoring, fire protection and heat dissipation, each part has its own unique design requirements and operating characteristics. These components are interrelated and affect each other. Problems in any link may affect the performance and safety of the entire energy storage system. The causes of safety accidents such as fires in energy storage power station systems usually involve multiple factors. We have summarized the following seven main reasons:
1. Battery problems: This is one of the main causes of energy storage power station accidents. Under the conditions of overcharge, overdischarge, internal short circuit, high temperature, etc., the battery may experience thermal runaway, release a large amount of heat and flammable gas, cause fire or even explosion.
For example, internal short circuit of the battery may be caused by damage to the diaphragm, aging of the battery cell, excessive temperature during use, dendritic crystal growth formed by lithium deposition on the negative electrode piercing the diaphragm, production quality problems or other external factors (such as transportation vibration, collision, puncture, etc.); quality problems or poor consistency of the battery cell itself may also increase the risk.
2. Thermal runaway management defects: The system will generate heat during operation. If the thermal runaway system of the energy storage system cannot accurately monitor and control the status of the battery, such as voltage, current, temperature, etc., it will not be able to detect and deal with potential problems in time, and cannot quickly and effectively control the thermal runaway phenomenon of the battery, increasing the risk of accidents.
3. Inadequate safety design: including unreasonable power station layout, such as the building-style stacked layout resulting in a large number of batteries concentrated in a confined space, and the lack of effective fire separation, fire fighting facilities and emergency plans. Once a fire occurs, it is difficult to quickly control the fire. The energy storage system has a certain fire risk, and should be equipped with appropriate fire extinguishing equipment, and ensure that the installation area meets the fire protection requirements.
4. Electronic device and line failure: Some electronic components and lines are usually used in energy storage systems, such as: battery management chips, power semiconductor devices, inductors, sensors, DC bus, AC lines, and control lines. The use of inferior electronic components and circuits may not accurately monitor and control the key parameters of the battery; affect the power supply quality of the system, and may damage the connected electrical equipment; provide inaccurate monitoring data, mislead the system’s control strategy, and make the system unable to operate within the normal working range. It will seriously affect the reliability of the energy storage system and bring potential safety risks.
5. Improper installation and operation: unprofessional staff, irregular operation, unfamiliarity with equipment, or failure to perform maintenance in accordance with regulations. For example, irregular installation of batteries, incorrect wiring, untimely maintenance, etc., may all pose safety hazards. It is recommended that after the energy storage system is installed, a comprehensive system debugging and testing should be carried out to check whether all functions are normal, and comply with the regulations of the Development and Reform Commission, power grid, fire protection and other departments to obtain the necessary licenses and approvals.
6. Abuse and aging: Frequent charge and discharge cycles will also accelerate the aging of the energy storage system. Improper charge and discharge methods such as deep discharge and fast charging will increase the pressure and loss inside the battery. As the use time increases, the chemical substances inside the battery will undergo irreversible changes, and the structure and performance of the electrode material will gradually decline, resulting in a decrease in battery capacity and an increase in internal resistance, increasing the instability and safety risks of the system. Aging batteries need to be closely monitored and replaced or maintained in time to ensure the safe operation of the energy storage system.
7. Environmental factors: Environmental conditions such as extreme temperature and humidity may affect battery performance and stability and increase the risk of fire. Natural disasters such as lightning strikes, floods, and earthquakes may damage the equipment of energy storage power stations and cause accidents. When installing energy storage systems, choose a dry, well-ventilated, temperature-appropriate installation location without flammable, explosive and other corrosive gases.
For example: The cause of the fire accident at the Gateway Energy Storage Power Station in California, USA, is believed to be caused by a combination of factors such as “ternary lithium batteries + stacked power stations + confined space + early warning failure”. The safety design and thermal runaway management of the energy storage power station are defective. A large number of batteries are concentrated in a confined space. After the fire-fighting agent is exhausted, water can only be added to the inside or sprayed from the outside, but the entire monitoring system fails, and the internal environment is completely invisible and uncontrollable, which leads to the re-ignition or even spread of the entire system, which lasts for a long time. In addition, the operation and maintenance means of the power station are relatively simple, the degree of intelligence is not high, and the safety warning is not done well.
The investigation results of the Beijing “4.16″ energy storage power station explosion accident showed that the direct cause of the fire in the south building was the internal short circuit failure of the lithium iron phosphate battery in the west battery room, which caused the battery to thermally run away and catch fire; the direct cause of the explosion in the north building was the internal short circuit failure of the single lithium iron phosphate battery in the battery room of the south building, which caused the battery and battery module to thermally run away and spread and catch fire. The flammable and explosive mixture produced by the accident entered the energy storage room of the north building through the cable trench and spread, mixed with the air to form explosive gas, and exploded when it encountered electrical sparks. In addition to the direct cause of the internal short circuit of the battery itself, the accident also had indirect causes such as the failure to implement the main safety responsibility of the relevant enterprises involved, and the insufficient research, deployment and supervision of the safety supervision and inspection work by the relevant units.
Summary: In order to reduce the occurrence of fires in energy storage power stations, measures need to be taken in many aspects, including battery quality testing, management system optimization, safety design, monitoring and early warning, and operation and maintenance management, including establishing a full life cycle management system for lithium batteries, optimizing the safety design of energy storage power stations, strengthening online monitoring and detection of battery data, improving the safety standard system of energy storage power stations, and improving the safety awareness and skill level of staff. At the same time, strict operating procedures and emergency plans should be formulated to promptly detect and deal with abnormal battery conditions.
When purchasing and installing energy storage systems, it is important to choose reliable, professional, and capable energy storage system integrators, rather than just being swayed by price.
Post time: Dec-02-2024