Synchronized Power Factor Correcting Current Resonance Converter

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In conventional two-stage DC-DC converters, the independent switching operations of the current resonance converter circuit and the power factor correcting converter circuit lead to unstable operations and increased complexity, resulting in noise interference and higher costs due to the need for multiple control circuits.

Innovation Solution

A power factor correcting current resonance converter is designed where the power factor correcting converter circuit operates in synchronization with the current resonance converter circuit, using a single control circuit and eliminating the need for a dedicated control circuit, thereby reducing noise and costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the current resonance converter circuit and power factor correcting converter circuit operate independently with different control circuits, then each circuit can be optimized for its specific function, but the device complexity increases and operation stability deteriorates due to switching interference

Engineering Contradiction:
Improvefunctional optimizationVSAvoidcontrol circuit complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the control functions of the current resonance converter and power factor correcting converter into a single control circuit. The control circuit generates switching signals for both circuits, coordinating their operations to eliminate interference while maintaining functional optimization. This reduces device complexity by eliminating separate control circuits while preserving the adaptive capabilities of each converter stage.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If the power factor correcting converter circuit uses a dedicated control circuit operating independently, then the power factor correction can be precisely controlled, but noise increases and operation becomes unstable due to interfering switching operations

Engineering Contradiction:
Improvepower factor control precisionVSAvoidnoise and instability
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent uses a single control circuit as an intermediary that coordinates the switching operations of both the current resonance converter and power factor correcting converter. By generating synchronized switching signals for both circuits, the control circuit eliminates interfering switching operations that cause noise and instability, while maintaining precise power factor correction control through unified signal generation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If multiple control circuits are used for the current resonance converter and power factor correcting converter, then each circuit can be independently optimized, but the cost increases due to the need for multiple control circuits

Engineering Contradiction:
Improvecircuit optimizationVSAvoidmanufacturing cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent implements a universal control circuit that performs multiple functions: it controls both the current resonance converter and the power factor correcting converter, generates switching signals for both circuits, and coordinates their operations. This multi-functional approach eliminates the need for separate control circuits, reducing manufacturing costs while preserving the ability to optimize each converter stage for its specific function.

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

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 stabilizes the operation of the power factor correcting current resonance converter, reduces noise, and improves performance by using a single integrated operation frequency, while minimizing the number of components and costs.

Implementation Method 1

a resonance capacitor Cr and a resonance inductor Lr connected in series

Methodology Applied
Scientific EffectResonance: Resonance

Implementation Method 2

a winding P1 on a primary side of a transformer T... Windings S1 and S2 on a secondary side of the transformer T

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

a power factor correcting converter circuit 110 which outputs the direct-current voltage Vs from a voltage Vd provided by rectifying a commercial alternating-current power source 120 with a diode bridge DB

Methodology Applied
Scientific EffectRectification: Diode

Implementation Method 4

a photocoupler PCe (light-emitting diode) which emits light depending on variations in the voltage Vo at the output and a photocoupler PCr (phototransistor) which receives the emitted light

Methodology Applied
Scientific EffectLight emission: Light Emitting Diode

Data Source

PatentEP2432105B1Power factor correcting current resonance converter
Publication Date: 2019.08.21 FUJI ELECTRIC CO LTD
  • EP2432105B1 patent drawingFigure 1
  • EP2432105B1 patent drawingFigure 2
  • EP2432105B1 patent drawingFigure 3

AI summary

To provide a power factor correct current resonance converter in which the interference of switching operation is eliminated between two cascade-connected converter circuits, the power factor correct current resonance converter includes a current resonance converter circuit having switches, a resonance capacitor, a resonance inductor, a transformer, diodes, a smoothing capacitor, and a control circuit. The power factor correct current resonance converter also includes a power factor correct converter circuit having a choke coil, a diode, a smoothing capacitor, and a switch. The switch is turned on or off in response to a voltage produced in a second winding of the transformer. Thus, the switching operation of the power factor correct converter circuit is performed in synchronization with the switching operation of the current resonance converter circuit, so that the interference of the switching operation is eliminated. In addition, since a dedicated control circuit is not required, the cost can be reduced.