Passive Harmonic Filter & Reactive Compensation Device for Rolling Mills
Product Overview
The RMRFC-ZJ series passive harmonic filter and reactive compensation device is specially developed for heavy-load rolling applications. In cold rolling, hot rolling, aluminum oxidation, electrophoresis, and related production lines, severe harmonic currents are generated. These harmonics cause rapid insulation degradation of cables and motors, increased losses, reduced motor efficiency, transformer derating, and potential failures.
When user-side harmonic distortion causes supply-side voltage waveform THD to exceed national limits, electricity tariffs increase and in severe cases power supply may be restricted or even cut off. Therefore, both from the perspective of equipment protection and user economic benefits, harmonic suppression and power factor improvement are essential.
Technical Performance
Uses controllable switching devices to achieve fully automatic harmonic filtering without inrush current, no switching transients, no capacitor overvoltage, and no repeated excitation
Supports continuous frequent switching without affecting capacitor lifespan; fast response; minimal noise
Adopts dynamic compensation controller with reaction time < 20 ms
Provides over-voltage, over-current, and over-temperature protection; filters 5th, 7th, 11th, 13th and other typical rolling-mill harmonics
Ensures system harmonic distortion meets national grid limits; THDu can be reduced below regulated thresholds
Rated for 10 kV class harmonic environments; compliant with national standards
Improves system power factor to COSΦ ≥ 0.92 (or 0.95–0.99 with optimized configuration)
Compensation Modes
The device offers three harmonic-reactive compensation configurations optimized for rolling mill loads:
Three-phase common compensation
Suitable for systems with balanced three-phase loads
Provides the highest cost-performance ratio
Recommended for rolling equipment with uniform operating conditions
Three-phase separated compensation
Designed for systems with significant three-phase imbalance
Corrects harmonic deviation and uneven reactive demand on each phase
Ensures stable electrical performance under sudden load shocks
Mixed common + separated compensation
For rolling lines with both global and localized phase imbalance
Avoids over-investment while maximizing compensation accuracy
Widely used in large hot-rolling and cold-rolling mills
Device Composition
Harmonic filter capacitor bank (210V / 315V / 400V / 600V / 900V / 1300V)
High-quality filter reactor
Controllable switching module
Dynamic harmonic compensation controller
Protective components and signal modules
Equipment Description
Our low-voltage dynamic harmonic filtering and reactive compensation system is designed for rolling mills and heavy-impact loads below 10 kV. Rolling mills generate high levels of harmonic and reactive power fluctuations caused by:
Continuous variable-load motors
Reversing mills
Pickling lines
Aluminum oxidation lines
Electrophoretic coating lines
The RMRFC-ZJ device suppresses harmonics and reduces THDu according to GB/T 14549-93 standards. It significantly improves power quality, lowers system losses, increases production reliability, and reduces enterprise operating costs.
It is widely used in:
Steel rolling mills
Aluminum rolling and oxidation lines
Oil & petrochemical plants
Ports & shipyards
Large factories and industrial parks
Rolling line auxiliary equipment
The device ensures safe operation, reduces penalties from excessive harmonic injection, and prevents transformer derating caused by rolling mill loads.
National Harmonic Limit Reference (GB/T 14549)
| Rated Voltage (kV) | THD (%) | Max Single Harmonic (%) | Typical Harmonic Orders |
|---|---|---|---|
| 0.38 | 5.0 | 4.0 | 5, 7, 11 |
| 6/10 | 4.0 | 3.2 | 5, 7, 11, 13 |
| 35 | 2.0 | 1.6 | 5, 7, 11, 13 |
(Values taken from GB/T 14549 national harmonic emission limits)
Core Advantages
Effectively suppresses rolling-mill harmonics: 5th, 7th, 11th, 13th
Improves motor and transformer efficiency, extends insulation life
Prevents cable overheating, reduces losses, prevents derating
Eliminates nuisance tripping and improves production stability
Reduces penalties due to excessive harmonic injection
Ensures contract compliance and prevents power-supply restrictions
Enhances power factor, reduces electricity costs
Ordering Information
Please specify the following when ordering:
System rated voltage (0.38kV / 0.4kV / 0.66kV / 6kV / 10kV…)
Harmonic levels and required filtering percentage
Rolling-mill type (cold / hot / reversing / continuous)
Load rated capacity and motor models
Required compensation mode (common / separated / mixed)
Installation method and cabinet size requirements
Ambient temperature, humidity, and site conditions
