Interleaved DC-DC Boost Converter for Aircraft Power Systems

Solution Overview

Problem

Direct current power generating systems for aircraft and vehicles often require large DC bus capacitors to reduce voltage ripple, leading to increased weight and size due to conventional 3-phase permanent magnet generators and rectifiers, which is inefficient and cumbersome.

Innovation Solution

A 6-phase permanent magnet generator coupled with two 6-pulse passive rectifiers and a 4-phase interleaved DC-DC boost converter, utilizing semiconductor switches to reduce conduction losses and eliminate the need for active rectification and position sensors, thereby minimizing voltage ripple and torque pulsation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a relatively large DC bus capacitor is used to reduce voltage ripple, then voltage ripple is reduced to meet specifications, but weight and size of the system increase

Engineering Contradiction:

Improvevoltage rippleVSAvoidsystem weight

Core Design Contradiction:

Object-affected harmful factorsVSWeight of stationary object

Solution Approach 1:

The patent divides the single-phase DC-DC converter into multiple interleaved phases (e.g., three-phase configuration with phases shifted by 120 degrees). Each phase processes a portion of the input current, and their combined output smooths the total current waveform, reducing voltage ripple on the DC bus without requiring a large capacitor.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The interleaved phases operate with periodic switching patterns that are phase-shifted relative to each other. This periodic action distributes the ripple current components across different time intervals, causing them to cancel each other out when combined, thereby reducing overall voltage ripple.

Inventive Principle:

Principle #19Periodic action

2Object-affected harmful factors

If a relatively large DC bus capacitor is used to reduce voltage ripple, then voltage ripple is reduced to meet specifications, but size of the system increases

Engineering Contradiction:

Improvevoltage rippleVSAvoidsystem size

Core Design Contradiction:

Object-affected harmful factorsVSArea of stationary object

Solution Approach 1:

The patent divides the single-phase DC-DC converter into multiple interleaved phases (e.g., three-phase configuration with phases shifted by 120 degrees). Each phase processes a portion of the input current, and their combined output smooths the total current waveform, reducing voltage ripple on the DC bus without requiring a large capacitor.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The interleaved phases operate with periodic switching patterns that are phase-shifted relative to each other. This periodic action distributes the ripple current components across different time intervals, causing them to cancel each other out when combined, thereby reducing overall voltage ripple.

Inventive Principle:

Principle #19Periodic action

3Power

If conventional 3-phase permanent magnet generators and rectifiers are used, then power generation is achieved, but weight and size increase due to large passive components

Engineering Contradiction:

Improvepower generationVSAvoidsystem weight

Core Design Contradiction:

PowerVSWeight of stationary object

Solution Approach 1:

The patent divides the single-phase DC-DC converter into multiple interleaved phases (e.g., three-phase configuration with phases shifted by 120 degrees). Each phase processes a portion of the input current, and their combined output smooths the total current waveform, reducing voltage ripple on the DC bus without requiring a large capacitor.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The interleaved phases operate with periodic switching patterns that are phase-shifted relative to each other. This periodic action distributes the ripple current components across different time intervals, causing them to cancel each other out when combined, thereby reducing overall voltage ripple.

Inventive Principle:

Principle #19Periodic action

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 reduces the size of passive components, improves power quality, and enhances power density by effectively reducing voltage ripple and torque pulsation, eliminating the need for large capacitors and position sensors, resulting in a more efficient and compact power generation system.

Implementation Method 1

a permanent magnet generator (PMG), wherein the PMG provides a 6-phase PMG

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a rectification stage coupled to the PMG

Methodology Applied

Scientific EffectRectification: Diode

Implementation Method 3

a boost converter stage coupled to the rectification stage, wherein the boost converter stage comprises four phases

Methodology Applied

Scientific EffectElectromagnetic switching:

Data Source

PatentUS20200044590A1Electric generating system with an interleaved DC-DC converter

Publication Date: 2020.02.06 HAMILTON SUNDSTRAND CORP

AI summary

Embodiments of a method, controller and system include an electric generating system with interleaved direct current DC-DC converter are provided. The embodiments include a controller, a permanent magnet generator (PMG), wherein the PMG provides a 6-phase PMG, and a rectification stage coupled to the PMG. The embodiments also include a boost converter stage coupled to the rectification stage, wherein the boost converter stage comprises four phases, a DC link capacitor coupled to the boost converter stage, and an output filtering stage coupled to the DC link capacitor.