A method for preventing and mitigating accidents based on energy storage power station accident classification PIRT and application

Abstract

The application relates to an accident prevention and mitigation implementation system method based on an energy storage power station accident grading PIRT and application. The method comprises the following steps: establishing a PIRT analysis model for different operation states of an energy storage power station; identifying and grading the importance of physical phenomena based on the model; according to the grading results, taking a prevention-oriented strategy for low / medium-grade phenomena and taking a relief-oriented strategy for high-grade phenomena; mapping the strategy into specific engineering measures and executing the specific engineering measures, so that dynamic risk control is realized. Through systematic PIRT analysis, the application dynamically matches the safety defense focus with the physical phenomenon grade, overcomes the limitations of traditional methods in dealing with complex system risks, provides a full-chain safety management solution from "phenomenon identification" to "engineering relief" for the whole life cycle of the energy storage power station, and significantly improves the intrinsic safety level of the energy storage power station.

Description

Technical Field

[0001] This invention belongs to the field of energy storage power station safety technology, specifically relating to a method and application of an accident prevention and mitigation implementation system based on the Accident Classification and Reduction Response (PIRT) system for energy storage power stations. Background Technology

[0002] With the deepening of the global energy transition, battery energy storage stations (BESS) have become a key support for building new power systems, and their installed capacity has experienced explosive growth. However, fires and explosions at energy storage stations have exposed the limitations of current safety management systems based on single-device failure analysis in dealing with complex system risks.

[0003] Biochemical energy storage power stations (BESS) integrate high-energy-density electrochemical components with high-voltage, high-current electrical components. Their accident evolution process involves the coupling of multiple physical fields such as thermodynamics, electrochemistry, electrical engineering, and fluid mechanics. Traditional failure mode and effects analysis (FMEA) focuses on single failure modes at the component level, making it difficult to capture the complex chain reactions in system-level accidents (such as secondary short circuits caused by thermal runaway propagation).

[0004] Currently, there is a lack of a systematic safety method that can cover the entire life cycle of a power plant, different operating states, and dynamically adjust the focus of defense according to the stage of accident evolution. Summary of the Invention

[0005] This invention aims to solve the above-mentioned technical problems and proposes a method and application for an accident prevention and mitigation implementation system based on the Accident Classification and Reduction Implementation (PIRT) of energy storage power stations.

[0006] To address the above technical problems, this invention provides a method for implementing an accident prevention and mitigation system based on the Accident Classification and Reduction Response (PIRT) of energy storage power stations, characterized by the following steps: S1: For energy storage power stations, including at least in-service operation, maintenance, startup and shutdown, establish a physical phenomenon identification and importance ranking table based on the safety objectives of the energy storage power station, i.e., the PIRT analysis model. S2: Based on the PIRT analysis model, identify the accident-related physical phenomena that affect the safety target, and classify their importance according to the degree of influence of each physical phenomenon on the safety target and the degree of understanding of its mechanism; S3: Based on the classification results of step S2, determine the accident prevention strategy; among which, for physical phenomena with low or medium importance level, determine the control strategy with accident prevention as the main focus; for physical phenomena with high importance level, determine the control strategy with accident mitigation as the main focus. S4: Map the accident prevention strategy determined in step S3 into specific engineering implementation measures corresponding to the operating state, and execute them in the energy storage power station through the monitoring system, control system and emergency response system; S5: Based on the implementation effect of the aforementioned engineering measures, dynamically manage the accident risks of the energy storage power station to achieve accident prevention and mitigation throughout its entire life cycle.

[0007] Furthermore, the core elements of the PIRT analysis model include: the security objective, the importance level used to characterize the degree of influence of physical phenomena on the security objective, and the level of knowledge mastery used to characterize the level of understanding of the mechanism of physical phenomena and their evolution process.

[0008] Furthermore, the high-importance physical phenomena identified in the in-service operating state described in step S1 include at least: lithium-ion battery thermal runaway, internal battery short circuit, thermal runaway propagation and its accompanying rapid gas evolution.

