In the modern era of complex industrial electronics and nonlinear loads, power quality issues such as harmonics are increasingly problematic. To combat these disturbances, two primary technologies are commonly used: Active Harmonic Filters (AHF) and traditional passive filters. At Sinava, we explore how AHFs offer a smarter, more dynamic solution in comparison to their passive counterparts.
1. Working Principle
Traditional Passive Filters work by using LC components (inductors and capacitors) to form resonant circuits tuned to specific harmonic frequencies. They suppress harmonics by providing low impedance paths for these frequencies. However, this method is static and fixed, effective only for specific harmonic orders and conditions.
Active Harmonic Filters (AHF) are based on power electronics. They detect system harmonics in real-time and generate an equal but opposite compensation current to cancel them out, achieving dynamic and precise filtering across a wide range of harmonic orders.
2. Active Harmonic Filter (AHF) vs Traditional Passive Filter
| Feature | Active Harmonic Filter (AHF) | Traditional Passive Filter |
| Working Principle | Real-time detection and active cancellation of harmonics | Resonant circuit using fixed LC components |
| Harmonic Compensation | Wide range (2nd–50th), dynamic adjustment | Fixed harmonic orders (e.g., 5th, 7th, 11th) |
| Adaptability | High – adapts to varying loads and harmonic sources | Low – fixed tuning, not adaptive to load changes |
| Resonance Risk | None – avoids resonance altogether | High – may amplify harmonics through resonance |
| Reactive Power Control | Dynamic – supports real-time power factor correction | May cause over-compensation under light load |
| System Stability | Stable – independent of system parameters | Sensitive to system impedance and grid changes |
| Installation | Compact, modular, and easy to integrate | Requires tuning, more space, and manual setup |
| Maintenance | Low – minimal ongoing adjustment needed | High – needs periodic tuning and upgrades |
| Initial Cost | Higher | Lower |
| Long-Term Cost | More cost-effective due to efficiency and reduced downtime | May increase due to failures, inefficiency, or penalties |
3. Why Choose Sinava's AHF Solutions?
At Sinava, we are committed to providing professional, intelligent power quality solutions. Our Active Harmonic Filter products feature:
·Real-time harmonic monitoring
·Full-spectrum harmonic compensation
·Support for reactive power compensation
·Easy installation and flexible configuration
Whether for new power systems or upgrades of existing ones, Sinava’s AHF helps users effectively reduce harmonic pollution, improve power quality, and ensure the safe and efficient operation of electrical equipment.
Our suggestion:
For systems with frequent load changes and complex harmonic composition, such as hospitals, office buildings, and data centers, active harmonic filters are a more reliable and flexible choice.
If the load is stable and the budget is limited, passive filters can be prioritized as an economically efficient harmonic suppression solution.
If the load type includes both VFD and other nonlinear devices, it is recommended to adopt an "active+passive hybrid scheme" to improve system stability while achieving a balance between cost and performance.
Leading the future on behalf of Sinava
As a pioneer in the field of power system optimization, Sinava offers a full range of harmonic filtering solutions. Our service highlights:
·Comprehensive system evaluation and scheme design
·Flexible deployment and post expansion capabilities
·Technical support that meets international power grid standards
·Professional operation and maintenance team support and remote upgrade and maintenance
Contact us immediately and have Sinava's experts customize the optimal filtering solution for your power system to improve efficiency, reduce faults and energy consumption!
