Dual Output Resonant Converter Linearization via Common Mode Control

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Solution Overview

Problem

Dual output resonant converters face challenges in efficiently regulating output voltages in LED television applications, particularly due to variations in load, which often require a second control stage for accurate voltage supply, increasing costs and complexity.

Innovation Solution

A power converter with a dual output resonant converter using a common mode and differential mode control system, where a dual output controller generates control signals based on error signals from both outputs, allowing independent control of the outputs without the need for a second stage controller, utilizing a clamping circuit to maintain signal ranges and a feedback loop for linearization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a second control stage is added to regulate the 165V output, then voltage regulation accuracy is improved, but device complexity and cost increase

Engineering Contradiction:
Improvevoltage regulation accuracyVSAvoidcontrol stage complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the regulation of both 12V and 165V outputs into a single control stage by using a dual-output controller that generates both common mode and differential mode control signals. This merging of functions eliminates the need for a separate second control stage while maintaining accurate voltage regulation for both outputs through unified control architecture.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The dual-output controller performs multiple functions simultaneously: it regulates both voltage outputs, generates common mode and differential mode signals, and provides feedback control for both channels. This multi-functional approach allows one control stage to accomplish what traditionally required two separate control stages, reducing overall system complexity.

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

2Measurement precision

If a second control stage is added to regulate the 165V output, then voltage regulation accuracy is improved, but cost increases

Engineering Contradiction:
Improvevoltage regulation accuracyVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent merges the control functions for both 12V and 165V outputs into a single dual-output controller, eliminating the need for a separate second control stage. This consolidation reduces the total component count and assembly requirements, directly lowering manufacturing costs while maintaining dual-output regulation capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The dual-output controller is designed to perform multiple regulation functions simultaneously for both voltage outputs, replacing what would traditionally require two separate control stages. This multi-functional design reduces component procurement costs, assembly complexity, and overall manufacturing expenses while achieving accurate voltage regulation.

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

3Device complexity

If dual output control is implemented without linearization, then device complexity is reduced, but output voltage stability deteriorates under load variations

Engineering Contradiction:
Improvecontrol system complexityVSAvoidoutput voltage stability
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The patent implements feedback control by sensing the actual 12V and 165V outputs and comparing them to reference values, generating error signals that are processed through common mode and differential mode control loops. This feedback mechanism automatically adjusts the control signals to maintain stable output voltages despite load variations, achieving voltage stability without requiring complex external regulation circuits.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3518407B1An apparatus and method for linearization of the control inputs for a dual output resonant converter
Publication Date: 2020.10.14 NXP BV
  • EP3518407B1 patent drawingFigure 1
  • EP3518407B1 patent drawingFigure 2
  • EP3518407B1 patent drawingFigure 3

AI summary

A power converter including: a dual output resonant converter including a first output, a second output, a common mode control input, and a differential mode control input, wherein a voltage/current at the first output and a voltage/current at the second output are controlled in response to a common mode control signal received at the common mode control input and a differential mode control signal received at the differential mode control input; and a dual output controller including a first error signal input, a second error signal input, a delta power signal input, a common mode control output, and a differential mode control output, wherein the dual output controller is configured to generate the common mode control signal and the differential mode control signal in response to a first error signal received at the first error signal input and a second error signal received at the second error signal input, wherein the first error signal is a function of the voltage/current at the first output and the second error signal is a function of the voltage/current at the second output, and wherein the common mode control signal is output from the common mode control output and the differential mode control signal is output from the differential mode control output, wherein the common mode control signal is generated using a feedback loop that uses a desired delta power signal based upon the first error signal and the second error signal and a delta power signal that is a function of the difference in output power at the first output and the second output.