[0009] Furthermore, for physical phenomena of medium or low importance under in-service operation, the engineering implementation measures corresponding to the control strategy mainly focused on accident prevention include at least: anomaly identification based on changes in electrochemical impedance characteristics; dynamic charge and discharge control of operating temperature, current, or state of charge; and temperature or consistency control of the battery operating environment to prevent the physical phenomenon from evolving to a higher level.

[0010] Furthermore, for physical phenomena of high importance in the operational state, the engineering implementation measures corresponding to the control strategy mainly focused on accident mitigation include at least: setting up thermal isolation or thermal blocking structures at the cell, module, or battery cluster level; setting up explosion-proof pressure relief devices to release accident gas pressure; and activating fire-fighting measures that combine suppression and cooling.

[0011] Furthermore, the high-importance physical phenomena identified in the maintenance state as described in step S1 include at least: DC electric arcs, and the risk of electric shock or arcing caused by residual energy.

[0012] Furthermore, in response to physical phenomena during maintenance, the accident prevention measures include at least: setting up anti-finger-touch structures or intrinsically safe structures, restricting live operations through programmed control or mechanical interlocking, and eliminating residual energy risks through lockout tagging and multi-energy isolation procedures; For physical phenomena of high importance during maintenance, the accident mitigation measures include at least: configuring personal protective equipment according to the risk of DC arcing, and reducing the probability of personnel being exposed to the risky environment through remote control or isolation operation.

[0013] Furthermore, the high or medium importance level physical phenomena identified in the start-up and shutdown states described in step S1 include at least: inrush current, contactor contact sticking, and load disconnection caused by control logic timing conflicts.

[0014] Furthermore, regarding the physical phenomena during startup and shutdown, the accident prevention measures include at least: configuring a pre-charge circuit to limit transient current, employing soft start or power ramp control to limit transient voltage or current changes, and performing logic verification on the contactor status. For physical phenomena of high importance during startup and shutdown, the accident mitigation measures include at least: online detection and alarm for abnormal contactor adhesion, and configuration of fuses or explosion-proof switches as backup fault current cut-off devices.

[0015] A safety management system for an energy storage power station, characterized in that the system is constructed and operated using the method described above.

[0016] Beneficial Effects: This invention aims to introduce the Phenomena Identification and Ranking Table (PIRT) method to construct a comprehensive safety methodology system covering identification, prevention, and mitigation for key operational states of energy storage power stations, including "in operation, maintenance, and start-up / shutdown." This system effectively identifies critical physical phenomena affecting the system's Figure of Merit (FOM) and classifies them according to their importance and knowledge level.1 Establishing a PIRT-based energy storage safety system not only clarifies the physical path of accident evolution but also guides the scientific allocation of resources between prevention and mitigation measures, which is of great significance for improving the inherent safety level of energy storage power stations.

[0017] This invention provides an in-depth analysis of the underlying mechanisms of high-level physical phenomena such as thermal runaway, DC arcing, and contactor adhesion in lithium-ion batteries, establishing a tiered defense strategy of "focusing on prevention for low-level phenomena and mitigation for high-level phenomena." By combining physical phenomena with engineering practice, this invention proposes a set of engineering application procedures, providing theoretical basis and practical guidance for the full lifecycle safety management of energy storage power stations. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating the overall implementation of the method system described in this invention. Detailed Implementation

[0019] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below.

[0020] This invention proposes a method for an accident prevention and mitigation implementation system based on the Accident Classification and Reduction Technology (PIRT) of energy storage power stations, characterized by the following steps: Step 1: Based on the operational characteristics of energy storage power stations under different conditions, establish a Physical Phenomenon Identification and Importance Ranking (PIRT) analysis model with the safety objectives of energy storage power stations as the evaluation benchmark. The different states include at least the in-service operating state, the maintenance state, and the start-up or shutdown state; The PIRT analysis model includes the following elements: (1) Safety objectives, used to characterize the risks of uncontrolled energy release and personnel injury; (2) Importance level, used to characterize the degree of influence of physical phenomena on security objectives; (3) Knowledge mastery level, used to characterize the level of understanding of the mechanism of physical phenomena and their evolution process.

