High Power Factor Single-Phase Rectifier with Averaging Circuit

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Solution Overview

Problem

Existing AC to DC conversion technologies face inefficiencies due to harmonic distortion, reduced power factor, and limited frequency range, particularly in high-frequency applications, leading to energy loss and poor performance in single-phase power systems.

Innovation Solution

A high power factor single-phase rectifier topology is implemented, utilizing a combination of first and second rectifier circuits with averaging circuits to reduce harmonics and improve power factor, allowing for efficient AC to DC conversion across a wide range of frequencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a conventional single-phase rectifier is used, then the circuit is simple, but harmonic distortion is high and power factor is low

Engineering Contradiction:
Improvecircuit complexityVSAvoidharmonic distortion
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The rectifier circuit is divided into multiple parallel rectifier circuits (first rectifier circuit, second rectifier circuit, etc.), each processing different portions of the AC input. This segmentation allows each individual rectifier to operate with lower harmonic distortion while the combined output achieves high power factor and low total harmonic distortion through the averaging effect of multiple phases.

Inventive Principle:
Principle #1Segmentation

2Object-generated harmful factors

If resonant filters are used to reduce harmonics, then harmonic distortion decreases, but device complexity and frequency limitations increase

Engineering Contradiction:
Improveharmonic distortionVSAvoidfilter complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the need for resonant filters by using a different approach: multiple parallel rectifier circuits with averaging. This removes the harmful dependency on resonant filters while still achieving low harmonic distortion, thereby reducing device complexity and enabling broadband frequency operation without frequency-specific tuning.

Inventive Principle:
Principle #2Taking out (Extraction)

3Object-generated harmful factors

If polyphase power is used, then power factor improves, but system complexity and cost increase

Engineering Contradiction:
Improvepower factorVSAvoidsystem complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The invention introduces an averaging circuit as an intermediary between multiple single-phase rectifier circuits and the final DC output. This averaging mediator combines the outputs of simpler single-phase rectifiers to achieve the power factor improvement typically associated with complex polyphase systems, thereby obtaining high power factor without the complexity of polyphase power infrastructure.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Speed

If high frequency operation is implemented, then power conversion speed increases, but harmonic distortion and efficiency deteriorate

Engineering Contradiction:
Improvepower conversion speedVSAvoidconversion efficiency
Core Design Contradiction:
SpeedVSProductivity

Solution Approach 1:

The rectifier system is designed to dynamically operate across a wide frequency range without requiring resonant tuning. The multiple parallel rectifier circuits with averaging provide dynamic adaptability that maintains low harmonic distortion and high efficiency at high frequencies, enabling fast power conversion while preserving conversion efficiency through frequency-independent operation.

Inventive Principle:
Principle #15Dynamics

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 significantly reduces harmonic distortion, increases power factor, and enhances efficiency in AC to DC conversion, enabling effective power delivery to loads across various frequency ranges without the need for resonant filters or polyphase power.

Implementation Method 1

a first rectifier circuit configured to rectify the alternating current to a first direct current

Methodology Applied
Scientific EffectRectification: Diode

Data Source

PatentEP2781012B1Systems, methods, and apparatus for a high power factor single phase rectifier
Publication Date: 2016.07.13 QUALCOMM INC
  • EP2781012B1 patent drawingFigure 1
  • EP2781012B1 patent drawingFigure 2
  • EP2781012B1 patent drawingFigure 3

AI summary

Systems, methods and apparatus are disclosed for broadband AC to DC conversion. In one aspect, a power conversion apparatus for providing direct current (DC) based at least in part on an alternating current is provided. The power conversion apparatus includes a first rectifier circuit configured to rectify the alternating current to a first direct current. The power conversion apparatus further includes an averaging circuit configured to average the first direct current received from the first rectifier circuit and to provide a second direct current. The power conversion apparatus further includes a second rectifier circuit configured to rectify the alternating current to a third direct current. The direct current is derived from the second direct current and the third direct current.