A Paper Mill in Hainan
Covering an area of 8,000 mu, this mill broke ground in May 2003 and commenced trial production in November 2004. Its primary product is chemically bleached kraft eucalyptus pulp.
A large number of frequency conversion devices are adopted in various sections of the 690 V pulping workshop, including chipping, cooking, washing, deaeration and bleaching processes. This has led to an increase in the total harmonic voltage distortion rate and total harmonic current distortion rate of the power supply system, resulting in additional harmonic losses and temperature rise of the equipment, which will shorten the service life of production equipment and increase equipment maintenance costs.
Figure 1: Pulping Workshop of the Paper Mill
The recommended solution is to install two sets of NCSF 5th Harmonic Filters to mitigate the 5th harmonic currents of the system and improve the power quality of the power supply system.
Key Features of NCSF Harmonic Filter
- Significantly reduces the harmonic current content and harmonic voltage distortion rate of the system
- Achieves an improvement effect of over 80% for targeted specific harmonics
- Compensates for the system's reactive power and improves the power factor
- Effectively reduces harmonic losses in the system
Since the harmonic filters were put into operation on September 3, 2012, they have significantly mitigated the 5th harmonic currents and harmonic voltages of the system. The power quality measurement data of the system main circuit before and after the improvement are summarized in Table 1.
Table 1: Summary of System Improvement Effects (Before & After)
Figure 3: System Voltage and Current Waveforms (Before Improvement)
Figure 4: System Voltage and Current Waveforms (After Improvement)
Figure 5: Time-Lapse Graph of Total Harmonic Current Distortion Rate (Before & After Improvement)