Load characteristics
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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 frequency converters. The large number of applications of frequency changer makes the harmonic content in the distribution system of petrochemical industry greatly increase. At present, most of the inverter commutation part is the application of 6-pulse rectifier to convert AC to DC, so the resulting harmonics to 5 times, 7 times, 11th harmonic-based.
Harm in the petrochemical industry
Harm of the harmonic in the petrochemical system is mainly manifested in the harm to the electric equipment as well as the measurement deviation. Research shows that the harmonic current can cause additional losses in the transformer, causing overheating, accelerating the aging of the dielectric and causing dielectric breakdown. The presence of harmonics will increase the apparent power. The relationship between apparent power S and active power P and reactive power Q is not considered harmonic; in the case of harmonics, the harmonic power D must be considered, and the relationship is as follows; while D and Q are the same, Can not be transformed into useful work. Thus, the harmonics have a significant negative impact on the efficiency of the transformer. At the same time, harmonics have a direct negative impact on the capacitors, circuit breakers, and relay protection equipment in the power system. For many meters, the true rms value is not measured but the average is measured. The hypothetical waveform is then a sine wave multiplied by a correction factor to get the reading. In severe harmonic, such readings will have greater deviation, resulting in measurement error.
Laboratory and automated production lines
Harmonic impact on precision equipment
In the laboratory or automated production line of electricity applications, there are a large number of sophisticated equipment. In many cases, these devices are both generators of harmonics and victims of harmonics. Harmonic wave will affect the normal operation of the equipment in the laboratory, making the ongoing experiment fall short; Harmonic will also affect the automation production line intelligent controller, PLC system, so that automation control equipment failure.
In many national laboratories, automatic production lines of tobacco companies and automatic production lines of paper companies have experienced equipment failures due to the effects of harmonics.
solution
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● Use LSDTSC dynamic compensation device, safe upgrade power factor
● LDIPF active filter part of the dynamic phase-compensation capacity of reactive power
Description: Reactive power compensation scheme design, can be based on the active part of the passive part of the capacity allocation, flexible configuration. If the active part of the bidirectional compensation reactive capacity sufficient to adjust dynamically changing reactive power, consider the use of static safety compensation device.
