Digital battery

Dorsal membrane localization: an inevitable choice for photovoltaics

The Chinese PV industry has grown rapidly in recent years, but problems such as blind investment and vicious competition, innovation and strong enough, and so on. At the same time, due to Sony VGP-BPS9/B Sony VGP-BPS9/S continuous improvement and breakthrough technology, the photovoltaic industry in China away from its high energy consumption, high pollution, the image of a larger exhibition showing the potential development. In March 2009, Dunhuang, China 10MW photovoltaic type GRID tender generation project, all offers are less than 2 yuan / kwh, the standard minimum 0.69 yuan / kWh, the second lowest standard 1 , 09 yuan / kWh, which shows that Chinese PV companies have significantly accessibility and competitiveness, reducing the cost of photovoltaic electricity production is likely to take world leadership.

 

The recently concluded Conference on Climate Change in Copenhagen, is a global response to climate change is an important step. With the rising cost of carbon future for solar energy, represented by the new energy alternative to traditional fossil fuels has become an inevitable trend. Must accelerate the replacement process for the photovoltaic industry is constantly improving technology at the same time, but also reduce costs. Packaging materials include component solar glass, EVA film, borders, film, junction box, silica gel, etc., now, with the exception of return of other films that packaging materials were included in the PV industry in China to achieve a high degree of localization significantly reduces the sun unit mounting the battery from the electricity generating costs of Inspiron 630m battery Inspiron 640m battery energy production. However, the film back as an important class of solar components of packaging materials, which require high technical threshold, and the raw materials involved, has long been patented abroad, fluoro-chemical giant technological constraints, as the extent of its domestic production is still very low, which now leads Domestic manufacturers of solar components diffusing film used mainly imported products, prices high and availability is not guaranteed. Therefore, the territorial unit of electricity produced from solar energy to reduce the manufacturing cost point of view, the location of the dorsal diaphragm is the inevitable choice for Chinese PV companies.

 

Double-sided fluoride material: high quality, essential to save movies

Solar back sheet can be divided into membrane and non-fluorinated membranes containing fluorine dorsal ridge two categories. How fluoride back sheet is divided into two sides of fluoride (as TPT) and single-sided fluoride (eg, TPE) of two kinds: without fluoride on the film back is primarily the adhesive is composed of several PET compounds adhesive layer. Currently, commercial crystalline silicon solar cell component requirements for the use of 25 years, while the film back as a direct contact with the external environment, a large area of photovoltaic materials packaging, which must have excellent resistance to long-term aging (moist heat, dry heat, ultraviolet), electrical insulation resistance, Satellite M55 battery Tecra A3 battery barrier properties of water vapor. Therefore, if aging-resistant strength of the dorsal membrane, insulation, water, gas, etc. can not meet the solar component of 25 years of environmental tests will eventually lead to the reliability of solar cells, stability and sustainability can not be guaranteed, so that the solar atmosphere and environment in general use 8 to 10 years or under special conditions for the environment (altitude, islands, wetlands, etc.) using 5 to 8 years is delamination, cracking and blistering, yellowing and other undesirable result of the battery module independent Drums sheet piece, battery power to reduce the other side of effective output, more dangerous is that the components of the battery voltage will be lower and the current values of power play emerged under the arc, resulting in stimulation of components of the cell combustion and fire, causing damage to the security and property.

 

Studies have shown that PET molecular main chain containing a large number of ester based, has a good affinity with water, likely plasticizing water, whereas even small amounts of moisture will lead to degradation main molecular chains. PET in the properties of hot and humid aging process aging modified by three factors: the degree of crystallinity, plasticizing water, hydrolysis, various factors are at work in different environments and at different stages a series of factors play a dominant role. Premature aging, crystallization is the dominant factor, it increases the Young’s modulus, maximum tensile stress, but brittle material, a lower impact resistance, and then the water plasticized be the main factor, it increases the resistance ThinkPad R52 battery ThinkPad T40 battery material, it has rapidly increased hydrolysis as the main factor causing the blade PET macromolecules, molecular weight loss, causing mechanical damage. The temperature will make the above process is significantly accelerated, so that water and PET heat caused a sharp decline in physical and mechanical properties of the main reasons. In addition, UV radiation are also PET molecular weight, strength and elongation greatly decreased the crystallinity increased, so that the fragile material. Thus, the multi-layer PET adhesive tape is composed of non-fluorinated membrane from the back of the characteristics of the material itself unable to meet the commercial component of solar cells, crystalline silicon 25 years of hot and humid , dry heat, ultraviolet and other environmental tests and use, it would be difficult to components used for encapsulation of solar cell silicon crystal.

