A Textile Mill in Suzhou
The specialized yarns produced by this mill include ultra-high-strength yarn, high-modulus low-shrinkage yarn, low-shrinkage and ultra-low-shrinkage yarn, anti-wicking yarn, activated yarn, wear-resistant yarn, colored yarn and flame-retardant yarn. These products are mainly used in sunshades, conveyor belts, geotextiles, high-pressure hoses, grids, ropes, safety belts, sewing threads, tarpaulins, textiles, tire cords and woven tapes.
Both the winding machines and twisting machines in the workshop are driven by frequency conversion devices to maximize the operational efficiency of the production line. However, the operation of these frequency conversion devices generates a large amount of harmonic current components, which are directly injected into the power supply system. This leads to distortion of the system voltage waveform, impairs power supply quality, causes additional noise and vibration of the equipment, and may even affect the normal operation of the production line.
Figure 1: Textile Mill Production Workshop
The recommended solution is to install one set of NCSF 5th Harmonic Filter and one set of NCSD Tuned Filter, so as to reduce the total harmonic voltage distortion rate, improve the system power factor, and enhance the power quality and reliability 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 lowers harmonic losses in the system
Figure 2: Cabinet Diagram of NCSF Harmonic Filter
Key Features of NCSD Tuned Filter
- Compensates for the system power factor
- Can effectively prevent the occurrence of system harmonic resonance
- Equipped with an automatic power factor controller, which allows stepwise switching and outputs reactive power according to the system's demand
Figure 3: Cabinet Diagram of NCSD Tuned Filter
Since the harmonic filters were put into operation on December 9, 2011, they have significantly mitigated the 5th harmonic currents and harmonic voltages of the system while reducing the harmonic losses 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 4: System Voltage and Current Waveforms (Before Improvement)
Figure 5: System Voltage and Current Waveforms (After Improvement)
Figure 6: Time-Lapse Graph of Total Harmonic Current Distortion Rate (Before & After Improvement)