Single-Phase Power Converter Ripple Suppression via Software Compensation

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Solution Overview

Problem

Single-phase power converters experience significant double-frequency ripple power flows, leading to increased losses and component stress, which existing technologies attempt to address through external circuit components or output current control, but these solutions are inflexible and add complexity.

Innovation Solution

A software-based approach that adds a secondary modulation to PWM signals within the power converter to generate a compensating waveform that destructively interferes with the double-frequency transient component, eliminating internal power distortion without requiring additional circuit components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional circuit-based methods are used to cancel double-frequency ripple power, then the ripple power can be suppressed, but additional external circuit components are required which increases device complexity and reduces flexibility

Engineering Contradiction:

Improveripple power suppressionVSAvoidcircuit components

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces physical circuit-based ripple cancellation methods with a software control algorithm. The controller executes computer-readable program code to generate a compensating waveform that destructively interferes with the double-frequency transient component, eliminating the need for additional external circuit components while maintaining effective ripple suppression

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a software model (compensating waveform) that replicates the function of physical ripple cancellation circuits. By computing and injecting a compensating signal through software control, the system achieves the same ripple suppression effect as hardware circuits would provide, but with greater flexibility and without additional physical components

Inventive Principle:

Principle #26Copying

2Reliability

If output current control is used to suppress double-frequency ripple power, then the source ripple can be reduced, but the control flexibility is limited and external connections are affected

Engineering Contradiction:

Improvesource ripple reductionVSAvoidcontrol flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent implements a self-contained ripple suppression system where the controller generates and applies the compensating waveform internally without requiring external circuit modifications or affecting external connections. The software-based solution operates autonomously within the existing system boundaries, providing both effective ripple reduction and full control flexibility

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent employs dynamic software control that can adapt the compensating waveform in real-time based on system conditions. Unlike fixed circuit-based solutions, the software algorithm can be adjusted through programming to optimize performance for different operating scenarios, providing superior adaptability and control flexibility

Inventive Principle:

Principle #15Dynamics

3Device complexity

If double-frequency ripple power flows to the DC voltage source, then the power converter operates simply, but losses and component stress increase reducing system reliability

Engineering Contradiction:

Improveconverter structureVSAvoidpower losses

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The patent applies preliminary anti-action by proactively generating a compensating waveform that counteracts the double-frequency ripple power before it reaches the DC voltage source. The controller continuously monitors the output power and preemptively injects the compensating signal through the power converter, preventing energy losses and component stress at the source while maintaining the simplicity of the converter structure

Inventive Principle:

Principle #9Preliminary anti-action

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 method effectively suppresses double-frequency ripple power, reducing stress on the DC source, extending its lifespan, and allowing for the use of lower tolerance components while maintaining sinusoidal output voltage, thus achieving flexible and efficient power conversion.

Implementation Method 1

the waveform and the compensating waveform superpose, and the double-frequency transient component of the waveform and the compensating waveform destructively interfere

Methodology Applied

Scientific EffectDestructive interference: Interference

Data Source

PatentUS11581798B2Suppressing double-frequency ripple power in single-phase power converters

Publication Date: 2023.02.14 EAST WEST MFG

AI summary

A method is provided for limiting double-frequency internal power distortion in a power system. The method includes receiving an input voltage from a voltage source at a power converter from which an output power is provided to an electrical load, measuring the output power having a waveform with a steady-state component and a double-frequency transient component, executing computer-readable program code, via processing circuitry, to determine a compensating waveform equal in amplitude to the double-frequency transient component, and that is anti-phase to the double-frequency transient component, and causing the power converter to generate the compensating waveform such that the waveform and the compensating waveform superpose, and the double-frequency transient component of the waveform and the compensating waveform destructively interfere, leaving the steady-state component that is delivered to the electrical load.