Controller Common Current-Sense Device Interleaved Regulators

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Solution Overview

Problem

Conventional controllers for power converters with two interleaved boost switching regulators often produce unequal currents, leading to higher levels of input and output ripple currents, which degrade electromagnetic interference performance.

Innovation Solution

A controller that includes a current-sense device and an error amplifier to produce a current-sense signal, which is used by a duty-cycle controller to regulate the power converter by sampling currents at mid-points of duty cycles and adjusting duty cycles to achieve balanced currents in both interleaved boost switching regulators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional average current-mode control is used in interleaved boost switching regulators, then power factor correction performance is improved, but current equality between regulators deteriorates

Engineering Contradiction:

Improvepower factor correction performanceVSAvoidcurrent equality

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent implements a feedback mechanism where the duty cycle of each power switch is adjusted based on the sensed current from the other regulator. Specifically, the first duty cycle is adjusted according to the second current, and the second duty cycle is adjusted according to the first current, creating a cross-regulation feedback loop that maintains current equality between the two interleaved regulators

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent replaces conventional current sensing methods with voltage sensing across switched terminals. By sensing voltage rather than directly measuring current, the system achieves more accurate current detection and control, enabling better current equality while maintaining power factor correction performance

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If unequal currents are produced in interleaved regulators, then control simplicity is improved, but electromagnetic interference performance deteriorates

Engineering Contradiction:

Improvecontrol simplicityVSAvoidripple currents

Core Design Contradiction:

Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent employs feedback control where each regulator's duty cycle is dynamically adjusted based on the other regulator's current output. This cross-coupled feedback ensures current equality without requiring complex multi-regulator control circuits, maintaining relative simplicity while eliminating harmful ripple currents

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent combines the control of two interleaved regulators into a unified control scheme where both duty cycles are determined by a shared control mechanism. This merging of control functions ensures coordinated operation and current equality, reducing electromagnetic interference while keeping the overall control structure manageable

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS9240712B2Controller including a common current-sense device for power switches of a power converter

Publication Date: 2016.01.19 POWER SYST TECH

AI summary

A controller for a power converter includes a current-sense device couplable in series with switched terminals of power switches of interleaved switching regulators and configured to produce a current-sense signal. The controller also includes an error amplifier configured to produce an error signal as a function of a characteristic of the power converter. The controller also includes a duty-cycle controller configured to sample the current-sense signal at mid-points of duty cycles of the power switches and regulate the characteristic as a function of the error signal and the current-sense signal.