[0021] Step 2: Based on the PIRT analysis model, identify the accident-related physical phenomena that affect the safety target, and classify them according to the degree of influence of the physical phenomena on the safety target and the degree of understanding of the mechanism of the physical phenomena. The high-level physical phenomena identified under the aforementioned in-service operating conditions include at least the following: (1) Thermal runaway of lithium-ion batteries; (2) Internal short circuit in the battery; (3) Thermal runaway propagation and the accompanying rapid gas evolution.

[0022] The high-level physical phenomena identified under the aforementioned maintenance conditions include at least the following: (1) DC electric arc; (2) Risk of electric shock or arcing caused by residual energy.

[0023] The high- or medium-level physical phenomena identified during the startup or shutdown state include at least the following: (1) Magnetizing inrush current; (2) Contactor contacts are stuck together; (3) Load interruption caused by timing conflicts in control logic.

[0024] Step 3: Based on the classification results of the physical phenomena, determine the accident prevention strategy, wherein: S3.1 For physical phenomena with low or medium importance, determine a control strategy focused on accident prevention to prevent the physical phenomena from evolving to a higher level. For medium- or low-level physical phenomena, the accident prevention measures shall include at least: (1) Anomaly identification based on changes in electrochemical impedance characteristics; (2) Dynamic charge and discharge control based on operating temperature, current or state of charge; (3) Control the temperature or consistency of the battery operating environment to prevent physical phenomena from evolving to a higher level; S3.2 For physical phenomena with high importance, determine control strategies that focus on accident mitigation to limit the impact of accident consequences. For high-level physical phenomena, the accident mitigation measures include at least: (1) Set up thermal isolation or thermal blocking structures at the cell, module or battery cluster level; (2) Install explosion-proof pressure relief devices to release gas pressure generated during an accident; (3) Activate fire-fighting measures that combine suppression and cooling to limit the scope of the accident's impact.

[0025] Step 4: Map the accident prevention strategy to engineering implementation measures corresponding to the operating state, and execute them in the energy storage power station through monitoring, control and emergency response means; Step 5: Based on the results of the implementation of the aforementioned engineering measures, control the accident risks of the energy storage power station, thereby achieving accident prevention and mitigation throughout the entire life cycle of the energy storage power station.

[0026] Furthermore, the high-level physical phenomena identified under the maintenance condition include at least: (1) DC electric arc; (2) Risk of electric shock or arcing caused by residual energy.

[0027] Furthermore, the accident mitigation measures under the maintenance status include at least: (1) Configure personnel protective equipment according to the risk of DC arc; (2) Reduce the risk of personnel exposure through remote control or isolation operations.

[0028] Furthermore, the accident prevention measures during the start-stop state include at least: (1) Limit transient current through a pre-charge circuit; (2) Limit transient voltage or current changes through soft start or power ramp control; (3) Perform logical verification on the contactor status.

[0029] The accident mitigation measures under the start-stop state include at least the following: (1) Detect abnormal conditions of the contactor and issue an alarm; (2) Cut off the faulty circuit by using a fuse or blasting switch.

[0030] This invention specifically covers: Multi-state analysis: Covers all operating conditions of energy storage power stations, including steady-state operation (in service), manual intervention (maintenance), and transient switching (start-up and shutdown).

[0031] Tiered defense logic: Establishing a dynamic response mechanism of "identification-prevention-mitigation". For high-PIRT level phenomena, the focus is on in-depth extension of the mechanism and design of mitigation measures; for low-level phenomena, the focus is on proactive prevention to block the evolution path.

[0032] Engineering practice mapping: Transforming theoretical analysis into specific operational procedures that conform to engineering standards, including monitoring plans, emergency response plans, and operation and maintenance procedures.

[0033] Definition of the core elements of PIRT energy storage: Safety objectives (FOM): Prevent uncontrolled release of energy (fire / explosion) and prevent personal injury (electric shock / poisoning).

