Switch-Mode Power Supply Segmentation for High Current Change Rate

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Solution Overview

Problem

Existing power supply technologies struggle to efficiently generate high-frequency electricity components, particularly in applications like radio transmitters and magnetic resonance imaging, where prior methods result in low efficiency due to high power dissipation and limited frequency capabilities.

Innovation Solution

The solution involves a circuit arrangement using multiple current supplies connected through switches, allowing for rapid current changes and binary weighting, enabling efficient generation of high-frequency current components by controlling the switches at speeds of at least 1 MHz, thereby minimizing power dissipation and maximizing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If switch-mode power supply is used to generate high-frequency current, then efficiency is improved, but the current change rate is limited due to inductive components

Engineering Contradiction:

Improvepower dissipationVSAvoidcurrent change rate

Core Design Contradiction:

Loss of energyVSSpeed

Solution Approach 1:

The power supply is divided into two separate stages: a switch-mode power converter that generates high-frequency current with high efficiency, and a linear power amplifier that boosts the current change rate. This segmentation allows each stage to optimize for its specific function, resolving the contradiction between efficiency and speed.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A coupling circuit is introduced as an intermediary between the switch-mode converter and the linear power amplifier. This coupling circuit efficiently transfers power while allowing the linear amplifier to operate at its full capability, enabling the system to achieve both high efficiency and high current change rate.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Speed

If linear power supply is used to generate high-frequency current, then current change rate is improved, but efficiency deteriorates due to high power dissipation

Engineering Contradiction:

Improvecurrent change rateVSAvoidpower dissipation

Core Design Contradiction:

SpeedVSLoss of energy

Solution Approach 1:

The system is segmented so that the linear power amplifier only handles the high-frequency current component rather than the full power, minimizing power dissipation while maintaining high current change rate capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The linear power amplifier performs only the partial function of boosting the current change rate, while the main power conversion is handled by the efficient switch-mode converter. This partial action approach minimizes the inefficiency inherent in linear amplification.

Inventive Principle:

Principle #16Partial or excessive action

3Loss of energy

If envelope tracking method is used to improve efficiency, then power dissipation is reduced, but the frequency of alternating current component is limited

Engineering Contradiction:

Improvepower dissipationVSAvoidfrequency of alternating current component

Core Design Contradiction:

Loss of energyVSProductivity

Solution Approach 1:

The envelope tracking system is segmented into a switch-mode converter for efficient power conversion and a linear power amplifier for high-frequency current generation. This allows the system to maintain high efficiency while extending the usable frequency range beyond what a single switch-mode converter could achieve alone.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS8692527B2Method and arrangement for efficiently generating current with a high rate of change

Publication Date: 2014.04.08 EFORE TELECOM FINLAND OY

AI summary

The invention relates to power supplies where the output current is controllable. In prior art, there is a problem to provide both high rate of change in the current output and high efficiency. The solution of the present invention is based on combining current elements, whereby the current is controlled by switching the outputs of the current elements. The current elements can be implemented with e.g. buck converters, whereby the power dissipation is small.