Vienna Rectifier R-TRU Control for DC Over-Voltage Protection

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Solution Overview

Problem

Traditional power supply systems for aircraft, such as Transformer Rectifier Units (TRUs) and Regulating Transformer Rectifier Units (R-TRUs), face inefficiencies and lack effective regulation, leading to potential over-voltage conditions that can damage equipment and pose safety risks due to their large size, low energy conversion efficiency, and inadequate protection against transient voltages.

Innovation Solution

A high-frequency switching power conversion architecture utilizing a Vienna Rectifier with power factor correction and a series resonant DC-DC converter, coupled with multiple compensator circuits for feedback control, to provide a compact, efficient, and protected DC power system that prevents over-voltage conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional line frequency transformers are used for galvanic isolation, then isolation is provided, but system size and weight increase significantly

Engineering Contradiction:
Improvegalvanic isolationVSAvoidtransformer weight
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent changes the operating frequency parameter from traditional line frequency (50/60 Hz) to high frequency (20 kHz or higher). This parameter change enables the use of smaller, lighter transformers while maintaining galvanic isolation functionality, directly resolving the contradiction between isolation reliability and transformer weight.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If traditional rectifiers are used for power conversion, then simple circuit structure is achieved, but energy conversion efficiency remains below 85%

Engineering Contradiction:
Improvecircuit structureVSAvoidenergy conversion efficiency
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent employs dynamic pulse width modulation (PWM) control of the switching elements instead of static rectification. This dynamic control enables the power conversion circuit to adaptively optimize its operation, achieving efficiency above 85% while maintaining reasonable circuit complexity through controlled switching operations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operating frequency to high frequency (20 kHz or higher), which enables more efficient power conversion through reduced switching losses and improved regulator performance, directly addressing the energy efficiency limitation of traditional rectifiers.

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If high frequency switching is implemented, then system size is reduced and efficiency improved, but complex control circuits are required

Engineering Contradiction:
Improveenergy conversion efficiencyVSAvoidcontrol circuit complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent implements feedback control circuits that monitor the power conversion process and adjust switching parameters accordingly. This feedback mechanism automates the control of high-frequency switching, reducing the need for complex manual control circuits while maintaining high efficiency through adaptive optimization of the power conversion process.

Inventive Principle:
Principle #23Feedback

4Reliability

If traditional R-TRU designs are used for voltage regulation, then some regulation capability is achieved, but over-voltage protection is insufficient and transient voltage rejection is poor

Engineering Contradiction:
Improvevoltage regulationVSAvoidover-voltage damage risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent incorporates preliminary protective measures including over-voltage detection circuits and transient voltage suppression elements that act before damaging voltage levels can affect the system. These preventive mechanisms detect potential over-voltage conditions and activate protection protocols in advance, preventing equipment damage before it occurs.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The patent uses feedback control to continuously monitor output voltage and adjust the power conversion process to maintain stable regulation. This feedback mechanism quickly responds to transient voltage variations and corrects them before they can cause damage, significantly improving both voltage regulation and over-voltage protection compared to traditional R-TRU designs.

Inventive Principle:
Principle #23Feedback

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

The solution achieves energy conversion efficiencies up to 96-98%, reduces system size, and effectively prevents over-voltage conditions, ensuring safer and more reliable power distribution by incorporating phase shift modulation control and multiple feedback loops for precise voltage regulation.

Implementation Method 1

a series resonant DC-DC converter

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Implementation Method 2

Vienna Rectifier with power factor correction

Methodology Applied
Scientific EffectRectification: Diode

Implementation Method 3

high-frequency switching power conversion architecture utilizing a Vienna Rectifier with power factor correction and a series resonant DC-DC converter

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP3455934B1Regulating transformer rectifier unit for DC power applications
Publication Date: 2024.03.20 ASTRONICS ADVANCED ELECTRONIC SYSTEMS CORP
  • EP3455934B1 patent drawingFigure 1
  • EP3455934B1 patent drawingFigure 1
  • EP3455934B1 patent drawingFigure 2a~2c

AI summary

A power supply system and related method for providing a regulated DC output from an unregulated AC input includes a Vienna rectifier (2) having power factor correction circuitry (29) and a series resonant DC to DC converter (5) to provide a regulated DC output. The power supply system further includes one or more compensator circuits (7, 12, 14) coupled in feedback configuration to control the Vienna rectifier (2) and/or the DC to DC converter (5) and avoid a potentially dangerous over-voltage condition at the regulated DC output.