How to significantly reduce the cost of photovolta

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How can high-speed slicing significantly reduce the cost of photovoltaic power generation?

more than 10 years ago, using the slicing technology of mortar can cut about 1000 pieces on a single crystal rod. Today, using the slicing technology of diamond wire can make this number develop to as many as pieces, and the cutting time of a crystal rod is shortened from more than ten hours in the past to 90 minutes. All this means that only in the slicing process, The cost of photovoltaic modules has been greatly reduced. However, this significant improvement in efficiency also means that the control system requires higher accuracy and corresponding capabilities

figure 1- basic schematic diagram of multi wire cutting

through unwinding tension control, wire arrangement through multiple rollers (double or three main rollers), feeding and winding of bar material, and cutting through the reciprocating of diamond wire, so as to improve the utilization rate of diamond wire. The whole diamond thread slicing system needs to achieve very high-precision and stable tension control, so that the machine can ensure the stability and efficiency of cutting, achieve high-quality production, and produce higher output than the previous slurry slicing

in order to reduce costs, large size and thin sheets are the development direction in the future. For diamond wire cutting, thinner diamond wire can cut more pieces, reduce surface roughness, and then better chip quality. For linear speed, it means that the cost brought by larger production capacity decreases, but this puts forward higher requirements for the control system, including constant tension control, high-precision wire arrangement, high-precision feeding, etc

Figure 2 - hardware architecture of Baccarat photovoltaic chip system solution

Figure 2 is the solution provided by baccarat for multi wire cutting system. Acoposmulti provides common DC bus driving technology and provides high-precision synchronization at the level of 100 microseconds through Powerlink real-time Ethernet

functional design of the slicing system

after the crystal rod is drawn, it goes through square cutting and enters multi wire cutting, which is a crucial link. Each crystal rod is valuable. If it cannot produce products with high quality, it will become the composition of the cost. As the diamond wire becomes thinner, it also makes the process control of slicing more precise. The slicing process must be able to be controlled very accurately and the synchronization accuracy is high, In order to ensure the high quality of the chip cutting process, the overall variance is the smallest in the development process of more than 40 years

figure 3- functional requirements of the multi wire cutting system

tension control technology

coil diameter and tension are the basic process control modules of the bekale control system. With the help of decades of accumulation in printing, plastics, packaging and many other fields, bekale can cope with the tension control of various tension scenes freely. Automatic wire arrangement, platform control, power failure and shutdown functions are special needs of the multi wire cutting industry, Baccalais has specially conducted a large number of tests and verifications for this purpose, and the mature technology ensures that it can be used immediately

figure 4-basic tension control model

figure 5-characteristics of Baccarat tension control

for baccarat tension control, torque feedforward can be realized, which ensures that stable tension control can also be realized in the acceleration and deceleration stages, not only for photovoltaic diamond wires, but also for tension control of other materials, because this can greatly reduce startup waste, which is usually considered inevitable in production. In addition, the self-adapting of tension and the decoupling of multiple groups of tension are the leading technical characteristics of baccalais tension control

therefore, it has good measurement performance. Automatic wire arrangement

because the diamond wire must be arranged through the master and slave rollers, and the rollers are processing rollers, and the arrangement of master/slave rollers makes its tension in a changing state in the whole process of wire arrangement, especially in the acceleration and deceleration process and the reversing process of wire arrangement. Therefore, high-precision electronic cam curve contour and high-order curve are needed to achieve higher precision control, which is for the machine, Only in this way can we ensure the high accuracy of wire arrangement and the minimum single-chip mean square deviation of slices

main roll control

the cutting composite industry calls for the main roll of the big data sharing platform room. During the winding and cutting process, it can realize the mode switching of current loop and position loop. Current synchronization can ensure the output synchronization of the two main rolls, effectively ensure the stability of the diamond wire tension in the cutting area, and also ensure the minimum cutting bow and the maximum cutting force, so as to obtain higher slice quality

audit trail

mappiaudit is a MAPP functional component in the baccalais system. It provides the system with audit trail ability. From the perspective of traceability of production, production needs to know who did what at what time, record it, and save the data in a tamper proof form, so as to ensure the traceability of quality and process, and bring data basis for the quality adjustment and optimization of production process personnel

Figure 6 - principle of audit trail

for photovoltaic chip manufacturers, audit trail is the key to improve their process quality control level. The system has this function, which will make this implementation simple. It comes from the mappiaudit function in the pharmaceutical field, which can also be used for the traceability of photovoltaic chip production by baccalais

figure 7- realize audit tracking and data application through the combination of MAPP modules

in the management of audit tracking, various parameters of the machine are collected and applied with mappdata module, and recorded through mappuser's user management and mappapudit's audit tracking module, and the connection between software is realized through mappcom

power failure shutdown function

for photovoltaic chips, synchronous shutdown in the case of sudden power failure is very necessary, otherwise, the waste of production is huge. In addition to the loss of diamond wire rod material, the cost of restoring the machine is also high. Therefore, the power failure shutdown function is a necessary option for photovoltaic chips

figure 8- power down shutdown function based on acoposmulti

acoposmulti common DC bus driving technology is adopted. When the main shaft of the system is braking, the current generated returns to the DC bus through the regeneration coil, and after dc/ac conversion, it is provided to other shafts for synchronous shutdown

data driven predictive maintenance technology

the silicon rod is cut into silicon wafers with uniform thickness and smooth cutting wall, which depends on the stable operation of the multi wire cutting machine. However, in actual production, it is inevitable that there will be equipment failure. In the cutting state, the sudden shutdown caused by the sudden failure of the equipment will cause irreparable damage to the expensive silicon rod, resulting in direct scrap. The material loss and shutdown loss caused by such sudden shutdown are huge. For the high-speed operation of the machine, the bearings of its main roll and line roll bear a great test, and are also the key components that have the greatest impact on the machine. Therefore, how to give an early warning of its health state before the failure occurs, so that engineers can timely intervene and repair the equipment during the working interval. The above problems of aluminum alloy cable connection and utilization have become the key to avoid economic losses and ensure production

Figure 9 - predictive maintenance based on cluster analysis

as shown in Figure 9, based on years of accumulated industry expert knowledge, first of all, appropriate feature extraction is carried out on the data of multiple devices to extract the most relevant information about the health status of the devices in the data. Then, the artificial intelligence algorithm is used to automatically cluster the data, so that the data with similar characteristics are clustered into one cluster, while the data with different characteristics are clustered into different clusters. It is natural to infer that among many similar types of devices, most of them are healthy and have similar data characteristics. Therefore, clusters with a large number of sample points in the clustering results can be regarded as healthy clusters. Those samples that are free from the healthy cluster and small clusters composed of a small number of points indicate the abnormal working state of the equipment

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