Load characteristics
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In recent years, various crystal materials, especially high-tech value-added materials represented by monocrystalline silicon, ingot silicon and high-purity silicon, and the related high-tech industries have become the pillar of the contemporary information technology industry, and the information industry Become the fastest growing leading industry in the global economic development. Common load furnace type are: single crystal furnace, vacuum furnace, polycrystalline furnace, IF furnace. The production process is usually divided into melt heating and DC heating, melting more use of intermediate frequency heating furnace, Czochralski multi-use direct current furnace. However, both medium frequency furnace or single crystal furnace are semiconductor controlled rectifier, will produce a very large current harmonics, resulting in harmonic pollution of the power grid, making precise precision instrument precision misoperation or even malfunction, undermining the system reactive power compensation , Resulting in increased system power loss and damage compensation capacitors, etc., for the complicated production process of monocrystalline silicon and precision machining processes later have a very big impact, so the quality of the power grid indirectly determines the quality of finished products, almost all of the single Crystallization of silicon production lines are facing harmonic problems.
■ crystal furnace
● load characteristics
◆ load harmonic content. The total distortion is as high as 30%, but mainly in 5,7,11,13,17,19 times, of which 5,7,11 times again the most serious.
◆ belong to the volatility of load, rapid fluctuations frequently; the use of traditional passive filters simply can not meet the requirements of fast tracking;
◆ low power factor, generally about 0.8;
■ IF furnace
● load characteristics
◆ load harmonic content, the total distortion up to 30% or more;
◆ Basically belongs to the stable load, only when it comes out, fluctuates when the temperature rises, the harmonics mainly concentrates in 5, 7, 11, 13, 17, 19, 23 times, among them the most serious
◆ IF furnace typically runs at 1KHz ~ 2KHz, so a wide range of spectral harmonics, not only the presence of a large number of low-order harmonics, such as 5,7,11 inferior, higher harmonics of more than 25 times abound, specific performance In the system voltage contains a large number of glitches;
◆ power factor is very low, generally around 0.7, facing a high reactive fine;
◆ Intermediate frequency power supply rectifier circuit before the commutation moment will have a great voltage gap, serious distortion, power supply poor quality;
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solution
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Adopting intelligent hybrid filter compensation device, the filter compensation module mainly absorbs the characteristic harmonic current, and most of the load harmonic current can be filtered out. APF module to offset the dynamic filter compensation module after filtering the remaining harmonics, to achieve fast and efficient precision filtering; and filter compensation module reactive power fine-tuning function to achieve two-way continuous single-phase high-efficiency reactive power compensation will be Will receive good results