 

Material containing fluorine Back fluoride membrane surface electronegativity of fluorine due to large radius van der Waals is small, can be a very strong carbon-fluorine bond (up 485KJ/mol), and its unique structure fluorinated chains in the spiral rod-shaped molecules in large type, rigid, smooth surface, making resistance to weather fluorine resin, heat resistance, high temperature and chemical resistance and other properties are extremely advantageous. Fluorine resin characteristics are remarkable materials fluorinated (fluorine or fluorocarbon coating film) has an excellent weatherability, can protect the long-term reliability of the outdoors. As the external environment and internal solar cells play the role of the barrier film back in contact with the surface of the outside air, as well as integration with EVA adhesive surface (light side) has suffered a major role in aging. However, due to support the development of film production and materials company, Studio 17 battery Studio 1735 battery taking into account the double-sided film of fluoride to return all the result of cost pressures, manufacturers have adopted EVA material (or other olefin polymers) alternative to fluorinated double-sided structure of TPT in the EVA back bonding surface (bright area) equipment fluoride contained in the structure of the TPE single-sided fluoride film. Such a structure of TPE on the film in packaging and system components with the EVA, because of its non-fluorinated materials held at the dorsal surface of the material of PET film as a basis for effective protection of principal components The installation of the film back does not sustain long-term aging tests UV components appear in a few years the film yellowing, aging embrittlement phenomena and other serious adverse impact on the long-term component of the efficiency term unilaterally structure of fluoride in the back of the membrane TPE is not applicable to crystalline silicon solar cell component package used.

 

Coating-Film Back Type: Returning membrane material development trend

Currently the cell mainstream film, solar energy back, mostly double-sided adhesive fluorine-containing complex-type film back and the back coating film type. Re-glue type solar back sheet (TPT, KPK, etc.) is based on Europe and the United States on the development of a number of fluoro-chemical companies such as fluoride PVF or PVDF membrane collage made with the PET substrate. Re-glue type back film because of its presence in the PET substrate adhesive on both sides, while the standards vary depending on the quality of bonding, combined with the complex process varies greatly in the components of the PP2182L HSTNN-LB31 battery pack outside the course of the long-term use of the composite backsheet by moisture and temperature factors, the combined effects of the double subject to hydrolysis, damaging the adhesive layer, leading eventually to the film fluoride (PVF or PVDF, etc.) and the substrate layer peeling PET, it is difficult to meet the needs long-term reliability of components of the battery.

 

At the same time, because of manufacturing constraints and technology patented technology fluoride membrane hydrophilic surface modification, and other reasons, such as fluorine and this FSP products PVDF membrane are not the China to allow localization. Therefore, the use of PVF or PVDF film development and production of fluorine and fluorine containing other two-sided cell membrane Chinese solar companies back of long-term control of a foreign manufacturer fluoride membrane back to the manufacturing costs of the film remain high, and the fluoride film and PET applied to the binding of high-quality adhesives are mostly very small number of foreign firms technological monopoly is difficult to import. The membrane behind some domestic manufacturers can take some ordinary polyurethane, epoxy or acrylic adhesive, the adhesive easily aging, performance does not meet the durability requirement of 25 years. Aspire 3000 battery LCBTP03003

 

Given the complex plastic film type solar cell membrane localization back fluoride does not realize the reality of the situation and back in the components of composite film adhesive is difficult to bear long-term use outdoors during the test hot and humid aging, develop a class does not use adhesive to high integration and excellent long term weathering performance, low cost products of high quality films back is the rear focusing cone and the direction of technology development and trends.

