A Chemical Plant in Ningbo
Established in 2006, it has achieved internationally advanced levels in product quality and unit consumption. It is mainly engaged in the R&D of a full range of polyurethane products such as isocyanates and polyols, petrochemical products such as acrylic acid and its esters, functional materials such as water-based coatings, and specialty chemicals. It is one of the world’s most competitive MDI manufacturers and also Europe’s largest TDI supplier.
The frequency conversion devices driving the compressors in the workshop generate a large amount of harmonic currents, leading to severe distortion of the power supply voltage waveform. In addition, the massive harmonic currents flowing through cables and transformers not only cause extra harmonic losses and temperature rise issues, but also reduce the service life of equipment and power supply reliability.
Figure 1: Chemical Plant Park
The recommended solution is to install one set of NCSA Active Harmonic Filter on each circuit and adopt the selective harmonic elimination mode to mitigate the 5th harmonic currents of the system. This solution can effectively reduce the total harmonic voltage distortion rate of the power supply system, improve the system power quality, and simultaneously alleviate issues such as harmonic losses and equipment temperature rise.
Key Features of NCSA Active Harmonic Filter
- Filters out system harmonics, suitable for various harmonic environments with no overload issues
- Fast dynamic compensation response time ≤ 20 ms
- Multiple harmonic filtering modes and compensation functions available
- Capable of full-load output current
- High-reliability IGBT protection architecture with excellent stability
- Touch-screen graphical human-machine interface for easy operation
Figure 2: On-site Installation Physical Diagram of NCSA Active Harmonic Filter
Since the NCSA Active Harmonic Filters were put into operation on March 20, 2012, they have significantly reduced the total harmonic voltage distortion rate 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)