Valley Switching Controller for Power Converter

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Solution Overview

Problem

Conventional valley-switching techniques in switching power converters face challenges in maintaining constant voltage regulation and efficient power transfer due to quantization of switching periods, leading to reduced average current supply and inefficiencies.

Innovation Solution

A controller is used to adjust the switching period and peak current of a switching power converter by increasing the switching period and peak current when it decreases below a minimum, and decreasing the switching period and peak current when it exceeds a maximum, to maintain a regulated current level, thereby compensating for transient effects and achieving accurate load regulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional valley-switching techniques are used to reduce switching losses, then power efficiency is improved, but voltage regulation accuracy deteriorates due to quantization of switching periods

Engineering Contradiction:
Improveswitching lossesVSAvoidvoltage regulation accuracy
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The patent changes the operating parameters by allowing the switching period to vary continuously rather than being quantized to fixed valleys. The controller adjusts the switching period and peak current dynamically to maintain regulated current level, resolving the contradiction between reducing switching losses and maintaining voltage regulation accuracy.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the switching period is decreased to increase switching frequency, then power transfer efficiency is improved, but transient flicker increases and regulation stability deteriorates

Engineering Contradiction:
Improvepower transfer efficiencyVSAvoidoutput current stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent implements a feedback control mechanism where the controller monitors the regulated current level and adjusts the switching period and peak current accordingly. When the switching period decreases below minimum or peak current exceeds maximum, the controller compensates by adjusting parameters to maintain stable output current, thus resolving the contradiction between power transfer efficiency and regulation stability.

Inventive Principle:
Principle #23Feedback

3Power

If peak current is increased to maintain regulated current level, then power transfer capability is improved, but power dissipation increases

Engineering Contradiction:
Improvepower transfer capabilityVSAvoidpower dissipation
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The patent employs dynamic adjustment of peak current based on real-time switching period conditions. The controller increases peak current only when necessary (when switching period decreases below minimum) and decreases it when switching period increases, optimizing the balance between power transfer capability and power dissipation rather than using fixed peak current levels.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3132530B1Systems and methods for valley switching in a switching power converter
Publication Date: 2019.06.12 SIGNIFY HOLDING BV
  • EP3132530B1 patent drawingFigure 1~2
  • EP3132530B1 patent drawingFigure 3~4
  • EP3132530B1 patent drawingFigure 5

AI summary

A controller may be configured to generate a control signal to activate and deactivate a switch of a switching power converter in order to control a switching period and a peak current of the switching power converter to maintain a regulated current of the switching power converter at a desired current level such that: if the switching period decreases below a minimum switching period, the controller increases the switching period by a ringing period of a voltage of the switch and increases the peak current to compensate for the increase of the switching period in order to maintain the regulated current, and if the peak current increases above a maximum peak current, the controller decreases the switching period by a ringing period of the voltage of the switch and decreases the peak current to compensate for the decrease of the switching period in order to maintain the regulated current.