Oil-Immersed Rectifier Transformers for VFSR
09-12 2025 | By:
In the era of industrial automation, variable frequency speed regulation (VFSR) has become a cornerstone technology for optimizing energy efficiency and operational precision across industries. At the heart of reliable VFSR systems lies the
oil-immersed rectifier transformer—a critical component that converts alternating current (AC) to direct current (DC) while stabilizing voltage, ensuring smooth speed control of motors and equipment. As a leading manufacturer of power transformers,
ZTELEC YUGUANG Factory specializes in designing and producing high-performance oil-immersed rectifier transformers tailored for VFSR applications. With decades of engineering expertise, strict quality control, and adherence to global standards (IEC, ANSI, GB), ZTELEC YUGUANG’s transformers are trusted by industrial clients worldwide for durability, efficiency, and consistent performance.
ZTELEC YUGUANG Factory is not just a producer of transformers—it is an innovator in power conversion technology. Our state-of-the-art manufacturing facility spans over 50,000 square meters, equipped with advanced machinery for core cutting, coil winding, and vacuum oil impregnation. Every step of production is overseen by a team of 200+ certified engineers and technicians, ensuring that each transformer meets or exceeds international quality benchmarks.
What sets ZTELEC YUGUANG apart? We combine traditional craftsmanship with modern R&D: our in-house laboratory conducts rigorous testing (including temperature rise, short-circuit, and insulation resistance tests) to guarantee reliability. Additionally, we prioritize sustainability—our oil-immersed transformers use high-grade mineral oil with excellent thermal conductivity and fire resistance, reducing environmental impact while extending service life. For clients seeking tailored solutions, ZTELEC YUGUANG offers custom design services to match specific VFSR system requirements, from voltage ratings to environmental adaptability.
ZTELEC YUGUANG’s product line of oil-immersed rectifier transformers for VFSR covers a wide range of power capacities and voltage levels, catering to both small-scale machinery and large industrial drives. Below are the most commonly used models, with detailed specifications to help you select the right solution for your application:
Designed for medium-sized VFSR systems (e.g., conveyor belts, pumps in manufacturing plants), this model balances compact size with high efficiency.
Core Specifications:
- Rated Power: 800 kVA
- Primary Voltage: 10 kV (±5% tap range for voltage adjustment)
- Secondary Voltage: 0.4 kV (DC output after rectification)
- Frequency: 50/60 Hz (universal for global markets)
- Cooling Method: Oil-immersed natural cooling (ONAN)
- Insulation Class: Class A (max operating temperature: 105°C)
- Protection Degree: IP23 (dust-proof, protected against vertical water droplets)
- Efficiency: ≥97.5% (at full load)
- Short-Circuit Withstand Time: 2 seconds
Ideal for large industrial VFSR applications (e.g., steel rolling mills, large fans), this model delivers high power output with stable performance.
Core Specifications:
- Rated Power: 3000 kVA
- Primary Voltage: 35 kV (±2.5% tap range)
- Secondary Voltage: 6.3 kV / 0.4 kV (dual secondary windings for flexible DC output)
- Frequency: 50 Hz (optimized for industrial grids)
- Cooling Method: Oil-immersed forced air cooling (OFAF)
- Insulation Class: Class B (max operating temperature: 130°C)
- Protection Degree: IP33 (dust-proof, protected against water spray)
- Efficiency: ≥98.2% (at full load)
- Short-Circuit Withstand Time: 3 seconds
Engineered for high-voltage VFSR systems (e.g., large-scale water pumps in irrigation projects, heavy-duty compressors), this model is built for durability in harsh industrial environments.
