As the maritime industry accelerates toward full electric propulsion, shipboard microgrids face an unprecedented threat. Variable Frequency Drives (VFDs) have become the core component of modern propulsion systems, offering precise control but introducing a critical side effect: Harmonic Distortion.
Due to the unidirectional conductivity of rectification devices, VFDs draw non-sinusoidal currents from the grid. These currents feed back into the power system, causing voltage drops across generators and transformers that distort the voltage waveform throughout the vessel. This distortion threatens the stability and safety of sensitive shipboard equipment.
For top-tier system integrators like ABB, the requirement is not just a voltage converter, but a marine drive transformer capable of "absorbing" harmonics and purifying the grid.
The Solution: Neutralizing Interference with Phase-Shifting Technology
CEEG's answer to this challenge is advanced Phase-Shifting RectifierTechnology.
Our expertise is built on years of collaboration with global leaders. CEEG leverages extensive experience cooperating with Siemens, Fuji, and ABB. We began developing 12-pulse and 24-pulse rectifier transformers in 2008, supplied marine dry-type transformers to ABB in 2008, and became an official qualified supplier in 2012.
To meet the rigorous demands of a converter duty transformer, we developed a specialized H-class marine phase shifting transformer. Our engineering approach utilizes a unique axially split design:
24-Pulse Rectification: The system utilizes a primary extended Delta (D) connection combined with two secondary output groups.
Precision Connec: By engineering a specific phase shift—D(+7.5∘)d0y11 and D(−7.5∘)d2y1—two transformers (or split windings) create a perfect 24-pulse rectification system. This ±7.5∘ shift effectively cancels out low-order harmonics, restoring power quality to the ship's grid.
The Reliability: The Fusion of Nomex® Insulation and VPI Technology
In harsh offshore environments, correct theory is not enough; equipment must withstand extreme heat and electrical stress.
Material Science: We utilize the DuPont Nomex® insulation system. While Nomex® is a C-class material capable of long-term operation at 220°C, CEEG designs its transformers to H-class standards (180°C), providing a massive thermal safety margin.
Electrical Performance: The low dielectric constant of Nomex® ensures a more uniform electric field distribution. This prevents partial discharge and ensures the transformer can withstand short-term operation at temperatures as high as 350°C without melting or supporting combustion.
Process Guarantee: We employ VPI (Vacuum Pressure Impregnation) technology. This process cures the coil into a solid, rigid mass, ensuring excellent heat dissipation and high mechanical strength to resist the intense vibrations of marine vessel operation.
Note: In 1999, CEEG pioneered the application of DuPont NOMEX® insulation paper in dry-type transformers and successfully developed its first VPI product line. In 2001, CEEG and DuPont signed a strategic partnership agreement. By 2004, CEEG VPI transformers had passed KEMA E2, C2, and F1 tests.
Built for Harsh Marine Environments: "Three-Proofing" and Advanced Cooling
The ocean environment is defined by high humidity, salt spray, and mold. CEEG’s shipboard transformer features a specialized "Three-Proofing" design. The main body is sprayed with TW32-4 organosilicon paint, and the enclosure and base use rigid connections to form a stable, vibration-resistant unit.
Beyond standard natural cooling (AN) and forced air (AF), CEEG is a pioneer in water-cooling technology. We began developing water-cooled marine transformers (AFWF transformer) in 2007. By 2010, we secured our first batch order for eight 1,600kVA water-cooled units.
These high-performance units are equipped with high-reliability German fans and advanced air-water coolers. With a protection rating as high as IP44, they solve the heat dissipation challenges of tight engine rooms while preventing the intrusion of water and foreign objects.
The Verdict: Global Recognition and Certified Quality
From standard marine distribution transformer units to complex offshore transformer systems and critical marine propulsion transformer solutions, CEEG has established a comprehensive maritime power portfolio.
We have formed stable supply relationships with multiple international leaders, including long-term supply agreements with ABB. Our brand is a passport to global markets, with products holding factory approval and type approval from virtually all major classification societies, including CCS, BV, DNVGL, ABS, LR, RINA, and NK.
Ready to Optimize Your Marine Power System?
Whether you require a customized marine phase shifting transformer solution, high-reliability AFWF transformers, or regular marine distribution transformers, CEEG's engineering team is ready to serve.
Contact Our Marine Power Experts: yz@ceeg.cn
ABB's Heads of Global Supply Chain Management and Mr. Xu, President of ABB Purchasing in Beijing, visited CEEG In 2017
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