[0034] Importance (I): High: This phenomenon directly leads to the loss of FOM or significantly accelerates the accident process (e.g., thermal runaway propagation).

[0035] Medium: This phenomenon has a significant impact on FOM, but it needs to be coupled with other phenomena (such as sensor drift).

[0036] Low: This phenomenon has a limited impact, or only acts as a weak source of disturbance (e.g., slight capacity decay).

[0037] Knowledge Level (K): Known: The mechanism is clear and supported by mature models and data.

[0038] Partially Known: The mechanism is basically clear, but there is uncertainty in quantitative prediction.

[0039] Deficiencies (Unknown): The mechanism is unclear or there is a lack of experimental data to support it.

[0040] The core logic of this invention lies in dynamically adjusting the focus of the defense strategy based on the PIRT level: Prevention Dominant for Low / Medium Level Phenomena: Such phenomena are often "precursors" or "triggers" of accidents (e.g., micro-short circuits in battery cells, deterioration of insulation performance). Since they have not yet caused catastrophic consequences and the physical processes are reversible or controllable, strategies should focus on eliminating or curbing their development through BMS algorithms, active balancing, and environmental control to prevent them from escalating into higher-level phenomena.

[0041] High-level phenomenon mitigation dominant: When a phenomenon evolves to a high level (e.g., thermal runaway of a battery cell, arc explosion), the physical processes are often irreversible and have extremely fast reaction rates (milliseconds to seconds). At this point, "prevention" becomes meaningless or has a very low success rate. The strategy must be quickly switched to mitigation, that is, to limit the consequences of the accident to a minimum (e.g., confining it to a single module or container) through physical isolation, fire suppression, pressure relief and explosion prevention, etc., to prevent the destruction of the entire site.

[0042] Example: I. PIRT Analysis and Response System in Service Status In-service status refers to the energy storage system being in charge-discharge cycle or standby mode, mainly involving electrochemical reactions, thermal management, and electrical conduction processes.

[0043] 1.1 Identification of Physical Phenomena: In-depth Extension of Mechanisms For high-level phenomena in service, in-depth mechanistic analysis is necessary to identify blind spots in conventional monitoring methods.

[0044] 1.1.1 High-level phenomenon: Thermal runaway of lithium-ion batteries PIRT rating: Importance - High (H) | Knowledge level - High (K, but difficult to predict) Further exploration of the mechanism: Thermal runaway is not a single instantaneous event, but a multi-stage chain chemical reaction process: SEI film decomposition (~90°C - 120°C): The solid electrolyte interphase (SEI) film on the negative electrode surface undergoes metastable decomposition and exothermic reaction. During this stage, the temperature rise is slow and buffered by the battery's thermal capacity, making it difficult for external temperature sensors to detect, but the internal impedance (EIS) has already changed.

[0045] The reaction between the negative electrode and the electrolyte (~120°C - 200°C): SEI decomposition causes the highly active lithium-ionized negative electrode to be directly exposed to the organic electrolyte, triggering a reduction reaction, producing flammable hydrocarbon gases (such as ethylene and propylene) and releasing heat, causing the membrane to shrink or melt due to heat.

[0046] Internal short circuit and positive electrode decomposition (>200°C): Separator failure leads to a large-area internal short circuit, releasing stored electrical energy. Subsequently, the positive electrode material (especially ternary NCM) undergoes lattice collapse, releasing oxygen. The oxygen mixes with high-temperature electrolyte vapor, forming a "self-oxygenated" combustion inside the battery, with the temperature instantly soaring to over 800°C, accompanied by violent gas ejection.

[0047] Fingerprint features generated by gas: Different chemical systems produce different gaseous products. Lithium iron phosphate (LFP) batteries produce an extremely high proportion of hydrogen (H2) during thermal runaway (up to 30%-50%), meaning that even though LFP batteries have relatively good thermal stability, their explosion risk may actually be higher than that of ternary lithium batteries. This is a physical difference that must be carefully considered during the "identification" process.

