In industrial and commercial energy storage systems, the choice of temperature control solution for battery storage cabinets plays a decisive role in the safety, economic efficiency, and service life of the entire system. As the two mainstream thermal management technologies, air cooling and liquid cooling each have their own advantages and limitations. Only through comprehensive evaluation across multiple dimensions—including technical characteristics, economic costs, and environmental adaptability—can the most suitable solution be determined.   1. Comparison of Core Technical Characteristics     1.1 Heat Dissipation Efficiency and Temperature Control   Air cooling systems dissipate heat by driving air circulation through fans. Since air has a thermal conductivity of only 0.026 W/(m·K), its heat transfer efficiency is relatively low. In actual operation, the cell temperature difference of air-cooled energy storage cabinets is generally in the range of 5–8 °C.   This temperature control method is suitable for scenarios with power density ≤ 1C and average daily charge-discharge cycles ≤ 2, such as peak-valley arbitrage projects in industrial parks. In such applications, requirements for heat dissipation efficiency are not stringent, and air cooling systems are fully sufficient.   Liquid cooling systems use coolants such as 50% ethylene glycol aqueous solution as the heat transfer medium, with a thermal conductivity as high as 0.58 W/(m·K), providing far superior heat dissipation performance compared to air cooling. With liquid cooling technology, the cell temperature difference can be precisely controlled within 3 °C.   Under high-rate charge-discharge conditions (above 3C), batteries generate a large amount of heat, which liquid cooling systems can quickly remove. Liquid cooling also performs excellently in extreme high-temperature environments above 40 °C, with desert photovoltaic plus energy storage projects as typical examples.     1.2 System Complexity and Maintenance Costs   Air cooling systems feature a relatively simple structure, mainly consisting of fans and air ducts, resulting in a lower initial investment cost of approximately 0.499 RMB/Wh. However, since air carries dust, filters need to be cleaned quarterly to maintain effective heat dissipation, leading to long-term O&M costs of around 0.02–0.05 RMB/Wh per year.   Liquid cooling systems require the integration of many components such as cold plates, pumps, valves, and heat exchangers, with initial costs 15%–20% higher than air cooling. Nevertheless, liquid cooling systems demand less frequent maintenance, with only one coolant inspection required annually. From a full life cycle perspective, costs for liquid cooling systems can be reduced by 10%–15%.     1.3 Space Occupancy and Environmental Adaptability   Air cooling systems do not require additional piping, allowing the energy storage cabinet volume to be reduced by 10%–15%. This gives air cooling a significant advantage in space-constrained industrial and commercial rooftop scenarios.   Liquid cooling systems have higher space requirements due to the need for coolant circulation channels. However, in harsh environments such as high-humidity coastal areas and dusty mines, liquid cooling systems ensure stable operation with a high protection rating of IP65.     2.Conclusion   For projects with power density ≤ 1C, limited budgets, and mild environmental conditions — such as typical industrial and commercial parks — air cooling is the preferred option. For applications involving high-rate charging and discharging, high-temperature or high-humidity environments, or from a long-term investment perspective (e.g., data centers and ports), liquid cooling is more suitable.   In addition, a hybrid solution of liquid-cooled PACK + air-cooled PCS can be adopted to balance heat dissipation efficiency and cost. In actual decision-making, it is recommended to combine specific project parameters, conduct economic modeling, and compare technical solutions from manufacturers to select the most appropriate thermal management scheme.    

