Unidirectional Matrix Converter with Regeneration

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Solution Overview

Problem

Conventional power converters used in aircraft applications lack high energy efficiency and power density due to two-stage conversions and the use of heavy transformer rectifier units and energy storage elements like capacitors or inductors, which also reduce system lifetime.

Innovation Solution

A matrix converter topology with a controlled rectifier input stage, an inverter output stage, and a regenerative unit that eliminates current harmonics and manages regenerative energy without a DC-link reactance, using series diodes for isolation and energy dissipating and storing elements to optimize energy delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If two-stage conversion with transformer rectifier unit and DC-link is used, then power conversion is achieved, but energy efficiency is insufficient and power density is reduced

Engineering Contradiction:
Improveenergy efficiencyVSAvoidtwo-stage conversion structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent combines the rectifier and inverter stages into a single matrix converter stage that directly converts AC to AC with variable frequency and voltage, eliminating the DC-link and intermediate energy storage components. This merging of stages reduces energy losses and improves overall conversion efficiency.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent extracts and removes the DC-link capacitor or inductor from the conventional two-stage converter topology, eliminating the need for large energy storage elements that reduce power density and increase system weight while maintaining the essential power conversion function.

Inventive Principle:
Principle #2Taking out (Extraction)

2Power

If transformer rectifier unit and DC-link energy storage elements are used, then power conversion is achieved, but weight increases and physical volume increases

Engineering Contradiction:
Improvepower conversion capabilityVSAvoidconverter weight
Core Design Contradiction:
PowerVSWeight of stationary object

Solution Approach 1:

The patent removes the heavy transformer rectifier unit and DC-link energy storage elements (capacitors or inductors) from the converter topology, replacing them with a direct matrix converter structure that achieves the same power conversion function with significantly reduced weight and volume.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

By merging the rectifier and inverter functions into a single matrix converter stage, the patent eliminates the need for separate transformer and energy storage components, thereby reducing the overall weight and physical footprint of the power conversion system.

Inventive Principle:
Principle #5Merging (Combining)

3Power

If transformer rectifier unit and DC-link energy storage elements are used, then power conversion is achieved, but system lifetime is reduced

Engineering Contradiction:
Improvepower conversion capabilityVSAvoidsystem lifetime
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent extracts and removes the DC-link capacitor or inductor from the system, eliminating components that are subject to degradation over time and reduce system lifetime, while maintaining power conversion capability through the direct matrix converter topology.

Inventive Principle:
Principle #2Taking out (Extraction)

4Power

If conventional two-stage converter is used, then power conversion is achieved, but power density is reduced

Engineering Contradiction:
Improvepower conversion capabilityVSAvoidconverter volume
Core Design Contradiction:
PowerVSVolume of moving object

Solution Approach 1:

The patent removes the bulky DC-link energy storage elements and transformer components from the converter topology, achieving the same power conversion function in a more compact form factor that significantly increases power density.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

By combining the rectifier and inverter stages into a single matrix converter, the patent reduces the overall physical volume of the system while maintaining full power conversion capability, thereby increasing power density.

Inventive Principle:
Principle #5Merging (Combining)

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 configuration enhances energy efficiency and power density by eliminating the need for reactances, reducing weight, and enabling efficient conversion and regenerative energy management, suitable for high-power aircraft applications.

Implementation Method 1

The controlled rectifier input stage is electrically connected to a power source and configured to convert AC input power from the power source into DC power

Methodology Applied
Scientific EffectRectification:

Implementation Method 2

The inverter output stage is electrically connected to a load and operates to convert the DC power into AC output power

Methodology Applied
Scientific EffectInversion:

Implementation Method 3

The regenerative unit also includes an energy storing element configured to store the energy generated by the load in the regenerative mode

Methodology Applied
Scientific EffectEnergy storage: Capacitance

Implementation Method 4

The regenerative unit includes an energy dissipating element configured to dissipate the energy generated by the load in the regenerative mode

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3100346B1Unidirectional matrix converter with regeneration system
Publication Date: 2021.11.03 EATON INTELLIGENT POWER LTD
  • EP3100346B1 patent drawingFigure 1
  • EP3100346B1 patent drawingFigure 2
  • EP3100346B1 patent drawingFigure 3

AI summary

An AC-to-AC matrix converter includes a controlled rectifier input stage, an inverter output stage, and a regenerative unit. The controlled rectifier input stage is electrically connected to a power source and configured to convert AC input power from the power source into DC power. The controlled rectifier input stage may be unidirectional. The inverter output stage is electrically connected to a load and operates to convert the DC power into AC output power, which is then fed into the load. The regenerative unit is electrically connected to the inverter output stage and operates control energy generated by the load in a regenerative mode within the inverter output stage. The controlled rectifier input stage may be isolated from the inverter output stage in the regenerative mode.