 

After decades of products coated with fluorocarbon rapid development in construction, chemical, electrical and electronic industry, mechanical industry, aeronautics, aerospace, and households are widely used in various fields, becoming the acrylic coating, the polyurethane coatings, silicone coatings, etc. After the high-performance coatings and comprehensive range of coatings performance higher. Currently, the application of resin coating of fluorine wider main PVDF, CTFE, PTFE three types, our country after the United States and Japan have a fluorocarbon coating, after the synthesis technology and third to realize the industrialization of the country. With companies of multinational fluorine resin (such as Japan, Asahi Glass, large gold Arkema et al) the development and production of PVDF, CTFE, PTFE as the main preparation of a coating resin Fluorocarbon is PA3383U-1BRS PA3395U-1BRS widely used in bridges, buildings, railways, communications facilities on the surface protection, and held for over 40 years of strained outdoors, and demonstrate excellent resistance to weathering. At the same time, including the low temperature plasma technology change, technology changes in radiation, vacuum technology, plasma chemical grafting materials, including the technology of surface modification is more mature. Therefore, fluorocarbon coatings, PET technology of surface modification, modification techniques surfacing fluoride applied to the development of film solar cells behind to reach the non-use of the adhesive has excellent long term weathering performance, low cost of such high quality, lined back Film Products is entirely feasible, and he is back in the future development and localization of membrane materials, the only way.

 

Dorsal process of membrane localization: to accelerate the

Currently, the national film industry is back in the early stages of development, development and production company are distributed in the delta region of Yangtze in mainland China to develop the types of films behind plastic are essentially cinema complex type back and type coating film distributing two major categories. With Taiwan-Hong, Sai Wu, Lucky, Multi Tone, represented mainly by the firms take the film Back to the PVF, PVDF, or ETFE film and PET substrate such as fluorine bonded by the adhesive compound and preparation of re - Back adhesive film type, membrane-based fluoride dependence on imports, back film manufacturing costs higher. Suzhou, in the past, fluoride Kazakhstan Long, Foster and other film companies represented at the rear by a PTFE resin (PTFE) resin, or chlorotrifluoroethylene (CTFE) as the main paint coating resin compound substrate and the ways Preparation and PET film, coated back type developed in the cost of return and membrane technology has more advantages. apple PowerBook G4 12 inch battery apple MacBook 13 inch battery

 

Because the domestic re-glue manufacturing companies return type of film in the main raw materials and base technologies have the advantages of cost and quality, which leads the overall competitiveness of commodities and profit margins low. And Suzhou, China Lilly and Company (Jolywood) by independent research and development in the area of PET and PTFE coating (FFC) on the surface of the plasma were taken by the first silicon in the world, treatment technology, titanium siloxane and fluoride-based plasma processing techniques, significantly increased the PET and the FFC of the surface energy and the number of active chemical groups, so that PET and between the FFC, FFC and l CVA is not only a physical adsorption between molecules but also the chemical graft, making FFC fluorine coating and binding superpower PET and EVA substantial increase in bond strength after 85 ℃ * 85% RH 2000 Xiao Shi aging test layers between them is no delamination. Currently, the Suzhou-based solar cell back into the PTFE film has passed TUV, SGS, UL and international certification of others and the photovoltaic business at home and abroad is widely used. F3172A PB995A

 

January 16, 2010, Suzhou, in the past (Jolywood) ’s annual production of 30 million square meters Back film solar cell expansion project based in Changshu City, Jiangsu Province, Shajiabang Industrial City Park, Chang-Kun officially started, the production base of sun battery backup film production in the Asian region and the world can be described as unique, his achievement will greatly accelerate high performance solar back sheet in the process of domestic production China, and completely break the back of foreign manufacturers of the dominance of high performance cell membrane solar products industry.

 

With the world economy as a whole for the better, China and the world photovoltaic industry will inaugurate a new period of high development speed. Meanwhile, the adjustments of the 2010 European Photovoltaic policy and implementation of the Chinese PV market to start cutting costs is imperative to make solar components, we have reason to believe that in the coming 1 ~ 2 years, the Chinese PV industry will achieve a return of packaging membrane localization, which will also be conducted on the true meaning of Applied Materials, solar components of the full localization. XPS M1210 battery XPS M1330 battery

Supporting the infrastructure of modern society must be based on a very high operational reliability. Internet and telecommunications switching center server farms to ensure nearly 100% of sentence “without run-time” or availability of the system, they rely primarily on a very mature technology - lead Sony VGP-BPS9/S Sony VGP-BPS9A battery of acid, while the center of data storage used in high technology. Typically, these key nodes, and many other important areas are equipped with standby power, the supply of electricity in standby mode is usually the first level inverter, the inverter pair of VRLA (VRLA) battery or yield similar battery sealed gel battery assembly section of energy conversion.

