Push-Pull Inverter With Tunable Resonant Network

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Solution Overview

Problem

Conventional switched-mode power amplifiers face inefficiencies and design constraints at high frequencies due to increased switching losses, parasitic reactances, and high voltage stress on transistors, limiting their operational frequency and power density.

Innovation Solution

The implementation of a push-pull inverter circuit with shared tunable resonant networks allows independent tuning of even and odd harmonics, reducing voltage stress and component size, and incorporating a resonant rectifier to convert AC to DC efficiently, thereby enhancing power density and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If switching frequency is increased to reduce passive component size, then power density increases, but switching losses and efficiency deteriorate

Engineering Contradiction:

Improvepassive component sizeVSAvoidswitching losses

Core Design Contradiction:

Volume of moving objectVSLoss of energy

Solution Approach 1:

The patent implements dynamic tuning of resonant networks that can independently adjust even and odd harmonics. This dynamic adaptation allows the system to maintain optimal resonant conditions across varying operating frequencies, enabling efficient high-frequency operation without the traditional trade-off between component size and switching losses.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention changes the impedance parameters of the resonant networks by independently tuning even and odd harmonics. This parameter optimization allows the system to achieve soft-switching conditions at high frequencies, reducing switching losses while maintaining reduced passive component sizes.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If switching frequency is increased beyond 10-20 MHz, then power density continues to increase, but voltage stress on transistors increases making operation difficult

Engineering Contradiction:

Improvepower densityVSAvoidvoltage stress on transistors

Core Design Contradiction:

ProductivityVSStress or pressure

Solution Approach 1:

The patent employs dynamically tunable resonant networks that adapt to operating conditions. By independently controlling even and odd harmonics, the system can shape voltage waveforms to reduce peak voltage stress on transistors while maintaining high switching frequencies for increased power density.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention converts the potentially harmful high-frequency voltage spikes into beneficial controlled resonant waveforms. By utilizing resonant networks tuned to specific harmonics, the system transforms what would be destructive voltage stress into controlled oscillations that reduce net voltage stress on semiconductor devices.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If conventional resonant networks are used, then soft switching can be achieved, but independent tuning of even and odd harmonics is not possible, limiting design flexibility

Engineering Contradiction:

Improvesoft switching performanceVSAvoiddesign flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent segments the resonant network into independent even-harmonic and odd-harmonic tuning sections. This segmentation allows each harmonic type to be independently optimized without affecting the other, providing both soft-switching performance and unprecedented design flexibility for various application requirements.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention implements dynamic independent tuning capabilities where even and odd harmonics can be adjusted separately in real-time. This dynamic control provides adaptability for different loading conditions and operating frequencies while maintaining reliable soft-switching 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

This configuration reduces semiconductor voltage stress, increases power density, and allows higher switching frequencies with reduced component count and size, improving efficiency and design flexibility in power conversion applications.

Implementation Method 1

An operational principle of efficient power conversion is the periodic controlled storage and release of energy, wherein the average flow of power from one port to another is regulated

Methodology Applied

Scientific EffectResonance: Resonance

Implementation Method 2

If the AC output of an inverter is rectified, i.e. converted back to DC, the complete system functions as a DC-DC converter

Methodology Applied

Scientific EffectRectification:

Data Source

PatentUS7924580B2Switching inverters and converters for power conversion

Publication Date: 2011.04.12 GENERAL ELECTRIC CO

AI summary

A switching inverter having two single-ended EF2 inverter sections coupled together with a shared ground and partially shared tunable resonant network that is coupled to at least one load, wherein each inverter section comprises a switching section, and wherein the shared tunable network section allows independent tuning of an impedance seen by the corresponding switching section thereby independently tuning even and odd harmonics of the switching frequency.