Space Solar Cell String Protection Diodes With Front-Side Cooling
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Solution Overview
Problem
The existing designs for space solar cells face challenges in repair and maintenance due to the complex integration of string protection diodes, which leads to increased manufacturing costs and reduced reliability, as well as insufficient cooling under intense solar radiation, resulting in potential failures and high reject rates.
Innovation Solution
The integration of string protection diodes on the front side of the string, connected via a metal strip with separate covers, allows for easier replacement and reduced wiring complexity, along with a metal-plated rear side for efficient heat dissipation and high reflectivity to manage thermal loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of repair
If string protection diodes are integrated on the front side of the string, then ease of repair is improved, but device complexity increases
Solution Approach 1:
The string protection diode assembly is segmented into a modular unit that includes the diode, metal strip, and separate cover as distinct but integrated components. This segmentation allows the entire protection diode assembly to be replaced as a single module without affecting other string components, significantly improving ease of repair while the modular nature helps manage device complexity through standardized interfaces.
Solution Approach 2:
The string protection diode is extracted from the traditional rear-side integration and placed on the front side of the string, separated from the solar cells by the transparent cover. This extraction allows independent access and replacement of the protection diode without disturbing the solar cell array, improving repairability while maintaining electrical functionality.
2Ease of manufacture
If metal strip with separate covers is used for string protection diodes, then ease of manufacture is improved, but manufacturing precision requirements increase
Solution Approach 1:
The cover is separated from the metal strip and diode assembly, allowing each component to be manufactured independently using optimized processes for each material and geometry. The separate cover can be produced with precise dimensional control, while the metal strip and diode assembly can be manufactured separately and then joined, improving overall ease of manufacture while distributing precision requirements across multiple simpler steps.
Solution Approach 2:
The transparent cover acts as an intermediary component between the metal strip and the external environment. It provides electrical isolation and mechanical protection while allowing optical transmission, enabling the metal strip to be manufactured with standard precision while the cover compensates for any minor positioning variations through its design tolerances.
3Temperature
If metal-plated rear side is used for heat dissipation, then temperature control is improved, but manufacturing complexity increases
Solution Approach 1:
The metal strip's rear side is metal-plated to create a self-cooling surface that radiates heat directly to space without requiring external cooling systems. The high thermal conductivity of the metal plate, combined with its high reflectivity and emissivity characteristics, enables passive heat dissipation that manages temperature effectively while adding minimal structural complexity to the overall assembly.
Solution Approach 2:
The metal plating on the rear side changes the thermal and optical parameters of the surface, providing high thermal conductivity for heat dissipation while maintaining high reflectivity for solar radiation. This parameter optimization allows effective temperature control through material selection and surface treatment rather than complex active cooling systems.
4Reliability
If protection arrangement is provided at both ends of the string, then reliability is improved, but weight increases
Solution Approach 1:
The protection diode assemblies at both ends of the string are merged into a symmetric design using identical components (metal strips, diodes, and covers). This merging of design principles allows for standardized manufacturing and reduces overall weight compared to asymmetric designs, while providing comprehensive protection that improves reliability by ensuring both ends are equally protected against electrical faults.
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 configuration reduces manufacturing costs, increases reliability, and enables effective heat management, allowing for the string protection diodes to operate without overheating, even under maximum power conditions and direct solar irradiation.
Implementation Method 1
the metal strip and/or the connection line and/or the metal-plated bottom side of the DIEs... for efficient heat dissipation
Implementation Method 2
Cooling for the string protection diodes or the DIE can be provided by the metal strip and/or the connection line and/or the metal-plated bottom side of the DIEs
Data Source
AI summary
A protection of space solar cells in an arrangement in the form of a string that extends in an X direction. In each case two space solar cells directly neighboring in the X direction are electrically connected to one another in series via a metallic connector of a first type. The string has a first end and a second end opposite from the first end, and a protection arrangement is provided directly at one of the two ends along a y direction. The protection arrangement includes a first string protection diode arrangement, a metal strip, and a second string protection diode arrangement provided in the Y direction. The protection arrangement is electrically connected to one of the two ends of the string via two spaced-apart metal strips, and each string protection diode arrangement includes multiple unhoused string protection diodes.