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)

(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