Against the backdrop of today's energy transition, photovoltaic energy storage systems are becoming a vital component of sustainable energy development due to their unique advantages. The coupling method of solar and storage serves as the pivotal link in achieving efficient energy utilization.   Today, Sailsolar will help you explore a crucial concept between two coupling architectures in solar power system: DC coupling and AC coupling in solar-storage systems.The key to understanding these two architectures lies in identifying where the energy from photovoltaics and the storage battery converges.   DC coupling: Circuit of PV and the storage battery converge on the DC side. AC coupling: Circuit of PV and storage battery will converge on the AC side.   1. DC Coupling Architecture In DC-coupled architecture, DC power from the PV array is stabilized by the DC-DC converter within a hybrid inverter (solar-storage inverter) and fed directly into the battery. When power is needed, it can be drawn from either the PV array or the battery. In either case, the DC power is converted to AC by the DC-AC module within a hybrid inverter before being supplied to the loads.   Key Point: The energy remains entirely in DC form when charging the battery from the PV array, avoiding any lossy DC-AC-DC conversion.   2. AC Coupling Architecture In AC-coupled architecture, the PV and energy storage systems operate relatively independently. The DC power generated by the PV array is first converted to AC via a PV inverter, which then supplies the grid or local loads directly. If AC power which convertered by solar inverter needs to be stored, it must be processed by a PCS (Power Conversion System), which converts it back to DC to charge the battery. When discharging, the PCS again converts the battery‘s DC power to AC for use by the loads.   Key Point: Charging the battery from the PV array requires a DC → AC → DC conversion process, and powering the loads adds a further DC → AC conversion.   3. Comparison for Both Architecture (1) Energy Flow Path & Conversion Steps DC Coupling: DC power generated by the PV modules can charge the battery directly (DC-DC), without undergoing DC-AC-DC conversion, resulting in lower energy losses.   AC Coupling: Storing PV power requires a two-step conversion (DC-AC-DC). When finally used, the power undergoes a total of three conversion steps, leading to relatively higher energy losses. (2) System Equipment & Cost DC Coupling: Utilizes an integrated hybrid inverter (or solar-storage inverter), which combines PV MPPT, bidirectional conversion, and battery management. This reduces the number of required components and interconnection cabling, lowering the initial investment. Fewer components also mean reduced installation and maintenance costs. AC Coupling: Requires separate solar inverters and a battery inverter (PCS), along with a corresponding AC distribution board. The greater number of components increases cabling costs and requires more installation space.   (3) DC-to-AC Ratio (Inverter Loading Ratio) Assuming a factory transformer capacity of 2.5MVA, the total inverter output is typically limited to 80% of that capacity (approx. 2MW) for safe operation. DC Coupling: Can support a 4MWp PV array. If the PV array generates 4MW of power, 2MW can flow directly to the battery for charging via the DC bus (a DC-DC process). The remaining 2MW is converted by the PCS within the hybrid inverter and output as 2MW of AC power. The stored green energy can be dispatched during evening peak hours, maximizing the utilization of solar generation to meet higher corporate demand for renewable energy. AC Coupling: PV generation is primarily limited by the PV inverter's capacity. With a 1.3 DC-to-AC ratio, a 2.6MWp PV array might be installed. If it generates 2.3MW DC, the 2MW AC PV inverter would constrain the output, causing the system to curtail PV generation and resulting in wasted solar energy.   (4) System Compatibility & Scalability DC Coupling: Features high integration between the PV and storage systems. However, it has poor compatibility for retrofitting existing PV systems, often requiring replacement of the original inverter. System expansion is also constrained by the hybrid inverter's maximum input/output power and battery port specifications. AC Coupling: Offers easy retrofitting for existing PV systems, as storage can be added by paralleling a battery inverter and batteries on the AC side. It allows flexible selection of equipment from different brands and provides stronger scalability.   4. How to Select AC&DC Coupling Solution (1) DC Coupling:Scenarios such as new solar-storage system construction, pursuit of higher conversion efficiency and DC-to-AC ratio, and where installation space is somewhat limited. (2) AC Coupling:Scenarios such as adding energy storage to existing PV systems, requiring compatibility with equipment from multiple brands, and hybrid integration of multiple energy sources.   Each method has its trade-offs, with no single optimal choice for all scenarios. The practical selection must be based on a comprehensive evaluation of the project's specific conditions and requirements. As both technologies continue to advance, they promise to deliver an ever-widening array of solutions, empowering users to make the optimal choice for their unique energy future.  

