Fixed Three-Phase to Two-Phase Transformer with Linked Flux

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing three-phase to two-phase transformers, such as Scott and Leblanc assemblies, face issues with bulk magnetic circuits, unequal winding turns, and asymmetrical conductor distribution, leading to inefficiencies in energy transfer and increased magnetizing current.

Innovation Solution

A three-phase to two-phase transformer design with a magnetic circuit comprising three magnetically connected columns, where three-phase coils and two-phase coils are symmetrically distributed, allowing for equal turn counts on the two-phase side and reducing the need for different conductor sections, enabling balanced phase resistances and inductances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If Scott configuration uses two single-phase transformers, then energy transfer from three-phase to two-phase is achieved, but magnetic circuit mass and size increase significantly

Engineering Contradiction:
Improveenergy transfer capabilityVSAvoidmagnetic circuit mass
Core Design Contradiction:
PowerVSWeight of stationary object

Solution Approach 1:

The patent merges two single-phase transformers into a single integrated three-phase to two-phase transformer with a unified magnetic circuit. The three-phase coils (T1, T2, T3) and two-phase coils (T4, T5, T6, T7) share common magnetic columns, combining functions that were previously separated into two independent transformers. This integration reduces the total magnetic circuit mass while maintaining the required power transfer capability.

Inventive Principle:
Principle #5Merging (Combining)

2Power

If Scott configuration uses different number of turns in primary windings, then quadrature secondary voltages are achieved, but conductor cross-sections must differ increasing complexity

Engineering Contradiction:
Improvequadrature voltage outputVSAvoidconductor distribution asymmetry
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent applies local quality by assigning different turn ratios to specific coil groups based on their functional requirements. The first and second three-phase coils have n1 turns, the third has n1' turns, while the two-phase coils have n2 and n2' turns respectively. This localized differentiation of winding parameters enables quadrature voltage output while maintaining symmetry in the overall magnetic circuit structure, reducing conductor distribution complexity.

Inventive Principle:
Principle #3Local quality

3Power

If Leblanc configuration uses three-column magnetic circuit, then magnetizing current is limited, but two-phase windings must be different increasing complexity

Engineering Contradiction:
Improvemagnetizing current limitationVSAvoidwinding asymmetry
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent deliberately introduces asymmetry in the winding connections to achieve symmetry in performance. The third three-phase coil is connected differently (with opposite polarity) compared to the first two, and the two-phase coils are distributed asymmetrically across the three columns. This controlled asymmetry in connection topology enables balanced phase resistances and inductances, limiting magnetizing current while maintaining electrical symmetry in the output.

Inventive Principle:
Principle #4Asymmetry

4Power

If two-phase coils have different number of turns, then voltage balance is achieved, but conductor cross-sections must differ increasing manufacturing complexity

Engineering Contradiction:
Improvevoltage balanceVSAvoidconductor uniformity
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

The patent changes the electrical parameters (turn ratios) rather than the physical parameters (conductor cross-sections) to achieve voltage balance. By adjusting the number of turns in different coil groups (n1, n1', n2, n2') while maintaining uniform conductor cross-sections, the invention achieves balanced voltages and currents. This parameter transformation simplifies manufacturing by allowing standard conductors to be used throughout while achieving the required electrical balance through winding ratio adjustments.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design reduces the mass and volume of the magnetic circuit, limits magnetizing current, and achieves balanced voltages and currents on the two-phase side, with voltages of the same value and in quadrature, while maintaining balanced phase resistances and inductances.

Implementation Method 1

the magnetic circuit comprises a first column, a second column and a third column magnetically connected... allows for flux coupling, which reduces the mass and volume of the magnetic circuit and limits the magnetizing current

Methodology Applied
Scientific EffectMagnetic flux coupling: Electromagnetic Induction

Data Source

PatentEP2834820B1Fixed three-phase to two-phase transformer with forced linked flux
Publication Date: 2020.03.18 SAFRAN ELECTRICAL & POWER
  • EP2834820B1 patent drawingFigure 1~2
  • EP2834820B1 patent drawingFigure 3~4
  • EP2834820B1 patent drawingFigure 5~6

AI summary

A three-phase to two-phase transformer (1) comprising a magnetic circuit (2), three-phase coils and two-phase coils, in which the magnetic circuit comprises a first column (3), a second column (4) and a third column (5) that are magnetically connected, the three-phase coils comprising a first coil (6), a second coil (7) and a third coil (8). This transformer is remarkable in that the two-phase coils comprise a fourth coil (9) around the first column (3), a fifth coil (10) around the first column (3), a sixth coil (11) around the third column (5) and a seventh coil (12) around the third column (5), the fourth coil (9) and the seventh coil (12) being connected in series and forming a first two-phase phase, the fifth coil (10) and the sixth coil (11) being connected in series and forming a second two-phase phase.