Multi-Stage Power Converter With Digital Isolator Control

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Solution Overview

Problem

Conventional multi-stage power converters face increased circuit complexity, debugging complexity, and higher costs due to the need for multiple control units and conventional communication methods, as well as issues with temperature drift and aging in linear optocouplers used for signal transmission.

Innovation Solution

A multi-stage power converter with a simplified circuitry structure using a single control unit and digital isolators for signal transmission, where pulse width modulation signals are generated and transmitted through a single isolation channel in a time-interleaving manner, eliminating the need for linear optocouplers and reducing hardware resource requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple control units are used for each stage, then closed-loop control of each stage can be performed, but circuit complexity increases

Engineering Contradiction:
Improveclosed-loop control capabilityVSAvoidcircuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple control units into a single control unit that manages all stages. The control unit receives feedback signals from multiple isolated sides through a single isolation channel and generates corresponding control signals for each stage, thereby reducing circuit complexity while maintaining closed-loop control capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single control unit is designed to perform multiple functions by controlling different stages through a unified architecture. It can process feedback signals from multiple isolated sides and generate appropriate control signals for each power conversion circuit, making the control unit universal across all stages.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Loss of information

If conventional communication methods are used to transmit feedback signals, then information can be transmitted, but hardware resource requirements increase and cost increases

Engineering Contradiction:
Improvefeedback signal transmissionVSAvoidhardware resource requirements
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent introduces a digital isolator as an intermediary component that enables feedback signal transmission between isolated sides and the control unit through a single isolation channel. This intermediary approach allows efficient signal transmission while reducing the number of communication interfaces and hardware resources required compared to conventional methods.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 results in a cost-effective, simplified, and less complex multi-stage power converter with reduced debugging complexity and improved reliability by avoiding temperature drift and aging issues, while maintaining efficient signal transmission and control.

Implementation Method 1

the at least one pulse width modulation signal is transmitted to the pulse width analyzer through a digital isolator in a digitalized manner

Methodology Applied
Scientific EffectElectromagnetic coupling: Electromagnetic Induction

Data Source

PatentEP3319217B1Multi-stage power converter and control method thereof
Publication Date: 2021.04.14 DELTA ELECTRONICS INC(CN)
  • EP3319217B1 patent drawingFigure 1
  • EP3319217B1 patent drawingFigure 2
  • EP3319217B1 patent drawingFigure 3

AI summary

A multi-stage power converter (1) includes a first-stage power conversion circuit (2), a second-stage power conversion circuit (3), a second-stage analogic sampler (4), a pulse width modulator (6), a first isolator (7), a pulse width analyzer (8) and a control unit (9). The second-stage analogic sampler (4) samples power parameter from the second-stage power conversion circuit (2). The pulse width modulator (6) converts the power parameter into a pulse width modulation signal. The pulse width analyzer (8) receives the pulse width modulation signal through the first isolator (7) in an isolation manner, calculates a duty ratio of the pulse width modulation signal according to a rising edge and a falling edge of the pulse width modulation signal, and calculates the power parameter according to the duty ratio. The control unit (9) controls operations of the second-stage power conversion circuit (3) according to the power parameter that is obtained by the pulse width analyzer (8).