"How to maintain and extend the lifespan of lithium batteries in a solar system"—is this something you've always been concerned about? Lithium battery maintenance requires consideration of many factors, such as charge/discharge management, environmental control, system compatibility, and daily monitoring. Below is a system maintenance guide:   1. Core Principles: Avoid "Three Highs and Two Lows" Three Highs: High-rate charge/discharge, high/low temperature environments, and long-term storage at high capacity (100% SOC).   Two Lows: Over-discharge (low SOC), and low-temperature charging (below 0°C).   2.Charge and Discharge Management (The Most Critical Aspect) (1) Avoid Over-Discharge Set a reasonable discharge cutoff voltage (e.g., the voltage of a single lithium iron phosphate cell should not be lower than 2.5V). The system needs to be equipped with a BMS for protection. It is recommended to maintain the battery level between 20% and 90% during daily use to avoid prolonged periods of low charge.   (2) Optimize Charging Strategy Use multi-stage charging (constant current-constant voltage-float charging) to avoid prolonged high-voltage float charging. Control the charging current between 0.2C and 0.5C (e.g., charge a 100Ah battery with 20A~50A) to reduce high-current surges. Avoid low-temperature charging: Charging below 0°C can easily lead to lithium deposition, requiring regulation through a BMS or heating system.   (3) Shallow Charge and Discharge Controlling the battery's depth of cycle (DOD) to below 70%~80% can significantly extend cycle life (e.g., using only 50% of the battery level per day may more than double the lifespan compared to using it at 100%).    3.Environment and Installation & Maintenance (1) Temperature Control Ideal Temperature: 15°C~25°C (Optimal charging/discharging range).   (2) High Temperature Protection: Avoid direct sunlight; ensure proper ventilation in the battery compartment. When the ambient temperature is >35°C, consider active cooling (fan/air conditioning).   (3) Low Temperature Protection: Stop charging below 0°C; if necessary, install insulation or a self-heating BMS. In extremely cold regions, consider underground insulated boxes or indoor installation.   (4) Installation and Connection Keep the battery pack dry and clean, avoiding dust or corrosive gases. Regularly check the tightness of cable connections to prevent poor contact leading to localized overheating. When using batteries in parallel, select batteries of the same model and batch to ensure consistent internal resistance.   4.System Co-optimization (1) The Importance of BMS (Battery Management System) Individual cell voltage/temperature monitoring Overcharge, over-discharge, overcurrent, and short-circuit protection Temperature balancing function (active balancing is preferred) Regularly check cell consistency via the BMS; if the voltage difference is >50mV, investigate the cause.   (2) Load Management Avoid sudden high-power loads (such as motor starting); a soft starter can be installed. Power design should include a margin to prevent prolonged high-rate discharge.   5.Daily Monitoring and Maintenance (1) Regular Inspections Monthly inspections of battery appearance (bulging, leakage), temperature, and connection terminals. Quarterly capacity degradation analysis using BMS data (capacity tester available). Annual professional testing: internal resistance test, equalization maintenance.   (2) Long-Term Storage Recommendations If the system is not used for an extended period, maintain the battery charge at 40%~60% (half-charge state). Disconnect the battery from the system and perform a top-up charge maintenance every 3 months.   Through the above measures, the key to maintaining and extending the lifespan of lithium batteries in solar energy systems lies in prevention rather than remediation. Keeping the batteries operating in their "comfort zone" is the most cost-effective maintenance method.