[0048] 1.1.2 High-level phenomenon: Internal short circuit PIRT Rating: Importance - High (H) | Knowledge Level - Medium / Low (Difficult to detect online) Further exploration of the mechanism: Internal short circuits are one of the main triggers for thermal runaway. Their formation mechanisms include: Lithium dendrite growth: Under low-temperature charging or high-rate charging conditions, lithium ions precipitate on the surface of the negative electrode to form metallic lithium dendrites, which pierce the separator.

[0049] Stress-induced failure: During long cycles, the volume expansion and contraction (breathing effect) of the electrode material causes core deformation. During this process, metal foreign objects or electrode burrs may puncture the diaphragm.

[0050] Corrosion of aluminum current collector under high SOC: Studies have shown that under high charge state (SOC>30%), the short circuit mode between aluminum current collector and negative electrode coating is particularly severe, and the heat generation rate is extremely fast.

[0051] 1.2 Prevention: Targeting low / medium level precursors The core of prevention in service is to keep the battery within the safe operating area (SOA) and prevent low-level phenomena from evolving into high-level phenomena.

[0052] Early warning based on electrochemical impedance spectroscopy (EIS): To address the weak signals during the SEI film decomposition stage, online EIS monitoring technology is introduced. By injecting a small-amplitude AC signal, the ohmic impedance and polarization impedance of the battery are measured in real time. The abnormal inflection point of the impedance often appears hours or even days before the temperature change, thus achieving preventative disconnection of "precursor to internal short circuit".

[0053] Refined charge / discharge strategy (to prevent lithium plating): To address lithium dendrite growth, a step-charging strategy and pulse charging technology are employed, along with dynamic adjustment of the current limit based on ambient temperature (C-rate derating). In low-temperature environments, the battery preheating system is forcibly activated, and high-current charging below 0°C is strictly prohibited to prevent physical damage from the outset.

[0054] 1.3 Mitigation: Targeting high-level loss of control Once thermal runaway (High Rank) occurs, preventative measures fail, and the system must immediately enter mitigation mode.

[0055] Multi-level physical isolation and thermal barrier design: At the module and pack levels, aerogel or mica sheets are used as thermal barrier materials to block heat transfer to adjacent cells, limiting accidents to the individual cell level. Engineering design must verify the thermal barrier material's tolerance at 1000°C.

[0056] Explosion-proof pressure relief design compliant with NFPA 68: Given the high hydrogen production characteristics of LFP batteries, the container design must include deflagration venting panels. The venting area is determined based on the maximum gas production rate calculated using PIRT analysis to ensure that internal pressure does not lead to structural collapse. Simultaneously, combustible gas detectors (H2 / CO / VOCs) are integrated with an emergency exhaust ventilation system to control gas concentrations below 25% of the lower explosive limit (LEL).

[0057] Precise selection of fire-fighting media: Conventional gas extinguishing agents (such as heptafluoropropane) can only suppress open flames and cannot cool the internal reaction of the battery. The mitigation strategy should include a dual mechanism of "suppression + cooling": first, release perfluorohexanone (Novec 1230) to suppress gas-phase combustion, and then activate the water deluge system to continuously penetrate and cool the module, remove the heat of reaction, and prevent reignition.

[0058] II. PIRT Analysis and Response System under Maintenance Status Maintenance is a stage where human factors and physical risks are strongly coupled, involving personnel entering high-voltage areas and contacting live components.

[0059] 2.1 Identification of Physical Phenomena 2.1.1 High-level phenomenon: DC arc flash PIRT Rating: Importance - High (H) | Knowledge Level - High (K) Further exploration of the mechanism: Unlike alternating current (AC) arcs, direct current (DC) arcs lack zero-crossing and are extremely difficult to extinguish once ignited. In the maintenance of energy storage battery clusters, DC voltages as high as 1000V-1500V mean that any short circuit caused by a slipping tool can trigger a sustained high-energy plasma explosion. The arc's center temperature can reach 20,000K, accompanied by a powerful shock wave and molten metal spewing out.

