Polyphase Converter Fault Tolerance via Segmented Arms

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Solution Overview

Problem

Existing power converters in aerospace applications face challenges in achieving fault tolerance without reconfiguration or performance degradation, particularly in high-reliability applications like electric actuators in launchers, where continuous availability is critical and the risk of component failures must be managed without increasing costs or parasitic inductances.

Innovation Solution

A switching power converter design that minimizes parasitic inductance by arranging switches and diodes in series and parallel configurations, ensuring a consistent current path and reducing overvoltages, while leveraging the redundancy of polyphase electrical receivers to limit component redundancy, thus maintaining performance and availability during faults.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If redundancy based on multiplication of active components is used to compensate for component failure, then fault tolerance is improved, but device complexity and parasitic inductances increase

Engineering Contradiction:
Improvefault toleranceVSAvoidcomponent multiplication
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The inverter is divided into multiple independent arms, each capable of operating autonomously. When a fault occurs in one arm, the other arms can continue to operate, providing fault tolerance without requiring complete system redundancy. This segmentation allows the system to maintain functionality with reduced complexity compared to full component multiplication.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The inverter architecture dynamically adapts its configuration based on operational needs and fault conditions. The system can switch between different operational modes (full power, reduced power, single-arm operation) without requiring permanent redundant components, thereby maintaining reliability while minimizing device complexity.

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If coplanar power supply arrangement is used to minimize parasitic inductance, then switching overvoltages are reduced, but manufacturing complexity increases

Engineering Contradiction:
Improveswitching overvoltagesVSAvoidcoplanar arrangement complexity
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The power supply lines are merged into a coplanar arrangement where the return path and forward path are positioned adjacently in the same plane. This merging of power and return paths minimizes the loop area and associated parasitic inductance, thereby reducing switching overvoltages. The design integrates this coplanar structure into the overall PCB layout to balance manufacturing feasibility with electrical performance.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If switches and diodes are arranged in series and parallel configurations with consistent current path, then fault tolerance is improved and overvoltages are reduced, but device complexity increases

Engineering Contradiction:
Improvefault toleranceVSAvoidswitching configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The switches and diodes within each inverter arm are configured with specific local arrangements optimized for that arm's operation. The series connection of switches and parallel connection of diodes creates consistent current paths locally within each arm, improving fault tolerance and reducing overvoltages. This localized optimization allows each arm to function independently with reduced complexity compared to optimizing the entire system at once.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3197034B1Switching power converter configured to control at least one phase of a polyphase electrical receiver with at least three phases
Publication Date: 2018.10.17 THALES SA
  • EP3197034B1 patent drawingFigure 1a~1b
  • EP3197034B1 patent drawingFigure 2a~2b
  • EP3197034B1 patent drawingFigure 3a

AI summary

Switching power converter configured to control at least one phase of a polyphase electrical receiver with at least three phases, comprising at least one block of two converter arms, in which one half of the converter arm comprises a first set (ENS1) of N switches, N being greater than or equal to two, arranged in series, and 2N power diodes arranged N to N in series and in parallel, forming second and third sets (ENS2, ENS3) of N diodes each comprising N diodes in series, the second and third sets (ENS2, ENS3) being mounted in parallel with each other and in series with the N switches in series, the first set (ENS1) of N switches in series being arranged between the second and third sets (ENS2, ENS3) of N diodes in series.