Introduction As renewable energy adoption accelerates worldwide, solar power has become one of the most efficient and sustainable energy sources. Yet, its intermittent generation poses challenges for grid stability and energy management. This is where Battery Energy Storage Systems (BESS) play a vital role. A well-designed solar energy storage system transforms renewable power into a controllable, stable, and efficient energy supply — enabling industries and businesses to achieve energy independence and long-term sustainability.1. What Is a Battery Energy Storage System (BESS)? A Battery Energy Storage System (BESS) is an integrated technology that stores electricity from renewable sources such as solar and wind, then releases it when needed. It typically consists of: LiFePO₄ battery modules with high energy density and safety; A Battery Management System (BMS) for real-time monitoring and protection; A Power Conversion System (PCS) for bidirectional energy flow; An Energy Management System (EMS) for intelligent control and scheduling. Together, these components ensure seamless energy conversion and optimize performance in hybrid solar and off-grid systems. Grid Support and Peak Shaving: BESS stabilizes power output and balances grid fluctuations. Energy Independence: Stores excess solar energy during the day for use at night, reducing dependence on the utility grid. System Efficiency Optimization: Prevents energy waste through intelligent load management and discharge scheduling. Backup Power Function: Provides reliable backup during power outages for industrial and commercial users. Modular Scalability: Flexible design allows easy capacity expansion for larger energy storage projects. 3. SAIL SOLAR — A Trusted BESS Manufacturer and Solution Provider SAIL SOLAR Energy Co., Ltd is a professional BESS manufacturer and LiFePO₄ battery supplier in China, focusing on high-voltage lithium battery systems for industrial and commercial energy storage. Our advanced products, such as the 358V 280Ah High-Voltage LiFePO₄ Battery, are engineered with precision and quality to deliver high efficiency, long cycle life, and superior safety. Each system integrates intelligent BMS protection, smart communication (RS485/CAN), and compatibility with mainstream PCS and EMS platforms — making SAIL SOLAR a reliable partner for solar energy storage system integrators and EPC companies worldwide. 4. The Future of Energy Storage Technology With the rapid growth of renewable energy, battery energy storage systems are becoming the backbone of modern smart grids. Future BESS technologies will focus on higher voltage platforms, better thermal management, and smarter software integration. At SAIL SOLAR, we continue to invest in energy storage R&D, offering scalable and sustainable lithium battery solutions that empower global customers to achieve net-zero carbon goals. Conclusion By integrating solar power systems with advanced BESS technology, SAIL SOLAR delivers reliable, efficient, and future-ready energy storage solutions. As a professional energy storage system manufacturer, we are dedicated to enabling customers to harness clean power with confidence — building a smarter, greener, and more sustainable world.

What is Anti-Islanding? Anti-islanding is a critical safety feature in grid-connected solar PV systems that prevents the system from continuing to supply power to a local grid section when the main utility grid fails or is disconnected. An "island" refers to an isolated portion of the grid that remains energized by the solar system, posing serious risks: Safety Hazard – Utility workers repairing the grid may be electrocuted if the solar system continues feeding power. Equipment Damage – Voltage and frequency fluctuations in an islanded system can damage connected loads or inverters. Grid Restoration Issues – Uncontrolled power generation can interfere with grid reconnection. How Do Solar Panels Prevent Islanding? Since solar panels themselves cannot prevent islanding, inverters and protection devices implement anti-islanding measures. The main methods include: 1. Passive Anti-Islanding Detects abnormal grid conditions without injecting disturbances: Under/Over Voltage (UV/OV) & Under/Over Frequency (UF/OF) Protection If the grid fails, the inverter monitors voltage (±10%) and frequency (±0.5Hz) deviations and shuts down if thresholds are exceeded. Phase Jump Detection A sudden phase shift in the inverter output indicates grid loss, triggering shutdown.   2. Active Anti-Islanding The inverter actively perturbs the grid to detect islanding conditions: Active Frequency Drift (AFD) The inverter slightly shifts its output frequency. If the grid is present, it stabilizes the frequency; if the grid is disconnected, the frequency drifts until the inverter trips. Impedance Measurement The inverter monitors grid impedance changes—if the grid is disconnected, impedance rises significantly, triggering protection.   3. Communication-Based Anti-Islanding Uses Power Line Communication (PLC) or wireless signals to maintain grid synchronization. If communication is lost, the inverter shuts down (common in large-scale PV plants).   4. Hardware Protection Devices Arc Fault Circuit Interrupters (AFCI) – Detect islanding conditions and disconnect the system.     Protection Relays – Work with voltage/frequency sensors to force disconnection.