[0060] 2.1.2 High-level phenomena: residual energy and LOTO failure PIRT Rating: Importance - High (H) | Knowledge Level - Medium (M, influenced by human factors) Further exploration of the mechanism: The inherent charge-carrying nature of energy storage systems means that even after external connections are disconnected, a fatal voltage remains inside the battery module. Furthermore, if the DC-side support capacitor of the PCS is not fully discharged, it can release a huge pulse current upon contact by maintenance personnel. LOTO (Lock-On-Demand) failures often stem from a lack of awareness regarding multiple energy sources (such as BMS auxiliary power supplies and photovoltaic backfeed).

[0061] 2.2 Prevention Measures Intrinsically safe design: During the engineering design phase, all high-voltage connection points (busbars, terminals) must be equipped with IP2X finger-touch resistant protective covers. Maintenance interfaces should be designed as foolproof plugs to prevent reverse polarity connection.

[0062] HRA-based programmatic control: Human Reliability Analysis (HRA) is introduced to identify high-risk operational procedures. A "key-swapping" mechanical interlocking system is implemented: the key can only be retrieved to open the battery cabinet door after the DC circuit breaker is disconnected and locked, thus physically and logically eliminating the possibility of opening the cabinet while it is energized.

[0063] 2.3 Mitigation Arc energy boundary and PPE configuration: Based on the calculated incident DC arc energy, an arc flashover protection boundary is defined. Personnel entering the boundary are required to wear appropriate arc protection clothing (e.g., 40 cal / cm² level) and UV protection face shields to mitigate burns and vision damage caused by arc explosions.

[0064] Insulated tools and remote operation: Mandate the use of insulated tools with a withstand voltage of 1000V. For high-risk circuit breaker opening and closing operations, promote the use of robots or remote control panels, and remove personnel from the potential blast radius.

[0065] III. PIRT Analysis and Response System under Start-up and Shutdown States The start-stop state involves the physical actions of electrical connections and transient changes in power flow, and is the stage where electrical stress is most concentrated.

[0066] 3.1 Identification of Physical Phenomena 3.1.1 High-level phenomenon: Inrush current sticking to the contactor PIRT Rating: Importance - High (H) | Knowledge Level - High (K) Further exploration of the mechanism: At the moment the main contactor closes during system startup, if the DC bus capacitor voltage is zero, the battery pack will inject a huge inrush current into the capacitor, with an amplitude reaching thousands of amperes. This current generates an electric arc in the tiny gap before the contactor contacts close, causing the contact metal to melt and weld together. A stuck contactor means that the system has lost its ability to interrupt fault current, which is an extremely dangerous latent fault.

[0067] 3.1.2 Medium-level phenomenon: Logical timing conflict PIRT Rating: Importance - Medium (M) | Knowledge Level - Medium (M) Further exploration of the mechanism: If there is a timing deviation in the communication handshake between BMS and PCS (such as the PCS requesting power before the contactor is fully engaged, or the BMS forcibly disconnecting the contactor under load), it will cause a load-bearing disconnection arc, burn the contacts, and generate overvoltage.

[0068] 3.2 Prevention Measures Pre-charge Circuit Design: A pre-charge resistor and a pre-charge contactor are connected in parallel in the main circuit. The startup logic must enforce the pre-charge process: first, close the pre-charge circuit to limit the current charging of the capacitor; then, close the main contactor when the bus voltage reaches more than 95% of the battery voltage. This measure can completely eliminate inrush current and prevent contact sticking from the source.

[0069] Soft start logic: The PCS control algorithm incorporates voltage / power ramp rate control to avoid transient overvoltage surges caused by step power jumps.

[0070] 3.3 Mitigation Contact status detection and redundant disconnection: The BMS must have contactor sticking detection logic (by detecting the voltage difference between the two terminals in the open state). Once sticking is detected, the system should immediately alarm and shut down. In practice, a series fuse or pyro-fuse should be configured as the final physical break point to cut off the circuit by blowing the fuse in the event of contactor failure.

[0071] IV. Integration of Engineering Application Methods, Processes, and Standards Based on the above PIRT analysis, a feasible engineering application process is constructed, and its correspondence with domestic and international standards is clarified.

