Custom-Engineered 6, 12 & 24-Pulse Solutions for Industrial Rectifier Systems

Our dry-type phase-shift rectifier transformers are engineered to deliver stable, low-harmonic DC power for demanding industrial environments. Available in 6-pulse, 12-pulse, and 24-pulse configurations, each unit is fully customized to match rectifier system requirements in industries such as aluminum smelting, chlor-alkali electrolysis, rail transit traction, and renewable energy conversion.

Unlike standard power transformers, phase-shift rectifier transformers require precise vector group design and controlled phase displacement to suppress harmonic distortion generated by rectifier bridges. We collaborate closely with EPC contractors, system integrators, and end users to ensure seamless integration with existing or new rectifier systems.

Advantages of Dry-Type Phase-Shift Rectifier Transformers

Dry-type technology provides a safer and more practical solution for indoor and environmentally sensitive installations compared to oil-immersed transformers.

It eliminates fire and explosion risks by removing insulating oil, reducing the need for fire suppression systems and containment infrastructure. Maintenance requirements are significantly reduced since there is no oil aging, leakage, or sampling required.

The design is environmentally friendly, avoiding soil and groundwater contamination risks, while also offering a compact footprint suitable for space-constrained substations. Installation is faster due to reduced civil engineering work.

Key Technical Features

Each transformer is engineered according to project-specific requirements. Typical configurations include:

Pulse Configuration: 6-pulse / 12-pulse / 24-pulse with custom vector groups
Cooling Method: AN (Air Natural) / AF (Air Forced)
Insulation Class: F or H (155°C / 180°C)
Voltage Class: Typically 6kV–35kV primary
Winding Material: Copper or aluminum
Standards: IEC 60076 series, IEEE C57.18.10, or customized standards
Harmonic Performance: Optimized THD reduction based on rectifier system design

All parameters are finalized after detailed engineering review to ensure optimal performance in real operating conditions.

Engineering Design Highlights

Precision Phase Displacement Design

Each winding group is carefully engineered with accurate phase-shift angles (commonly 7.5° or 15° depending on pulse configuration) to achieve effective harmonic cancellation in multi-pulse rectifier systems.

Optimized Impedance Matching

Short-circuit impedance is precisely controlled across all windings to ensure balanced load sharing between rectifier bridges, improving system stability and operational reliability.

High Mechanical Strength Construction

Windings are vacuum pressure impregnated (VPI) or cast-resin encapsulated depending on application needs, providing excellent resistance to harmonic forces, thermal stress, and load fluctuations.

Advanced Thermal Management

Class F or H insulation systems combined with optimized air duct design ensure stable operation under continuous high-current rectifier duty cycles.

Typical Applications

Dry-type phase-shift rectifier transformers are widely used in high-power industrial DC supply systems, including:

Non-ferrous metal electrolysis such as aluminum, zinc, and copper smelting requiring high-current DC output
Chlor-alkali chemical production and electroplating processes
Rail transit traction substations for metro and light rail systems
Large-scale renewable energy conversion systems and power electronics interfaces
Industrial VFD front-end rectification for high-power motor drives
HVDC test platforms and power electronics laboratories

Manufacturing & Quality Assurance

Each transformer undergoes a strict quality control process to ensure compliance with international standards and project specifications.

Design verification ensures all electrical and mechanical parameters meet system requirements. Incoming materials such as electrical steel, copper/aluminum conductors, and insulation systems are inspected before production.

During manufacturing, winding, impregnation, and assembly processes are continuously monitored. Routine tests include winding resistance, transformation ratio, polarity verification, insulation resistance, and dielectric withstand tests.

Type testing, including temperature rise and impulse withstand tests, is available upon request. Factory Acceptance Tests (FAT) can be witnessed by customers or third-party inspectors.

Engineering Support & Customization

We provide full engineering support throughout the project lifecycle to ensure optimal transformer-system compatibility.

Services include technical specification review, harmonic analysis coordination with rectifier suppliers, customized enclosure design (IP20–IP54), and special adaptations for high altitude, high humidity, or extreme temperature environments.

We also support third-party inspection coordination and provide complete documentation packages including test reports, drawings, and installation manuals.

Get a Custom Technical Proposal

Every rectifier system has unique requirements. To receive a tailored solution, please provide system parameters such as pulse number, DC voltage and current, and installation conditions. Our engineering team will deliver a customized technical proposal and quotation optimized for your application.