The following string design formula is proposed with reference to the "Design Specifications for Photovoltaic Power Stations (GB 50797-2012)", which meets two conditions at the same time: The maximum open-circuit voltage of the PV modules after series connection is lower than the maximum access voltage of the inverter; The MPPT voltage of the PV modules after series connection is within the MPPT voltage range of the inverter. Formula (1) Parameter meaning: Vdcmax: maximum input voltage of the inverter; the denominator parameter has been introduced above. Formula (2) Parameter meaning: Vmpptmin: minimum MPPT input voltage of the inverter; Vmpptmax: maximum MPPT input voltage of the inverter; t′: maximum high temperature at the installation location of the component; t: maximum low temperature at the installation location of the component; Vpm: peak power voltage of the component; Kv′: temperature coefficient of peak power voltage of the component (generally calculated using the open circuit voltage temperature coefficient Kv).  

Choosing the right solar photovoltaic system depends on your specific energy needs, budget, and available space. Residential and commercial systems serve different purposes and have distinct characteristics, making it essential to understand their key differences to make an informed decision.   Residential solar PV systems are designed for individual homes, catering to relatively stable electricity needs. They are typically installed on rooftops, with the roof size directly affecting the system’s capacity. Homeowners can select systems based on monthly electricity consumption, factoring in appliances like air conditioners and refrigerators. Most residential systems aim to achieve a  return on investment  ( ROI ) within a few years, thanks to government subsidies and tax incentives. While monocrystalline panels offer higher efficiency, they come at a higher cost than polycrystalline options. Additionally, smart monitoring systems enable users to track energy production and optimize usage.   On the other hand, commercial PV systems are ideal for factories, offices, and other large-scale facilities with higher and more variable energy demands. These systems often require extensive rooftop or ground-mounted space and involve more complex planning and installation. While the upfront investment for commercial systems is significantly higher, they provide substantial long-term benefits, including reduced energy costs and the ability to sell surplus power to the grid. Advanced technologies, such as high-capacity inverters and optimized configurations, help maximize efficiency and output.   The main differences between residential and commercial systems lie in scale, cost, and installation complexity. Residential systems are smaller, more affordable, and easier to install, while commercial systems are larger, more expensive, and involve detailed planning. Both benefit from incentives like subsidies and tax credits, though commercial projects may also leverage power purchase agreements (PPAs).   By evaluating your energy needs, budget, and space availability, you can select the right system to achieve both environmental and financial benefits. Solar power is a sustainable investment, whether for a home or a business.

Off-grid energy storage: 1. The main function is to convert the DC power generated by solar panels into AC power for load use. 2. Usually equipped with energy storage batteries to store excess power and release it when needed. 3. Independent operation, not dependent on the power grid, suitable for remote areas or areas without grid access. Application scenarios: 1. Mainly used in remote mountainous areas, deserts, islands and other areas without grid access or unstable grid. 2. Suitable for families, small commercial projects or occasions requiring independent power supply.   Hybrid energy storage: 1. It has both off-grid and grid-connected functions. It can convert the DC power generated by solar panels into AC power for load use, and can also be connected to the grid to achieve two-way flow of power. 2. When the power supply of the grid is normal, it can obtain power from the grid to supplement the shortage of solar power generation; when the power grid is out of power, it can switch to off-grid mode to provide power for the load. 3. It has efficient inverter capability and intelligent charging function, which can automatically adjust the charging parameters according to the battery status to extend the battery life. Application scenarios: 1. Applicable to places with grid access and where solar power generation is used to reduce electricity bills or achieve energy self-sufficiency. 2. Applicable to various occasions such as homes, enterprises, and public facilities, especially in areas where grid power supply is unstable or where energy efficiency is desired.