[0072] 4.1 “Recognition” Application Process: Construction of a Multi-Dimensional Perception System Process steps: Benchmark establishment: Configure basic voltage, temperature, and current sensors according to standard requirements (such as GB / T 42288).

[0073] Enhanced Sensing: To address the high-level phenomena of "internal short circuit" and "gas evolution" identified by PIRT, the following features will be added to engineering processes: Composite gas detector: integrates CO, H2, VOCs and aerosol detection, and is installed above the module and on the top of the container.

[0074] Fiber Optic Sensing (Optional): In key demonstration projects, fiber Bragg grating (FBG) sensors are embedded to enable in-situ monitoring at the cell level by utilizing their immunity to electromagnetic interference and high sensitivity to temperature / strain.

[0075] Data fusion: Establish a cloud-based diagnostic model that integrates BMS data and environmental data to identify outliers.

[0076] 4.2 "Prevention" Application Process: Operation and Control Strategy Updates Process steps: Dynamic thresholding: Abandoning fixed alarm thresholds, a dynamic strategy based on the rate of temperature rise (dT / dt) and the rate of change of differential pressure (dV / dt) is adopted.

[0077] Preventive maintenance (PM): Based on PIRT analysis, "contactor impedance measurement", "DC bus insulation inspection" and "thermal imaging scan" are listed as quarterly standard operating procedures (SOPs).

[0078] Environmental closed loop: Link the air conditioning system (HVAC) with the BMS to ensure that the temperature difference of the battery cells is controlled within 5°C, and prevent the inconsistency deterioration caused by temperature difference.

[0079] 4.3 “Mitigation” Application Process: Tiered Emergency Response (ERP) Process steps: Level 1 Response (Individual Cluster Anomaly): The BMS automatically reduces power or disconnects the cluster, and starts the cluster-level fans to run at full speed.

[0080] Level 2 response (gas alarm / temperature runaway): Immediately disconnect the main circuit and PCS.

[0081] Trigger an audible and visual alarm to evacuate personnel.

[0082] The emergency exhaust fan (explosion-proof mode) will be activated in conjunction with the system.

[0083] Activate the heptafluoropropane / perfluorohexanone inhibition system.

[0084] Level 3 Response (Fire Confirmation): The fire alarm control panel (FACP) confirms the fire alarm signal.

[0085] Activate the water spray / mist system (which must comply with NFPA 15 and GB 51048 requirements) for continuous immersion cooling for at least 24 hours to prevent reignition.

[0086] Notify external fire departments and provide system status information (whether it is electrified, chemical composition).

[0087] The table below summarizes the corresponding measures based on PIRT levels:

[0088] In summary, this invention, by introducing the PIRT method, systematically organizes and establishes a PIRT (Key Physical Phenomena Level Table) that summarizes key physical phenomena in energy storage power station accidents. Research on the content of this invention shows that energy storage safety is not a single-dimensional technical issue, but rather a complex systems engineering problem involving multi-state and multi-physical field coupling.

[0089] 1. Deepening the understanding of mechanisms: For high-level phenomena such as thermal runaway, it is necessary to delve into the microscopic chemical reactions and gas composition levels (such as the hydrogen production problem of LFP) in order to formulate effective detection and explosion suppression strategies.

[0090] 2. The dialectical unity of strategies: prevention and mitigation complement each other. In the low-level stage, we can "prevent problems before they occur" through refined management and advanced algorithms; in the high-level stage, we must acknowledge the inevitability of physical failure and "stop the damage in the present" through redundant design and powerful fire protection.

[0091] 3. The key to successful project implementation: Theoretical analysis must ultimately be translated into standard execution. Whether based on fire protection regulations in Chinese national standards (such as GB / T 42288) or hazard mitigation analysis (HMA) requirements in relevant fire protection standards of other countries (such as NFPA 855), the essence is an engineering response to high-risk phenomena identified by PIRT.

[0092] This invention provides a systematic method and implementation process for promoting PIRT analysis in the construction of future energy storage power stations. It can update the phenomenon list for different battery chemical systems (such as sodium ion and solid-state batteries) and build a dynamically evolving safety defense system.

