Low-Voltage Dynamic Filtering & Compensation Device Harmonic Mitigation Solutions

Product Overview

The RWTSF Series Low-Voltage Dynamic Filtering and Compensation Device is designed to address complex power quality challenges commonly found in modern industrial electrical networks. By integrating advanced power electronics technology with intelligent control algorithms, the system effectively resolves switching issues associated with capacitor compensation under harmonic distortion conditions. It dynamically suppresses or mitigates harmonic currents according to real operating conditions, purifies the power distribution network, and enhances the power factor.
This series is widely recognized for its technical sophistication, reliability, and suitability for a broad range of low-voltage harmonic governance applications.

Working Principle

The RWTSF device consists of several main functional modules, including the monitoring unit, switching elements, filter capacitors, reactors, protection components, and the intelligent control system.
Its operating logic is based on real-time detection of network harmonic content and reactive power demand. Through harmonic current sampling, frequency identification, and dynamic judgment algorithms, the controller determines the required filtering steps and reactive compensation levels.
The device then performs fast, smooth, and zero-impact switching via the dedicated zero-crossing switching module to ensure stable and precise harmonic suppression under various operating conditions.

A typical filter branch is tuned to specific harmonic orders, such as 3rd (150Hz), 5th (250Hz), 7th (350Hz), 11th (550Hz), and 13th (650Hz), depending on the application environment.
The RWTSF system connects in parallel with the load and ensures real-time filtering performance.

• Zero-Impact Switching：Utilizes high-power thyristor zero-crossing switching technology to achieve soft switching without inrush current or overvoltage. The device ensures smooth, stable operation without causing system disturbances.

•  Ultra-Fast Dynamic Response：Dynamic response time is shorter than 20ms. It quickly tracks network load fluctuations and provides real-time compensation to maintain stable power quality.

• Intelligent Control Logic：Based on advanced DSP digital control, the system completes data acquisition, power quality computation, and control command execution within 10ms. Real-time monitoring and digital management enable precise remote communication and smooth network integration.

• Comprehensive Protection Functions：Equipped with multiple safety mechanisms including overcurrent protection, overload protection, overvoltage protection, short-circuit protection, module overheating protection, and branch fuse protection. These ensure long-term stability and system safety.

•  Real-Time Display & Monitoring：Displays key parameters such as voltage, current, reactive power, active power, power factor, harmonic data, and branch operating status.

• Tuned Filter Bank Design：Each filter branch adopts a tuned capacitor–reactor structure to target specific harmonic orders.

Technical Specifications

• Rated Voltage: 220V, 400V, 690V, 770V, 1140V

• Rated Frequency: 50Hz / 60Hz

• Dynamic Response Time: < 20ms

• Harmonic Filtering Range: 1st–50th harmonic

• Achievable Power Factor: ≥ 0.92–0.95 adjustable

• Harmonic Reduction Performance: Compliant with GB/T 14549-1993 (Power Quality – Harmonics)

• Filtering Targets: 3rd, 5th, 7th, 11th, 13th, 17th, 19th, 23rd harmonic orders

• Thermal Stability: Meets GB12326-1990 standards

• Capacitor Discharge Performance: 70% within 5 seconds, 75% within 2 seconds (typical values)

• Protection Level: IP2X

Application Fields

Suitable for environments where low-voltage systems experience severe harmonic pollution and fluctuating reactive power demand, including:

• Arc furnaces & induction melting systems：Characterized by large fluctuations, three-phase imbalance, and significant harmonic generation (3rd, 5th, 7th, 11th, 13th).

• Electric arc furnaces, refining furnaces, and ladle furnaces：Heavy fluctuating loads with high harmonic content.

• Large rolling mills and metallurgical equipment：Nonlinear loads generating 5th, 7th, 11th harmonic distortion.

• Cement plants, mining operations, conveyors, crushers, grinders：With strong shock loads and frequent operational fluctuations.

• Chemical and pharmaceutical industries：Rich in rectifier loads, inverters, soft starters, and nonlinear equipment.

• Textile and manufacturing plants：Multiple motor drives with poor power factor and high harmonic currents.

• Industrial UPS systems, data centers, and information processing lines：Sensitive loads prone to harmonic interference.

• Municipal facilities, commercial complexes, and public buildings：Where power quality directly affects service reliability.

Environmental Conditions

• Operating Temperature: –25°C to +45°C

• Relative Humidity: ≤ 95% (at 25°C)

• Altitude: ≤ 2000m

• Installation Site Requirements:

Indoor environment

Free from severe vibration or impact

Non-explosive atmosphere

No corrosive gases or conductive dust

Technical Services

• On-site harmonic measurements and detailed analysis reports

• Customized harmonic mitigation and power factor compensation plans

• System-level power quality testing

• Optimization recommendations for filtering schemes

• Technical support throughout installation, commissioning, and long-term operation

Required Ordering Information

To ensure correct system configuration, the user should provide:

• Transformer capacity and secondary voltage

• Short-circuit current levels

• Load characteristics and operating patterns

• Voltage, current, and harmonic data (before installation)

• Target power factor requirements

• Compensation capacity required

• Site layout drawings and space dimensions

• Any special environmental or operational requirements