As of February 2019, only 21 fire accidents have occurred in South Korea's energy storage power stations! South Korea ’s Ministry of Industry, Commerce and Energy has shut down more than 300 utility storage battery systems. The spontaneous combustion caused by the lithium battery of electric vehicles, especially the recent Tesla ModelS spontaneous combustion in the underground garage, which caused the explosion of several vehicles on the side within two seconds, sounded the alarm for everyone: lithium battery energy storage Power stations urgently need to establish sound technical standards and demonstration systems to escort their sustainable development.
However, the rapid development of lithium battery energy storage systems based on the scale effect of electric vehicles continues the characteristics of power lithium batteries in inspection and testing standards: it has strict requirements for single lithium batteries, battery management systems (BMS), and energy storage. Inverter (PowerControlSystem, PCS) and new lithium battery system detection standards, but lack of effective detection and evaluation system for lithium battery energy storage systems that have been put into operation. The current scenario has made colleagues in the industry realize that safety is a major bottleneck in the development of the energy storage industry. Modern power grids have a safety guarantee system that conducts regular operational testing of major equipment. As a new emerging foreign power grid, lithium battery energy storage power plants need to develop a complete inspection and testing standard system for their entire life cycle, from inception, operation to exit. To ensure the safe operation of modern power grids.
How to prevent energy storage safety?
At present, the energy management system (Energy Management System, EMS) of the lithium battery energy storage power station is responsible for managing the energy interaction of the power station. The BMS controls the charge and discharge of all lithium battery cells and the internal balance. The following characteristics are generally present: 1.BMS charge and discharge of the lithium battery. The initial setting of the control threshold cannot be changed; 2. There is a deviation in the estimation of the battery state after the aging of the lithium battery. The original BMS control threshold may be slightly overcharged and overdischarged at each charge and discharge, and the battery is inconsistent. The weakest battery causes the most severe loss of active lithium ions or the formation of microlithium dendrites each time, accelerating its aging process;
The power battery laboratory of Shanghai University of Engineering and Technology has conducted a series of performance and durability tests on lithium iron phosphate and ternary lithium batteries from battery cells (cells), battery modules to battery stacks, especially the full life cycle and Experiments on decommissioned lithium batteries, by studying the changes in the symptoms of lithium battery charge and discharge curves from the anomaly to the end of life, several detection methods and diagnostic algorithms for battery characteristic values including internal resistance have been established, and developed A battery doctor suitable for rapid detection, analysis, and evaluation during operation can quickly troubleshoot high-voltage safety hazards, locate problem battery cells, and form analysis and recommendation reports.
Combined with a one-click analysis of the operation big data of Shanghai New Energy Vehicle Monitoring Center, Shanghai MAKESENS (MS Energy Storage) developed a cloud-edge combination preventive diagnostic security system based on cloud-native edge technology (PrognosticSafetySystem, PSS), an intelligent communication management machine iRouter obtains the battery charge and discharge data at the cell level in real time from the energy management system (Energy Management System, EMS) of the energy storage station, analyzes, calculates, diagnoses and uploads to the diagnostic cloud; Cloud builds a prediction model of its development trend and constant false alarm threshold based on the data flow of key battery parameters, forming a multi-parameter virtual radar system; issues an early warning when the actual monitoring data exceeds the threshold, and proposes to bring the key parameters back to the threshold The measures that can be implemented include replacing, balancing the battery, or updating the control parameters in the iRouter configuration file to provide a basis for the EMS to update the dynamic control strategy of the BMS.
How to manage energy storage safety
We believe that the safety of energy storage should not be just the inspection and testing of various energy storage equipment before the power station is put into operation, especially the safety of energy storage batteries. Since the energy storage battery is a gradual electrochemical system, as the energy storage battery ages, various battery parameters will change accordingly. Through the preventive diagnostic safety system PSS, the potential risks of the energy storage battery can be predicted. Equipment manufacturers, power plant operators, centralized control centers, and service providers provide the latest battery data analysis and diagnosis support in the areas of spare parts optimization, power plant operation management, remote expert professional technical support, and inspection team, etc. Service, the effect of intelligent operation and maintenance.
Currently, an intelligent integrated operation inspection of online and offline integration is being prepared for the energy storage system on the grid side. Real-time diagnosis of the online cloud brain system to analyze the health status of the battery; combined with the inspection plan, line content, and inspection point inspections scheduled by the offline inspection personnel, it is flexible to dispatch and repair defects in time to achieve 7 * 24 Hourly active real-time monitoring eliminates paper-based records and information collection blind spots, and changes mechanical operation and maintenance to active and flexible operation and maintenance.