1. Check the DC cables and grounding of the components First, the reason for abnormal insulation impedance is that the DC cables are damaged, including cables between components, cables between components and inverters, especially cables in corners and cables laid outdoors without pipes. All cables need to be carefully checked for damage. Secondly, the photovoltaic system is not well grounded, including the grounding holes of the components are not connected, the component blocks and the brackets are not in good contact, and some branch cable sleeves are flooded, which will lead to low insulation impedance.   2. Rely on the inverter to check string by string If the DC side of the inverter is multi-channel access, the components can be checked one by one. Only one string of components is retained on the DC side of the inverter. After the inverter is turned on, check whether it continues to report errors. If it does not continue to report errors, it means that the insulation performance of the connected components is good. If it continues to report errors, it means that it is very likely that the insulation of the string of components does not meet the requirements. For example, if the Growatt MAC 60KTL3-X LV inverter is connected to an 8-way string and one of the strings is unplugged, if the fault alarm disappears, it means that the string is faulty.   3. When using a megohmmeter or other professional equipment to detect each string on site, use a megohmmeter to measure the insulation resistance of the PV+/PV- to the ground on the component side string by string. The impedance needs to be greater than the threshold requirement of the inverter insulation impedance. In some projects, dedicated insulation measurement equipment can also be used.

Solar inverters play a critical role in converting direct current generated by solar panels into alternating current suitable for household or industrial use. One of the key challenges in maintaining the efficiency and longevity of inverters is managing heat dissipation effectively.     During operation, inverters generate heat due to energy conversion losses and electronic component activity. If this heat is not dissipated efficiently, it can lead to overheating, which in turn reduces the system’s efficiency and shortens the lifespan of components. To address this, modern inverters employ various cooling strategies, including passive cooling, active cooling, and hybrid methods.   Passive cooling systems rely on natural convection and radiation, utilizing heat sinks and optimized airflow design. These systems are low-maintenance and energy-efficient but may struggle in high-temperature environments. Active cooling systems, on the other hand, use fans or liquid cooling mechanisms to enhance heat dissipation.     In conclusion, efficient heat dissipation in inverters is crucial for maintaining their performance and durability, especially as the demand for renewable energy systems continues to grow.

1. Analysis of lithium-ion battery capacity attenuation Positive and negative electrodes, electrolytes and diaphragms are important components of lithium-ion batteries. The positive and negative electrodes of lithium-ion batteries undergo lithium insertion and extraction reactions respectively, and the amount of lithium inserted in the positive and negative electrodes becomes the main factor affecting the capacity of lithium-ion batteries. Therefore, the balance of the positive and negative electrode capacities of lithium-ion batteries must be maintained to ensure that the battery has optimal performance.   2. Overcharge 2.1 Negative electrode overcharge reaction There are many types of active materials that can be used as negative electrodes of lithium-ion batteries, with carbon-based negative electrode materials, silicon-based, tin-based negative electrode materials, lithium titanate negative electrode materials, etc. as the main materials. Different types of carbon materials have different electrochemical properties. Among them, graphite has the advantages of high conductivity, excellent layered structure and high crystallinity, which is more suitable for lithium insertion and extraction. At the same time, graphite materials are affordable and have a large stock, so they are widely used.   When a lithium-ion battery is charged and discharged for the first time, solvent molecules will decompose on the graphite surface and form a passivation film called SEI. This reaction will cause battery capacity loss and is an irreversible process. During the overcharging process of a lithium-ion battery, metal lithium deposition will occur on the negative electrode surface. This situation is prone to occur when the positive electrode active material is excessive relative to the negative electrode active material. At the same time, metal lithium deposition may also occur under high rate conditions.   