Interleaving Converter Phase Control for Stable PV Output

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Solution Overview

Problem

Existing power conversion systems for photovoltaic modules experience instantaneous reduction in output power due to changes in switching frequency, leading to inefficiencies and potential distortion in output current.

Innovation Solution

The implementation of a power conversion apparatus with interleaving converters, where the switching periods and phase differences between converters are dynamically adjusted in response to changes in switching frequencies, ensuring stable output power and preventing instantaneous power reduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the switching frequency of interleaving converters is changed, then the power conversion efficiency is improved, but the output power experiences instantaneous reduction

Engineering Contradiction:
Improvepower conversion efficiencyVSAvoidoutput power
Core Design Contradiction:
Use of energy by moving objectVSPower

Solution Approach 1:

The patent applies dynamics by making the switching periods of interleaving converters adjustable rather than fixed. The controller dynamically changes switching periods to optimize power conversion efficiency while maintaining stable output power, resolving the contradiction between efficiency improvement and power stability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of switching period to improve power conversion efficiency. By adjusting the switching period parameter of interleaving converters, the system achieves better efficiency while the controller compensates for any output power fluctuations through coordinated control of multiple converters.

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If the switching frequency of interleaving converters is changed, then the power conversion efficiency is improved, but the output current becomes distorted

Engineering Contradiction:
Improvepower conversion efficiencyVSAvoidoutput current quality
Core Design Contradiction:
Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The system dynamically adjusts switching periods while the controller coordinates multiple interleaving converters to maintain proper phase relationships. This dynamic control ensures that output current quality is preserved even as switching frequency changes to improve efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The controller monitors the operation of interleaving converters and adjusts switching periods based on feedback to maintain both high efficiency and clean output current. The coordinated control of multiple converters with adjusted switching periods prevents current distortion while achieving efficiency improvements.

Inventive Principle:
Principle #23Feedback

3Use of energy by moving object

If the switching period of interleaving converters is adjusted, then the power conversion efficiency is improved, but the phase relationship between converters becomes unstable

Engineering Contradiction:
Improvepower conversion efficiencyVSAvoidphase relationship
Core Design Contradiction:
Use of energy by moving objectVSStability of the object's composition

Solution Approach 1:

The patent changes the switching period parameter to improve efficiency while the controller coordinates multiple interleaving converters to maintain stable phase relationships. The coordinated control ensures that even with different switching periods, the phase relationships between converters remain stable and synchronized.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2897267B1Power conversion apparatus and photovoltaic module including the same
Publication Date: 2020.01.15 LG ELECTRONICS INC
  • EP2897267B1 patent drawingFigure 1
  • EP2897267B1 patent drawingFigure 2
  • EP2897267B1 patent drawingFigure 3

AI summary

Discussed are a power conversion apparatus and a photovoltaic module including the power conversion apparatus. The power conversion apparatus includes a converter unit to convert DC voltage from a solar cell module, the converter unit including a plurality of interleaving converters, and a controller to control the converter unit, wherein the controller changes switching periods of the interleaving converters and changes phase differences between the interleaving converters during operation sections of the interleaving converters, in response to a change of the switching periods of the interleaving converters. Consequently, it is possible to prevent instantaneous reduction of output power due to change of switching frequencies of the interleaving converters.