N-Phase Transformer with Series Phase Cells for High-Voltage Conversion

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Solution Overview

Problem

Converter systems with multiple phases face challenges such as high cost, size, and weight due to the need for increased output voltage, which complicates the design and material usage.

Innovation Solution

A converter system comprising an N-phase DC-to-AC converter with magnetically coupled primary and secondary windings, reducing the number of cores and windings required, and utilizing single-phase AC-to-DC converters to achieve constant output voltages and lower semiconductor blocking voltages, thereby minimizing material and cost while optimizing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the output voltage is increased to meet higher voltage requirements, then the voltage output capability is improved, but the converter becomes bigger and heavier

Engineering Contradiction:
Improveoutput voltageVSAvoidconverter weight
Core Design Contradiction:
PowerVSWeight of stationary object

Solution Approach 1:

The patent divides the converter system into multiple single-phase AC-to-DC converter modules connected in series. Each module handles a portion of the total voltage requirement, allowing the system to achieve high output voltage without requiring a single large, heavy converter unit. The segmentation of functional blocks enables modular scaling of voltage output.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single-phase high-voltage converter design to a multi-phase series-connected architecture. By adding the dimension of phase multiplication (N-phase system), the system achieves high voltage output through series connection of multiple lower-voltage modules, avoiding the need for a single high-voltage transformer that would increase weight.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If separate DC-to-AC converters are used for each phase, then the voltage control flexibility is improved, but the material usage and cost increase

Engineering Contradiction:
Improvevoltage control flexibilityVSAvoidmaterial usage
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent merges multiple single-phase AC-to-DC converter modules into a single N-phase DC-to-AC converter system. By combining the converter functions while maintaining separate phase windings, the system achieves voltage control flexibility without requiring fully separate converter units for each phase, thus reducing material usage and cost.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The N-phase DC-to-AC converter is designed to perform multiple functions simultaneously: it provides voltage conversion for N different phases, enables series connection for high voltage output, and maintains independent control capability for each phase. This multi-functionality reduces the need for separate dedicated converters for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Power

If more windings are used to achieve higher voltage output, then the voltage output capability is improved, but the device complexity and material usage increase

Engineering Contradiction:
Improvevoltage output capabilityVSAvoidwinding complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent segments the winding structure into N separate primary windings (one for each phase) that are connected in series. Each winding handles a portion of the total voltage, simplifying the design of individual windings while achieving high overall voltage output through series connection. This segmentation reduces the complexity of designing and manufacturing single high-voltage windings.

Inventive Principle:
Principle #1Segmentation

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

The solution reduces material usage, lowers semiconductor costs, and minimizes leakage inductance, allowing for higher voltage outputs without increasing the number of cores, thus addressing the size, weight, and cost issues of traditional converter systems.

Implementation Method 1

The first primary-side winding and the first secondary-side winding are magnetically coupled to each other by being wound around a first core, and wherein the second primary-side winding and the second secondary-side winding are magnetically coupled to each other by being wound around a second core

Methodology Applied
Scientific EffectMagnetic coupling: Electromagnetic Induction

Data Source

PatentEP4465313A1N-phase transformer with use of serial connected phase cells
Publication Date: 2024.11.20 HITACHI ENERGY LTD
  • EP4465313A1 patent drawingFigure 1~2b
  • EP4465313A1 patent drawingFigure 3a~3d
  • EP4465313A1 patent drawingFigure 4

AI summary

The invention a converter system comprising: an N-phase DC-to-AC converter, wherein N is greater than or equal to 2; a plurality of single-phase AC-to-DC converters comprising a first single-phase AC-to-DC converter and a second single-phase AC-to-DC converter; a plurality of primary-side windings comprising a first primary-side winding connected to a first phase output of the N-phase DC-to-AC converter and a second primary-side winding connected to a second phase output of the N-phase DC-to-AC converter; a plurality of secondary-side windings comprising a first secondary-side winding connected to the first single-phase AC-to-DC converter and a second secondary-side winding connected to the second single-phase AC-to-DC converter, wherein the first primary-side winding and the first secondary-side winding are magnetically coupled to each other by being wound around a first core, and wherein the second primary-side winding and the second secondary-side winding are magnetically coupled to each other by being wound around a second core.