Nei moderni impianti industriali, soprattutto i settori manifatturieri ad alta intensità energetica come la produzione di silicio monocristallino, il mantenimento di un'elevata qualità dell'energia è fondamentale per l'affidabilità operativa, efficienza energetica, and equipment longevity. As production automation and power electronics become increasingly prevalent, harmonic pollution has emerged as one of the most challenging power quality issues.
Al CoEpower, we recently completed a successful harmonic mitigation project for a leading monocrystalline silicon manufacturer located in Ningxia, Cina. By deploying our CoEpo-APF-1200/0.4 Filtro di potenza attivo, we significantly reduced harmonic distortion, restored stable operation of the compensation system, and improved overall electrical performance.
This article presents the project background, challenges, progettazione della soluzione, commissioning results, and lessons learned from the field.
Sfondo del progetto
The customer operates a large-scale monocrystalline silicon manufacturing facility. The production process relies heavily on monocrystalline furnaces, which are nonlinear loads that generate substantial harmonic currents.
During routine power quality inspections, the customer discovered severe harmonic distortion throughout the low-voltage distribution network. The existing passive compensation system frequently malfunctioned and was unable to provide effective reactive power compensation due to harmonic resonance issues.
According to on-site measurements, the primary affected equipment was a:
- 3150 trasformatore kVA
- 10 kV / 0.4 kV distribution system
- Multiple monocrystalline silicon furnaces
The customer required an immediate and reliable solution capable of:
- Reducing harmonic distortion
- Protecting electrical equipment
- Restoring capacitor bank operation
- Migliorare il fattore di potenza
- Ensuring compliance with power quality standards
Why Harmonics Are a Serious Problem in Silicon Manufacturing
Monocrystalline silicon production facilities utilize a large number of:
- Drive di frequenza variabile (Vfds)
- Raddrizzatori
- Power electronic converters
- High-power heating equipment
Questi dispositivi prelevano correnti non sinusoidali dalla rete, creating harmonics that can lead to:
Surriscaldamento del trasformatore
Excessive harmonic currents increase copper and iron losses, reducing transformer life expectancy.
Capacitor Failures
Capacitor banks may resonate with system inductance, causing overheating and frequent tripping.
Equipment Malfunctions
Sensitive control systems can experience false triggering, communication failures, and unexpected shutdowns.
Increased Energy Losses
Higher harmonic content results in additional system losses and reduced energy efficiency.
Poor Power Factor
Harmonics distort current waveforms, negatively affecting apparent power and increasing utility penalties.
For this Ningxia project, harmonic levels had already reached a point where the existing compensation system could no longer operate reliably.
CoEpower Solution Design
After conducting a comprehensive site survey and power quality analysis, our engineering team recommended the installation of a high-capacity active harmonic filtering system.
Attrezzatura installata
| Parameter | Specification |
| Product Model | CoEpo-APF-1200/0.4 |
| Capacità di compensazione totale | 1200UN |
| Installation Quantity | 1 Cabinet |
| Transformer Capacity | 3150 kva |
| Tensione del sistema | 400V |
| Posizione di installazione | Behind Compensation Cabinet |
The APF cabinet dimensions were:
1200mm × 1000mm × 2200mm
The solution was designed to dynamically detect and compensate harmonic currents in real time, ensuring continuous power quality improvement under varying load conditions.
How Active Power Filters Work
Unlike traditional passive filters that target specific harmonic frequencies, Active Power Filters continuously monitor the electrical system and inject equal but opposite harmonic currents.
This process effectively cancels unwanted harmonics before they propagate through the network.
Key advantages include:
- Compensazione armonica in tempo reale
- Dynamic load adaptation
- No resonance risk
- Simultaneous reactive power compensation
- Reduced maintenance requirements
- Affidabilità del sistema migliorata
For facilities with rapidly changing production loads, APFs are often the preferred solution compared to passive filtering technologies.
Installation and Commissioning
The commissioning process was carried out under normal production conditions to ensure accurate performance evaluation.
Test Equipment
The measurements were conducted using a:
FLUKE 435-II Power Quality Analyzer
Key specifications included:
- CEI 61000-4-30 Class A compliance
- Precisione della tensione: 0.1%
- Precisione attuale: 0.5%
- Comprehensive harmonic analysis capability
The testing location was the incoming distribution cabinet, allowing us to evaluate overall system performance before and after APF activation.