 

The reason why traditional techniques are widely used, there are many reasons, including lead acid batteries affordable, but also with exceptional reliability. But while Great but not perfect. VRLA battery life is limited (generally 12 years of life from conception), often mission critical systems using the battery as a source of backup power, but changed regularly. Failure may indeed occur. In a typical standby power, the role of the battery as its name - they still maintain a fully charged state to await the primary power failure. And when fully responsible for the prosecution small current through the float “charge to keep. If the float current is below a ceiling, then the battery in the gas produced by electrolysis will be re-chemical combination. In this case, a single voltage battery float is slightly higher than the standard value of 2.27 V, may also damage the battery. A little more tension will cause precipitation of the electrolyte capacity of more recombination more gas, these gases are not handled by the overflow valve. If the battery temperature is too high, even if the charging voltage is appropriate, can lead to loss of electrolytes. Inspiron 630m battery Inspiron 640m battery

 

Other methods of early termination of sulfation, columns and very bad network connection, the connection plate to the network and evil, the stratification of electrolyte and a grid to accelerate corrosion. There is still another, if a failure mode low, but catastrophic - thermal runaway, which is peculiar to VRLA gel batteries, and a failure mode can lead to catching fire. The only way to avoid thermal runaway is to control the internal temperature of the battery.

 

Simply monitoring the battery voltage on the detection of lead-acid battery capacity decline in the role is very limited, it has been recognized in the industry. When the battery performance diminishes, it is usually presented is that the nominal voltage, until the release of large currents can only apparent, but when its capacity has been considerably reduced voltage drop prematurely. By measuring the proportion of electrolyte to determine the condition of the battery accurately, the method of the VRLA or sealed gel batteries do not apply; routine battery of tests used in the only way is to discharge the battery to a state controlled the next, but this approach need to stop using the battery. In addition, the depth of discharge also reduces the life of lead acid battery; in on a regular basis to conduct its test backup battery discharge, and its principal power with high reliability of the system, most programs use this test to determine the battery life. Satellite M55 battery Tecra A3 battery

 

Recently, continuous monitoring may be a non-interference electronic method of detecting a single cell near the failed state, this method can not only save costs, while maintaining overall system availability. The predecessor of these systems is usually measured cell or battery (battery industry term meaning that the shell in the same packages multiple battery) voltage - despite its limitations is well known - with charge / discharge current and temperature ambient. Some systems attempt to guess the extent or strength of the internal battery, its effectiveness varies.

 

LEM Sentinel system is dependent on basic parameters of a simple analog measurement of change leading product has now become the first of three generations of the Sentinel III. It is tailored in a single chip SoC (System on Chip) IC on the integration of analog and digital technologies. The device configured in a measured terminal voltage, the temperature of the internal battery and internal resistance of the module, can provide accurate measurement results for the cost of new in most of the configuration of the backup system can afford in the budget system is the design of a key. IBM ThinkPad R51 battery  IBM ThinkPad R52 battery

 

Battery temperature and / or the internal impedance of the exponential growth, the value of the instructions they are close to failure, the system of records to track data over time, d ‘ identify possible approaches fail. All modules are configured Sentinel III with a probe for measuring the outside temperature or the patch can be bound directly to a single cell or battery casing to accurately monitor the battery temperature as much as possible.

 

The battery is used or is being loaded, you can use a mature technology assessment of the internal impedance. Typically, the float voltage superimposed DC measuring low AC voltage and AC current at that time, and then measures the results of the projection of the internal impedance, the methods of specific implementation are different. However, this method has limitations, it can not cope with a form of the exponential curve. And expiring at the failure process of a single cell in the data recorder of their failure to recognize the trends appeared in good condition, on the contrary, the problems of failure, the battery may be short term be completely ineffective.

 

LEM has developed a more sophisticated algorithm, which can be detected as early as possible is a single cell performance decay. The result is a methods test very reliable, it can completely penetrate the energy of a single layer of cells to ensure maximum reliability. It is commonly called the Randles equivalent circuit, based on the performance of the electrochemical cell from the electrical components of a network circuit, each electrical component consisting of a single cell of associated physical factors. PB994A PP2182D

 

The same features or capabilities during the discharge period of falling have also been confirmed. All the impedance of the equivalent circuit of factors are to follow curves similar fall in the early stages of failure or capacity, no significant change. If the impedance state to a single main battery indicator, it will not provide meaningful guidance, unless the volume down more than 25-30%. Because the industry standard is to replace the provisions of the performance has fallen below 80% of cell performance, it is clear that the importance of early identification of possible failure.