Core Specifications:
- Rated Power: 6300 kVA
- Primary Voltage: 110 kV (±1.25% tap range for precise voltage regulation)
- Secondary Voltage: 35 kV / 10 kV (dual high-voltage secondary windings)
- Frequency: 50 Hz
- Cooling Method: Oil-immersed forced oil circulation with air cooling (ODAF)
- Insulation Class: Class H (max operating temperature: 180°C)
- Protection Degree: IP44 (dust-tight, protected against water splashing from all directions)
- Efficiency: ≥98.8% (at full load)
- Short-Circuit Withstand Time: 4 seconds
All ZTELEC YUGUANG oil-immersed rectifier transformers for VFSR include built-in safety features: temperature sensors (to trigger alarms on overheating), pressure relief valves (to prevent oil leakage), and surge arresters (to protect against voltage spikes). These features minimize downtime and extend the transformer’s service life to 25+ years.
ZTELEC YUGUANG’s oil-immersed rectifier transformers are versatile, supporting VFSR systems across diverse industries. Their ability to stabilize voltage, reduce harmonic distortion, and handle variable loads makes them indispensable for:
In steel and aluminum plants, VFSR systems control the speed of rolling mills, extrusion machines, and ventilation fans. ZTELEC YUGUANG’s transformers provide a steady DC power supply to these systems, ensuring uniform metal processing and reducing energy consumption by up to 30% compared to fixed-speed drives. For example, our ZY-OIRT-3000/35 model is widely used in hot rolling mills, where it withstands high temperatures and heavy load fluctuations.
Water pumps and blowers in treatment plants rely on VFSR to adjust flow rates based on demand. ZTELEC YUGUANG’s transformers (e.g., ZY-OIRT-6300/110) ensure reliable DC power for these systems, preventing pump damage from voltage instability and lowering operational costs. In large irrigation projects, these transformers also adapt to rural grid conditions, minimizing power loss during long-distance transmission.
In chemical plants, VFSR systems regulate the speed of mixers, compressors, and conveyor belts. ZTELEC YUGUANG’s oil-immersed transformers are designed to resist corrosion from chemical fumes and operate in high-humidity environments. The ZY-OIRT-800/10 model, for instance, is used in small-scale chemical reactors, where its compact size and IP23 protection make it suitable for indoor installations.
Mining equipment (e.g., crushers, hoists, and underground conveyors) requires robust VFSR systems to handle heavy loads. ZTELEC YUGUANG’s transformers (such as ZY-OIRT-3000/35) are built with reinforced casings and dust-proof IP33 protection, ensuring reliable performance in dusty, vibration-prone mining sites. Their high short-circuit withstand capacity also protects against power surges common in remote mining grids.
When selecting a transformer for your VFSR system, ZTELEC YUGUANG Factory offers unmatched advantages:
- Global Quality Standards: All transformers are certified to IEC 60076 (international standard for power transformers) and ANSI C57.12.00 (North American standard), ensuring compatibility with global industrial grids.
- Energy Efficiency: Our transformers exceed minimum efficiency requirements set by the EU’s ErP Directive and China’s GB 20052 standard, helping clients reduce carbon footprints and energy bills.
- Customization: We design transformers for unique VFSR needs—whether you require special voltage ratings, extreme temperature resistance (-40°C to 60°C), or explosion-proof enclosures for hazardous areas.
- After-Sales Support: ZTELEC YUGUANG provides 24/7 technical support, on-site installation, and annual maintenance services. Our global spare parts network ensures quick replacements, minimizing downtime.
- Cost-Effectiveness: By optimizing manufacturing processes and using high-quality, long-lasting materials, we offer competitive pricing without compromising on performance.
For industrial clients seeking reliable, efficient
oil-immersed rectifier transformers for variable frequency speed regulation,
ZTELEC YUGUANG Factory is the trusted partner. Our diverse product line, strict quality control, and customer-centric approach ensure that every transformer meets your VFSR system’s unique needs—whether for small-scale manufacturing or large industrial projects.
To learn more about our models, request a custom quote, or consult with our engineering team, visit ZTELEC YUGUANG’s official website or contact our sales team . We are committed to powering your industrial automation journey with innovative, durable transformer solutions.