Harmonic Mitigation Results
The commissioning data demonstrated substantial improvements in both current and voltage quality.
Current THD Reduction
Prima del risarcimento
Current Total Harmonic Distortion (Thd):
28.9%
Dopo il risarcimento
Current Total Harmonic Distortion (Thd):
5.2%
This represents an approximate:
82% reduction in current harmonic distortion.
Voltage Quality Improvement
Before APF Operation
Voltage THD:
6.3%
After APF Operation
Voltage THD:
5.2%
Although voltage distortion was less severe than current distortion, the APF still produced a measurable improvement in voltage waveform quality.
Harmonic Order Analysis
The most dominant harmonics observed on-site were the:
- 5th armonica
- 7th armonica
- 11th armonica
The APF effectively suppressed these components.
| Harmonic Order | Prima dell'APF | Dopo l'APF | Reduction |
| 5th | 398.3 UN | 19.6 UN | 95% |
| 7th | 169 UN | 12.5 UN | 92.6% |
| 11th | 123.9 UN | 10.5 UN | 91.5% |
The reduction of these dominant harmonics significantly improved overall system stability and reduced electrical stress on transformers and capacitor banks.
Waveform Improvement
One of the most visible indicators of APF effectiveness was the transformation of system waveforms.
Prima del risarcimento:
- Grave distorsione della forma d’onda
- Significant harmonic content
- Increased electrical stress
After compensation:
- Waveforms became nearly sinusoidal
- Lower distortion levels
- Improved power transmission efficiency
This improvement directly contributes to longer equipment lifespan and reduced maintenance costs.
Power Factor Optimization
In addition to harmonic mitigation, the APF system was configured to provide reactive power compensation.
After enabling compensation mode:
Power Factor Achieved
PF = 1.0
Achieving unity power factor provides several benefits:
- Sanzioni di utilità ridotte
- Improved transformer utilization
- Lower system losses
- Increased electrical efficiency
- Better voltage regulation
For industrial users with high monthly energy consumption, even small improvements in power factor can generate substantial cost savings over time.
Vantaggi del cliente
Following commissioning, the customer experienced several immediate advantages:
Improved Production Reliability
Reduced harmonic interference minimized risks of unexpected equipment shutdowns.
Enhanced Equipment Protection
Lower harmonic currents reduced thermal stress on transformers, Cavi, e quadri.
Stable Capacitor Operation
The existing compensation system could now operate without resonance-related failures.
Costi di manutenzione ridotti
Cleaner power quality translates into longer equipment life and fewer repairs.
Future Expansion Readiness
The APF provides dynamic compensation capable of adapting to future production growth.
Conclusione
This project demonstrates how advanced Active Power Filter technology can effectively solve severe harmonic problems in high-energy industrial applications such as monocrystalline silicon manufacturing.
By installing the CoEpower CoEpo-APF-1200/0.4 Active Power Filter, the Ningxia facility achieved:
✔ Current THD reduced from 28.9% A 5.2%
✔ Voltage THD reduced from 6.3% A 5.2%
✔ 5th harmonic reduced by 95%
✔ Power factor improved to 1.0
✔ Near-sinusoidal current and voltage waveforms
✔ Reliable operation of the compensation system
As industries continue adopting more power electronic equipment, harmonic mitigation will become increasingly important for maintaining power quality and operational efficiency. CoEpower remains committed to delivering innovative APF solutions that help industrial customers achieve safer, cleaner, and more reliable electrical systems.
A proposito di CoEpower
CoEpower specializes in power quality solutions including:
- Active Power Filters (APF)
- Generatori Var statici (Svg)
- Filtri armonici ibridi
- Sistemi di rifasamento
- Energy Efficiency Solutions
Se la tua struttura presenta una distorsione armonica, guasti ai condensatori, transformer overheating, or poor power factor, contact CoEpower’s engineering team to discuss a customized power quality improvement solution.
Tag：
Filtro di potenza attivo, APF Solution, Mitigazione armonica, Filtro armonico, Miglioramento della qualità dell'energia, Monocrystalline Silicon Manufacturing, Industrial Harmonics, Correzione del fattore di potenza, CoEpower APF, Riduzione della distorsione armonica, Electrical Energy Efficiency, Industrial Power System, CEI 61000-4-30, Compensazione armonica, Power Quality Case Study, Fornitori, produttori, fabbrica, azienda, Cina, all'ingrosso, acquistare, prezzo, preventivo, massa, in vendita, aziende, azione, costo.