Generally speaking, the reasons for the formation of metal lithium leading to the change in lithium battery capacity decay mainly include the following aspects: first, it leads to a decrease in the amount of circulatory lithium in the battery; second, metal lithium reacts with electrolytes or solvents to form other by-products; third, metal lithium is mainly deposited between the negative electrode and the diaphragm, causing the pores of the diaphragm to be blocked, resulting in an increase in the internal resistance of the battery. The influencing mechanism of lithium-ion battery capacity decay varies depending on the graphite material. Natural graphite has a high specific surface area, so the self-discharge reaction will cause the lithium battery capacity loss, and the electrochemical reaction impedance of natural graphite as the negative electrode of the battery is also higher than that of artificial graphite. In addition, factors such as the dissociation of the negative electrode layered structure during the cycle, the dispersion of the conductive agent during the production of the pole piece, and the increase in the impedance of the electrochemical reaction during storage are all important factors that lead to the loss of lithium battery capacity.   2.2 Positive electrode overcharge reaction Positive electrode overcharge mainly occurs when the proportion of positive electrode material is too low, resulting in an imbalance in the capacity between the electrodes, causing irreversible loss of lithium battery capacity, and the coexistence and continuous accumulation of oxygen and combustible gases decomposed from the positive electrode material and the electrolyte may bring safety hazards to the use of lithium batteries.   2.3 Electrolyte reacts at high voltage If the charging voltage of the lithium battery is too high, the electrolyte will undergo an oxidation reaction and generate some by-products, which will block the electrode micropores and hinder the migration of lithium ions, thereby causing the cycle capacity to decay. The change trend of the electrolyte concentration and the stability of the electrolyte is inversely proportional. The higher the electrolyte concentration, the lower the electrolyte stability, which in turn affects the capacity of the lithium-ion battery. During the charging process, the electrolyte will be consumed to a certain extent. Therefore, it needs to be supplemented during assembly, resulting in a reduction in battery active materials and affecting the initial capacity of the battery.   3. Decomposition of electrolyte The electrolyte includes electrolytes, solvents and additives, and its properties will affect the service life, specific capacity, rate charge and discharge performance and safety performance of the battery. The decomposition of electrolytes and solvents in the electrolyte will cause the battery capacity to be lost. During the first charge and discharge, the formation of SEI film on the surface of the negative electrode by solvents and other substances will cause irreversible capacity loss, but this is inevitable. If there are impurities such as water or hydrogen fluoride in the electrolyte, the electrolyte LiPF6 may decompose at high temperatures, and the generated products will react with the positive electrode material, resulting in the battery capacity being affected. At the same time, some products will also react with the solvent and affect the stability of the SEI film on the surface of the negative electrode, causing the performance of the lithium-ion battery to decay. In addition, if the products of the electrolyte decomposition are not compatible with the electrolyte, they will block the positive electrode pores during the migration process, resulting in battery capacity decay. In general, the occurrence of side reactions between the electrolyte and the positive and negative electrodes of the battery, as well as the generated by-products, are the main factors causing battery capacity decay.   4. Self-discharge Lithium-ion batteries generally experience capacity loss, a process called self-discharge, which is divided into reversible capacity loss and irreversible capacity loss. The solvent oxidation rate has a direct impact on the self-discharge rate. The positive and negative active materials may react with the solute during the charging process, resulting in capacity imbalance and irreversible attenuation of lithium ion migration. Therefore, it can be seen that reducing the surface area of ​​the active material can reduce the capacity loss rate, and the decomposition of the solvent will affect the storage life of the battery. In addition, diaphragm leakage can also lead to capacity loss, but this possibility is low. If the self-discharge phenomenon exists for a long time, it will lead to the deposition of metallic lithium and further lead to the attenuation of the positive and negative electrode capacities.   5. Electrode instability During the charging process, the active material of the positive electrode of the battery is unstable, which will cause it to react with the electrolyte and affect the battery capacity. Among them, structural defects of the positive electrode material, excessive charging potential, and carbon black content are the main factors affecting battery capacity.