[0093] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for implementing an accident prevention and mitigation system based on the Accident Classification and Remediation Theory (PIRT) of energy storage power stations, characterized in that, Includes the following steps: S1: For energy storage power stations, including at least in-service operation, maintenance, startup and shutdown, establish a physical phenomenon identification and importance ranking table based on the safety objectives of the energy storage power station, i.e., the PIRT analysis model. S2: Based on the PIRT analysis model, identify the accident-related physical phenomena that affect the safety target, and classify their importance according to the degree of influence of each physical phenomenon on the safety target and the degree of understanding of its mechanism; S3: Based on the classification results of step S2, determine the accident prevention strategy; among which, for physical phenomena with low or medium importance level, determine the control strategy with accident prevention as the main focus; for physical phenomena with high importance level, determine the control strategy with accident mitigation as the main focus. S4: Map the accident prevention strategy determined in step S3 into specific engineering implementation measures corresponding to the operating state, and execute them in the energy storage power station through the monitoring system, control system and emergency response system; S5: Based on the implementation effect of the aforementioned engineering measures, dynamically manage the accident risks of the energy storage power station to achieve accident prevention and mitigation throughout its entire life cycle.

2. The method according to claim 1, characterized in that, The core elements of the PIRT analysis model include: the security objective, the importance level used to characterize the degree of influence of physical phenomena on the security objective, and the level of knowledge mastery used to characterize the level of understanding of the mechanism and evolution of physical phenomena.

3. The method according to claim 1, characterized in that, The high-importance physical phenomena identified in the in-service operating state as described in step S1 include at least: lithium-ion battery thermal runaway, internal battery short circuit, thermal runaway propagation and its accompanying rapid gas evolution.

4. The method according to claim 3, characterized in that, For physical phenomena of medium or low importance under in-service operation, the engineering implementation measures corresponding to the control strategy with accident prevention as the main focus include at least: anomaly identification based on changes in electrochemical impedance characteristics; dynamic charge and discharge control of operating temperature, current or state of charge; and temperature or consistency control of the battery operating environment to prevent the physical phenomenon from evolving to a higher level.

5. The method according to claim 3, characterized in that, For physical phenomena of high importance in the operational state, the engineering implementation measures corresponding to the control strategy mainly based on accident mitigation include at least: setting up thermal isolation or thermal blocking structures at the cell, module or battery cluster level; setting up explosion-proof pressure relief devices to release accident gas pressure; and activating fire-fighting measures that combine suppression and cooling.

6. The method according to claim 1, characterized in that, The high-importance physical phenomena identified in the maintenance state as described in step S1 include at least: DC arcs, and the risk of electric shock or arcing caused by residual energy.

7. The method according to claim 6, characterized in that, In response to physical phenomena during maintenance, the accident prevention measures include at least: setting up finger-touch-proof structures or intrinsically safe structures, restricting live operations through programmed control or mechanical interlocking, and eliminating residual energy risks through lockout tagging and multi-energy isolation procedures; For physical phenomena of high importance during maintenance, the accident mitigation measures include at least: configuring personal protective equipment according to the risk of DC arcing, and reducing the probability of personnel being exposed to the risky environment through remote control or isolation operation.

8. The method according to claim 1, characterized in that, The high or medium importance level physical phenomena identified in the start-up and shutdown states described in step S1 include at least: inrush current, contactor contact sticking, and load disconnection caused by control logic timing conflicts.

9. The method according to claim 8, characterized in that, In response to the physical phenomena during startup and shutdown, the accident prevention measures include at least: configuring a pre-charge circuit to limit transient current, using soft start or power ramp control to limit transient voltage or current changes, and performing logic verification on the contactor status. For physical phenomena of high importance during startup and shutdown, the accident mitigation measures include at least: online detection and alarm for abnormal contactor adhesion, and configuration of fuses or explosion-proof switches as backup fault current cut-off devices.

10. A safety management system for an energy storage power station, characterized in that, The system is constructed and operated using the method described in any one of claims 1 to 9.

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