Dielectric Power Converter Shielding for Undersea Voltage Stress
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Solution Overview
Problem
Power converters for undersea applications face challenges in achieving high power density and reliability due to voltage concentration across air gaps, leading to corona discharges and insulation breakdown, which are sensitive to humidity and altitude changes.
Innovation Solution
A compact power converter module with a two-compartment enclosure made of dielectric material, featuring conductive shields lining the compartments to reduce electric field intensity and ionization, along with leakage current sensors and guard rings to prevent breakdowns, and a method of forming an enclosed power converter with conductive shields and rings to manage voltage differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high voltage is applied across air gaps between components and insulation barriers, then power density is improved, but voltage concentration causes corona discharges and insulation breakdown
Solution Approach 1:
A conductive shield is introduced as an intermediary component between the high voltage components and the insulation barrier. The shield is held at a fixed potential (ground or other reference potential) and physically positioned between the high voltage region and the insulation barrier, thereby eliminating direct voltage stress on the insulation and preventing corona discharges while allowing high power density operation
2Reliability
If conductive shields are added to reduce electric field intensity, then insulation reliability is improved, but device complexity increases
Solution Approach 1:
The conductive shield is implemented as a thin conductive layer or coating applied to the insulation barrier surface, rather than a bulky three-dimensional structure. This thin-film approach provides the necessary electrical shielding function while minimizing additional volume, weight, and structural complexity
3Volume of moving object
If compact enclosure is used to achieve high power density, then volume is reduced, but voltage stress concentration increases leading to breakdown
Solution Approach 1:
The conductive shield acts as a mediator that allows compact spacing between high voltage components and external structures. By eliminating voltage stress on the insulation barrier, the shield enables reduced clearance requirements and more compact overall converter volume while maintaining high reliability
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 effectively reduces the risk of insulation breakdown and enhances reliability by minimizing voltage stress and detecting impending failures, ensuring stable operation over extended periods in harsh undersea environments.
Implementation Method 1
conductive shields lining the compartments to reduce electric field intensity and ionization
Implementation Method 2
conductive shields lining the compartments to reduce electric field intensity and ionization
Implementation Method 3
outer housing formed of dielectric material and including a low voltage compartment and a high voltage compartment
Implementation Method 4
A first leakage current sensor is disposed between the low voltage compartment and the high voltage compartment
Data Source
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AI summary
A power converter includes an outer housing formed of dielectric material and including a low voltage compartment and a high voltage compartment is disclosed. The power converter also includes a low voltage DC-to-AC converter disposed in the low voltage compartment, a first coil in the low voltage compartment, a first conductive shield element lining an outer wall of the low voltage compartment, the first conductive shield element being electrically coupled to an electrical input of the DC-to-AC converter and a second conductive shield element lining an outer wall of the high voltage compartment.