                                                                                                Preface As an important equipment in the field of modern energy conversion and transmission, the careful design and reasonable composition of the inverter-boost integrated silo are the key to achieving efficient and stable operation. The inverter-boost integrated cabin, as the name suggests, integrates the two key functions of PCS and boost into a compact and efficient cabin. This integrated design brings many significant advantages. The following takes a 2MW inverter-boost integrated silo as an example to analyze the internal composition and design. 1. Composition of the inverter-boost integrated warehouse The inverter-boost integrated warehouse adopts a standard container design, which is flexible in deployment and convenient for operation and maintenance. It can generally adapt to 500kW and 630kW energy storage converter PCS. The built-in transformer can adapt to voltage levels of 35kV and below, and supports local and remote monitoring. The inverter-boost integrated warehouse integrates energy storage converters, boost transformers, high-voltage ring network cabinets, low-voltage distribution boxes and other equipment in one container. It has a high degree of integration, reduces the difficulty of on-site construction, and is easy to transport, install, use and maintain. It has built-in emergency lighting system, fire protection system, access control system, and heat dissipation system. There are fireproof partitions inside the box, ventilation openings on both sides of the box, and heat dissipation ducts specially designed for PCS, which can effectively ensure the normal operation and safety of the equipment inside the boost integrated warehouse. 2. Design of the main circuit of the inverter-boost integrated warehouse From the perspective of space utilization, the integrated cabin greatly saves the floor space required for equipment installation. Compared with traditional distributed inverter and boost equipment, it integrates complex circuits and components into a cabin, which not only reduces the connection lines between equipment and reduces line losses, but also makes the entire system more concise and beautiful, and is easy to layout in a limited space. The 2 MW containerized energy storage boost transformer system mainly consists of a container body, four 500kW energy storage bidirectional converters, a 1250 kVA, 10 kV/0.38 kV transformer, a 1250 kVA, 10 kV/0.38 kV transformer, a 250 kVA, 10kV/0.38 kV isolation transformer, and supporting high-voltage switch cabinets, low-voltage distribution cabinets, and local monitoring system cabinets.   Two energy storage bidirectional converters are used as a group. The DC side of each group of energy storage bidirectional converters is connected to the energy storage system, and the AC side is connected to the secondary side of the 1250 kVA, 10 kV/0.38 kV transformer. The high voltage side of two 1250kVA transformers are connected in parallel to a 10kV high voltage switchgear. The total output of the system is 2MW, 10 kV three-phase AC, and energy can flow in both directions on the DC side and the AC side. 3. The high-voltage side of the high-voltage system uses a 10kV high-voltage switch cabinet to access the park's 10kV busbar, with one in and two out. One way is to supply power to two 1250 kVA transformers in parallel through a high-voltage circuit breaker, and the other way is to supply power to a 250kVA isolation transformer through a load isolation switch plus a fuse. The ring network cabinet is equipped with an isolation switch, a fuse, a circuit breaker, a lightning protection device, a live indication device, a fault indication device, a current transformer, and a comprehensive protection device. The comprehensive protection device controls the circuit breaker tripping by monitoring system parameters to achieve local and remote operation. 4. Local monitoring system The local monitoring system is installed in the local monitoring cabinet, with a programmable controller as the core, and is used to realize the status acquisition and system communication of transformers, high and low voltage switches, converters, fire equipment, air conditioners, lighting equipment, security equipment, etc. It has a human-computer interaction interface to display the status and parameters of the 2 MW container-type energy storage booster system. 5. Energy Storage Bidirectional Converter The energy storage bidirectional converter is the core component and is an important guarantee for achieving efficient, stable, safe and reliable operation of the 2 MW containerized energy storage boost converter system and maximizing the utilization of wind and solar energy. Combined with the on-site use environment and actual operation requirements, the energy storage bidirectional converter is designed to achieve grid-connected and off-grid operation functions.   The energy storage bidirectional converter is connected to the large power grid for a long time. The battery system is charged when the park load is small, and the battery is discharged when the park load is large. The energy storage bidirectional converter is required to have the function of grid-connected operation, realize independent decoupling control of active power and reactive power, and be able to coordinate with the superior monitoring system to realize various applications of the power grid system in the park.