However, in the Randles equivalent circuit, there is a parameter in a battery failure unique (except for a simple metal corrosion, the parameters of this mode of failure by increasing Rm forthcoming) will start to change, ie CDL-in, double-layer capacitance. Figure 3 below Natiao curves of their properties; In addition, the stage performance in the ordinary course of normal cells, and the assumption that power is fully charged batteries failed, its curved shape is similar Cdl.

 

Monitoring Technology

 

This article does not detail the surveillance techniques as described below, a brief description of their behavior.

 

One by one, to feed test signals into a single cell, without requiring the entire battery in high current, there was no connection to the DC system external interference. Bipolar test signal using the original algorithm is modified, but the results show that the reliability of the signal pole. However, when tested with a unipolar signal, the DC drift. Easy to eliminate this drift and can not maintain all data features, which is characterized by precise determination of parameters needed. Use of frequency scanning signal pulse method rearrangement of different frequencies (including the test signal), allows the response of the battery voltage curves coincide with the book. RN873 Y6142

 

Once the curve derived from the potential to become a rule, you can set the firmware algorithm that style drift and eliminating it and thus be adapted to the direct input Sentinel algorithm, the average zero-sets of data voltage. This method can be reduced to the drift error of 0.1%, it will not cause a significant distortion of the data sets. Therefore, measures of waveform can also be used in the algorithm, so that the accuracy of equivalent circuit parameters above.

 

Dealing with many measurement functions and algorithms have been integrated in a monolithic integrated circuit. Sentinel module can measure a single monomer battery, also measured on all 12V battery). Up to 250 measuring points are the forms module for measurement, the measurement results can be submitted by a data bus dedicated to the battery from the data recorder, S-Box. In the large-scale systems of the battery may be a few stocks such as data flow synthesis, which is a management system locally or remotely, can make use of the S-Box in the embedded web server through a standard bus or an Internet connection to use these data streams.

 

SOC by using measures to determine the actual status of each battery, not only can provide fault detection, near this sophisticated monitoring framework will be able to have functions; can also configure other functions and services. Aspire 3000 battery LCBTP03003

 

For example, the battery internal resistance within a single cell is usually different. Over time, this state will be a problem. SoC intelligent control system can quickly detect this single cell, the terminal voltage optimization system can be transferred can not continue to charge a single battery floating around the news…

 

Real-load time management can extend the battery life: In the voltage across the same situation, VRLA battery float in the current ratio flooded high-tech batteries. This may accelerate corrosion of the anode plate, which reduces the effective life of the battery up to 30%. On the life of a certain percentage of the float can be reduced to eliminate this bad effect. However, side effects such as the life cycle are also an advantage is to reduce the incidence of thermal runaway.

 

Installing a battery pack can also provide the full life cycle of the voltage and temperature records, that manufacturers and users use. Vostro 1510 battery Vostro 1520 battery

 

Over-discharge protection: The device in the charger / UPS systems are common, especially in the battery monitor, they are based on the average voltage of individual cells of the termination of the landfill to protect the battery. However, the poor performance of the voltage across the battery may be much lower than the average voltage in the battery, but also in its termination voltage is reached before the landfill was good. Therefore, the development of a dynamic high-accuracy ‘Time to Run (outstanding Running)’ algorithm, in any single cell will be depleted when an alert is given.

 

Monitoring of battery backup required parameter as detailed as possible in order to generate the most accurately reflects the results of the battery status. This is not just a technical problem, is also an economic issue. Avoid battery failure is essential, but replaced prematurely and did not even approach the end of the battery life is extremely profitable. In addition to the measurement of each battery voltage, impedance and discharge performance, LEM will also measure the internal temperature of the battery is defined as a standard feature, is a leading global position. LEM is currently developing a magnetic flux, the sensor technology is to float, with a resolution greater than 10mA, with little or no drift of temperature, high current discharge with almost no residual magnetism, the repeatability of measurements better. The integration of these advanced features, the battery monitor is more expensive systems, but the overall life of extreme cost-effective management system. Studio 17 battery Studio 1735 battery