Multi-bridge AC Power Converter Phase Control

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Solution Overview

Problem

Existing power converter systems for AC mains power supply face challenges in efficiently addressing voltage regulation, voltage sag, and voltage surge correction, particularly in large power loads, due to the need for significant magnetic components and semiconductors, which can lead to inefficiencies and audible noise.

Innovation Solution

A multi-bridge power converter system utilizing a controller to generate control signals for half-bridge switches, operating at specific frequencies to eliminate fundamental frequencies and reduce harmonics, thereby increasing efficiency and minimizing audible noise, while using energy storage elements and filters to regulate voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional power converter systems use large magnetic components and semiconductors for voltage regulation, then voltage regulation and surge correction capabilities are improved, but device complexity and efficiency are worsened

Engineering Contradiction:

Improvevoltage regulation capabilityVSAvoidmagnetic components size

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the conventional single power converter system into multiple independent half-bridge power converter modules. Each module operates autonomously at a common switching frequency, collectively providing the required voltage regulation and surge correction capabilities. This segmentation eliminates the need for large magnetic components while maintaining reliability through distributed architecture.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent combines multiple half-bridge power converter modules into a unified multi-bridge system that shares common DC voltage sources and control architecture. The modules work in parallel to deliver enhanced voltage regulation and surge correction capabilities, achieving improved reliability without requiring proportionally larger magnetic components in each individual module.

Inventive Principle:

Principle #5Merging (Combining)

2Power

If conventional power converters operate at high switching frequencies, then power density is improved, but audible noise increases

Engineering Contradiction:

Improvepower densityVSAvoidaudible noise

Core Design Contradiction:

PowerVSObject-generated harmful factors

Solution Approach 1:

The patent employs synchronous switching of multiple half-bridge modules at carefully coordinated phases, creating periodic cancellation of fundamental frequency components in the inductor currents. This periodic action occurs at the common switching frequency, enabling high power density operation while the coordinated phase relationships eliminate audible noise through destructive interference of acoustic waves.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent converts the potentially harmful fundamental frequency components and harmonics in the inductor currents into beneficial canceling effects. By coordinating the switching phases of multiple modules, the fundamental frequencies that would normally generate audible noise are transformed into canceling waveforms, while the harmonics are reduced through the multi-bridge architecture.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Use of energy by moving object

If conventional power converters use large magnetic components for energy storage, then energy storage capability is improved, but device complexity and size are worsened

Engineering Contradiction:

Improveenergy storage capabilityVSAvoidmagnetic components volume

Core Design Contradiction:

Use of energy by moving objectVSVolume of stationary object

Solution Approach 1:

The patent segments the total energy storage requirement across multiple smaller half-bridge modules, each with its own compact DC voltage sources and minimal magnetic components. The distributed energy storage capability of multiple modules collectively provides the required energy buffer, eliminating the need for a single large magnetic component while maintaining energy storage capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent replaces traditional large magnetic energy storage components with an electrical energy storage architecture based on multiple DC voltage sources and capacitive elements in the multi-bridge configuration. This substitution of electrical energy storage for magnetic energy storage dramatically reduces the volume of magnetic components while maintaining adequate energy storage capability for voltage regulation and surge correction.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS9768705B1Multibridge power converter for AC mains

Publication Date: 2017.09.19 TSI POWER CORP

AI summary

An AC power converter converts power from an AC power source to an AC load. A DC power holding source is coupled to an input half-bridge switch, a common half-bridge switch and an output half-bridge switch. A controller is coupled to the input half-bridge switch, the common half-bridge switch, and an output half-bridge switch to generate at least two control signals at a common switching frequency, wherein the controller generates the at least two control signals with a phase difference there between chosen to cause a ripple frequency in both the input low pass filter and the output low pass filter to be double the common switching frequency. An input low pass filter can eliminate switching frequency energy from entering the AC power source. An output low pass filter can eliminate switching frequency energy from entering the AC load.