Active power filters can be widely used in industrial, commercial and institutional distribution networks, such as: power systems, electrolytic plating enterprises, water treatment equipment, petrochemical enterprises, large shopping malls and office buildings, precision electronics enterprises, airport/port power supply systems, medical institutions, etc. According to the different application objects, the application of active power filter will play a role in ensuring the reliability of power supply, reducing interference, improving product quality, increasing equipment life and reducing equipment damage.
1.Communication industry
In order to meet the operation requirements of large-scale data centers, the capacity of UPS in the communication and distribution system is increasing significantly. According to the survey, the main harmonic source equipment of the communication low-voltage distribution system is UPS, switching power supply, frequency conversion air conditioning and so on. The harmonic content is high, and the displacement power factor of these harmonic source devices is very high. Through the use of active filter can improve the stability of communication system and power distribution system, extend the service life of communication equipment and power equipment, and make the power distribution system more in line with the design specifications of harmonic environment.
2.Semiconductor industry
The 3rd harmonic in most semiconductor industries is very serious, mainly due to the large number of single-phase rectification equipment used in enterprises. The third harmonic belongs to zero sequence harmonics, which has the characteristics of gathering in the neutral line, resulting in excessive pressure on the neutral line, and even ignition phenomenon, which has great hidden dangers in production safety. Harmonics can also cause circuit breakers to trip, delaying production time. The third harmonic forms a circulation in the transformer and accelerates the aging of the transformer. Serious harmonic pollution will inevitably affect the service efficiency and life of the equipment in the power distribution system.
3.Petrochemical industry
Due to the needs of production, there are a large number of pump loads in the petrochemical industry, and many pump loads are equipped with inverters. The application of frequency converter greatly increases the harmonic content in power distribution system in petrochemical industry. Most of the inverter rectification links are the application of 6 pulses to convert AC to DC, so the harmonics generated are mainly 5, 7, 11 times. Its main hazards are the hazards to power equipment and the deviation in measurement. The use of active filter can be a good solution to this problem.
4.Chemical fiber industry
In order to greatly improve the melting rate, improve the melting quality of glass, as well as extend the furnace life and save energy, electric melting heating equipment is commonly used in the chemical fiber industry, and electricity is directly sent into the glass tank kiln heated by fuel with the help of electrodes. These devices will produce a large number of harmonics, and the spectrum and amplitude of the three-phase harmonics are quite different.
5.Steel/medium frequency heating industry
Intermediate frequency furnace, rolling mill, electric arc furnace and other equipment commonly used in the steel industry will have a significant impact on the power quality of the power grid, so that the capacitor compensation cabinet overload protection action is frequent, the transformer and the power supply line heat is serious, the fuse is frequently blown, and even cause voltage drop, flicker.
6.Automobile manufacturing industry
Welding machine is an indispensable equipment in the automobile manufacturing industry, because the welding machine has the characteristics of randomness, fast and impact, so that a large number of welding machines cause serious power quality problems, resulting in unstable welding quality, robots with a high degree of automation can not work due to voltage instability, reactive power compensation system can not be used normally.
7.Harmonic control of DC motor
Large DC airports need to convert AC to DC through rectifier equipment first, because the load capacity of such projects is large, so there is serious harmonic pollution on the AC side, resulting in voltage distortion, and serious accidents.
8.Use of automated production lines and precision equipment
In the automatic production line and precision equipment, harmonics will affect its normal use, so that intelligent control system, PLC system, etc., failure.
9.Hospital system
Hospitals have very strict requirements on the continuity and reliability of power supply. The automatic power supply restoration time of Class 0 places is T≤15S, the automatic power supply restoration time of Class 1 places is 0.5S≤T≤15S, the automatic power supply restoration time of class 2 places is T≤0.5S, and the total harmonic distortion rate of voltage THDu is ≤3%. X-ray machines, CT machines, and nuclear magnetic resonance are all loads with extremely high harmonic content.
10.Theater/Gymnasium
Thyristor dimming system, large LED equipment and so on are harmonic sources, in the operation process will produce a large number of third harmonic, not only cause the power distribution system of the power equipment inefficiency, but also cause light strobe, communication, cable TV and other weak electrical circuit noise, and even produce failure.
Post time: Jul-17-2023