Introduction to the revolutionary 3D transformer technology

Technology Benefits

• Increased electricity savings, lower Total Owning Cost (TOC) and reduced CO2 emissions (in and energy saving models)
• More robust and durable
• Quieter
• Promotes better stability in electrical network

Technology History

In 1880, a European engineer and inventor theorized that the optimal three-phase transformer should have a symmetrical delta-shaped (3D) core. However, his theories could not be transformed into reality because there was no manufacturing technology available at the time that could make it commercially viable.

Technology Introduction

• The core:
  3D wound core
• The active part:
  3D wound core + coil winding
• The transformer: 3D energy saving
  oil-immersed hermetically sealed distribution transformer (outdoor installation)

• The 3D transformer has been commercially available in Europe since 2004 and is billed as the "transformers of the future"
• Thai Maxwell Electric (TME) began its 3D transformer development program in 2008 and is the first manufacturer in ASEAN to introduce the 3D energy saving oil-immersed distribution transformer in 2012
• The innovative 3D wound core can only be manufactured using the latest wound core technology (TME has employed similar wound core technology since 1979)
• The 3D transformer is also known as "Tri-dimensional wound core transformer" or "Triangular wound core transformer"

• The revolutionary 3D wound core
• The conventional stacked core

Technology Highlights

Better core construction

• 3D wound core - Continuously wound 1-piece core ring assembled using automatic winding machine (negligible number of joints and air gaps present results in low stray magnetic loss). 3 identical core rings are combined to make a 3 phase core.
• Stacked core - Comprises of 3 core limbs & 2 yokes assembled together to make a complete 3 phase core (numerous number of joints and air gaps present results in higher stray magnetic loss).
• 3D wound core – Each core ring limb resembles a semi-circle allowing 2 core ring limbs of equal cross section to combine to make a core limb. Cross section of core limbs takes closer shape of a circle, with a higher filling factor of approx. 98% resulting in magnetic flux being almost fully utilized.
• Stacked core - Cross section of core limbs are stacked type, with a lower filling factor of approx. 93% resulting in magnetic flux not being fully utilized.

Better core construction

• 3D wound core - Core limbs are in symmetrical delta shape (symmetrical 3 phase magnetic circuit) resulting in optimized magnetic flux distribution.
• Stacked core - Core limbs are not in symmetry (non-symmetrical 3 phase magnetic circuit) resulting in under optimized magnetic flux distribution.
• 3D wound core - The different magnetic path directions (red arrow)of both core ring limbs that make a core limb combine to achieve zero vector sum for the magnetic flux (green arrow) , resulting in magnetic flux being balanced in each phase.
  Magnetic path of 3 phases are of equal distance(red arrows) , resulting in 3 phases having better balanced magnetic circuits and reduced exciting currents.
• Stacked core - The stacked core design is unable to achieve zero vector sum for magnetic flux, hence magnetic flux is distorted in the direction of silicon steel resulting in magnetic flux not being fully utilized.
  Magnetic path of 3 phases are of unequal distance (red arrows – magnetic path A and C are longer than magnetic path B), resulting in 3 phases having unbalanced magnetic circuits and higher exciting currents.

Technology Advantages

The revolutionary 3D wound core is the ideal transformer technology. It offers

• Balanced magnetic circuits and exciting current in all 3 phases
• Lower no-load losses
• Reduced vibrations
• Reduced in-rush currents
• Better short circuit withstanding capability
• Reduced exciting (a.k.a. reactive or no-load) currents

Reduced 3rd harmonic effects and total harmonics distortion

Remarks: All comparisons made using a 225kVA 3D wound core transformer and conventional stacked core under specific operating conditions unless otherwise stated.

Technology Benefits

Increased electricity savings

• 3D energy saving transformer saves 43% more than standard loss transformer in electricity cost from total transformer loss reductions in 5 years.

• 3D energy saving
  transformer
• Standard loss
  transformer

• Electricity cost savings from transformer loss reductions achieved by 3D energy saving transformer
• Electricity cost from transformer no-load losses
• Electricity cost from transformer load losses

5 year Return on Investment (ROI)

• Price of 3D energy saving transformer minus 5 years electricity cost savings from total transformer loss reductions is equal to price of standard loss transformer.

• 3D energy saving transformer
  
• Standard loss
  transformer

• Electricity cost savings from transformer loss reductions achieved by 3D energy saving transformer
• Price of 3D energy saving transformer
• Price of standard loss transformer

Lower Total Owning Cost (TOC)

• TOC of 3D energy saving transformer over a 20 year period is 28% lower than that of standard loss transformer.

• 3D energy saving
  transformer
• Standard loss
  transformer

• Electricity cost savings from transformer loss reductions achieved by 3D energy saving transformer
• Electricity cost from transformer no-load losses
• Electricity cost from transformer load losses
• Price of 3D energy saving transformer
• Price of standard loss transformer

Reduced CO2 emissions and trees to offset CO2 emissions

• The 3D energy saving transformer emits 43% less CO2 and requires 43% less trees to offset CO2 emissions than the standard loss transformer (calculated at 80% average load).

Remarks: All comparisons made using a 1000kVA 3D wound core energy saving transformer (European standard Ao + Ak losses) and conventional stacked core standard loss transformer under specific operating conditions unless otherwise stated.

Applications

• Ideal for installation sites where low operating sound levels are required
• Ideal for installation sites with sensitive instruments/equipment (eg. data centers) where low harmonic effects are required or for use as an isolating transformer
• Ideal for reducing electricity costs in high electricity consumption installation sites (eg. cold storage warehouses that operate 24 hours a day, 365 days a year)

Installation

• Complies with current outdoor installation conditions and standards
• Can easily replace existing conventional stacked core standard loss transformers

Installation conditions

Suitable for outdoor installation in Thailand or similar tropical environment or the following environmental conditions

• Altitude: up to 1,000 m above sea level
• Maximum ambient temperature: 40oc
• Average ambient temperature on one (1) day: 35oc
• Average maximum relative humidity in any one (1) year: 94%
• Able to design and manufacture to suit other environmental conditions